General outbreaks of infectious intestinal disease in England and Wales 1992 to 1994

Data from the surveillance scheme of general outbreaks of infectious intestinal disease in England and Wales, reported to the PHLS Communicable Disease Surveillance Centre (CDSC), were used to review 1280 of the 1594 outbreaks identified between 1 January 1992 and 31 December 1994 for which a minimum data set was captured. The number of outbreaks reported in each regional health authority ranged from 31 in Mersey to 221 in Yorkshire. The commonest pathogens reported were salmonellas in 32% (412) of outbreaks, small round structured virus (SRSV) in 27% (342), Clostridium perfringens in 7% (90), and Shigella sonnei in 4% (46). The main mode of transmission was described as foodborne in 50% (642), over half of which were caused by salmonellas, and person to person in 39% (496), over half of which were caused by SRSV. Most outbreaks transmitted from person to person occurred in hospitals and in residential institutions for elderly people. Outbreaks lasted from one to 217 days (median five days) and their duration varied with the pathogen. The median attack rate was 37%. Illness was reported in 34,158 people, 751 of whom (2%) were admitted to hospital. There were 55 deaths, 28 of which were associated with salmonella and 12 with SRSV. Most of the outbreaks reported and the associated morbidity and mortality could have been prevented by following standard food hygiene practices, implementing infection control policies, and ensuring that food entering kitchens was of the highest microbiological quality possible.