Outbreaks of salmonellosis in hospitals in England and Wales: 1992–1994

Data from the surveillance scheme of general outbreaks of infectious intestinal disease in England and Wales were used to describe the epidemiology of outbreaks of salmonellosis in hospitals from 1992-1994. Outbreaks of infectious intestinal disease in hospitals accounted for 15% (189/1275) of all outbreaks. A salmonella was the implicated pathogen in 12% (22/189). The mode of transmission was described as mainly person to person in 12 outbreaks, mainly foodborne in eight and equal or unknown proportions of foodborne and person to person in two. The most common strain involved was Salmonella enteritidis PT4 (11 outbreaks). The mean duration of outbreaks was 16 days. The mean attack rate in patients was 25% but varied from 2-67%. Illness was reported in 260 patients, of whom 130 had a laboratory confirmed infection. Eight hundred and twenty-six asymptomatic patients were tested, 31 of whom were positive. The salmonella infection was believed to have contributed to the deaths of five patients. Ill staff (115) were tested and 68 were positive; 1508 well staff were tested and 33 were positive. Outbreaks of salmonellosis in hospitals are preventable. Attack rates can be high and outbreaks are often prolonged, with high morbidity and associated disruption of hospital services. There is need for effective infection control policies, appropriate training of staff, simple surveillance systems and readily available expert advice to ensure outbreaks are rapidly controlled.