Report No DWI0790

Mar 1997

The possibility always exists for pathogenic organisms to contaminate water supplies and cause outbreaks of waterborne illness. The threat which is posed by an organism, in terms of its occurrence and distribution in water sources and amenability to rem oval or inactivation during conventional water treatment, is often poorly understood or completely unknown.

Government Departments, Local Authorities, Water Utilities, Managers of water treatment processes, and others with responsibility for consumer and media relations may be expected to give assurances about the effectiveness of water treatment processes in protecting public health against emerging pathogens. In such situations it would be important to have access to concise, accurate information on which to base an assessment of the threat to the health of water consumers.

The fact sheets which are included as Appendix A to this report are intended to provide this kind of information, by summarising the state of existing knowledge of the public health significance of selected organisms, the likelihood of their occurrence m water sources, and whether conventional water treatment processes could be expected to give adequate protection against them.

This first series of twenty-two fact sheets includes information on bacteria (Aeromonas, Helicobacter pylori, Campylobacter, Yersinia enterocolitica, the Mycobacterium avium complex, the enterovirulent strains of Escherichia coli, Vibrio, Arcobacter, Salmonella and Legionella), protozoa (Microsporidia, Cyclospora, Isospora, Toxoplasma, and Acanthamoeba) and viruses (Norwalk-like viruses, Coxsackieviruses, Adenoviruses, Astroviruses, Non-Group A Rotaviruses, Hepatitis E virus, and Caliciviruses). The fact sheets have been produced in a standardised format, and each has been restricted to a single sheet of A4-sized paper, printed on both sides.

The fact sheets have been jointly prepared by the Public Health Laboratory Service and WRc.

Copies of this report may be available as an Acrobat pdf download under the 'Find Completed Research' heading on the DWI website.