Microbial Agents Associated with Waterborne Diseases

Many classes of pathogens excreted in feces are able to initiate waterborne infections. There are bacterial pathogens, including enteric and aquatic bacteria, enteric viruses, and enteric protozoa, which are strongly resistant in the water environment and to most disinfectants. The infection dose of viral and protozoan agents is lower than bacteria, in the range of one to ten infectious units or oocysts. Waterborne outbreaks of bacterial origin (particularly typhoid fever) in the developing countries have declined dramatically from 1900s. Therefore, some early bacterial agents such as Shigella sonnei remains prevalent and new pathogens of fecal origin such as zoonotic C. jejuni and E. coli O157:H7 may…