A HOSPITAL OUTBREAK OF SALMONELLA FOOD POISONING DUE TO INADEQUATE DEEP-FAT FRYING

In an outbreak of plasmid-free Salmonella enteritidis phage type 4 (PT 4) food poisoning at a hospital for mentally handicapped people in Jul y 1990, 101 residents and 8 staff were affected and a cohort study imp licated beef rissoles cooked by deep-fat frying as the vehicle of infe ction (relative risk 292, 95% confidence interval 1.73-4.93, P much le ss than 0.001). Replication of the cooking process demonstrated that t he rissoles achieved core temperatures of only 48-60 degrees C despite external temperatures of 91-95 degrees C and an oil temperature of 14 2-154 degrees C. No residual food was available for microbiological te sting but plasmid-containing S. enteritidis PT 4 was isolated in shell eggs from the hospital kitchen.