Staphylococcal food poisoning in the United Kingdom, 1969–90

Abstract

SUMMARY: Between 1969 and 1990 strains ofStaphylococcus aureusfrom 359 outbreaks and sporadic cases of staphylococcal food poisoning in the United Kingdom were examined in the PHLS Food Hygiene Laboratory for the production of enterotoxin. In a number of instances the incriminated foods were also examined for the presence of enterotoxin. Strains from 79% of incidents produced enterotoxin A alone or together with another enterotoxin. The level ofS. aureuspresent in the foods ranged from no viableS. aureusdetected to 1.5 × 10¹⁰c.f.u./g with a median of 3.0 × 10⁷c.f.u./g. Enterotoxin was detected in foods in the absence of viableS. aureusin only two outbreaks and in both cheese was the implicated food. Meat. poultry or their products were the vehicle in 75% of incidents with ham and chicken most frequently implicated. Other foods included fish and shellfish (7%) and milk and milk products (8%). Most contamination took place in the home followed by restaurants and shops. Seventy-one percent of the incident strains were lysed by phages of group III or I/III.