ABSTRACT
A considerable number of protozoan and helminth parasites of man now occur outside the tropics, and many of them could theoretically be transmitted through sewage. In fact, however, it seems rare for sewage-borne transmission to take place in developed countries. The beef tapeworm, Taenia saginata, is probably the only helminth parasite of man which is regularly transmitted through sewage in the United Kingdom. This is probably because it has an indirect life cycle, with transmission through cattle which serve as intermediate hosts, and so it is not necessary for the sewage-borne stage (the egg) to be ingested by man.
