Pasteurisation and strict hygiene prevent serious morbidity and death

In this week's BMJ Desenclos et al (p 91) describe a nationwide outbreak in France of 273 confirmed infections with Salmonella paratyphi B.1 The source of the infections was traced to cheese made from unpasteurised goats' milk. A third of the patients were so ill that they were admitted to hospital, and one died. As with most outbreaks of food poisoning, the patients with confirmed infection were probably only a minority of those affected. The outbreak began during the second week of August 1993 and continued until the second week of October, two months later. The questions that must be asked are, how could an outbreak of infection with such a serious pathogen with a common source have continued uncontrolled for so long and why was the source not identified sooner?

It was estimated by the authors that production of contaminated cheese started in mid-June; but the producer's protocol for internal quality control depended on sampling six finished cheeses from one batch each week, and it was not until 6 October that tests detected S paratyphi B in a sample of cheese. S paratyphi was then found in milk pooled from the 40 suppliers on 6 and 9 October and from milk from a tank on the farm of one supplier. The company took immediate steps to prevent further contamination of the cheese and also destroyed all batches that were still in store at the plant. It was …