Sanitary MicrobiologySanitary MicrobiologyCurrent issues facing the developed and developing worldCurrent issues facing the developed and developing world

3rd MICROBIOLOGYSEMINAR

Dr Gavin CollinsMicrobial Ecology Lab (3783)Environmental Change Institute (5047)

… … is responsible for, is responsible for, by some estimates, approximatelyby some estimates, approximately

Sanitary MicrobiologySanitary Microbiology

WATER…WATER…

80%80% of all infectious disease - of all infectious disease - not just waterborne diseases, not just waterborne diseases, but but any disease any disease where water plays a role… WATER where water plays a role… WATER ASSOCIATED DISEASESASSOCIATED DISEASES

Water-washedWater-washed diseases,diseases, such as such as trachoma, scabies, dysentery, louse-trachoma, scabies, dysentery, louse-borne fever;borne fever;

1

2

There are There are waterborne diseases,waterborne diseases, such as such as cholera, typhoid, bacillary dysentery, cholera, typhoid, bacillary dysentery, infectious hepatitis;infectious hepatitis;

4

3 Water-based diseases,Water-based diseases, such as such as schistosomiasis, and Guinea worm;schistosomiasis, and Guinea worm;

And And water-related diseaseswater-related diseases (involving (involving an insect vector) such as malaria, an insect vector) such as malaria, sleeping sickness, or onchocerciasis.sleeping sickness, or onchocerciasis.

40% of 40% of annual annual

worldwide worldwide deaths deaths

attributed to attributed to these these

diseasesdiseases

HH22O can act as a vector for the transmission of O can act as a vector for the transmission of bacterial, viral and protozoan agents which bacterial, viral and protozoan agents which

cause a variety of diseases (mainly intestinal)cause a variety of diseases (mainly intestinal)

It can also be linked to worm invasions and It can also be linked to worm invasions and viral/protozoan diseases transmitted by insects viral/protozoan diseases transmitted by insects

(aquatic hosts or insect breeding in H(aquatic hosts or insect breeding in H22O - O - indirect)indirect)

Water-associated diseases can be classified Water-associated diseases can be classified under 4 different categories: -under 4 different categories: -

1. Water-borne diseases1. Water-borne diseases

Mainly enteric diseases resulting from the ingestion Mainly enteric diseases resulting from the ingestion of faecally-contaminated Hof faecally-contaminated H22O (man, animal and O (man, animal and bird excreta)bird excreta)

In developed countries, classical HIn developed countries, classical H22O -borne diseases O -borne diseases are mostly are mostly lowlow infective dose infections - cholera infective dose infections - cholera and typhoid fever (rare), leptospirosis (rare); viral and typhoid fever (rare), leptospirosis (rare); viral infections; infections; CampylobacterCampylobacter (bacterium) and (bacterium) and GiardiaGiardia and and CryptosporidiumCryptosporidium (protozoa) infections - (protozoa) infections - becoming more common in Irelandbecoming more common in Ireland

In developing countries (or as a result of the In developing countries (or as a result of the breakdown of sanitary services in developed breakdown of sanitary services in developed countries - earthquakes, war etc.), a variety of countries - earthquakes, war etc.), a variety of other, high-infective dose diseases can be other, high-infective dose diseases can be transmitted via Htransmitted via H22O - infectious hepatitis, O - infectious hepatitis, VibrioVibrio (bacterial) infections; bacillary dysentery; other (bacterial) infections; bacillary dysentery; other viral infections etc. (human and/or animal originviral infections etc. (human and/or animal origin

All water borne diseases can also be transmitted by All water borne diseases can also be transmitted by other routes that permit ingestion of faecal matter other routes that permit ingestion of faecal matter - e.g. contaminated food- e.g. contaminated food

2. Water-washed 2. Water-washed diseasesdiseases

Diseases linked to HDiseases linked to H220 scarcity and resultant poor 0 scarcity and resultant poor personal hygienepersonal hygiene

Obviously more common in tropical, 3rd world Obviously more common in tropical, 3rd world countries where Hcountries where H22O supplies may be scarceO supplies may be scarce

Intestinal and non-intestinal infectionsIntestinal and non-intestinal infections

Intestinal: Intestinal: ShigellaShigella (dysentery); typhoid; cholera; (dysentery); typhoid; cholera; CampylobacterCampylobacter; Giardia; Cryptosporidium; ; Giardia; Cryptosporidium; virusesviruses

Non-intestinal: Infections of the skin and Non-intestinal: Infections of the skin and mucous membranes - bacterial skin sepsis; mucous membranes - bacterial skin sepsis; scabies; fungal infections such as ring-scabies; fungal infections such as ring-worm; fungal mouth ulcers etc.worm; fungal mouth ulcers etc.

3. Water-based diseases3. Water-based diseases Diseases caused by pathogens that have a complex Diseases caused by pathogens that have a complex

life-cycle which involves an intermediate aquatic life-cycle which involves an intermediate aquatic hosthost

All of these diseases are caused by worms, e.g. All of these diseases are caused by worms, e.g. SchistosomiasisSchistosomiasis caused by the Schistosoma worm caused by the Schistosoma worm which uses aquatic snails as an intermediate host, which uses aquatic snails as an intermediate host, also the Guinea worm (also the Guinea worm (Dracunculus medimensisDracunculus medimensis) ) which uses a small crustacean as an intermediate which uses a small crustacean as an intermediate hosthost

SchistosomiasisSchistosomiasis affects affects 200 million people 200 million people worldwide per annumworldwide per annum

4. Water-related 4. Water-related diseasesdiseases

Diseases caused by pathogens carried by Diseases caused by pathogens carried by

insects that live near Hinsects that live near H22O and act as O and act as

mechanical vectorsmechanical vectors

Very difficult to control and diseases are very Very difficult to control and diseases are very

severesevere

Examples: Examples: Yellow feverYellow fever (viral disease) is transmitted by (viral disease) is transmitted by

the mosquito the mosquito AedesAedes spp.; spp.; Dengue (viral) carried by the mosquito Dengue (viral) carried by the mosquito Aedes Aedes

aegyptiaegypti (breeds in water); (breeds in water); Malaria is caused by a protozoan Malaria is caused by a protozoan

((PlasmodiumPlasmodium spp.) and is also spread by a spp.) and is also spread by a mosquito (mosquito (AnophelesAnopheles spp.); spp.);

Trypanosomiasis (Gambian sleeping sickness) Trypanosomiasis (Gambian sleeping sickness) is also caused by a protozoan transmitted by is also caused by a protozoan transmitted by the riverine Tetse fly (the riverine Tetse fly (GlossinaGlossina spp.) spp.)

(increasing numbers of elderly & (increasing numbers of elderly & immuno-suppressed people)immuno-suppressed people)

(such as water treatment and (such as water treatment and distribution systems)distribution systems)

with increased flooding leads towith increased flooding leads to breakdown of sanitary breakdown of sanitary

infrastructure and further spread of infrastructure and further spread of diseasedisease

Increasing Crises WorldwideIncreasing Crises Worldwide

Population growthPopulation growth

PollutionPollution

Climate changeClimate change

Engineered systemsEngineered systems

Population Population susceptibilitysusceptibility

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Simpler moleculesBiogas (CH4 & CO2)

Complex molecules

ANAEROBIC DIGESTIONANAEROBIC DIGESTION

Greenhouse Greenhouse effecteffect

Methane (CH4) from anaerobic digestion

Bovine generated CH4

CO2 from industry

From World Book © 2002 World Book, Inc., 233 N. Michigan Avenue, Suite 2000, Chicago, IL 60601. All rights reserved.(C) Rod Planck, Photo Researchers

From World Book © 2002 World Book, Inc., 233 N. Michigan Avenue, Suite 2000, Chicago, IL 60601. All rights reserved.© Nik Wheeler

Urbanisation

Globalisation

Celtic Tiger economy

Wealth & Wastefulness

Kyoto treaty

The diseases that result from flooding vary according to geographic region.

Typical ones include cholera, typhoid, dengue, Rift Valley fever, malaria, hepatitis A, AGI [acute gastro-intestinal illness], and ARI [acute respiratory illness].

Flooding

Problems involved in getting clean, Problems involved in getting clean, safe water to people in the safe water to people in the

developing worlddeveloping world

Water supplies in communities Water supplies in communities highly susceptible to municipal, highly susceptible to municipal, agricultural, and industrial agricultural, and industrial contamination.contamination.

e.g., in India, huge e.g., in India, huge numbers of people live in numbers of people live in slums sited in low-lying slums sited in low-lying points, and at end-of-pipe points, and at end-of-pipe sites.sites.

Water has maximum "residence time" in Water has maximum "residence time" in deteriorating distribution systems. Uses deteriorating distribution systems. Uses antiquated British water treatment technology antiquated British water treatment technology designed for a much smaller population, only designed for a much smaller population, only supplies water for 2 hours per day.supplies water for 2 hours per day.

CASE STUDY

Hyderabad, IndiaHyderabad, India

The remaining time, The remaining time, 22 hours per day,22 hours per day, water sits water sits stagnantstagnant in the distribution in the distribution system. In addition to pathogens in system. In addition to pathogens in drinking water, slums tend to be sited drinking water, slums tend to be sited near standing water.near standing water.

Standing waterStanding water is a major problem in malaria is a major problem in malaria and other vector-borne diseases.and other vector-borne diseases.

Moreover, children routinely play in this Moreover, children routinely play in this water - both fouling it and further water - both fouling it and further exposing themselves to disease.exposing themselves to disease.

Cholera, giardiasis, hepatitis, shigellosis, Cholera, giardiasis, hepatitis, shigellosis, typhoid, and AGItyphoid, and AGI

Other infections such as legionellosis, Other infections such as legionellosis, cryptosporidiosis, and mycobacterial cryptosporidiosis, and mycobacterial infections occur, but are seldom infections occur, but are seldom diagnoseddiagnosed..

Absence of Sanitary Absence of Sanitary InfrastructureInfrastructure

Often in the developing world gastroenteritis Often in the developing world gastroenteritis and other infections cause unnecessary and other infections cause unnecessary mortalitymortality

e.g. Massai in Kenya each e.g. Massai in Kenya each year the current infant year the current infant mortality rate is mortality rate is 20%20% for for children < 5 years old from children < 5 years old from diarrhoeal infections - diarrhoeal infections - Campylobacter/E. coliCampylobacter/E. coli

Treatment for these infections does not need Treatment for these infections does not need expensive drugs or antibiotics (self-limiting expensive drugs or antibiotics (self-limiting infections)infections)

Needs only water and salt to balance loss - Needs only water and salt to balance loss - but if available water is contaminated??but if available water is contaminated??

Diarrhoea kills 15000 < 5 year olds every day, Diarrhoea kills 15000 < 5 year olds every day, 5.5m/annum5.5m/annum

Treatable at the cost of <10 cent per childTreatable at the cost of <10 cent per child

HOWEVER, NOT JUST A HOWEVER, NOT JUST A PROBLEM OF THE PROBLEM OF THE

DEVELOPING WORLDDEVELOPING WORLD

WBD’s in a developed world WBD’s in a developed world contextcontext

Growing problem in Ireland primarily due to Growing problem in Ireland primarily due to deterioration of ground and surface water deterioration of ground and surface water quality quality

Massive volume of wastes produced in Massive volume of wastes produced in intensive agriculture can contaminate a intensive agriculture can contaminate a water supply if not managed correctlywater supply if not managed correctly

General causes of WBDOs include:General causes of WBDOs include:

1) No treatment1) No treatment

2) Breakthrough at treatment plant2) Breakthrough at treatment plant

3) No disinfectant residual3) No disinfectant residual

4) Direct sewage contamination through pipe 4) Direct sewage contamination through pipe

leakage, breakage, back-siphoning, and leakage, breakage, back-siphoning, and

cross-connectionscross-connections

30%30% of rivers polluted; of rivers polluted;

50%50% of group water supplies of group water supplies contaminated with contaminated with E. coliE. coli

Where the problems ariseWhere the problems ariseCorrosion of pipe networks allowing Corrosion of pipe networks allowing contamination during distributioncontamination during distribution

biofouling; biofouling; foul odour, smell, colour, and the general foul odour, smell, colour, and the general impression of "dirty water”; impression of "dirty water”; biocorrosion; biocorrosion; survival and proliferation of pathogens; survival and proliferation of pathogens; disinfection resistance; disinfection resistance; transfer of antibiotic and virulence factorstransfer of antibiotic and virulence factors

BiofilmBiofilm formation leads to:formation leads to:

The presence of coliforms in water only The presence of coliforms in water only reflects sewage contamination - not potential reflects sewage contamination - not potential pathogens likepathogens like Legionella Legionella

Coliform behaviour and die-off is not Coliform behaviour and die-off is not comparable to the behaviour of viruses and comparable to the behaviour of viruses and protozoaprotozoa

Die-off rates of faecal coliforms have been Die-off rates of faecal coliforms have been demonstrated to vary enormouslydemonstrated to vary enormously

Problems with Problems with Microbiological MonitoringMicrobiological Monitoring

Current Current indicator organismsindicator organisms may not be may not be adequate for the following reasons:adequate for the following reasons:

Problems with Microbiological Problems with Microbiological Methods (cont’d)Methods (cont’d)

Techniques used to identify indicators Techniques used to identify indicators rely on growth and culture - many rely on growth and culture - many organisms can be viable in the organisms can be viable in the environment but unculturable using environment but unculturable using current methodscurrent methods (‘Plate-count anomaly’)(‘Plate-count anomaly’)

Molecular methods based on DNA Molecular methods based on DNA probes and PCR still not adequateprobes and PCR still not adequate

Challenges for the future: controlling Challenges for the future: controlling LegionellaLegionella and other organisms and other organisms

Legionella pneumophilaLegionella pneumophila an emerging an emerging pathogen - first recognized in the 1970spathogen - first recognized in the 1970s

Example of how creation of a unique Example of how creation of a unique environment in our water systems that has environment in our water systems that has lead to a "new" or newly recognized disease. lead to a "new" or newly recognized disease.

Incidence of Legionnaires' disease in the U.S.: Incidence of Legionnaires' disease in the U.S.: approximately 1,000 cases annuallyapproximately 1,000 cases annually

Estimated that over 25,000 cases of the illness Estimated that over 25,000 cases of the illness occur each year, causing more than 4,000 deathsoccur each year, causing more than 4,000 deaths..

LegionellaLegionella is one of the top three causes of sporadic, is one of the top three causes of sporadic,

community-acquired pneumonia. Difficult to community-acquired pneumonia. Difficult to

distinguish, many cases go unreported.distinguish, many cases go unreported.

For growth For growth LegionellaLegionella requires the following: requires the following:

stagnation; temps between 20° and 50°C (optimal stagnation; temps between 20° and 50°C (optimal

growth range is 35° - 46°C);growth range is 35° - 46°C);

pH between 5.0 and 8.5;pH between 5.0 and 8.5;

Microbes incl algae, flavobacteria, and Microbes incl algae, flavobacteria, and PseudomonasPseudomonas, ,

which supply essential nutrients or harbor the which supply essential nutrients or harbor the

organism (protozoa)organism (protozoa)

Optimal conditions created for Optimal conditions created for LegionellaLegionella growth in many modern buildings:growth in many modern buildings:

Domestic hot-water systems with water Domestic hot-water systems with water heaters that operate below 60°C; centralized heaters that operate below 60°C; centralized hot water systems [common in eastern hot water systems [common in eastern European countries]European countries]

Cooling towers, and fluid coolers that use Cooling towers, and fluid coolers that use evaporation; humidifiers and decorative evaporation; humidifiers and decorative fountains that create a water spray; spas fountains that create a water spray; spas and whirlpools.and whirlpools.

GiardiaGiardia and and CryptosporidiumCryptosporidium

Protozoa and common causes of GI infectionsProtozoa and common causes of GI infections

Used to be rare in Ireland, incidence nowUsed to be rare in Ireland, incidence nowincreasingincreasing

Form oocysts as part of the life-cycleForm oocysts as part of the life-cycle

These oocysts are resistant to chlorination These oocysts are resistant to chlorination which is the only method used to disinfect which is the only method used to disinfect water in Irelandwater in Ireland

How many of the How many of the 350,000350,000 cases cases of food/water borne illnesses in of food/water borne illnesses in Ireland last year caused by Ireland last year caused by these organisms??these organisms??

No detection methods for these No detection methods for these organisms at the momentorganisms at the moment

Use of conventional indicators Use of conventional indicators meaninglessmeaningless

ConclusionsConclusions

Partial solutions to the problems of Partial solutions to the problems of maintaining clean safe water for all include:maintaining clean safe water for all include:

1. Active surveillance1. Active surveillance

2. Population surveys2. Population surveys

3. Low-cost solutions to treatment3. Low-cost solutions to treatment

4. Waste-water reclamation4. Waste-water reclamation

5.5. Appropriate valuation of the resourceAppropriate valuation of the resource

6.6. Assessments of impacts of engineered Assessments of impacts of engineered "ecosystems”"ecosystems”

7.7. Monitoring of antibiotic resistance and Monitoring of antibiotic resistance and changing virulencechanging virulence

8.8. Tighter regulation guided by precautionary Tighter regulation guided by precautionary principlesprinciples

www.nuigalway.ie/microbiology/mel

Further Info

http://www.doh.ie/

http://www.who.int

http://www.cdc.gov/health/

http://www.cfsan.fda.gov/~mow/intro.html

http://www.epa.ie/

http://www.aem.org

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