Food safe restaurants: don’t wash lettuce in same sink as raw chicken, don’t wash raw chicken, don’t let sick workers work; UK salmonella outbreak sickened 75 in 2009

In Aug. 2009, reports of patients with Salmonella Enteritidis phage type 8 began to increase in Portsmouth, UK.

Health types launched an investigation centered on one restaurant that served up to 250 customers today, which at the time was identified by local media as Tenth Hole Tea Rooms in Southsea.

In results published in the current issue of Epidemiology and Infection, investigators identified 75 people sickened. The abstract is below. But the paper contains some unplucked gems on how – or how not – to run a restaurant and the role of designing microbiological safety into operations. Among the observations, all which contributed to the outbreak:

SE PT8 was isolated from a cloth in the pot wash area. A sample of precooked pasta had a total viable count of 1.3r 108 /g of SE PT8 suggestive of poor hygiene.

• The supplier of lettuce had been changed prior to the outbreak resulting in the replacement of ready washed lettuce to lettuce which required washing. The new lettuce was washed in a sink also used for washing raw chicken.

• Although some staff had defined working responsibilities, there was a complex system of rotas and responsibilities between full-time/part-time staff due to long opening hours (07:00–20:00 hours) with up to 250 customers per day. During the investigation, it became clear that processes and procedures were complex as well. Staff would quickly change working responsibilities at short notice, depending on the demands at the time, increasing the risk of contamination unless satisfactory standards of hygiene were continually observed.

• Staff were assigned to one of four roles on the work rota. These were front of house, chefs and kitchen, wash up and runners, with a large amount of interchange and multitasking. Positive Salmonella results were obtained from staff in each of these work areas.

Don’t wash lettuce in the same sink as raw chicken; don’t even wash raw chicken; and don’t let sick workers work.

Large outbreak of Salmonella Enteritidis PT8 in Portsmouth, UK, associated with a restaurant***
Epidemiology and Infection, FirstView Article : pp 1-9
E. Severi, L. Booth, S. Johnson, P. Cleary, M. Rimington, D. Saunders, P. Cockcroft and C. Ihekweazu
Seventy-five individuals with Salmonella infection were identified in the Portsmouth area during August and September 2009, predominantly Salmonella Enteritidis phage type 8. Five patients were admitted to hospital. A case-case comparison study showed that a local restaurant was the most likely source of the infection with a risk of illness among its customers 25-fold higher than that of those who did not attend the restaurant. A case-control study conducted to investigate specific risk factors for infection at the restaurant showed that eating salad was associated with a threefold increase in probability of illness. Changing from using ready washed lettuces to lettuces requiring washing and not adhering strictly to the 48 hours exclusion policy for food handlers with diarrhoea were likely to have contributed to the initiation and propagation of this outbreak. Possibilities for cross-contamination and environmental contamination were identified in the restaurant.