ABSTRACT
More waterborne disease outbreaks were reported during 1971 to 1985 than during any 15-year period since 1920. The increase in reported waterborne disease outbreaks due to Cryptosporidium and other infectious agents is of great concern to the water industry. Cryptosporidium in surface drinking waters in Sheffield, England, was postulated to cause cases of cryptosporidiosis reported in 1986. The development of methods for detecting parasites in water has largely paralleled the rise in interest in Giardia as a waterborne disease entity. In Sheffield, England, a peak in cryptosporidiosis was recorded during the summer of 1986 among individuals whose only epidemiological source link was drinking water supplied from a common reservoir. Water sampling has demonstrated that Cryptosporidium is ubiquitous in the environment and always likely to be present as a waterborne pathogen. Smaller suspected waterborne outbreaks of cryptosporidiosis have subsequently been reported to Ayrshire, Scotland, and Oxfordshire-Swindon, England.
