Between February 1988 and March 1989 chicken carcases delivered to the kitchen of a long stay psycho–geriatric hospital were screened every week for salmonella contamination. While 214 of 477 (45▒) individual carcases carried one or more salmonella types, every single consignment examined contained affected carcases.
Simultaneously sewers draining the residential accommodation and excluding kitchen effluent, were also monitored. Thirty out of 79 (38▒) of Moore's swabs were positive for salmonella. There was a statistically significant association between the salmonella types isolated from chicken and those isolated from sewers the following week.
Following a change in kitchen policy to order only cooked chicken there was a significant reduction in the isolation of salmonella from the sewers.