Dr. Julie Ann Kase Public Health Scientist – Bioterrorism and Emerging Pathogens Unit

1. Environmental Transmission of Pathogenic Microbes – why they are where they are when they arePart 2 Dr. Julie Ann Kase Public Health Scientist – Bioterrorism and Emerging Pathogens Unit NC State Laboratory of Public Health Julie.Kase@ncmail.net

2. 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)

3. Environmental Transmission of Pathogenic Microbes : Water, Soil, Air • Sources of pathogenic soil microbes • Domestic drainage/septic systems • Land applied municipal sewage • Land applied agricultural waste • Landfills • Disposable diapers and animal waste– untreated waste penetrating subsurface • Naturally occurring

4. 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

5. 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

6. 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 (small size=greatest potential to be transported) thru soil mostly studied • In one study, indigenous enteroviruses were found in 9m deep well, 14m from recharge basin • Movement of larger microbes (bacteria and protozoans) theoretically less

7. 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

8. 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

9. 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

10. Some Examples of Bioaerosols Living Source Examples Microorganisms (microbes): • Bacteria Legionella, Anthrax, endotoxins • Fungi Histoplasma,Cyptococcus, Pencillium, Aspergillus, Stachybotrys aflatoxins, • Protozoa Naegleria, Acanthamoeba • Viruses Rhinoviruses (colds), Influenza (flu), Coronaviruses (SARS), Hantavirus • Algae Chlorococus • Green plants Ambrosia (ragweed) pollen • Arthropods Dermatophagoides (dust mites) • Mammals Horse or cat dander

11. 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

12. Environmental Transmission of Pathogenic Microbes : Water, Soil,Air Airborne Microbes and their Reservoirs – Bacteria Bacillus anthracis • Reservoirs and amplifiers: • 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 • 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

13. 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 • Air monitors set up in last 3 yrs; 30 metro areas • Goal: detect w/in 36 hrs release of anthrax, sm pox, plague • ~10 sensors per city, tested once a day • Not intended to prevent attack, hundreds of thousands of victims, instead start mass treatment

14. Environmental Transmission of Pathogenic Microbes : Water, Soil,Air Airborne Microbes and their Reservoirs – Viruses Coronaviruses • 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 • SARS: • 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!!??

15. 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

16. Environmental Transmission of Pathogenic Microbes : Water, Soil,Air Airborne Microbes and their Reservoirs – Fungi Cryptococcus neoformans • Reservoirs and amplifiers: • 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 • In the United States, 85% of cases occur in HIV-infected persons