Section I. Fungi and Sick Building Syndrome

Fungi and the Indoor Environment: Their Impact on Human HealthAND D. C. STRAUS* *Department of Microbiology and Immunology, Texas Tech University

J. D. COOLEY,* W. C. WONG,* C. A. JUMPER,y

Health Sciences Center, Lubbock, Texas 79430y

Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas, 79430

I. II. III. IV.

V. VI. VII. VIII. IX.

Introduction Inhalation of Fungal Spores Causes Respiratory Disease in Humans Correlation Between the Presence of Certain Fungi and SBS Development of an Animal Model for Allergic Penicilliosis Induced by the Intranasal Instillation of Viable Penicillium chrysogenum Conidia Cellular and Humoral Responses in an Animal Model Inhaling Penicillium chrysogenum Continually Measured Fungal Profiles in SBS Evaluation of Fungal Growth on Cellulose-Containing and Inorganic Ceiling Tile The Presence of Fungi Associated with SBS in North American Zoological Institutions The Role (?) of Mycotoxins in SBS References

3 5 9

13 16 19 22 23 24 27

I. Introduction Yeast, molds, mushrooms, mildews, and the other fungi pervade our world. They work great good and terrible evil. Upon them, indeed, hangs the balance of life; for without their presence in the cycle of decay and regeneration, neither man nor any other living thing could survive (Kavaler, 1965). One of the most common questions asked concerning the seemingly recent phenomenon of sick building syndrome (SBS) and fungal involvement is, Is this a new thing and why havent I heard of it before? Mans realization that mold growth in his buildings is a bad thing began over 3300 years ago in the time of Moses. Leviticus 14:3345 (the Old Testament) describes this quite well. If the mildew reappears in the house after the stones have been torn out and the house scraped and plastered, the priest is to go and examine it and, if the mildew has spread in the house, it is a destructive mildew; the house is unclean. It must be torn downits stones, timbers and all the plasterand taken out of the town to an unclean place. What is3ADVANCES IN APPLIED MICROBIOLOGY, VOLUME 55 Copyright 2004, Elsevier Inc. All rights reserved. 0065-2164/04 $35.00

4

J. D. COOLEY et al.

truly amazing is that this course of action is not too different from what we do today, over 33 centuries later. The building material used at that time was straw bricks, that is, cellulose-based stones and plaster. What of course is different today is that we now know what microorganisms cause these problems and we know, or at least strongly suspect, what products these fungi produce that can cause health problems in human beings. One of the early scientic papers published regarding the effects of mold spores on humans appeared in 1873 (Blackley). Charles Blackley, who was one of the early describers of pollen skin tests, wrote about his asthmatic responses to the inhalation of Penicillium species conidia (spores) (Licorish et al., 1985). It now appears that the literature is quite clear on the importance of the inhalation of fungal spores on respiratory disease in man. The Centers for Disease Control (CDC) recently published a statement for the record for the United States House of Representatives (Redd, 2002). In it they state, While there remain many unresolved scientic questions, we do know that exposure to high levels of mold causes some illnesses in susceptible people. Because molds can be harmful, it is important to maintain buildings, prevent water damage and mold growth, and clean up moldy materials. We have spent the last decade trying to understand the above concepts. It is our humble hope that some of the work we have done can help elucidate the role of fungi in the phenomenon known as sick building syndrome. Reports in the literature about building structures with poor indoor air quality (IAQ) increasingly appeared soon after the mid1970s (Hodgson, 1992; Spangler and Sexton, 1983). SBS, a term that is sometimes used for symptoms commonly associated with poor IAQ, was rst described in 1982. The rst study examining more than one building with SBS was published in 1984 (Finnigan et al.). Although SBS has been difcult to dene, evidence is now coming to the fore that seems to indicate the importance of indoor fungal growth in this phenomenon (Straus, 2001). SBS literally means that there is something inside of said building that is actually making people sick. These symptoms most commonly are fatigue, runny nose, itchy eyes, sore throat, and headaches (Cooley et al., 1998). Although no single cause for the above symptoms is likely to be found, the presence of certain molds is becoming increasingly associated with this phenomenon (Burrell, 1991; Cooley et al., 1998; Dales et al., 1991; Jaakkola et al., 2002; Lehrer et al., 1983; Miller, 1992).

FUNGI AND THE INDOOR ENVIRONMENT

5

II. Inhalation of Fungal Spores Causes Respiratory Disease in Humans Our rst study examining the role of fungi in SBS was published in 1998 (Cooley et al.). In that paper we showed that there was a correlation between certain fungi (Penicillium species [Figs. 1 and 2, see color insert] in the air and Stachybotrys species [Figs. 3 and 4, see color insert] on building surfaces) and the symptoms seen in SBS. The nding that the elevation of culturable (viable) Penicillium species conidia in the indoor air over those levels in the outside air caused health problems in human beings should not have been a surprise. As mentioned previously, the inhalation of Penicillium species conidia was associated with the initiation of an asthmatic attack as early as 1873 (Blackley). Alternaria species spores and Penicillium species conidia were shown to provoke immediate and delayed-type asthma in individuals already sensitized to these organisms (Licorish et al., 1985). A 1998 study (Garret et al.) demonstrated that childhood asthma could be correlated with exposure to Penicillium species conidia levels in the air but not to visible mold. In many of our investigations, we observed that Penicillium

FIG. 1. Penicillium chrysogenum colonies on PDA for 7 days.

6

J. D. COOLEY et al.

FIG. 2. Penicillium chrysogenum at 400 magnication.

species tended to colonize the heating, ventilation, and air conditioning (HVAC) systems of buildings (Cooley and Wong, unpublished data from ARAL database, 2003). In 2002, Gent et al., showed that infants with high risk for development of asthma who were exposed to high levels of Penicillium species conidia were at signicant risk for persistent cough and wheeze. This study was particularly interesting, because this correlation between respiratory distress and mold exposure was valid for Penicillium species conidia but not for Cladosporium species spores. Obviously there is something different about the genus Penicillium that sets it apart from other fungal genera in this regard. In 1984, Fergussen et al. described for the rst time Penicillium species allergic alveolitis caused by the faulty installation of a central heating system unit that introduced a great deal of water into a residence. In this case the two fungal species found growing in the dwelling were

FUNGI AND THE INDOOR ENVIRONMENT

7

FIG. 3. Stachybotrys chartarum colonies on PDA for 14 days.

P. chrysogenum and P. cyclopium. Finally, there is one other important respiratory disease caused by the inhalation of Penicillium species conidia. This disease is called cheese workers lung or cheese washers disease (Straus, 2002). This is an occupational disease that can occur in individuals who work in the cheese industry. Occupational lung diseases become more common as the world becomes more industrialized. Some of the other more common occupational lung diseases include maltsters lung, farmers lung, bagassosis, suberosis, and wood pulp workers lung. The organisms that cause the above diseases are Aspergillus clavatus, thermophilic actinomycetes, Penicillium frequentans, and Alternaria species, respectively (Straus, 2002). These diseases are all phenomena related to hypersensitivity pneumonitis (HP). HP is an allergic reaction to a wide variety of different inhaled antigens. In the case of cheese washers disease, the inhaled antigen is a fungus (either Penicillium casei or Penicillium roqueforti, which are used to avor the cheese). The rst report of cheese washers disease was in Germany in 1969 (DeWeck et al.). In this study, two individuals reported difculty

8

J. D. COOLEY et al.

FIG. 4. Stachybotrys chartarum at 400 magnication.

in breathing, fever, fatigue, and productive cough. These individuals were cheese washers, and their symptoms appeared to be job related. Because Penicillium species are grown on the surface of cheese as it is being produced, it is necessary to have employees remove the fungi. These individuals are, of course, called cheese washers. Cheese washing is performed by rubbing a course salt on the formed product and then scrubbing it with a damp cloth (Marcer et al., 1996). The cheese product itself supplies all the food and water that the fungi need to multiply. Naturally, during this scrubbing process large numbers of fungal conidia are emitted into the air surrounding the cheese product. The organism most commonly found growing on the cheese in those situations is P. casei (Schleuter, 1993). As expected, antibodies to P. casei were detected in the sera of the two individuals described in the above 1969 study (DeWeck et al.). Fortunately, the disease appears to

FUNGI AND THE INDOOR ENVIRONMENT

9

be reversible when the individual is no longer inhaling P. casei conidia (DeWeck et al., 1969). However, if one is continually inhaling the same type of fungal spores, progressive pulmonary brosis can occur with resultant granulomatous tissue formation and subsequent shortness of breath (Sell, 1996). Cheese washers disease was originally described in Europe by DeWeck et al. (1969), but it has also been reported in the United States. Campbell et al. (1983) examined a worker who developed extrinsic allergic alveolitis (another term for hypersensitivity pneumonitis) caused by her inhalation of a fungus that was used in the production of the cheese and not one that grew on the cheese wheel as was described by DeWeck et al. (1969). In this case, the cheese worker was involved in the processing of blue cheese, which employs P. roqueforti. Her job involved the breaking up of the blue cheese so it could be more easily put in salad dressing bottles. This activity, of course, dispersed high concentrations of P. roqueforti conidia into the air in her immediate vicinity. Antibodies to P. roqueforti were found in her serum and lung washes (Campbell et al., 1983). There have been other reports in the literature describing similar cases of cheese washers disease (Guglielminetti et al., 2001; Marcer et al., 1996). III. Correlation Between the Presence of Certain Fungi and SBS In the 1998 study (Cooley et al.), we showed that there is a correlation between the presence of certain fungi in a building and the symptoms associated with SBS. The symptoms associated with SBS and described in this study can be seen in Table I. In Table I, allergic-like symptoms were the main complaint at all of the schools, and with the moderate to high counts of culturable Penicillium species conidia found in the complaint areas, this is not surprising. However, with the exception of nausea, numerous symptoms other than allergic-like were reported at each school. This implies that there may be other mechanisms that may be inducing adverse health effects. In fact, we always observed a variety of different visible fungal growth on surfaces in the schools. This 22-month study of 48 schools in the southern United States examined buildings in which there were concerns about poor IAQ and health. Surface samples and indoor air and outdoor culturable air samples were taken at all 48 buildings to look for visible fungal growth as well as culturable airborne fungal spores. Five fungal genera were usually found in the outdoor air. They were Cladosporium (81.5%), Penicillium (5.2%), Chrysosporium (4.9%), Alternaria (2.8%), and Aspergillus (1.1%). Cladosporium species are commonly the dominant fungal species in the outdoor air (Shelton et al., 2002).

TABLE I INCIDENCES PER 100 EMPLOYEES (95% Cl) OF REPORTED COMPLAINTS AND SYMPTOMS REGARDING INDOOR AIR QUALITY (IAQ) UNITED STATES SCHOOLS BETWEEN 1994 AND 1996 Type of symptom Nasal drainage and congestion Itchy or watering eyes Contact problems Headaches Sinus Severe sinus Increased airway infections Cough Shortness of breath Sneezing Dizziness Fatigue Flu-like symptoms Nausea Allergies Asthma Other health conditions Incidence 95% Cl 19.8 14.3 5.6 12.5 10.3 3.4 14.3 6.5 5.9 6.8 2.2 1.1 1.8 1.8 17.0 1.4 1.2 1.3 1.1 1.2 0.6 0.5 0.4 1.0 0.6 0.4 1.0 0.5 0.3 0.6 3.4 1.0 0.3 0.5 When do symptoms go away? Never Leave work Weekends Vacations Medications 3.5 2.1 4.3 14.7 4.4 0.8 0.6 0.9 2.5 0.2 Onset of symptoms Entering the building Working in the building Start of school 3.4 11.0 11.3 0.9 1.7 1.9 Phenomenon Discomfort complaints Odors Temperature (hot/cold) Noise Ventilation 5.2 7.2 0.8 6.1 0.4 0.1 0.3 0.3 Incidence 95% Cl Phenomenon When are symptoms the worst? High humidity Low humidity Spring Summer Fall Winter Start of School Morning Afternoon Monday Late in week No pattern Always Before remedy IAQ complaints or symptoms After remedy IAQ complaints or symptoms 2.5 1.1 31.3 6.8 12.0 0.0 3.9 0.0 2.7 4.5 5.7 3.4 1.1 0.8 0.8 1.1 2.3 0.9 0.0 0.8 0.0 0.6 0.5 2.0 0.4 0.3 0.3 0.3 0.3 0.6AT

48

Incidence 95% Cl

FUNGI AND THE INDOOR ENVIRONMENT

11

Visible surface fungal growth was observed at all 48 schools. At 20 of the 48 schools studied, there were signicantly (P < 0.0001) more colony forming units per cubic meter of air (CFU/m3) of culturable Penicillium species conidia in the air samples from complaint areas as compared with the outside air samples and the indoor air samples from noncomplaint areas (Figs. 5 and 6). At 5 of the 48 schools, there were more (P 0.10) Penicillium species conidia in the air samples from complaint areas when compared with the outdoor air samples and the indoor air samples from noncomplaint areas were similar to those in the outdoor air. However, in 11 of these schools, Stachybotrys atra (aka chartarum) was isolated from building surfaces. Although visible surface fungal growth was observed in the remaining 11 schools, the culturable fungal air proles were not signicantly different between the complaint and noncomplaint areas. When the various schools took remedial action that resulted in an indoor fungal prole that was similar to that observed outdoors and no visible fungal growth was observed, the complaint prole dropped

FIG. 5. Bar graph of all air samples taken at the 48 schools.

12

J. D. COOLEY et al.

FIG. 6. Bar graph of all air samples taken at the 20 schools where Penicillium species were the dominant fungi.

from 31.3% to 2.5%, which was a signicant (P < 0.001) decrease (Table I). However, from our experience over the last decade, if the building is not properly maintained, with moisture events remediated within 72 hours, these buildings can rapidly become microbially contaminated. Three basic strategies should be followed to maintain building performance and prevent microbial contamination: (a) routine surveillance inspections and prompt response to problems, (b) adequate preventive maintenance of the building structure as well as HVAC and plumbing systems, and (c) adequate housekeeping including an emphasis on proper and routine cleaning (Shaughnessy and Morey, 1999).

FUNGI AND THE INDOOR ENVIRONMENT

13

IV. Development of an Animal Model for Allergic Penicilliosis Induced by the Intranasal Instillation of Viable Penicillium chrysogenum Conidia In an effort to try to determine why the inhalation of Penicillium species conidia could produce the symptoms associated with SBS, we developed an animal model for allergic penicilliosis induced by the intranasal instillation of viable (culturable) P. chrysogenum conidia (Cooley et al., 2000). Once we were able to singly disperse the P. chrysogenums conidia, we determined that there were only approximately 25% of the conidia that were actually viablethat is, capable of reproducing. Since we could not readily determine the difference between a viable conidium and a non-viable conidium, we rendered one group of conidia totally non-viable. Therefore we could assume that any difference between the two groups could be contributed to the viability of the conidia. In this study, C57 black/6 mice were inoculated intranasally (IN) with 104 viable (V) and non-viable (NV) P. chrysogenum for 6 weeks. This study showed that mice inoculated IN for 6 weeks with 104 V PC (average viability % 25%) produced signicantly more IgE (total serum), peripheral eosinophils, and airway eosinophils (Figs. 7 and 8). Except for airway neutrophilia, mice

FIG. 7. Serum levels of IgG2a (solid bars) and total IgE (shaded bars) in mice inoculated intranasally with viable and non-viable Penicillium chrysogenum conidia once a week for 6 weeks. *P < 0.05 compared with controls. Error bars represent standard error of means (SEM).

14

J. D. COOLEY et al.

FIG. 8. BAL uid levels of eosinophils (solid bars) and IL-5 (shaded bars) in mice inoculated intranasally with viable and non-viable Penicillium chrysogenum conidia once a week for 6 weeks. *P < 0.05 compared with controls. Error bars represent standard error of means (SEM).

receiving 104 NV P. chrysogenum IN did not demonstrate signicant increases in IgE (total serum), peripheral, or airway eosinophils (Fig. 7 and 8). However, the NV P. chrysogenum IN 104 group showed a signicant increase in total serum IgG2a and bronchoalveolar lavage (BAL) uid levels of interferon (IFN)-. Additionally, BAL from mice inoculated IN with 104 V P. chrysogenum conidia demonstrated significant increases in the levels of interleukin (IL)-4 and IL-5 (Fig. 9). The IgG2a/IgE ratio and the IFN-/IL-4 ratio were found to be lower in the mice inoculated IN with 104 V P. chrysogenum conidia than in those inoculated with 104 NV P. chrysogenum conidia and the control mice. This suggests that the inammatory response observed in the V P. chrysogenum group was type 2 T helper cell (Th2) mediated. This concept was supported by the demonstration that proteins extracted from P. chrysogenum conidia incubated with serum from the V P. chrysogenum inoculated conidia mice were IgE-specic, while the serum from the NV P. chrysogenum group was not (Fig. 10). In this paper we also clearly demonstrated that P. chrysogenum conidia are easily phagocytized by mouse alveolar macrophages and degraded

FUNGI AND THE INDOOR ENVIRONMENT

15

FIG. 9. BAL uid levels of IL-4 (solid bars) and IFN- (shaded bars) in mice inoculated intranasally with viable and non-viable Penicillium chrysogenum conidia once a week for 6 weeks. *P < 0.05 compared with controls. Error bars represent standard error of means (SEM).

(Fig. 11). This study showed that the long-term (6-week) inhalation of V P. chrysogenum conidia induced type 2 helper cell mediated inammatory responses such as increases in total and conidia-specic serum IgG1 and IgE. This was observed together with BAL uid level increases in IL-4 and IL-5, as well as airway and peripheral eosinophilia, both of which are allergic reaction mediators. Since the viable P. chrysogenum conidia are capable of reproducing, these ndings suggest that there is a difference between the viable P. chrysogenum conidia and non-viable P. chrysogenum conidia. Many researchers and clinicians in the past have been under the impression that spores (conidia) are unlikely to release any antigens unless they germinate, a process that requires several hours. This is because the mucocilliary tract and the alveolar macrophages will remove most of the fungal propagules prior to germination or attempted germination (Platt-Mills et al., 1998).

16

J. D. COOLEY et al.

FIG. 10. Levels of conidia-specic IgG1 (shaded bars), IgE (white bars), and IgG2a (solid bars) in pooled serum samples from mice inoculated intranasally with viable and nonviable Penicillium chrysogenum conidia once a week for 6 weeks. *P < 0.05 compared with controls. Error bars represent standard error of means (SEM).

V. Cellular and Humoral Responses in an Animal Model Inhaling Penicillium chrysogenum We also examined the cellular and humoral responses in a mouse model inhaling P. chrysogenum conidia (Cooley et al., 1999). The retention of a particle is determined by the deposition and clearance of the particle. The output of particles previously deposited in the lungs is called clearance and refers to the process that physically expels the particles from the lungs. This mechanism includes absorption, sneeze, cough, mucocilliary transport, and alveolar macrophage clearance (Brain and Valberg, 1979). It should be kept in mind that clearance is often of greater signicance than deposition. Therefore, clearance efciency may be the determining factor for total integrated exposure, and, consequently, the probability of a pathologic or physiological response, especially when particles are viable conidia.

FUNGI AND THE INDOOR ENVIRONMENT

17

FIG. 11. Ultrastructure of alveolar macrophages taken from the BAL uid of mice (A) 3 hours, (B) 6 hours, and (C) 24 hours after instillation of viable conidia (magnication 10,000). Phagocytosed conidia (arrows) at various stages of digestion were commonly observed within phagosomes of the macrophage at all the times studied. Temporal correlation of conidia destruction was not apparent as many macrophages contained conidia in various stages of breakdown, even after 3 hours. Residual bodies were present in cells at all times, typical of alveolar macrophages. (D) Ultrastructure of Penicillium chrysogenum conidia (magnication 43,750) before instillation (spore coat (sc) between the arrow heads and spore vacuoles (v)). This morphology is comparable to the minimally damaged installed conidia captured in (C). The conidia in (A) and (B) are apparently in later stages of destruction.

Continuous exposure to moderate to high levels of P. chrysogenum conidia in a structure over a period of time will have an impact on the clearance efciency versus a one-time exposure. Fungi produce a variety of secondary metabolites, including mycotoxins and fungal volatile organic compounds (VOCs). Mycotoxins are harmful to animals and humans. In addition to mycotoxins, some VOCs produced by

18

J. D. COOLEY et al.

FIG. 12. Female C57Bl/6 mice were inoculated IN with 1 106 Penicillium chrysogenum spores (viability 26%), resulting in a dose of 2.6 105 CFU. At various time periods after the acute inoculation, the mice were euthanized, the lungs and tracheas aseptically removed, homogenized, and serial dilutions plated on SDA plates to determine percent spore viability. Each time period had a minimum of 6 mice. The -0indicates no viable spores were recovered. The error bars represent the standard error of means (SEM).

actively growing fungi are known irritants or hazardous chemicals and may pose a health risk to building occupants and have an impact on the clearance efciency of the lungs (Yang and Johanning, 1997). In this study, viable P. chrysogenum conidia were recovered from mouse lungs, as early as 15 minutes and 3 hours through 36 hours after IN inoculation of 106 conidia (26% viability) (Fig. 12). We demonstrated that approximately 18% of the viable conidia were actually deposited in the mouse lungs. However, by 12 hours postinoculation, only 104 viable conidia were detected. These data suggest that the mucocilliary tract had cleared most of the inoculated conidia, but 4% of the viable conidia were housed in the airways, probably in the alveolar spaces, where they remained viable for up to 36 hours.

FUNGI AND THE INDOOR ENVIRONMENT

19

One 106 doses of viable P. chrysogenum conidia induced signicant (P < 0.001) increases in tumor necrosis factor- (TNF-), while NV P. chrysogenum conidia did not. When 1 104 doses (repeated for 3 weeks) of viable P. chrysogenum conidia were inoculated IN into mice (C57 Black/6), signicant (P < 0.05) increases in total serum IgE and BAL IL-4 were observed, whereas this did not occur in mice receiving 1 104 NV P. chrysogenum conidia. These data also suggest that viable P. chrysogenum conidia are capable of inducing an allergic response. Moisture will stimulate viable P. chrysogenum conidia to attempt to germinate. If there is a sufcient nutrient source, the conidia (spores) will form germ tubes and hyphae and colonization will initiate. Although there is enough moisture in the lungs to stimulate germination of P. chrysogenum conidia, the temperature (37 C) and the lack of nutrients would inhibit the formation of a germ tube (Yang and Johanning, 1997). However, observing viable P. chrysogenum conidia in the lungs 36 hours after instillation certainly allows enough time for attempted germination and the production of potential antigens. In fact, we have been able to demonstrate that the viable P. chrysogenum conidia are capable of producing such antigens (Schwab et al., 2003). VI. Continually Measured Fungal Profiles in SBS In a 1999 study (McGrath et al.), we sought to answer two questions. The rst was, when taking a culturable indoor air sample, is that sample an accurate reection of the air in that building or is it just a snapshot that changes immediately after the picture is taken? The second question was do sick or contaminated buildings stay or remain contaminated over an extended period of time or do they get better and then become contaminated again? To answer these questions, we compared culturable fungal air proles measured continually over 6 hours in a documented sick building. We measured culturable indoor air (IDA) samples in a room experiencing IAQ problems (heavily colonized with P. chrysogenum) with fungal proles measured concurrently in the culturable outdoor air (ODA) samples. Investigators often use ODA samples as a baseline measurement in which to compare what is found in the IDA samples. Indoor/outdoor comparisons are commonly used to document the presence or infer the absence of indoor, biologically derived contamination (Burge et al., 1999). However, one should use caution and compare genera and species and not genera only. The dominant species collected in the IDA and ODA were Alternaria species, Cladosporium species, and Penicillium species (Fig. 13). In the

20

J. D. COOLEY et al.

FIG. 13. Fungal concentrations measured in indoor and outdoor air. Values are mean SEM. Each bar represents the average of all samples.

IDA, Penicillium species were consistently the dominant organisms, ranging from 150 to 567 CFU/m3 (89.8100% of the total viable fungi) (Fig. 14). In the ODA, Cladosporium species were dominant in four of the samples (40.070.6%), while Penicillium species were dominant (52.779.6%) in two samples (Fig. 15). This study showed that as expected, ODA fungal proles are continually changing. Outdoor concentrations of some biological agents vary with time of day, wind directions, relative humidity, and other factors. Depending on the source of a biological agent, indoor air concentrations may be affected by outdoor air ventilation rates, number of occupants or occupant activity, and vibration and air movements within the structure (Macher, 1999). The IDA fungal proles in this particular sick building tended not to change, at least for the 6 hours we measured, which was probably due to the very heavy colonization of Penicillium species growing in the room. However, it has been our experience in sampling hundreds of buildings that the IDA may only be a snapshot. If the IDA is positive for increased fungal presence, as compared to the ODA, then that suggests a strong indication of interior fungal growth. It should be noted that failure to nd a biological agent or related environmental

FUNGI AND THE INDOOR ENVIRONMENT

21

FIG. 14. Fungal proles measured in indoor air. Values are mean SEM. Each bar represents the mean of 3 samples.

FIG. 15. Fungal proles measured in outdoor air. Values are mean SEM. Each bar represents the mean of 3 samples.

22

J. D. COOLEY et al.

condition is not absolute assurance of their absence nor the absence of exposure or risk. Many investigators take only total spore trap sampling and usually do not take any or few culturable (viable) air sampling. The Penicillium species and Aspergillus species conidia are single cell, spherical in shape, 1 to 5 m in diameter, and are reported as Aspergillus/Penicillium-like spores. However, this can be very misleading in that there are numerous genera of fungi that produce similar-looking spores. With Penicillium species as one of the most common indoor fungal colonizers, especially in the HVAC systems, the only way to determine its presence is by culturable air sampling. Investigators can never denitively conclude or prove that an environment is safe and presents no risk of exposure to biological agents. In part, this means that if the investigators have not looked for biological agents, they cannot say that it is not there (Burge et al., 1999). VII. Evaluation of Fungal Growth on Cellulose-Containing and Inorganic Ceiling Tile As we stated earlier in our introduction, mold has plagued mankind since Moses. The construction materials used during biblical times were straw bricks, cellulose-based stones, and plaster. As the standard of living has increased in the industrialized nations, the invention of air conditioning, which led to increased productivity and laborsaving products, has also allowed the industrialized nations freedom of architectural design, ignoring thousands of years of building experience. As the postWorld War II building boom started, the industrialized nations changed the way buildings were constructed. Inorganic plaster-covered walls were labor intensive and expensive. To reduce the cost of construction and meet the burgeoning demand, the use of gypsum board (1/200 to 3/400 gypsum covered with processed-paper [cellulose-based] to maintain its rigidity) was begun. It is inexpensive to manufacture and relatively labor free and rapid to install. A variety of cellulose-based compounds could be used to texture and paint it or it could be covered with wallpaper or vinyl paper. However, in the process, we reverted back to the straw bricks, using processedcellulose substances that were ideal food sources for mold. The only thing that was lacking to induce fungal growth was moisture. The standard of living continued to increase and there was and still is a great demand for gypsum board. When the energy crisis occurred in 1972, we sealed up our buildings, closed our windows, and recirculated our air so that we could reduce the soaring energy costs.

FUNGI AND THE INDOOR ENVIRONMENT

23

Because we knew that mold growth in buildings was due to water intrusion, we thought that it was essentially impossible to keep water out of buildings. This is due to the fact that many uncontrollable events occur (e.g., roof leaks, water pipe breaks, and oods). When these things happen, moisture is trapped in buildings, and combined with poor preventive maintenance and ignorance, all of the ingredients are in place to have mold problems associated with SBS. We thus decided to see if it was possible to develop building materials that would not support fungal growth, even after a signicant water event. The objective of this study was to examine building materials that would not support the growth of certain fungi after a wetting event, regardless of whether an external food source was supplied (Karunasena et al., 2000). The growth of three fungal genera (Stachybotrys, Penicillium, and Cladosporium) was examined on inorganic ceiling tile (ICT) and cellulose-containing ceiling tile (CCT) (Figs. 16 and 17). Both types of ceiling tiles were wetted and inoculated with fungal spores of the above three genera. The study showed that the ICT did not allow for fungal growth while the CCT did (Fig. 18). These data demonstrate that it is possible to develop building materials that will not support fungal growth, even after a signicant water event. VIII. The Presence of Fungi Associated with SBS in North American Zoological Institutions The last study we would like to discuss addressed the presence of fungi associated with SBS in American zoos (Wilson and Straus, 2002). One of the ideas that led to this study was a perception that it is often difcult to get animals to breed in captivity, especially in zoos. We wondered if chronic exposure to SBS-associated fungi could affect breeding success or animal morbidity and/or mortality. We examined a total of 110 sites from ve zoos in the United States to determine whether SBS-associated fungi could be isolated. We also investigated whether the presence of said fungi could be correlated with adverse breeding success and/or morbidity and mortality. Culturable air samples and surface samples were taken at the above zoos. High levels of P. chrysogenum conidia were found in the air of 16 sites at all 5 zoos. Five viable growth sites of Stachybotrys chartarum (atra) were found at 2 zoos. A number of other fungal species were recovered from all zoos. A Fisher exact test analysis demonstrated a nonrandom, signicant (P < 0.001) relationship between sites with a record of poor animal health and high levels of airborne P. chrysogenum conidia. This study suggests that signicant numbers of airborne fungi associated with SBS

24

J. D. COOLEY et al.

FIG. 16. Colony-forming units of three different fungal genera on cellulose-containing ceiling tile (CCT) and inorganic ceiling tile (ICT) exposed to fungal conidia and incubated for 7 days. Horizontal bars represent original conidia concentrations. Error bars represent standard deviation. The single asterisk (*) indicates a signicant increase in the number of viable spores harvested from the tiles compared to the original inocula, and the double asterisk (**) indicates a signicant decrease in the number of viable spores harvested from the tiles compared to the original inocula. A Mann-Whitney rank sum test was utilized (P < 0.05) to compare the inocula to the conidia harvested from the tiles. Clado signies Cladosporium cladosporioides, Pen signies Penicillium chrysogenum, and Stach signies Stachybotrys chartarum.

are in North American zoological institutions, and therefore zookeepers need to be aware of them and the potential problems they can cause. IX. The Role (?) of Mycotoxins in SBS Finally, we would like to briey discuss the role of mycotoxin production by fungi in the role of SBS. There is little doubt that mycotoxins are produced by fungi inside buildings in which the organisms are growing. This has been shown by a number of investigators (Croft et al., 1986; Engelhart et al., 2002; Kielsen et al., 1999; Nieminen et al., 2002; Nikulin et al., 1994; Tuomi et al., 2000). We know that there are

FUNGI AND THE INDOOR ENVIRONMENT

25

FIG. 17. Colony-forming units of three different fungal genera on CCT and ICT with 400 l of TSB exposed to fungal conidia and incubated for 7 days. Horizontal bars represent original conidia concentrations. Error bars represent standard deviation. The single asterisk (*) indicates a signicant increase in the number of viable spores harvested from the tiles compared to the original inocula, and the double asterisk (**) indicates a signicant decrease in the number of viable spores harvested from the tiles compared to the original inocula. A Mann-Whitney rank sum test was utilized (P < 0.05) to compare the inocula to the viable conidia harvested from the ceiling tiles. Clado signies Cladosporium cladosporioides, Pen signies Penicillium chrysogenum, and Stach signies Stachybotrys chartarum.

trichothecene mycotoxins on the spores of Stachybotrys atra (Sorenson et al., 1987) and that these spores can be taken into the human lung (Elidemir et al., 1999). In many of our examinations of tape surface samples, we observed Penicillium species growing with Stachybotrys atra colonies (Cooley and Wong, unpublished data from ARAL database, 2003). Therefore the obvious conclusion one can draw from this is that trichothecene mycotoxins can enter the lungs of human beings in Stachybotrys-infested houses. There is some evidence that implicates trichothecene mycotoxins in illnesses seen in Stachybotrysinfested buildings and/or houses (Croft et al., 1986; Elidemir et al., 1999; Flappan et al., 1999; Hodgson et al., 1998; Smoragiewicz et al., 1993). Indeed, Croft et al. (2002) recently demonstrated the presence of

26

J. D. COOLEY et al.

FIG. 18. Fungal growth on cellulose-containing ceiling tile (CCT) and inorganic ceiling tile (ICT). CCT (B, C) and ICT (E, F) were inoculated with 3.0 104 CFU of S. chartarum and incubated for 7 days at 25 C and 80% RH. A and D represent uninoculated CCT and ICT, respectively. B and E represent CCT and ICT inoculated with 3.0 104 CFU of S. chartarum plus 0 l of TSB, respectively. C and F represent CCT and ICT inoculated with 3.0 104 CFU of S. chartarum plus 400 l of TSB, respectively. These results are representative of all of the fungi used in this study.

trichothecene mycotoxins in the urine of patients who had been exposed to these compounds in mold-contaminated buildings. We know what kinds of symptoms trichothecene mycotoxins can produce in human beings. Phase I clinical evaluation of anguidine (a simple trichothecene produced by Fusarium equiseti) was administered by rapid intravenous infusion daily to a number of patients to determine its effectiveness as an anti-cancer drug (Goodwin et al., 1978; Murphy et al., 1978). While this compound had little or no anti-tumor activity, it was quite toxic at some of the dosages employed. Symptoms of toxicity included nausea; vomiting; low blood pressure; central nervous system symptoms such as drowsiness, ataxia, and confusion; diarrhea; fever and chills; burning erythema, inammation of the mucous membranes of the mouth; difculty in breathing; and moderate myelosuppression. Higher doses showed an association with lifethreatening liver function impairment. While we can not yet say that

FUNGI AND THE INDOOR ENVIRONMENT

27

mycotoxin production in our buildings is denitely responsible for some of the illnesses seen in those living or working in Stachybotrysinfested buildings, it is clear that exposure to these structures by human beings is something to be avoided.ACKNOWLEDGMENTS The authors would like to thank the following for financial support: Assured IAQ, Dallas; Texas Tech University Health Sciences Center; and the State of Texas Higher Education Coordinating Board. We would also like to thank Enusha Karunasena, Trevor Brasel, and Nancy Markham, and also Drs. Chris Schwab, Jim Hutson, Jim Williams, Steve Wilson, and Jim McGrath, who helped generate the data reported here.

REFERENCES Blackley, C. H. Experimental researches on the causes and nature of catarrhus aestivus (hay fever or hay asthma). London, 1959, Dawson Publishing Co. (reprinted from Bailliere Tindall and Cox, 1873), pp. 5758. Brain, J. D., and Valberg, P. A. (1979). Deposition of aerosol in the respiratory tract. Am. Rev. Respir. Dis. 120, 13251373. Burge, H. A., Macher, J. M., Milton, D. K., and Ammann, H. M. (1999). Data Evaluation. In Bioaerosols: Assessment and Control ( J. Macher, ed.), Chapter 14. American Conference of Governmental Industrial Hygienists, Cincinnati, OH. Burrell, R. (1991). Microbiological agents as health risks in indoor air. Environ. Hlth. Perspect. 95, 2934. Campbell, J. A., Kryda, M. J., Treuhaft, M. W., Marx, J. J., Jr., and Roberts, R. C. (1983). Cheese workers hypersensitivity pneumonitis. Am. Rev. Respir. Dis. 127, 495496. Cooley, J. D., and Wong, W. C. (2003). Aerobiology Research and Analytical Laboratory, Unpublished Database. Corpus Christi, TX. Cooley, J. D., Wong, W. C., Jumper, C. A., Hutson, J. C., Williams, H. J., Schwab, C. J., and Straus, D. C. (2000). An animal model for allergic penicilliosis induced by the intranasal instillation of viable Penicillium chrysogenum conidia. Thorax 55, 489496. Cooley, J. D., Wong, W. C., Jumper, C. A., and Straus, D. C. (1999). Cellular and humoral responses in an animal model inhaling Penicillium chrysogenum spores. In Proceedings of the Third International Conference on Bioaerosols, Fungi, and Mycotoxins, pp. 403410. Cooley, J. D., Wong, W. C., Jumper, C. A., and Straus, D. C. (1998). Correlation between the prevalence of certain fungi and sick building syndrome. Occup. Environ. Med. 55, 579584. Croft, W. A., Jarvis, B. J., and Yatawara, C. S. (1986). Airborne outbreak of trichothecene toxicosis. Atmos. Environ. 20, 549552. Croft, W. A., Jastromski, B. M., Croft, A. L., and Peters, H. A. (2002). Clinical conrmation of trichothecene mycotoxins in patient urine. J. Environ. Biol. 23, 301320. Dales, R. E., Burnett, R., and Zwanenburg, H. (1991). Adverse health effects among adults exposed to home dampness and molds. Am. Rev. Respir. Dis. 143, 505509.

28

J. D. COOLEY et al.

DeWeck, A. L., Gutersohn, J., and Butikofer, E. (1969). La Maladie des laveurs de fromage (Kasewascherkrankheit) une forme particuliere du syndrome du poumon de fermier. Schweiz Med. Wochenschr 99, 872876. Elidemir, O., Colasurdo, G. N., Rossman, S. N., and Fan, L. L. (1999). Isolation of Stachybotrys from the lung of a child with pulmonary hemosiderosis. Pediatrics 104, 964966. Engelhart, S., Loock, A., Skutlarek, D., Sagunski, H., Lommel, A., Farber, H., and Exner, M. (2002). Occurrence of toxigenic Aspergillus versicolor isolates and sterigmatocystin in carpet dust from damp indoor environments. Appl. Environ. Microbiol. 68, 38863890. Finnigan, M. S., Pickering, C. A. C., and Burge, P. S. (1984). The sick building syndrome: prevalence studies. Brit. Med. J. 289, 15731575. Flappan, S. M., Portnoy, J., Jones, P., and Barnes, C. (1999). Infant pulmonary hemorrhage in a suburban home with water damage and mold (Stachybotrys atra). Environ. Hlth. Perspect. 107, 927930. Garret, M. H., Rayment, R. P., Hooper, M. A., Abramson, M. J., and Hooper, B. M. (1998). Indoor airborne fungal spores, house dampness and associations with environmental factors and respiratory health in children. Clin. Exper. Allergy 28, 459467. Gent, J. F., Ren, P., Belanger, K., Triche, E., Bracken, M. B., Holford, T. R., and Leaderer, B. P. (2002). Levels of household mold associated with respiratory symptoms in the rst year of life in a cohort at risk for asthma. Environ. Hlth. Perspect. 110, A 781A 786. Goodwin, W., Haas, C. D., Fabian, C., Heller-Bettinger, I., and Hoogstraten, B. (1978). Phase 1 evaluation of anguidine (diacetoxyscirpenol, NSC141537). Cancer 42, 2326. Guglielminetti, M., Valoti, E., Cassini, P., Taino, G., and Caretta, G. (2001). Respiratory syndrome very similar to extrinsic allergic alveolitis due to Penicillium verrucosum in workers in a cheese factory. Mycopathologica 149, 123129. Hodgson, M. (1992). Field studies on the sick building syndrome. Ann. N. Y. Acad. Sci. 641, 2136. Hodgson, M. J., Morey, P., Leung, W.-Y., Morrow, L., Miller, D., Jarvis, B. B., Robbins, H., Halsey, J. F., and Storey, E. (1998). Building-associated pulmonary disease from exposure to Stachybotrys chartarum and Aspergillus versicolor. J. Environ. Med. 40, 241249. Jaakkola, M. S., Nordman, H., Piipari, R., Uitti, J., Laitinen, J., Karjalainen, A., Hahtola, P., and Jaakkola, J. K. (2002). Indoor dampness and molds and development of adultonset asthma: a population-based incident case-control study. Environ. Hlth. Perspect. 110, 543547. Karunasena, E., Markham, N., Brasel, T., Cooley, J. D., and Straus, D. C. (2000). Evaluation of fungal growth on cellulose-containing and inorganic ceiling tile. Mycopathologica 150, 9195. Kavaler, L. (1965). Mushrooms, Molds, and Miracles: The Strange Realm of Fungi. John Day Co. Kielsen, K. F., Gravesen, S., Nielsen, P. A., Andersen, B., Thrane, U., and Frisvad, J. C. (1999). Production of mycotoxins on articially and naturally infested building materials. Mycopathologica 145, 4356. Lehrer, S. B., Aukrust, L., and Salvaggio, J. E. (1983). Respiratory allergy induced by fungi. Clin. Chest Med. 4, 2341. Leviticus. The Bible (Old Testament) 14, 3345.

FUNGI AND THE INDOOR ENVIRONMENT

29

Licorish, K., Novey, H. S., Kozack, P., Fairshter, R. D., and Wilson, A. F. (1985). Role of Alternaria and Penicillium spores in the pathogenesis of asthma. J. Allergy Clin. Immunol. 76, 819825. Macher, J. M. (1999). Data Analysis. In Bioaerosols: Assessment and Control ( J. Macher, ed.), Chapter 13. American Conference of Governmental Industrial Hygienists, Cincinnati, OH. Marcer, G., Franchini, M., Germignani, C., Zancanaro, A., Semenzato, G., Tassinari, C., Cipriani, A., Festi, G., and Saia, B. (1996). Cheese workers lung. Allergy 51, 959966. McGrath, J. J., Wong, W. C., Cooley, J. D., and Straus, D. C. (1999). Continually measured fungal proles in sick building syndrome. Curr. Microbiol. 38, 3336. Miller, J. D. (1992). Fungi as contaminants of indoor air. Atmosp. Environ. 26, 21632172. Murphy, W. K., Burgess, M. A., Valdivieso, M., Livingston, R. B., Bodey, G. P., and Freireich, E. J. (1978). Phase 1 clinical evaluation of anguidine. Cancer Treat. Rep. 62, 14971502. Nieminen, S. M., Karki, R., Auriola, S., Toivola, M., Laatsch, H., Laatikainen, R., Hyvar inen, A., and von Wright, A. (2002). Isolation and identication of Aspergillus fumigatus mycotoxins on growth medium and some building materials. Appl. Environ. Microbiol. 68, 48714875. Nikulin, M., Pasanen, A-L., Berg, S., and Hintikka, E.-L. (1994). Stachybotrys atra growth and toxin production in some building materials and fodder under different relative humidities. Appl. Environ. Microbiol. 60, 34213424. Platt-Mills, T. A. E., Woodfolk, J. A., and Wheatley, L. M. (1998). Environmental Allergens. In Allergy and Allergic Diseases: The New Mechanisms and Therapeutics (J. A. DeBurg, ed.), pp. 4160. Humana Press, New Jersey, NJ. Redd, S. C. (2002). In Statement for the record before the subcommittees on oversight and investigations and housing and community opportunity on nancial services, United States House of Representatives, State of the Science on Molds and Human Health, July 18, pp. 111. Schleuter, D. P. (1993). Cheesewashers disease: A new occupational hazard? Ann. Int. Med. 78, 606. Schwab, C. J., Cooley, J. D., Brasel, T., Jumper, C. A., Graham, S. C., and Straus, D. C. (2003). Characterization of exposure to low levels of viable Penicillium chrysogenum conidia and allergic sensitization induced by a protease allergen extract from viable P. chrysogenum conidia in mice. Int. Arch. Allergy Immunol. 130, 200208. Sell, S. (1996). Granulomatous reactions. In Immunology, Immunopathology, and Immunity, 5th edn., pp. 463488. Appleton and Lange, Stanford, CT. Shaughnessy, R. J., and Morey, P. R. (1999). Remediation of Microbial Contamination. In Bioaerosols: Assessment and Control ( J. Macher, ed.), Chapter 15. American Conference of Governmental Industrial Hygienists, Cincinnati, OH. Shelton, B. G., Kirkland, K. H., Flanders, W. D., and Morris, G. K. (2002). Proles of airborne fungi in buildings and outdoor environments in the United States. Appl. Environ. Microbiol. 68, 17431753. Smoragiewicz, W., Cossette, B., Boutard, A., and Krzystyniak, K. (1993). Trichothecene mycotoxins in dust of ventilation systems in ofce buildings. Int. Arch. Environ. Hlth. 65, 113117. Sorenson, W. G., Frazer, D. G., Jarvis, B. B., Simpson, J., and Robinson, V. A. (1987). Trichothecene mycotoxins in aerosolized conidia of Stachybotrys atra. Appl. Environ. Microbiol. 53, 13701375. Spangler, J. D., and Sexton, K. (1983). Indoor air pollution: a public health perspective. Science 221, 917.

30

J. D. COOLEY et al.

Straus, D. C. (2001). Consequences of mold exposure in buildings. Texas J. Rural Hlth. 19, 813. Straus, D. C. (2002). Cheese workers lung. Columns-Mold. October: 5859. Tuomi, T., Reijula, K., Johnson, T., Hemminki, K., Hintikka, E. -L., Lindroos, O., Kalso, S., Koukila-Kahkola, P., Mussalo-Rauhamaa, H., and Haahtela, T. (2000). Mycotoxins in crude building materials from water-damaged buildings. Appl. Environ. Microbiol. 66, 18991904. Wilson, S. C., and Straus, D. C. (2002). The presence of fungi associated with sick building syndrome in North American zoological institutions. J. Zoo Wildlife Med. 33, 322327. Yang, C. H., and Johanning, E. (1997). Airborne Fungi and Mycotoxins. In Manual of Environmental Microbiology (C. J. Hurst, G. R. Knudsen, M. J. McInerney, L. D. Stetzenbach, and M. V. Walter, eds.), pp. 651660. ASM Press, Washington, D.C.

Fungal Contamination as a Major Contributor to Sick Building SyndromeDE-WEI LIAND

CHIN S. YANG

P & K Microbiology Services, Inc., 1936 Olney Ave Cherry Hill, New Jersey 08003

I. Introduction II. Effects of Indoor Fungi on Human Health A. Fungal Allergies and Allergenic Respiratory Diseases B. Infectious Diseases C. Mycotoxins and Their Significance to Human Health D. Volatile Organic Compounds (VOCs) E. Glucans III. Indoor Fungi A. Fungal Identification B. Airborne Fungi C. Fungi Growing on Indoor/Building Materials D. Fungal Biodiversity Indoors E. Stachybotrys chartarum and Other Stachybotrys spp. F. PCR and Molecular Techniques IV. Ecological Factors of Fungi Indoors A. Physical Factors B. Building Characteristics C. Succession and Changes in Indoor Fungi V. Recent Studies on Limits/Exposures of Indoor Fungi VI. Conclusions References

31 32 32 42 50 59 62 63 63 64 72 74 74 77 78 78 86 91 94 96 97

I. Introduction Fungi are heterotrophic eukaryotes producing exoenzymes and absorbing their nutrients by a network of hyphae and reproducing through development of spores. They belong to Kingdom Eumycota (Kingdom of Fungi) or Kingdom Chromista (Kendrick, 2000). However, there is one group of organisms, which are traditionally studied by mycologists, called pseudofungi (such as slime molds in myxomycetes), that belong to Kingdom Protozoa (Kirk et al., 2001). Fungi are a very large, diverse, and heterogeneous group of organisms found in nearly every ecological niche (Alexopoulos et al., 1996). They play a very important role in our ecosystem and our daily life. Fungi always play dual roles on the earth: (a) a positive one as food, medicine, key components in food processing, decomposers breaking down organic matters to recycle the nutrients in the ecosystem and to form symbiotic31ADVANCES IN APPLIED MICROBIOLOGY, VOLUME 55 Copyright 2004, Elsevier Inc. All rights reserved. 0065-2164/04 $35.00

32

LI AND YANG

relationship with other organisms; (b) a negative one as pathogens to humans, plants, and animals; as allergens, producing secondary metabolites, mycotoxins, fungal volatile organic compounds (VOCs); and as glucans, which are detrimental to human health and building occupants (Batterman, 1995; Ezeonu et al., 1994; Miller, 1992, 1993). A large number of fungi are saprophytes or decomposers, which mainly occur in natural environments (outdoors) such as soil and plant debris. Some of these fungi can be found in indoor environments. One key factor that we should keep in mind is that most indoor fungi originate from the outdoor environment. Certain indoor fungal contaminants pose a potential health risk to building occupants and may lead to sick building syndrome (Gravesen et al., 1994; Miller, 1992, 1993; Samson et al., 1994). Indoor fungi have attracted unprecedented attention because of their potential health effects on humans in the last decade. Public awareness of indoor fungi in return generates more research to elucidate their roles in indoor environments and human health. Indoor fungus is not only a scientic issue but is also becoming a social issue. Public awareness does not automatically mean a good understanding of the indoor molds. There are still many key questions that need to be answered to have a better understanding of the indoor mold issue. This chapter reviews available literature on fungal contamination as a major contributor to sick building syndrome.

II. Effects of Indoor Fungi on Human Health A. FUNGAL ALLERGIES AND ALLERGENIC RESPIRATORY DISEASES Allergy (Gk allos, other; ergon, work) is a disease or reaction caused by an immunoglobin E (IgE)-mediated immune response to one or more environmental agents, resulting in tissue inammation and organ dysfunction, and an exaggerated and pathological variant of a normal immune mechanism (Klein, 1990; Middleton, Jr. et al., 1988; Paul, 1989; Raven and Johnson, 1986). Fungal spores are a well known cause of allergic diseases (Chapman, 1999; Gravesen, 1979; Horwitz and Bush, 1997) and were identied as one of the major indoor allergens (Burr, 1999; Pope et al., 1993; Ruotsalainen et al., 1995). Allergy is common throughout the world. The prevalence of sensitivity to specific allergens is determined by both genetic predilection and geographic and cultural factors responsible for exposure to the allergen (Stites and Terr, 1991). All fungi may be allergenic, depending on the individual, the exposure situation, and the dose (Ruotsalainen et al., 1995). The genera

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR

33

of fungi, which have been reported to be allergenic, are compiled in Table I. Since the late 1870s, when Blakeley developed symptoms of bronchial asthma and chest tightness after inhaling spores from Penicillium cultures, it has been believed that mold sensitization is an important cause of respiratory allergy (Barth, 1981; Karlsson-Borga, 1989; Salvaggio, 1986). Allergy is perhaps the most common human reaction to airborne fungal spores (including conidia). About 20% of the population are allergic individuals with a genetic predisposition to produce IgE antibody to allergens that are either inhaled or ingested (Kaplan et al., 1991; Tizard, 1988). The percentages of populations allergic to molds vary from 2% to 18%, and around 80% of asthmatic patients are allergic to molds (Flannigan et al., 1991). About 20% of the population are atopic and easily sensitized by concentrations usually found in the outdoor air spora (up to 106 spores/m3). These people react immediately on exposure in the upper airways with hay-fever-like symptoms or asthma and may become sensitive to several of the allergens to which they are exposed. The remainder of the population requires more intensive exposure (106109 spores/m3) for sensitization (Lacey, 1981). The incidence and prevalence of allergic diseases is increasing (Ruotsalainen et al., 1995). Allergies affect as many as 50 million people in the United States, costing them up to $5 billion annually (Jaroff, 1992), and the number is obviously much higher at present. Asthma, rhinitis, hypersensitivity pneumonitis, and humidier lung are allergenic respiratory diseases that, to a certain degree, may be related to exposure to airborne fungi. Asthma is the most common chronic respiratory disease in all countries. Both the severity and prevalence of persistent asthma appear to be increasing, leading to urgency in the search for its causes (Woolcock, 1991). Four thousand people a year reportedly died from allergic asthma attack in the United States (Jaroff, 1992). In Australia, asthma mortality rates doubled from 1978 to 1988 (Young et al., 1991). Immediate-type asthma symptoms were produced with both whole spores and spore extracts of Alternaria and Penicillium (Licorish et al., 1985; Salvaggio, 1986). Airborne fungal spores are ubiquitous (Howard, 1984) and are known in many cases to be allergenic, so it is not surprising that mold spores are an important cause of asthma. At present the relationship between mold spores and asthma is still poorly understood. In Madison, Wisconsin, in a series of 100 consecutive patients with allergic asthma, skin tests were uniformly positive to Alternaria (Reed, 1985). Most of these patients had asthma symptoms not only before and after the ragweed season (about August 10 to

34

LI AND YANG TABLE I FUNGAL GENERA REPORTED TO BE ASSOCIATED WITH ALLERGY Fungus Order Mucorales Division Zygomycota Hyphomycetes Hyphomycetes Hyphomycetes Agaricales Agaricales Agaricales Agaricales Basidiomycotina Basidiomycotina Hyphomycetes Basidiomycotina Basidiomycotina Hyphomycetes Hyphomycetes Hyphomycetes Hyphomycetes Boletales Boletales Lycoperdales Yeast Aphyllophorales Sordariales Agaricales Hypocreales Agaricales Aphyllophorales Basidiomycotina Ascomycotina Basidiomycotina Hyphomycetes Ascomycotina Hyphomycetes Basidiomycotina Basidiomycotina Hyphomycetes Hyphomycetes Mucorales Dacrymycetales Xylariales Saccharomycetales (Yeast) Zygomycota) Hyphomycetes Basidiomycotina Ascomycotina Ascomycotina Hyphomycetes (continued) Basidiomycotina Basidiomycotina Hyphomycetes Basidiomycotina

Absidia Acremonium Acrogenospora Acrothecium Agaricus Agrocybe Alternaria Amanita Armillaria Arthrinium Aspergillus Aureobasidium Bispora Boletinellus Boletus Botrytis Calvatia Candida Cantharellus Chaetomium Chlorophyllum Cladosporium Claviceps Coniosporium Coprinus Coriolus Cryptococcus Cryptostroma Cunninghamella Curvularia Dacrymyces Daldinia Debaryomyces Dicoccum (Trichocladium)

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR TABLE I (Continued ) Fungus Didymella Drechslera Epicoccum Epidermophyton Erysiphe Eurotium Fomes Fuligo Fusarium Ganoderma Geastrum Geotrichum Gibberella Gliocladium Gnomonia Graphium Helminthosporium Hypholoma Inonotus Leptosphaeria Leptosphaerulina Lycoperdon Malassezia Merulius (=Phlebia) Microsphaera Microsporum Monilia Mucor Mycogone Naematoloma Neurospora Nigrospora Oidium Paecilomyces Papularia Agaricales Sordariales Mucorales Erysiphales Agaricales Aphyllophorales Dothideales Dothideales Lycoperdales Diaporthales Hypocreales Aphyllophorales Lycoperdales Erysiphales Eurotiales Aphyllophorales Order Dothideales Division

35

Ascomycotina Hyphomycetes Hyphomycetes Hyphomycetes Ascomycotina Ascomycotina Basidiomycotina Myxomycetes Hyphomycetes Basidiomycotina Basidiomycotina Hyphomycetes Ascomycotina Hyphomycetes Ascomycotina Hyphomycetes Hyphomycetes Basidiomycotina Basidiomycotina Ascomycotina Ascomycotina Basidiomycotina Hyphomycetes Basidiomycotina Ascomycotina Hyphomycetes Hyphomycetes Zygomycota Hyphomycetes Basidiomycotina Ascomycotina Hyphomycetes Hyphomycetes Hyphomycetes Hyphomycetes (continued)

36

LI AND YANG TABLE I (Continued ) Fungus Order Division Hyphomycetes Coelomycetes Mucorales Peronosporales Aphyllophorales Sclerodermatales Dothideales Aphyllophorales Podaxales Aphyllophorales Aphyllophorales Agaricales Uredinales Mucorales Yeast Endomycetales (Yeast) Sclerodermatales Aphyllophorales Erysiphales Yeast Zygomycota Oomycota Basidiomycotina Basidiomycotina Ascomycotina Basidiomycotina Basidiomycotina Basidiomycotina Basidiomycotina Basidiomycotina Basidiomycotina Zygomycota Basidiomycotina Ascomycotina Basidiomycotina Hyphomycetes Basidiomycotina Ascomycotina Hyphomycetes Basidiomycotina Hyphomycetes Hyphomycetes Myxomycetes Hyphomycetes Aphyllophorales Mucorales Basidiomycotina Zygomycota Hyphomycetes Hyphomycetes Hyphomycetes Basidiomycotina Hyphomycetes Hyphomycetes Hyphomycetes (continued)

Penicillium Phoma Phycomyces Phytophthora Piptoporus Pisolithus Pleospora Pleurotus Podaxis Polyporus Poria Psilocybe Puccinia Rhizopus Rhodotorula Saccharomyces Scleroderma Scopulariopsis Serpula Sphaerotheca Spondylocladium Sporobolomyces Sporotrichum Stachybotrys Stemonitis Stemphylium Stereum Syncephalastrum Tetracoccosporium Thermomyces Tilletiopsis Tilletia Torula Trichoderma Trichophyton

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR TABLE I (Continued ) Fungus Trichothecium Typhula Urocystis Ustilago Verticillium Wallemia Xylaria Xylobolus Xylariales Aphyllophorales Ustilaginales Aphyllophorales Order Division

37

Hyphomycetes Basidiomycotina Basidiomycotina Basidiomycotina Hyphomycetes Hyphomycetes Ascomycotina Basidiomycotina

Chapman (1986); Ibanez et al. (1988); Latge and Paris (1991); Santilli et al. (1990); Shen et al. (1990); Smith (1990); Van Bronswijk et al. (1986).

September 20) but also during the time of year Alternaria spore counts are high (July through October) (Reed, 1985). Cladosporium herbarum has been shown to be a potential cause of allergic asthma and rhinitis (Malling, 1990). In a recent study, the prevalence of most building-related symptoms was between 32% and 62%. Positive basophile histamine release (HRT), showing serum IgE specic to one or more of the molds, was observed in 37% of the individuals (Lander et al., 2001). The highest frequency of positive HRT was found to Penicillium chrysogenum and then to Aspergillus species, Cladosporium sphaerospermum, and Stachybotrys chartarum (Lander et al., 2001). Savilahti et al. (2000) showed that moisture damage and exposure to molds increased the indoor air problems of schools and affected the respiratory health of children. Cladosporium, Alternaria, Penicillium, Aspergillus, and Mucor were reported to be the commonest allergenic fungi (Furuuchi and Baba, 1986; Malling et al., 1985). Cladosporium is believed to be the most common one causing mold allergy (Malling et al., 1985). However, the most prevalent airborne fungi are not necessarily the most potent allergens, at least as determined by prick testing (Terracina and Rogers, 1982). Spores of Alternaria alternata and those of the closely related genera Stemphylium and Ulocladium are considered to be the most important mold allergens in the United States (Hoffman, 1984; OHollaren et al., 1991; Reed, 1985). Penicillium exposure was a risk factor for asthma, while Aspergillus exposure was a risk factor for atopy (a genetic trait of increased allergen sensitivity) (Garrett et al., 1998).

38

LI AND YANG

Chow et al. (2000) characterized Pen n 13 as a major allergen of Penicillium notatum (a synonym of P. chrysogenum). Aspergillus restrictus was demonstrated to be a potentially important causative agent in atopic diseases when using skin prick tests and radioallergosorbent test (RAST) on 24 patients (Sakamoto et al., 1990). Aspergillus species and in particular Aspergillus fumigatus appeared to be the etiological agents in various lung diseases and allergens. Inhalation of low doses of Aspergillus spores may induce sensitization and asthma in sensitive patients, while inhalation of high doses may trigger alveolitis and farmers lung (Wallenbeck et al., 1991). Martinez Ordaz et al. (2002) of Mexico found that the association of skin reactivity and indoor exposure was signicant only for Aspergillus. Curvularia lunata was found to be a cause of allergic bronchopulmonary disease (Halwig et al., 1985). Epicoccum nigrum was reported to be able to colonize nasal sinuses and cause allergic fungal sinusitis (Noble et al., 1997). Sooty molds caused allergies ranging from rhinitis to asthma in the eastern United States (Santilli et al., 1985). Ascospores are important airborne allergens and present unique antigens (Eversmeyer and Kramer, 1987). Fifteen of 18 patients reportedly reacted to Leptosphaeria ascospores (Burge, 1986). About 40% of atopic patients reacted to at least 1 ascomycete preparation. Chaetomium species, particularly C. globosum, are important ascomycetes commonly found growing indoors on water-damaged paper and wood products. Basidiospores of Agaricus campestris, Coprinus micaceus, Lycoperdon perlatum, Scleroderma lycoperdoides, and Ustilago maydis caused allergies ranging from rhinitis to asthma in the eastern United States (Santilli et al., 1985). Basidiospores are antigenic and can elicit immediate skin reactivity in sensitive patients. Mushrooms and basidiospores are considered most likely to be of outdoor origin, although mycelia and conidia of wood decay fungi and, occasionally, mushrooms of the genus Coprinus and wood decay fungi have been identied in indoor environments with a chronic water-damage history. In a military hospital building in Finland with severe, repeated, and enduring water and mold damage, the most abundant species was Sporobolomyces salmonicolor. Four new cases of asthma, conrmed by S. salmonicolor inhalation provocation tests, were found among the hospital personnel, one of whom was also found to have alveolitis (Seuri et al., 2000). Seven other workers with newly diagnosed rhinitis reacted positively in nasal S. salmonicolor provocation tests. Skin prick tests of Sporobolomyces were negative among all 14 workers (Seuri et al., 2000).

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR

39

Several epidemiologic studies concerning water damage, fungal growth, and exposure to mold spores have been conducted in a number of countries. The occurrence of Cladosporium, Aspergillus versicolor, and Stachybotrys showed some value as an indicator of moisture damage. Presence of moisture damage in school buildings was a signicant risk factor for respiratory symptoms in school children (Meklin et al., 2002). The association between moisture damage and respiratory symptoms of children was signicant for buildings of concrete/brick construction but not for wooden school buildings. The highest symptom prevalence was found during spring seasons, after a long exposure period in damaged schools (Meklin et al., 2002). Questionnaire surveys conducted in the United Kingdom, Canada, United States, and the Netherlands showed positive correlations between self-reported allergenic respiratory symptoms and self-reported water damage and indoor fungi problems (Andrae et al., 1988; Brunekreef, 1989; Dales et al., 1991a; Dekker et al., 1991; Melia et al., 1982; Strachan, 1988; Strachan and Sanders, 1989; Strachan et al., 1990; Waegemaekers et al., 1989). Most studies identied an association between airborne fungal spore concentrations and selfreported allergic symptoms in the United Kingdom, Sweden, and the Netherlands (Holmberg, 1987; Platt et al., 1989; Strachan et al., 1990; Waegemaekers et al., 1989), but there is not always a correlation between indoor spore counts and symptoms found in research (Tobin et al., 1987). Yang et al. (1997) showed that the prevalence of respiratory symptoms was consistently higher in homes with dampness than in nondamp homes. Dampness in the home can be used as a strong predictor of and a risk factor for respiratory symptoms and is a considerable public health problem in Taiwan (Yang et al., 1997). A signicant relationship was found between dampness and work-related sick building syndrome in day-care-center workers in Taiwan (Li et al., 1997). A signicant association was found between most buildingrelated symptoms (BRS) and positive basophil histamine release (Lander et al., 2001). Jacob et al. (2002) found that mold spore counts for Cladosporium and Aspergillus were associated with an increased risk of allergic sensitization. Sensitized children exposed to high levels of mold spores (>90th percentile) were more likely to suffer from symptoms of rhinoconjunctivitis. Fungal allergies were more common among children exposed to Cladosporium or Penicillium in winter or to musty odor (Garrett et al., 1998). In atopic children, total IgE showed a signicant linear relation with age. Prevalence of specic IgE for Cladosporium ranked rst, followed

40

LI AND YANG

closely by Aspergillus and Alternaria (Nolles et al., 2001). Sensitization to fungi is prevalent in childhood, with an age-dependent distribution reaching maximum values at 7.77.8 years, followed by a decline for all fungal sensitization with increasing age (Nolles et al., 2001). Jaakkola et al. showed that the risk of asthma was related to the presence of visible mold and/or mold odor in the workplace but not to water damage or damp stains alone. The fraction of asthma attributable to workplace mold exposure was estimated to be 35.1% among the exposed (Jaakkola et al., 2002). Large airborne fungal spore concentrations were recorded in association with musty odor, water intrusion, high indoor humidity, limited ventilation through open windows, few extractor fans, and failure to remove indoor mold growth in the homes in the Latrobe Valley, Victoria, Australia (Garrett et al., 1998). Aspergillus was associated strongly with work-related sick building syndrome in day-care-center workers (Li et al., 1997). The diagnosis of sick building syndrome related diseases, such as asthma, rhinitis, and allergic alveolitis, can be very difcult. In the study of Thorn et al. (1996) the symptoms of a school teacher, who was working in a school that had indoor air quality problems on and off for several years, were rst interpreted as pulmonary embolism and later as atypical sarcoidosis. However, 6 years later the diagnosis of the illness was revised to chronic allergic alveolitis. It is important to understand that even correlations do not necessarily mean causal relations. Most studies on indoor airborne fungi were conducted without taking allergic symptoms into account. Several recent epidemiological studies have shown that long-duration indoor exposure to certain fungi can result in hypersensitivity reaction and chronic diseases. Mold spore levels comparable to outside background levels are usually well tolerated by most people. Normal or typical indoor molds may vary depending on diurnal and seasonal patterns of outdoor fungi, weather conditions, climate variations, and geographical regions (Li and Kendrick, 1995a). There are other diseases caused by airborne fungal allergens, such as rhinitis, hypersensitivity pneumonitis, and humidier lung (Burge, 1990b; Salvaggio, 1986). A number of occupational hypersensitivity diseases of the lung can be implicated by fungi (Table II). Hypersensitivity pneumonitis, also called extrinsic allergic alveolitis, is a wellrecognized occupational disease. Hypersensitivity pneumonitis caused by inhalation of spores from the edible mushroom Pholiota nameko was documented by Nakazawa and Tochigi (1989). A diagnosis of hypersensitivity pneumonitis caused by an Aspergillus species was made by Jacobs et al. (1989). Pleurotus ostreatus was dened to be an

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR TABLE II FUNGI-IMPLICATED OCCUPATIONAL HYPERSENSITIVITY DISEASES OF THE LUNG Fungal agent Alternaria sp. Aspergillus clavatus Aspergillus fumigatus Aspergillus sp. Aspergillus sp. Aureobasidium pullulans Aureobasidium pullulans Botrytis cinerea Farnai rectivirgula Cryptostrama corticale Graphium sp. Micropolyspora faeni Micropolyspora faeni Micropolyspora faeni Mucor sp. Penicillium casei Penicillium spp. Rhizopus sp. Rhizopus (Mucor) stolonifer Serpula (Merulius) lacrymans Disease Pulpmill workers lung Malt workers lung Wood trimmers disease Sawmill workers lung Woodchip handlers disease Sauna takers lung Sequoiosis Vinegrowers lung Potato riddlers lung Maple bark disease Maple bark disease Farmers lung Mushroom workers lung Woodchip handlers disease Woodchip handlers disease Cheese workers lung Suberosis, woodmans disease Wood trimmers disease Paprika workers lung Dry rot lung Source

41

Moldy pulpwood Moldy malt Moldy timber Moldy Moldy woodchip Sauna steam Moldy sawdust Moldy fruit Straw Moldy maple bark Moldy maple bark Moldy hay Mushroom compost Moldy woodchip Moldy woodchip Cheese Cork Moldy timber Moldy paprika Moldy building

allergen by Horner et al. (1988). Extrinsic allergic alveolitis caused by spores of Pleurotus ostreatus was reported by Cox et al. (1988). In general, the adverse effects of fungal exposure by inhalation are related to duration and intensity. Many studies have shown that atypical mold spore levels in the indoor environment increase because of recurrent water leaks, home dampness, and high humidity, resulting in increases of allergies and respiratory problems (Burge, 1990a,b; Dales et al., 1991; Flannigan et al., 1991; Johanning et al., 1993; Rylander, 1994; Solomon et al., 1978; Strachan et al., 1990; Streifel and Rhame, 1993; Tripi et al., 2000). Path analysis showed that indoor total fungal spores, indoor Aspergillus/Penicillium, and the age of the residences had signicant direct effects on allergic symptoms (Li, 1994). There are still signicant methodological problems in the preparation and production of reliable allergen extracts from fungi as

42

LI AND YANG

compared with those from cats, dust mites, and other better-characterized allergens. Extracts that are available correspond poorly with the fungi often found in indoor surveys (Horner and Lehrer, 1999). One of the technical difculties is to produce enough spores for allergen extraction. Common practice in fungal allergen extraction is to use a mixture of spores and mycelia, which was believed to be a contributing factor to inconsistency in the low sensitivity of fungal allergenic tests. Because of the low sensitivity of some of the commercially available mold allergen extracts, false-negative results are not uncommon. Patients with an atopy are frequently allergic to multiple fungal species and manifest type I reactions (asthma, rhinitis, eczema, and hay fever). One of the reasons for the poor correlations is reportedly that fungal allergens are extracted from mostly vegetative hyphae grown in liquid cultures, not from spores. The differences in allergencity between hyphae and spores should be studied. B. INFECTIOUS DISEASES Fungi are mostly known to cause not only allergies but also infectious diseases to the skin and other body organs (Table III). Infections caused by fungi are called mycoses. Mycoses are categorized into endemic and opportunistic. Endemic mycosis is caused by the inhalation of airborne fungal spores found in certain geographic regions where there is a higher frequency of such fungi because of unique soil and ora (Lacey, 1991; Pitt, 1979). Opportunistic fungal pathogens have a great public health importance, especially in immune system compromised individuals such as those with human immunodeciency virus (HIV) and organ transplants (Keller et al., 1999). These infections are not contagious, and the fungi are not obligatory pathogens. Immunocompromised patients may be at an increased risk for opportunistic infections if opportunistic fungal pathogens become airborne and their concentrations are signicantly elevated in indoor air. The major fungi causing mycosis and their medical signicance are listed in Table III. Aspergillus fumigatus, A. avus, and A. niger are among the fungi of signicant concern. Aspergillus fumigatus is the most important airborne pathogenic fungus (Brakhage and Langfelder, 2003) because of its small respirable-size spores and its thermophilic nature (Klich and Pitt, 1988). This is the very reason why A. fumigatus could cause a signicant problem in organ transplant wards in hospitals. Water damaged materials, houseplants, soil, bird and bat droppings, organic waste, or other organic substrates in buildings may be a source of these

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR TABLE III PATHOGENIC FUNGI Fungus Absidia sp. Classification Opportunistic Systemic mycosis Disease Affected area

43

Zygomycosis Face, sinuses, (Mucormycosis, gastrointestinal phycomycosis) tract, lungs

Cunninghamelia sp. Mortierella sp. Mucor sp. Rhizopus sp. Syncephalastrum sp. Basidobolus ranarum Rhizomucor sp. Conidiobolus coronatus Acremonium sp. Cutaneous mycosis Subcutaneous mycosis Opportunistic Systemic mycosis Alternaria sp. Opportunistic Systemic mycosis Subcutaneous mycosis Opportunistic Systemic mycosis Keratomycosis Maduromycetoma Systemic opportunistic fungal disease Systemic opportunistic fungal disease Dermatomycosis Aspergillosis Lungs, deep tissue, body organs, blood Lungs, deep tissue, body organs, blood Skin Lung, skin, mucocutaneous tissue, any of the body organs Eye

Arthrographis sp. Aspergillus fumigatus

Asp. avus Asp. niger Asp. terreus Asp. ustus Aspergillus spp. Aspergillus sp. Cutaneous mycosis Outer cutaneous mycoses Onychomycosis Otomycosis Keratomycosis Skin Nails Ear Eye (continued)

44

LI AND YANG TABLE III (Continued ) Fungus Classication Opportunistic Systemic mycosis Disease Systemic opportunistic fungal disease Affected area Lungs, deep tissue, body organs, blood Smooth skin

Aureobasidium pullulans Basidiobolus sp. Beauveria bassiana Blastomyces dermatitidis

Rare Entomophthora subcutaneous basidiobolae mycosis Opportunistic Systemic mycosis Systemic mycosis Systemic opportunistic fungal disease Blastomycosis

Lungs, deep tissue, body organs, blood Primary infection in lung, may spread to all organs, skin lesions are common Moist skin areas: groin, glans penis, scrotum, folds of buttocks, under the breast, axilla, interdigital spaces Diaper area Hands, feet, face, and scalp

Candida albicans

Cutaneous mycosis

Intertriginous candidosis

Candida diaper rash Candidal granuloma

Candida Nails and skin around paronychia and nail onychomycosis Mucocutaneoius candidosis Thrush Perleche Vaginal candidosis Candida balinitis Esophageal candidosis Perianal candidosis Chronic mucocutaneous candidosis Candida albicans, Candida spp. Cutaneous mycosis Onychomycosis Nails Mucocutaneous areas Mouth and tongue Corners of mouth Vagina Glans penis Esophagus Anal ara

(continued)

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR TABLE III (Continued ) Fungus Classication Opportunistic Systemic mycosis Disease Systemic candidosis Affected area

45

Blood, heart tissue, kidney, bladder, mucocutaneous tissue (lungs are colonized, but rarely invaded) Ear Eye Lungs, deep tissue, body organs, blood Lungs, deep tissue, body organs, blood Lungs, deep tissue, body organs, blood Skin surface, mostly lower extremities

Cutaneous mycosis Candida sp. Cercospora apii Chaetoconidium sp. Chrysosporium parvum Cladosporium carrionii Cladosporium trichoides Coccidioides immitis Cutaneous mycosis Opportunistic Systemic mycosis Opportunistic Systemic mycosis Opportunistic Systemic mycosis Subcutaneous mycosis Opportunistic Systemic mycosis Systemic mycosis

Otomycosis Keratomycosis Systemic Opportunistic fungal disease Systemic Opportunistic fungal disease Systemic Opportunistic fungal disease Chromomycosis

Cerebral Brain or central chromomycosis nervous system Coccidioidomycosis Primary infection in the lung may spread to other organs of the body; skin lesion may be produced

Coprinus sp.

Miscellaneous and rare mycosis Systemic mycosis Opportunistic Systemic mycosis Opportunistic Systemic mycosis

Basidiomycosis

Cryptococcus neoformans Curvularia geniculata Drechslera hawaiiensis Entomophthora (conidiobolus) coronata

Cryptococcosis

Lungs, central nervous system, skin, any organ of body Lungs, deep tissue, body organs, blood

Systemic Opportunistic fungal disease

Rare Entomophthorosubcutaneous mycosis mycosis conididobolae

Nasal tissue and face

(continued)

46

LI AND YANG TABLE III (Continued ) Fungus Classication Cutaneous mycosis Disease Tinea cruris Tinea pedis Tinea manuum Tinea unguium Groin Feet, interdigital spaces, and soles Palms and ngers Nails Keratinized layers of body: skin, hair, nails Smooth skin Affected area

Epidermophyton occosum

Epidermophyton spp. Exophiala (Phialophora) jeanselmei Exophiala (Phialophora) spinifera Exophiala jeanselmei Fonsecaea compactum Fonsecaea pedrosoi Fonsecaea pedrosoi Fusarium sp.

Cutaneous mycosis Subcutaneous mycosis Subcutaneous mycosis Subcutaneous mycosis Subcutaneous mycosis Opportunistic Systemic mycosis Subcutaneous mycosis Opportunistic Systemic mycosis Cutaneous mycosis Opportunistic Systemic mycosis Opportunistic Systemic mycosis Subcutaneous mycosis Systemic mycosis

Dermatomycoses

Phaeomycotic Cyst Phaeomycotic Cyst Maduromycetoma Chromomycosis

Smooth skin

Skin surface, mostly lower extremities

Cerebral Brain or central chromomycosis nervous system Chromomycosis Skin surface, mostly lower extremities

Fusarium sp. Geotrichum candidum Helminthosporium sp. Hendersonula sp. Histoplasma capsulatum

Keratomycosis

Eye

Dermatomycosis Histoplasmosis

Skin Primary infection in lung (continued)

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR TABLE III (Continued ) Fungus (H. duboisii in Africa) Classication Disease Affected area

47

Recticulorendothelial system is invaded; bone and kidney and other organs, including the skin, may be involved Supercial mycosis Tinea nigra Thick stratum corneum, palms, and feet

Hortaea (Phaeoannellomyces or Exophiala) werneckii Loboa loboi

Rare Lobomycosis subcutaneous mycosis Supercial infections Cutaneous mycosis Pityriasis versicolor Tinea capitis

Smooth skin

Malassezia furfur Microsporum audouinii M. canis Microsporum spp. Microsporum canis M. gypseum Microsporum spp. Microsporum spp. Microsporum spp. Paecilomyces sp.

Scalp

Cutaneous mycosis

Tinea corporis

Smooth body skin

Cutaneous mycosis Cutaneous mycosis Opportunistic Systemic mycosis Systemic mycosis

Tinea barbae Tinea favosa Dermatomycoses

Beard and coarse body hair Scalp, skin, and nails Keratinized layers of body: skin, hair, nails

Paracoccidioides brasiliensis

Paracoccidioidomycosis

Subclinical infection in lung, mucous membranes, and skin are involved

Penicillium sp.

Opportunistic Systemic mycosis Subcutaneous mycosis Maduromycetoma

Pseudallescheria (Allescheria or Petriellidium), boydii

(continued)

48

LI AND YANG TABLE III (Continued ) Fungus Classication Opportunistic Systemic mycosis Subcutaneous mycosis Phaeomycotic Cyst Phaeomycotic Cyst Phaeomycotic Cyst Chromomycosis Smooth skin Smooth skin Smooth skin Skin surface, mostly lower extremities Disease Affected area

Phialophora parasitica

Phialophora repens Phialophora richardsiae Phialophora verrucosa Phoma hibernica Phoma sp. Piadraia hortae Pityrosporum orbiculare Pseudallescheria (Allescheria or Petriellidium), boydii Pythium

Subcutaneous mycosis Subcutaneous mycosis Subcutaneous mycosis Opportunistic Systemic mycosis Subcutaneous mycosis Supercial mycosis Supercial mycosis Opportunistic Systemic mycosis Miscellaneous and rare mycosis

Phaeomycotic Cyst Black piedra Tinea versicolor

Smooth skin Scalp and beard Smooth body skin

Pythiosis

Rhinosporidium seeberi Schizophyllum commune Scopulariopsis brevicaulis Scopulariopsis sp. Scytalidium sp.

Rare Rhinosporidiosis subcutaneous mycosis Miscellaneous and rare mycosis Opportunistic Systemic mycosis Cutaneous mycosis Subcutaneous mycosis Onychomycosis Dermatomycosis Basidiomycosis

Nasal mucosa

Nails Skin

(continued)

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR TABLE III (Continued ) Fungus Sporothrix schenckii Torulopsis glabrata Trichophyton concentriucum Trichophyton rubrum T. mentagrophyte Trichophyton spp. Tinea pedis Tinea unguium Tinea cruris Tinea corporis Trichophyton schoenleinii Trichophyton spp. Trichophyton spp. Trichophyton tonsurans Trichophyton spp. Trichophyton verrucosum T. mentagrophytes Trichophyton spp. Trichosporon beigelii Wangiella (Phialophora) dermatitidis Supercial mycosis Opportunistic Systemic mycosis Subcutaneous mycosis Wangiella mansonii Supercial mycosis White piedra Beard, scalp, pubic hair Cutaneous mycosis Tinea barbae Beard and coarse body hair Cutaneous mycosis Cutaneous mycosis Dermatomycoses Tinea capitis Keratinized layers of body: skin, hair, nails Scalp Cutaneous mycosis Tinea favosa Feet, interdigital spaces, and soles Nails Groin Smooth body skin Scalp, skin, and nails Classication Subcutaneous mycosis Opportunistic Systemic mycosis Cutaneous mycosis Cutaneous mycosis Tinea imbricate Tinea manuum Smooth body skin Palms and ngers Disease Sporotichosis Affected area Skin, primarily hands, arms, and legs

49

Cerebral Brain or central nervous chromomycosis system Chromomycosis Maduromycetoma Tinea nigera Thick stratum corneum, palms, and feet Skin surface, mostly lower extremities

Compiled from Campbell and Stewart (1980); Henry (1984); Howard (2003); Rippon (1988).

50

LI AND YANG

fungi (Benenson, 1990; Burge 1990a; Larsen and Frisvad, 1995). These fungi can cause aspergillosis. In a hospital where an epidemic of aspergillosis occurred, the source of Aspergillus spores was attributed to a defective disposal conduit door and the dispersal of a contaminated aerosol from the ward vacuum cleaner, which had the highest measured concentrations of Aspergillus fumigatus in or around the building (65 colony forming units/m3 as compared with 06 cfu/m3 elsewhere). No further cases were identied in the hospital in the 2 years after relevant hygiene arrangements were incorporated (Anderson et al., 1996). Other clinically important fungal infections include candidiasis with local mucocutaneous or disseminated systemic organ manifestations and skin mycoses such as dermatophytoses, keratomycosis, tinea nigra, piedra, and malassezia-caused dermatitis. Invasive fungal diseases of the paranasal sinuses may also be associated with allergic sinusitis in atopic patients (Fatterpekar, 1999). Aspergillus species are frequently involved. Noninvasive forms may colonize body cavities and may be asymptomatic as long as some degree of immunological resistance can be maintained. Cryptococcus neoformans var. neoformans was isolated from 20 (13%) dwellings out of 154 dwellings in the metropolitan area of Rio de Janeiro, Brazil, comprising 5 (15.6%) of 32 dwellings of patients with AIDS-associated cryptococcosis (Passoni et al., 1998). Histoplasmosis is an intracellular mycotic infection of the reticuloendothelial system caused by the inhalation of conidia from the fungus Histoplasma capsulatum (Howard, 2003). Histoplasma capsulatum has a worldwide distribution, but the MississippiOhio River Valley in the United States is a major endemic region, and the spore is occasionally found in certain indoor environments there (Collier et al., 1998). Coccidioides immitis causes coccidioiomycosis, a highly infectious upper respiratory disease, and infection is caused by inhalation of its airborne arthrospores (Howard, 2003). The disease is endemic in certain regions, mainly in desert soils and also in the air of endemic areas in North America (Cox and Wathes, 1995). Exposure to dustborne spores outdoors is the major risk factor of infection (Al-Doory and Ramsey, 1987). C. MYCOTOXINS AND THEIR SIGNIFICANCE TO HUMAN HEALTH Another public health concern is mycotoxins produced by some indoor fungi (Table IV). Fungi are capable of producing a number of secondary metabolites (Nielsen, 2002). Most of these secondary

FUNGAL CONTAMINATION AS A MAJOR CONTRIBUTOR TABLE IV COMMON MYCOTOXIGENIC INDOOR FUNGI Fungus Alternaria alternata Aspergillus avus Aspergillus fumigatus Aspergillus niger Aspergillus ochrrachceus Aspergillus parasiticus Aspergillus versicolar Aspergillus ustus Chaetomium globosum Cladosporium cladosporioides Mycotoxins* Tenuazonic acid, alternatiol, alternatiol mononethyl ether, altertoxins Aatoxin B1 Gliotoxin, verrucologen, fumitremorgceusins, fumitoxins, tryptoquivalins Naphthopyrone, malformins, nigragillin, orlandin Ochratoxin A (a carcinogenic kidney toxin) Aatoxin B1 Sterigmatocystin and methoxysterigmatocystin

51

Austaminde, austdiol, austins, austocystins, kotanins X and Y Chaetoglobosins, chetomin Cladosporin, emodin

Emericella (Aspergillus) Sterigmatocystin, nudulotoxin nidulans Fusarium culmorum T-2 toxin (immunosuppressive) Fusarium graminearum Zealralenone Fusarium verticillioides Fumonisins ( F. moniliforme) Memnoniella echinata Paecilomyces variotii Penicillium aurantiogriseum Penicillium brevcompactum Penicillium chrysogenum Penicillium expansum Penicillium polonicum Roquefortine C, meleagrin, chrysogin, penicillin Citrinin, patulin (nephrotoxic), cytotoxic metabolite of unknown origin 3-methoxyviridicatin, verrucosidin, verrucofortine Trichodermol, trichodermin, dechlorogrisseofulvins, memnobotrins A and B, memenoconol, memnoconone Patulin, viriditoxin Auranthine, penicillic acid, verrucosidin, nephrotoxic glycopeptides Mycophenolic acid

Penicillium verrucosum Ochratoxin A (a carcinogenic kidney toxin) Stachybotrys chartarum Macrocyclic trichothecenes: satratoxins, verrucarins, (syn S. atra). roridins, atranones, dolabellanes, stachybotrylactones, and lactams Trichoderma harzianum Alamethicins, emodin, suzukacillin, trichodermin Wallemia sebi Walleminols A and B, walleminone

*Toxins in boldface are of high potency. Compiled in part from Al-Doory and Domson, 1984; Frank et al., 1999; Macher et al., 1999; Samson, 2000; St-Germain and Summerbell, 1996.

52

LI AND YANG

metabolites are mainly to enhance the tness of the fungi in nature. However, when some o