LETTERS

Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 11, No. 5, May 2005 775

NosocomialDengue by

MucocutaneousTransmission

To the Editor: Wagner and col-leagues report nosocomial denguetransmitted by needlestick and notethat it is the fourth case of nosocomi-al dengue to their knowledge (1). Inthe same issue of Emerging InfectiousDiseases, Nemes and colleaguesreport a separate case of nosocomialdengue also transmitted by needle-stick (2). Three other cases of nosoco-mial dengue transmission by needle-stick have previously been published(3–5).

We have recently published a caseof nosocomial dengue infection thatwas transmitted by mucocutaneousexposure to blood from a febrile trav-eler who had recently returned fromPeru (6). During phlebotomy, ahealthcare worker was splashed in theface with the traveler’s blood. Boththe traveler and the healthcare workerwere subsequently found to havedengue fever with dengue virus type3. This route of infection is biologi-cally plausible because infectionthrough mucosal surfaces (intranasaland oral routes) has been shown pos-sible for arboviruses (7). In ourreview of the literature, we also founda report of dengue virus transmissionby bone marrow transplantation (8).Other cases of transmission of denguevirus without a mosquito vector haveoccurred in 5 reported instances ofinfection in newborns as a result ofintrapartum or vertical transmissionfrom mother to child (9–12).

We agree that nosocomial trans-mission may become more commonin temperate areas as more travelersreturn home with acute dengue fever.As Wagner and colleagues pointedout, travelers visiting Southeast Asiahave the greatest risk of acquiringdengue infections because of the highendemicity of these viruses there. Our

report further illustrates the occur-rence of dengue infection in theAmericas (13) and the risk for dengueto travelers visiting this region.Among 33 returned travelers withdengue infection reported in theUnited States in 1999 and 2000, 20had acquired infection in theCaribbean islands (12 cases) orCentral or South America (8 cases)(14). Clinicians and laboratoriansshould be alert to the possibility ofacquiring infection with a denguevirus after needlestick or mucocuta-neous blood exposure. The magnitudeof nosocomial transmission indengue-endemic areas is unknownand more difficult to assess becausehealthcare workers may be exposed todengue virus–infected mosquitoesoutside the clinical setting.

Lin H. Chen*† and Mary E. Wilson*†

*Mount Auburn Hospital, Cambridge,Massachusetts, USA; and †HarvardMedical School, Boston, Massachusetts,USA

References

1. Wagner D, de With K, Huzly D, Hufert F,Weidmann M, Breisinger S, et al.Nosocomial acquisition of dengue. EmergInfect Dis. 2004;10:1872–3.

2. Nemes Z, Kiss G, Madarassi EP, Peterfi Z,Ferenczi E, Bakonyi T, et al. Nosocomialtransmission of dengue [letter]. EmergInfect Dis. 2004;10:1880–1.

3. de Wazieres B, Gil H, Vuitton DA, DupondJL. Nosocomial transmission of denguefrom a needlestick injury. Lancet.1998;351:498.

4. Hirsch JF, Deschamps C, Lhuillier M.Transmission métropolitaine d’une denguepar inoculation accidentelle hospitalière.Ann Med Interne (Paris). 1990;141:629.

5. Langgartner J, Audebert F, Schölmerich J,Glück T. Dengue virus infection transmit-ted by needle stick injury. J Infect.2002;44:269–70.

6. Chen LH, Wilson ME. Transmission ofdengue virus without a mosquito vector:nosocomial mucocutaneous transmissionand other routes of transmission. Clin InfectDis. 2004;39:e56–60.

7. Kuno G. Transmission of arboviruses with-out involvement of arthropod vectors. ActaVirol. 2001;45:139–50.

8. Rigau-Perez JG, Vorndam AV, Clark GG.The dengue and dengue hemorrhagic feverepidemic in Puerto Rico, 1994–1995. Am JTrop Med Hyg. 2001;64:67–74.

9. Chye JK, Lim CT, Ng KB, Lim JMH,George R, Lam SK. Vertical transmissionof dengue. Clin Infect Dis.1997;25:1374–7.

10. Kerdpanich A, Watanaveeradej V, Sama-koses R, Chumnanvanakij S, Chulyamit-porn T, Sumeksri P, et al. Perinatal dengueinfection. Southeast Asian J Trop MedPublic Health. 2001;32:488–93.

11. Boussemart T, Babe P, Sibille G, Neyret C,Berchel C. Prenatal transmission of dengue:two new cases. J Perinatol. 2001;21:255–7.

12. Thaithumyanon P, Thisyakorn U,Deerojnawong J, Innis BL. Dengue infec-tion complicated by severe hemorrhage andvertical transmission in a parturient woman.Clin Infect Dis. 1994;18:248–9.

13. Wilson ME, Chen LH. Dengue in theAmericas. Dengue Bulletin. 2002;26:44–61.

14. Clark GG, Rigau-Perez JG, Vorndam V,Hayes JM. Imported dengue—UnitedStates, 1999 and 2000. MMWR MorbMortal Wkly Rep. 2002;51:281–3.

Address for correspondence: Lin H. Chen,Travel Medicine Center, Division of InfectiousDiseases, Mount Auburn Hospital, 330 MountAuburn St, Cambridge, MA 02138, USA; fax:617-499-5453; email: lchen@hms.harvard.edu

Barriers toCreutzfeldt-Jakob

Disease Autopsies,California

To the Editor: The recent articleby Louie et al. underscores a moregeneral disparity between the need forautopsies in potential infectious dis-ease deaths and our present nationalcapacity (1). In addition to confirmingCreutzfeldt-Jakob disease (CJD) andallowing the differentiation of classicand variant CJD, autopsies identifypreviously undetected infections, dis-cover causative organisms in unex-plained infectious disease deaths, andprovide insights into the pathogenesis

LETTERS

of new or unusual infections (2,3).This information is essential for pub-lic health and medical interventions.

As outlined by Louie et al., hospi-tal autopsy rates have dropped to sin-gle digits, and concerns by patholo-gists about occupational risks andbiosafety have likely contributed tothis decline. Currently, the last strong-hold of autopsy expertise is forensicpathology (4). However, themedicolegal death investigative sys-tem does not have jurisdiction over allpotential infectious disease deaths noris it adequately supported to assumethe cases that are missed by our pres-ent hospital autopsy system.Additionally, many medicolegal andhospital autopsy facilities with outdat-ed or poorly-designed air flow sys-tems are ill suited to handle autopsieswhen infectious disease is suspected(5). Air-handling systems can beexpensive to fix.

Reference centers such as theNational Prion Disease PathologySurveillance Center, while providingdiagnostic expertise, fail to surmountthe biosafety obstacles (real and per-ceived) that prevent pathologists fromenthusiastically performing autopsieson those who died of potential infec-tious diseases, including prion dis-eases. One potential solution is thecreation of regional centers of excel-lence for infectious disease autopsiesthat could operate in conjunction witha mobile containment autopsy facility(5,6). Such centers could providediagnostic expertise as well asbiosafety capacity.

Kurt B. Nolte* *University of New Mexico, Albuquerque,New Mexico, USA

References

1. Louie JK, Gavali SS, Belay ED, Trevejo R,Hammond LH, Schonberger LB, et al.Barriers to Creutzfeldt-Jakob diseaseautopsies, California. Emerg Infect Dis.2004;10:1677–80.

2. Nolte KB, Simpson GL, Parrish RG.Emerging infectious agents and the forensicpathologist: the New Mexico model. ArchPathol Lab Med. 1996;120:125–8.

3. Schwartz DA, Bryan RT, Hughes JM.Pathology and emerging infections—quovadimus? Am J Pathol. 1995;147:1525–33.

4. Hirsch CS. Forensic pathology and theautopsy. Arch Pathol Lab Med.1984;108:484–9.

5. Nolte KB, Taylor DG, Richmond JY.Biosafety considerations for autopsy. Am JForensic Med Pathol. 2002;23:107–22.

6. Centers for Disease Control andPrevention. Medical examiners, coroners,and biologic terrorism: a guidebook for sur-veillance and case management. MMWRMorb Mortal Wkly Rep. 2004;53 (No. RR-8):1–36.

Address for correspondence: Kurt B. Nolte,Office of the Medical Investigator, MSC116030, University of New Mexico, Albuquerque,NM 87131-0001, USA; fax: 505-272-0727;email: knolte@salud.unm.edu

Q Fever WildlifeReservoir

To the Editor: To the list ofzoonotic infections with wildlifesources reported by Kruse et al. (1), Iwould add Coxiella burnetii infectionbecause of its global impact, exten-sive presence in the animal kingdom,and potential for use as an agent ofbioterrorism (2). C. burnetii causes Qfever, a self-limited disease that usual-ly appears as undifferentiated fever,pneumonia, or hepatitis, but whichmay progress into chronic disease,especially endocarditis, among sus-ceptible persons. Q fever is endemicworldwide in domestic mammals,especially ungulates (cattle, sheep,and goats), but also has been found inwild mammals, birds, and arthropods.The transmission of Q fever tohumans from wild rabbits was docu-mented in the 1980s (3). More recent-ly, a study showed seroprevalence ofQ fever ranging from 7% to 53% in

brown rats (Rattus norvegicus) inOxfordshire, which suggests that theyare a possible reservoir for C. burnetiiin the United Kingdom. The studyalso speculated why cats, as frequentpredators of rats, are important inmaintaining the transmission cycle ofthe disease (4).

A case-control study published in2001 (5) attempted to define the riskfactors for an increase in the incidenceof Q fever in French Guiana in 1996.The study found no link between Qfever and domestic ungulates, theusual source of outbreaks. The role ofpets, basically dogs and cats, as areservoir was also excluded.Multivariate analysis showed that liv-ing in close proximity to the forest,exposure to wild animals (includingbats), and working in public trade orpublic works were all associated withinfection. A strong correlationbetween large amounts of rainfall andhigher incidence of Q fever was foundalso. All of these findings suggested awild reservoir as a potential source ofthe epidemics, although theresearchers could not identify a par-ticular species as the specific source.

Miguel G. Madariaga**University of Nebraska Medical Center,Omaha, Nebraska, USA

References

1. Kruse H, Kirkemo AM, Handeland K.Wildlife as source of zoonotic infections.Emerg Infect Dis. 2004;10:2067–72.

2. Madariaga MG, Rezai K, Trenholme GM,Weinstein RA. Q fever: a biologicalweapon in your backyard. Lancet InfectDis. 2003;3:709–21.

3. Marrie TJ, Schlech WF 3rd, Williams JC,Yates L. Q fever pneumonia associated withexposure to wild rabbits. Lancet.1986;1:427–9.

4. Webster JP, Lloyd G, Macdonald DW. Qfever (Coxiella burnetii) reservoir in wildbrown rat (Rattus norvegicus) populationsin the UK. Parasitology. 1995;110:31–5.

5. Gardon J, Heraud JM, Laventure S, LadamA, Capot P, Fouquet E, et al. Suburbantransmission of Q fever in French Guiana:evidence of a wild reservoir. J Infect Dis.2001;184:278–84.

776 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 11, No. 5, May 2005