An outbreak of Q fever was likely caused by renovation work that aerosolized contaminated straw board.

In developing public policy on food safety, systematic identification and thorough investigation of all general outbreaks is necessary in order to avoid bias towards highly publicised outbreaks. In Wales, from 1986 to 1998, 87 general foodborne outbreaks of salmonellosis were identified. Most outbreaks occurred at functions or were associated with small catering outlets such as bakeries and sandwich bars. In 50 outbreaks, a vehicle of infection was confirmed microbiologically and/or epidemiologically. The most common food vehicles were those containing shell eggs. Salmonella enteritidis outbreaks were significantly more likely than outbreaks of other serotypes to be associated with vehicles containing shell eggs, suggesting that eggs were also the source of infection in many outbreaks. The routine use of analytical epidemiological studies to identify vehicles in outbreaks is recommended.

During July 1995, an outbreak of Salmonella typhimurium definitive type (DT) 170, an unusual strain, occurred in South Wales. A case-control study found that illness was associated with eating kebabs (odds ratio undefined, P = 0.002), doner kebabs (odds ratio 7.9, 95 % confidence interval 1.5-20.5, P = 0.02) and kebabs with yoghurt based relish (odds ratio undefined, P = 0.009) but not with eating kebabs with mayonnaise-based relish (odds ratio 2.4, 95 % confidence interval 0.4-13.9, P = 0.53). Environmental investigations discovered a complex web of producers and wholesale suppliers. Kebab meat and yoghurt had been supplied to the two main implicated outlets by a single wholesaler. Samples of raw minced lamb and several environmental swabs taken at the wholesaler were positive for S. typhimurium DT170. Blood-stained, unsealed yoghurt pots were observed to be stored under a rack of raw lamb. Investigators of food poisoning outbreaks linked to takeaway food should consider cross-contaminated relishes and dressings as well as undercooked meat as potential vehicles of infection.

No abstract

An outbreak of Campylobacter jejuni infection occurred in a South Wales Valleys housing estate. Illness in estate residents was associated with tap water consumption [population attributable risk (PAR) 50%, relative risk (RR) 2.53, 95% confidence interval (CI) 1.9-3.37] and residence in the upper estate (PAR 49%, RR 2.44, 95% CI 1.83-3.24). Amongst upper estate residents, rates of diarrhoeal illness increased with rates of water consumption (OR 18, 95% CI 3.5-92.4 for heaviest consumers, chi2 trend P<0.0001). The upper estate received mains water via a covered holding reservoir. A crack in the wall of the holding reservoir was identified. Contamination with surface water from nearby pasture land was the likely cause of this outbreak. Service reservoirs are common in rural communities and need regular maintenance and inspection. The role of water in sporadic cases of campylobacter enteritis may be underestimated.