Outbreaks of waterborne infectious intestinal disease in England and Wales, 1992–5

Abstract

Following the introduction of an improved surveillance system for infectious intestinal disease outbreaks in England and Wales, the Public Health Laboratory Service Communicable Disease Surveillance Centre received reports of 26 outbreaks between 1 January 1992 and 31 December 1995 in which there was evidence for waterborne transmission of infection. In these 26 outbreaks, 1756 laboratory confirmed cases were identified of whom 69 (4%) were admitted to hospital. In 19 outbreaks, illness was associated with the consumption of drinking water from public supplies (10 outbreaks) or private supplies (9 outbreaks). The largest outbreak consisted of 575 cases. In 4 of the remaining 7 outbreaks, illness was associated with exposure to swimming pool water. Cryptosporidium was identified as the probable causative organism in all 14 outbreaks associated with public water supplies and swimming pools. Campylobacter was responsible for most outbreaks associated with private water supplies. This review confirms a continuing risk of cryptosporidiosis from chlorinated water supplies in England and Wales, and reinforces governmental advice to water utilities that water treatment processes should be rigorously applied to ensure effective particle removal. High standards of surveillance are important for prompt recognition of outbreaks and institution of control measures. As microbiological evidence of water contamination may be absent or insufficient to implicate a particular water supply, a high standard of epidemiological investigation is recommended in all outbreaks of suspected waterborne disease.

Detection of Toxoplasma gondii oocysts in water: proposition of a strategy and evaluation in Champagne-Ardenne Region, France

“…Protozoan agents are very robust in water environments and are strongly resistant to most disinfectants, including chemical procedures (like chlorination) used to disinfect drinking water. Over the last 30 years, giardiasis has become the most common cause of human waterborne disease in the United States (Furtado et al 1998, Karanis & Kourenti et al 2007). However, waterborne cryptosporidiosis outbreaks have also been reported during that time, including one in Milwaukee in 1993 affecting 403,000 people (Mc Kenzie et al 1994).…”

Detection of Cryptosporidium and Identification to the Species Level by Nested PCR and Restriction Fragment Length Polymorphism

“…Human cryptosporidiosis is usually self-resolving within a few days, but immunocompromised patients can develop life-threatening complications. Outbreaks due to drinking water contamination continue to occur (7,10,18,32), and there is no effective treatment, making cryptosporidiosis a major public health issue and economic problem. Diagnosis is generally based on microscopic detection of oocysts in stools, but this offers no information on the infecting species and is not suited to epidemiological investigations.…”

Application of Hybrid Process of Coagulation/Flocculation and Membrane Filtration for the Removal of Protozoan Parasites from Water

“…transmission associated with their ability to survive in the environment generate an extensive network of transmission and sources of infection for humans and animals (Furtado et al, 1998). The individual's susceptibility to infection as well as the severity and duration of that vary considerably from individual to individual, depending on immune health, nutritional status and previous exposure.…”