Transcript Environmental Transmission of Pathogenic Microbes

Environmental Transmission of
Pathogenic Microbes – why they
are, where they are, when they are
Dr. Julie Ann Kase
Public Health Scientist – Bioterrorism and
Emerging Pathogens Unit
NC State Laboratory of Public Health
[email protected]
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1976 Legionnaires' disease
Outbreak of pneumonia occurred among persons attending a convention of the
American Legion in Philadelphia
– ~ 8,000 to 18,000 cases in the US each year; 5% to 30% die
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1981 AIDS
– report in MMWR of 5 CA men with severe immunodeficency (1983 HIV recovered
from lymph node)
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1993 Cryptosporidiosis
– 400,000 people sick and killed more than 100
– worst waterborne disease outbreak in the United States
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1995 Ebola Hemorrhagic Fever
– Ebola Virus initial recognition in 1976
– Occurred in Kikwit and surrounding area
– 315 cases 81% death of cases
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2002 (November) Severe acute respiratory syndrome (SARS)
– Viral respiratory illness that was recognized as a global threat in March 2003
– first appearing in Southern China in November
– November 2002 - July 2003, a total of 8,098 people worldwide became sick; 774
died
– By late July 2003, no new cases, and WHO declared the global outbreak to be over
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Late 2003 and Early 2004 Avian influenza
– Outbreaks of influenza H5N1 occurred among poultry in eight countries in Asia
(Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam)
– By March 2004, the outbreak was reported to be under control until late June 2004
– Human infections (H5N1) have been reported in Thailand, Vietnam and Cambodia
E. coli O157:H7 Outbreak Case
Counts by State
(As of October 6, 2006)
www.cdc.gov
Cases infected with the outbreak strain of
Salmonella Saintpaul, United States, by state,
as of August 25, 2008 9pm EDT
www.cdc.gov
Seek and Ye Shall Find
• Environmental Transmission
– Presence
• Cover our planet
– Several 100m deep in glacial ice sheets
– Deep-ocean thermal vents
– Survival and transport
• Media
– Water
– Soil
– Air
• Natural fate + influence of man’s actions
Microbial Survival in the Environment
Pathogen survival
• Differs widely among microbes:
– Bacteria:
• Spores survive better than vegetative cell
– Viruses:
• non-enveloped viruses survive better than enveloped viruses under
most environmental conditions
– Envelopes are relatively fragile compared to outer capsids (protein
coats)
– Parasites:
• protozoan (oo)cysts and spores and helminth ova survive better than
active life stages of these parasites or than those with no resting or
special environmental forms
– Fungi:
• spores survive better than other forms
Environmental Factors Influencing Survival
or Proliferation of Infectious Agents
• Temperature
– Greater inactivation/death rates at higher temps
– Environmental temperatures influence pathogen spread by insect
vectors
• pH
– Extreme pH inactivates microbes
– Important exceptions: enteric pathogens survive pH 3.0
• Moisture content
– Drying or low moisture inactivates /kills some microbes
– Ex. Preserving food by desiccation
• Sunlight (UV)
– Nucleic acids absorb the UV energy and is damaged
Environmental Factors Influencing Survival
or Proliferation of Infectious Agents
• Pressure (atmospheric & hydrostatic)
– Typical atmospheric pressure
– Use of high hydrostatic pressure in shellfish
• Weather
– Microbes levels may increase or decrease
– Warmer weather increases some microbes (ex. Vibrio bacteria in NC
coastal waters during warmer months) and vectors, like mosquitoes
– Wet weather carries microbes also resuspension in water resources
• Chemicals & nutrients
– Levels influence microbe survival
– Ex. Lack of nutrients (e.g. carbon, nitrogen) will limit proliferation
• Biological factors
– Predation, vectors, reservoirs (animals), microbe species/type
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
• Microbes can be found anywhere in which water
is maintained in a liquid state
• Human illness associated with water – usually acute
in nature but some have chronic sequelae (e.g. stomach
cancer (Helicobacter pylori), myocarditis & diabetes
(coxsackieviruses))
• Highly effective means of introducing an
infectious microbe to a large population
– Person-to-person not efficient in reaching a large
population
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Reservoirs for pathogenic microbes found in water:
humans, animals, environment
– Source tracking
– Human sources – important contributor of pathogens in
water
• Recreational activities (e.g. water theme parks)
• Domestic wastewater
– Discharge of wastewater into surface waters
– Aquifer contamination
Infectious Disease Water Transmission
Model
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Microbial agents associated with waterborne
diseases
– Enteric, non-enteric,and aquatic bacteria
– Enteric viruses
– Enteric protozoa
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Enteric bacteria
– Shigellosis: Shigella spp. (classical bacillary dysentery)
• occur around the world, with most victims being children in
developing countries
• 300,000 cases of shigellosis are reported in the United States (not all
confirmed)
• Shigella dysenteriae type 1 – deadly epidemics in dev. world
• Spread can be via vector, food, water, and fomites
– Cholera: Vibrio cholerae serogroup O1 or O139 (1992) that
produces toxin
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Endemic poverty, summer rains, poor health & living conditions
56 countries, 101,383 cases (2345 deaths) in 2004
Africa - 94% cases in 2004
No major outbreaks of this disease have occurred in the United States
since 1911
• Easily treatable
– Infectious dose variable: 10 - 500 orgs
http://www.cfsan.fda.gov
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Aeromonas hydrophila
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Commonly found in water but recently implicated as a cause of GI
illness, also wound infection
Potential to grow in water distribution systems, especially in
biofilms, where it may be resistant to chlorination
EPA list (candidate contaminant list) for drinking water
Legionella pneumophila
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Ubiquitous in water, aerosol transmission
Proliferate at high temperatures (hot water systems, cooling
towers and evaporative condensers)
Etiologic agent of Legionnaires’disease, Pontiac fever
Leptospira spp.
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Species not enteric or aquatic - Urine from dom. & wild animals
Outbreak during Eco-Challenge - grueling 2-week contest in late
Aug and early Sept [2000] island of Borneo
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http://www.youtube.com/watch?v=RMIFu5qWjSU&feature=related
Leptospirosis
• Reports of outbreaks occurring following flooding, tropical storms,
hurricanes – all can increase the exposure to contaminated water
• Asymptomatic, high fever, severe headache, muscle aches
• LA- found in cattle, skunks, rodents
• Most common in tropic climates
• Recent outbreaks of leptospirosis in the US have occurred in Illinois
and Florida (CDC, unpublished data), while leptospirosis is endemic to
Hawaii
• According to the Centers for Disease Control and Prevention (CDC),
between 100 and 200 cases of leptospirosis are reported in the United
States each year as of the early 2000s.
http://www.cdc.gov/ncidod/dbmd/diseaseinfo/leptospirosis_t.htm
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Enteric viruses
– Generally more persistent than enteric bacteria but can
not multiply in environment
– Survival influenced by physical, chemical, and
microbial factors as well as virus type
• Non-enveloped viruses most persistent – protein coat offers
stability and resistant barrier to stressors
• Majority of enteric viruses are non-enveloped
– Require more sophisticated detection methods
• Tissue cultivation, electron microscopy, molecular techniques
(e.g. PCR, nucleic acid hybridization)
• Limit microbe ID from clinical & environmental samples
• Distinguish between infectious/non-infectious - MAYBE
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Implicated in majority of AGI outbreaks in US based upon clinical & epidemiological
evidence
• Rotavirus –
– the virus is stable in the environment, transmission can occur through ingestion of
contaminated water, global problem
– Rotavirus is the most common cause of severe diarrhea among children, resulting
in the hospitalization of approximately 55,000 children each year in the United
States and the death of over 600,000 children annually worldwide
• Norovirus –
– Among the 232 outbreaks of illness reported to CDC from July 1997 to June 2000,
3% were waterborne; in 23% of outbreaks, the cause of transmission was not
determined
– Waterborne outbreaks of norovirus disease in community settings have often been
caused by sewage contamination of wells and recreational water.
– Infectious dose: typically low, maybe 1 to 10 infectious units
– Developing countries: Hepatitis A virus, Hepatitis E virus
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Proposed EPA drinking water contaminant list
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The Safe Drinking Water Act directs that periodically publish a CCL
• 2003 - regulatory determinations for nine contaminants from the first CCL (60
contaminants in March 1998)
• Summer of 2005 - second cycle of preliminary regulatory determinations - continue
research on the list of contaminants on the first CCL
– Adenoviruses Helicobacter pylori
– Noroviruses
Aeromonas hydrophila
– Coxsackieviruses Cyanobacteria
– Echoviruses
• February 2008 = Draft CCL 3 efforts to expand and strengthen the CCL listing process
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Caliciviruses
Campylobacter jejuni
Entamoeba histolytica
Escherichia coli (0157)
Helicobacter pylori
Hepatitis A virus
Legionella pneumophila
Naegleria fowleri
Salmonella enterica
Shigella sonnei
Vibrio cholerae
“Payment Intervention Studies”: References
• Payment P., et al, (1991). A Randomized Trial to Evaluate the
Risk of Gastrointestinal Disease due to Consumption of
Drinking Water Meeting Current Microbiological Standards.
American Journal of Public Health 81 (6) 703-708.
• Payment P., et al (1997). A prospective epidemiological study
of gastrointestinal health effects due to the consumption of
drinking water. International Journal of Environmental Health
Research. 7(1). 1997. 5-31
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Payment et al. intervention studies
Wanted to know risk of GI illness associated
w/consumption of municipal drinking H2O
– Municipal H2O source = river polluted with human
sewage
– 1st study: 606 households; ~half had RO filters, others
no intervention; 15mo
• 35% higher rate of GI symptoms households w/o intervention;
symptoms & serologic evidence pointed to enteric viruses
– 2nd study: 1400 households; 3 groups w/tap H2O, 1
group purified bottle H2O; 16 mo
• ~20% more GI illness in tap H2O consumers
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Enteric protozoa
– Recently recognized as water borne pathogens
– Thick-walled protozoan cysts and oocysts are
environmentally resistant
– Recovery and detection technically challenging
• Filtering liters of water
• Immunofluorescence microscopy
• May not distinguish between nonviable/viable orgs
– Infectious dose is low
• C. parvum ~ 100 oocysts
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Enteric protozoa (cont.)
– Ex. Cryptosporidium, Giardia
• Size: Cryptosporidium oocysts (4-6 µm) Giardia cysts (7-14 µm)
• Animal reservoirs
• Size limits movement thru soil, thus surface waters contamination
mostly (esp. unfiltered)
• Greater than half of 300 surface water supplies in US contained
Cryptosporidium oocysts
– Ex. Toxoplasma gondii
– Matures only inside cats and spreads through their feces
– Lethal parasite that has infected or killed hundreds of California sea
otters
– Parasite can concentrate inside clams and other bivalves, favorite of
otters
– Flushable cat litter runoff from land, affecting the ecosystem, including
the clams that otters eat
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Other aquatic microbes
• Cyanobacteria – algal blooms, dermatitis
• Naegleria fowleri – meningoencephalitis, usually fatal
– small, free-living amoeba – occ. infects humans & other mammals
N. fowleri can invade the CNS via the nose & nasal tissues
– 2003 case in North Carolina
– In August 2008, a 9-year-old boy was killed after having been
exposed to the amoeba while swimming several times in Lake Elsinore in CA
• Acanthamoeba species – subcutaneous abscesses, conjunctivitis
– Contact lens wearers, EPA published warning: Acanthamoeba Guidance
Document EPA-822-B-04-001
– Amoebae invades the cornea of the eye
– EPA determined not to regulate because “regulation would not present a
meaningful opportunity for health risk reduction”
• Schistosoma species – dermatitis, swimmer’s itch
– Debilitating (liver and intestinal damage) illness that results from infection of the blood
with a parasitic flatworm (schistosome)
– Found in Asia, Africa, and South America, especially in areas with water that is
contaminated with fresh water snails, which contain the parasite
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Categories of water-related infectious hazards
– Waterborne
– Water contact
– Water related
– Water washed
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Waterborne
– Physical contact w/microbially contaminated
H2O
– Bathing, recreational activities, ingesting water
(also ice)
– Example: cholera
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Water Contact
– Infections caused by aquatic
organisms
• Pathogenic
microorganisms or
macroorganisms (worms)
• Naturally spend part of life
cycle in aquatic envr or
within a host that resides
in water
– Ingestion or immersion in
water
– Example: Schistosomiasis
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Water Related
– Disease as a consequence of
being bitten by an
invertebrate vector whose
life cycle requires access to
H2O
– Influences of season, rain
events (monsoon, flooding)
– Example: Malaria (parasite)
and yellow fever, west nile
infection (viruses)
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Water Washed
– Infections associated
with inadequate
hygiene
– Eliminate hazard by
using microbe-free
water for cleaning of
eating and cooking
utensils, plates, self,
etc.
– Example: Shigellosis
Environmental Transmission of
Pathogenic Microbes –
Part 2
Dr. Julie Ann Kase
Public Health Scientist – Bioterrorism and
Emerging Pathogens Unit
NC State Laboratory of Public Health
[email protected]
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
• Improve microbiological water quality,
reduce diarrhea morbidity and mortality
associated with waterborne disease
• Standards for water quality
– EPA
– World Health Organization (WHO)
• Total and fecal coliforms
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
Methods to measure water quality
– Accurate and reproducible
– Rapid
– Relatively simple techniques, applicable to
most laboratories
– Common reagents, inexpensive
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
Detection of specific infectious agents in
water
– Many are difficult to detect/quantify
• May require expensive equipment
• Complex techniques – specialized reference
laboratories
– Newly recognized agents, methods are still
being developed
– Pathogen occurrence surveys and special
studies
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
Detection of infectious agents in water
– Laboratory investigations of disease outbreaks
often never detect the etiologic agent
• Contamination was temporary (e.g. problem was
discovered and fixed before investigation)
• Microbe died off or flushed away
• Sensitivity/specificity of methods
• Size of event
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
Detection of infectious agents in water
– Microbial Indicator Organism
• Traditional approach to protect/assess the "sanitary"
quality of water (food) with respect to fecal
contamination
• Quantify bacteria commonly present in intestines of
warm blooded animals; surrogates for pathogens,
especially bacterial
• May not be reliable indicators of viruses and
parasites
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
Criteria for an Ideal Indicator of Fecal Contamination
• Applicable to all types of water (and other relevant samples)
• Present in feces, sewage and fecally contaminated samples when
pathogens are present; numbers correlate with amount of fecal
contamination; outnumber pathogens
• No "after growth" or "regrowth" in the environment
• Survive/persist > than or = to pathogens
• Easily detected/quantified by simple lab tests in a short time
• Constant characteristics
• Harmless to humans and other animals
• Numbers in water are associated with risks of enteric illness in
consumers (dose-response relationship)
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
The Quest for The Ideal Indicator(s)
• No single indicator (so far discovered) meets all of
the criteria of an ideal indicator
• It is unlikely that a single organism or (taxonomic)
group will meet all of the indicator criteria when
applied to viruses, bacteria and parasites
• Current microbial indicator criteria do not address
those pathogens that are not associated with fecal
contamination
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
Current and Candidate Bacterial Indicators of Fecal
Contamination
• Total coliforms: standards for drinking, bathing and shellfish
harvesting waters; not feces-specific (environmental sources)
• Fecal ("thermotolerant") coliforms: ditto for total coliforms
• E. coli: the "fecal" coliform; may occur naturally in tropics
• Fecal streptococci: another group of enteric, fecally excreted bacteria;
not feces-specific (environmental sources)
• Enterococci: Streptococcus faecalis and S. faecium; a sub-set of the
fecal streptococci considered more feces-specific; EPA guide-line for
bathing water quality used as standards in some states
• Clostridium perfringens: anaerobe; feces-specific?; very (too?)
resistant spores; candidate indicator for protozoan cysts
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
Microbial Indicators of Fecal Contamination and Treatment
Efficacy for Enteric Protozoan Pathogens
• Clostridium perfringens spores may be useful indicators of enteric
protozoan parasites
– Plentiful in feces, raw sewage, treated effluents and receiving
waters and soils
– Spores of aerobic bacilli (Bacillus spp.) may be useful indicators of
water treatment efficacy
– Plentiful in water and other environmental media
– But, not feces-specific
– Spores are reduced less than are conventional vegetative indicator
bacteria by water and sewage treatment processes
– Spores of C. perfringens and Bacillus spp. superficially resemble
enteric protozoan parasite cysts and oocysts
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
CANDIDATE VIRAL INDICATORS OF FECAL CONTAMINATION
OF WATER
Coliphages: viruses (bacteriophages) infecting E. coli and perhaps other
coliforms; attach directly to cell wall (somatic) heterogeneous group;
may not be feces-specific; host-dependent detection.
Male-specific (F+) coliphages: coliphages infecting "male" strains of E.
coli (posses pili); may be feces-specific.
May distinguish human from animal fecal contamination by group
classification (II & III human; I & IV animal);
but, pigs may harbor groups II & III, too.
Bacteroides fragilis phages: may be human feces specific; USA studies
do not show human-specificity; concentrations too low.
Salmonella phages: in human and animal feces; may indicate presence of
Salmonella bacteria; concentrations too low.
Cary residents told to boil water (Aug 18, 2006)
http://rdu.news14.com/content/story_links/?ArID=89457&SecID=231
Town of Cary Press Release
CARY, N.C. -- Officials told the approximately 100,000 residents of the
Wake County town of Cary to boil their water and they closed restaurants
because fecal coliform was found Friday in a sample from one home.
Results of the Town of Cary’s routine sampling and testing of its water
supply has revealed the presence of E. coli on Coronado Way in the
Coronado Village subdivision in central Cary.
Water Contamination In Cary Costs Restaurants Millions
August 22, 2006
http://www.wral.com/apncnews/9718848/detail.html
CARY, N.C. -- The restaurant shutdown ordered here over the weekend after
E. coli was found in the water supply may have cost owners and
employees some $6 million. Health officials ordered the town's 115,000 residents
To boil tap water and forced restaurants to close Friday night
after the bacteria was detected.
Cary has 'weird' water mix-up
News and Observer July 25 2007
"In a place like Cary, it never even occurred to me that this might even be a possibility,"
Vinay Jain said Tuesday as Cary workers walked through his house testing taps.
"This gives the impression of a Third World country.
At least in India, we knew the water was bad, and we boiled it."
Cary Families' Faucets Delivered Treated Wastewater
www.wral.com July 25 2007
N.C. family drinks lawn water for 5 months
www.sciencedaily.com July 26 2007
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
Sources of drinking water
• Surface water
– Widely used as a supply for municipal DW
– Need to protect from sources of contamination (land
run-off, wildlife, recreational activities)
• Ground water
– Comprises 95% of water serving rural populations in
US (>100 million people)
– Assumed that soil will filter out most microbes
– Rarely are private wells treated, also public H2O supply
Environmental Monitoring of Pathogenic
Microbes : Water, Soil, Air
• Traditionally, more than half waterborne disease
outbreaks – groundwater responsible
– From 1997-98 15/17 (88%) reported outbreaks groundwater responsible
– Most common pathogens identified = Shigella spp. and
Hepatitis A virus
– 2/3 of the time no etiologic agent identified
– EPA estimates: 185,000 viral illnesses/yr from ground
water
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
• Soil microbial communities
– Complex set of natural communities
– 10,000 species per gram of soil
• Traditionally soil microbiology has focused on
metabolic activities of microbes (e.g.
biogeochemical cycles – nitrogen fixation)
• Concern when pathogens on/in soil reach
surface/ground waters or are disturbed
(transmitted via air)
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
• Sources of pathogenic soil microbes
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Domestic drainage/septic systems
Land applied municipal sewage
Land applied agricultural waste
Landfills
• Disposable diapers and animal waste– untreated
waste penetrating subsurface
– Naturally occurring
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
• Although most of us don’t routinely ingest soil…
– Infiltrated ground water
– Surface of raw fruits & vegetables
• Sampling
– Surface soils
– Subsurface soils
• Horizontal and vertical variations
• Perturbation of site, contamination
• Specialized technologies for drilling and coring
– Cost and expertise
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Survival and persistence of soil microbes
• Some things to consider …
– Soil type
• Texture: sand>silt>clay
• Moisture content: below 10% is biocidal
– Adsorption to soil (esp. viruses)
– Migration of microbes thru soil layers
• Type and species of microbe (physiological & morphological
characteristics)
– Smaller microbes penetrate soil better
– Virus>bacteria>protozoa
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Ground water recharge• Lack of water in arid SW US has prompted actions such as
the land application or injection of treated wastewater to
recharge subsurface aquifers
• Movement of viruses thru soil mostly studied
– Small size = greatest potential to be transported
– In one study, enteroviruses were found in 9m deep well, 14m from
recharge basin
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Airborne transmission
• Bioaerosol –
– “collection of airborne biological particles”
– Droplets or particles 0.5 to 30 μm diameter
– Composition will vary with source &
environmental conditions
• Airplane
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Sources: any object that can produce droplets or aerosols
– Humans and other animals (cough, sneezes)
– Mechanical ventilation system
– Fresh and marine surface waters, showers, whirlpool
baths, toilets
• Splash/wave action : microbes enclosed within droplet
– Soil, plants
• associated with particles, dust; act as “raft”
• spores
– US postal letters – mail-borne attack Oct. 2001
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Type of microbes found in bioaerosols:
– Viruses, bacteria, fungi (spores & hyphae)
– Generally protozoans are too large to remain
airborne
Some Examples of Bioaerosols
Living Source
Examples
• Bacteria
• Fungi
Legionella, Anthrax, endotoxins
Histoplasma,Cyptococcus, Pencillium,
Aspergillus, Stachybotrys aflatoxins,
Naegleria, Acanthamoeba
Rhinoviruses (colds), Influenza (flu),
Coronaviruses (SARS), Hantavirus
Chlorococus
Ambrosia (ragweed) pollen
Dermatophagoides (dust mites)
Horse or cat dander
• Protozoa
• Viruses
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Algae
Green plants
Arthropods
Mammals
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Airborne Microbes and their Reservoirs – Bacteria
Legionella pneumophila
• Reservoirs and amplifiers:
– Hot water systems, circulating water ventilation systems (cooling
towers), plumbing (e.g., shower heads), hot tubs, whirlpools, produce
fresheners
• Legionnaire's disease:
– A bacterial pneumonia that affects the lungs and may also affect the
stomach and intestines, kidneys, and central nervous system
– Frequently requires hospitalization
– Aug 2008 – Elmira (NY) Housing Authority said they suspended the use of hot water in
the senior housing complex. Tests revealed Legionella pneumophila in the hot water
system
– 10 cases & health officials have been advising residents to take sponge baths instead
of showers to avoid breathing in water vapor
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Airborne Microbes and their Reservoirs – Bacteria
Bacillus anthracis
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Reservoirs and amplifiers:
– Herbivores (e.g., cattle, sheep, goats ) may become infected by ingesting spores
while grazing in areas of high soil contamination
– Anthrax can be found globally
– Endemic to the parts of US (Dakotas, OK, TX)
– Spores are extremely resistant, 50 years or more in soil
– Animal carcass – vegetative cells will sporolate when exposed to air
– Person-person spread unlikely
– 2005: South Dakota: 11 counties: 39 outbreaks, 330 head; North Dakota: 13
counties, 86 cases
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Anthrax:
– Cutaneous: skin lesions from contact with spores or contaminated meat
– Gastrointestinal: ingestion of spores or contaminated foods
– Inhalation: often fatal, especially with inhalation of weapons-grade spores,
symptoms resemble common cold, severe breathing problems, shock
Inhalation Anthrax Associated with Dried
Animal Hides --- Pennsylvania and New York
City, 2006 (Feb)
March 17, 2006 / 55(10);280-282
•This report describes the first case of naturally acquired inhalation anthrax
in the United States since 1976
•The patient made traditional African drums by using hard-dried animal
hides (e.g., air-dried until brittle enough to crack) obtained in NYC from
importers who primarily sold African goat and cow hides.
•Making the drums involved soaking hides for 1 hour in water and then
scraping hair from the hides with a razor, which reportedly generated a large
amount of aerosolized dust in the patient's workspace as the hides dried.
•The man did not wear any personal protective equipment (e.g., mask or
gloves) while working.
Cutaneous Anthrax Associated with Dried
Animal Hides (Sept 2007)
• Two family members in Danbury, CT; on antibiotics and
recovering
• Goat and cattle hides imported from Africa used in drum
making
• Wore masks while working
• Traffic rerouted around location; FBI, EPA, and other state
officials notified
• Neighbors evacuated
• Samples taken from house, shed and soil
• Positive samples from shed, door to shed, and rear entrance
of home
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
• Biohazard Detection System (BDS)
– Combined automated air sampling w/internal automated testing
system
– Sampling interval 1.5 hrs, 30 min analysis
– Currently only set-up for B. anthracis spores
– Used across the US in USPS PDC
• BioWatch Program
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Air monitors set up since 2003; >30 metro areas
Goal: detect w/in 36 hrs release of anthrax, sm pox, plague (20)
~10 sensors per city, tested once a day
15 positives
Not intended to prevent attack, hundreds of thousands of victims,
instead start mass treatment
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Airborne Microbes and their Reservoirs – Viruses
Coronaviruses (SARS)
• Reservoirs and amplifiers:
– First reported in Asia 2003, global outbreak-few months spread to
two dozen countries
– Person-person spread – respiratory droplets travel short distances
(~ 3ft)
– Knowledge is still evolving
• Morbidity/Mortality:
– Flu-like symptoms, most develop pneumonia
– 8,437 people worldwide w/ 813 deaths
– US: 192 cases, none died, very little transmission among close
contacts and generally did not spread thru community!!??
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Airborne Microbes and their Reservoirs – Viruses
Hantaviruses
• Reservoirs and amplifiers:
– Wild rodents - pass it in their droppings, urine, or saliva. The
common house mouse does not carry hantavirus.
– Human exposure - touch rodent urine, droppings, or places where
these animals have nested. Most exposed (by inhalation) when
sweeping areas with dried droppings or urine
• Hantavirus pulmonary syndrome:
– Flu-like symptoms, most develop cough and shortness of breath
– Person-to-person spread unlikely
– Around in US since 1950s, took outbreak in “four corners” area of
US to be recognized
– 15 Aug 2008: A policeman, 34, died at Yakima Valley Memorial
Hospital Wa, barely 48 hours after suffering symptoms
Environmental Transmission of Pathogenic
Microbes : Water, Soil, Air
Airborne Microbes and their Reservoirs – Fungi
Cryptococcus neoformans
• Reservoirs and amplifiers:
– Fungal Pathogen
– Isolated from the soil worldwide, usually in association with bird
droppings
– Inhalation of airborne cells and/or spores
• Cryptococcosis:
– Initial pulmonary infection - usually asymptomatic
– Disseminated infection, especially meningoencephalitis
– one of the most common life-threatening fungal infections in AIDS
patients
– In the United States, 85% of cases occur in HIV-infected persons