Water-borne Cryptosporidium: a perspective from the USA

In the USA, Cryptosporidium parvum has attracted considerable interest due to recent outbreaks of cryptosporidiosis attributed to water supplies contaminated with oocysts. Because of its unprecedented magnitude, the outbreak which occurred in Milwaukee in April 1993 was widely publicized and studied. Information collected during this and other recent outbreaks is being evaluated by regulatory agencies and the water industry with the aim of designing cost-effective measures that will reduce the risk of future water-borne outbreaks, as discussed here by Giovanni Widmer, Margaretha Carraway and Saul Tzipori.