Environmentally Transmitted Human Pathogens

1. Environmentally Transmitted Human Pathogens

2. Pathogens Soil-, water-, foodborne pathogens can be bacteria, viruses, single-cell and multicellular eukaryotes. Frank vs opportunistic vs accidental vs cryptic Frank human pathogens have no other known hosts (Salmonella typhi). Generally, pretty low Infectious Dose Opportunistic pathogens infect many hosts. Immunocompromised hosts are more susceptible (most pathogens to some degree). Moderate-high ID. Accidental pathogens have not evolved as “pathogens” (e.g. Legionella). Require very high ID to infect Cryptic pathogens. May have animal hosts that are not yet discovered Toxin producing organisms that are not “pathogens” Cyanobacteria, Clostridium

3. Where are they? Biofilms on submerged or wet surfaces on fruits/vegetables Homes carpets kitchen surfaces toilet seats and air Soils and manure actively metabolizing, culturable viable non culturable state? In other hosts other animals (“warm”- and “cold-blooded”) insects (flies, fruit flies) inside plants