Packed with Salmonella--investigation of an international outbreak of Salmonella Senftenberg infection linked to contamination of prepacked basil in 2007.

Salmonella Senftenberg is uncommon in the United Kingdom. In January-June 2007, the Health Protection Agency reported on 55 primary human cases of Salmonella Senftenberg in England and Wales. In May 2007, fresh basil sold in the United Kingdom was found to be contaminated with Salmonella Senftenberg. We launched an investigation to elucidate the cause of this outbreak. Isolates were examined using plasmid profiling and pulsed-field gel electrophoresis, and the outbreak strain (SSFTXB.0014) was identified. We enquired via Enter-net whether other countries had isolated the outbreak strain, analyzed samples of fresh herbs from U.K. retailers, and interviewed patients on food history. Thirty-two patient-cases were referred to this outbreak in England and Wales. Onsets of illness occurred between 5 March and 6 June 2007. Fifty-six percent of patient-cases were females and 90% adults (>20 years old); three were admitted to hospital as a result of Salmonella infection. Scotland, Denmark, the Netherlands, and the United States reported on 19 cases of Salmonella Senftenberg infection presenting with the outbreak strain since January 2007. Eight samples of prepacked fresh basil imported from Israel tested positive with the same strain. A minority of patients could recall the consumption of basil before illness, and some reported consumption of products where basil was a likely ingredient. Environmental investigations in Israel did not identify the contamination source. Microbiological evidence suggested an association between contamination of fresh basil and the cases of Salmonella Senftenberg infection, leading to withdrawal of basil from all potentially affected batches from the U.K. market.

Disease risks from foods, England and Wales, 1996-2000.

Data from population-based studies and national surveillance systems were collated and analyzed to estimate the impact of disease and risks associated with eating different foods in England and Wales. From 1996 to 2000, an estimated 1,724,315 cases of indigenous foodborne disease per year resulted in 21,997 hospitalizations and 687 deaths. The greatest impact on the healthcare sector arose from foodborne Campylobacter infection (160,788 primary care visits and 15,918 hospitalizations), while salmonellosis caused the most deaths (209). The most important cause of indigenous foodborne disease was contaminated chicken (398,420 cases, risk [cases/million servings] = 111; case-fatality rate [deaths/100,000 cases] = 35, deaths = 141). Red meat (beef, lamb, and pork) contributed heavily to deaths, despite lower levels of risk (287,485 cases, risk = 24, case-fatality rate = 57, deaths = 164). Reducing the impact of indigenous foodborne disease is mainly dependent on controlling the contamination of chicken.