Norwegian officials are investigating a national outbreak of Shigella linked to sugar peas, also referred to as sugar snaps, from Kenya.

The Norwegian Institute of Public Health (Folkehelseinstituttet), local authorities and the Norwegian Food Safety Authority (Mattilsynet) are investigating the eight illnesses in people aged 29 to 63 years old. None of those sick are believed to be seriously ill.

In early December, several people became ill with gastrointestinal symptoms after eating in a canteen in Oslo. Shigella sonnei was found in samples from five of the patients.

Heat treatment advice
The outbreak investigation found three people in Akershus and Hedmark are also ill from the same type of bacteria.

The product was labeled “Sugersnaps” or “Sukkererter” and come in 150-gram packages. They were packed by Spring Fresh and distributed in Norway by Bernhard Botolfsen Import AS with lot number 194819.

The sugar peas associated with the outbreak in Oslo were distributed to other parts of the country. Authorities believe the affected product is no longer on the market due to its shelf life but advised any consumers that still have a pack to discard it.

Margrethe Hovda Røed, from the Norwegian Food Safety Authority, said the agency recommends sugar peas imported from exotic areas be heat treated before serving to reduce the risk of infection.

The product is traditionally heat treated before consumption in some countries from which it is exported but in Norway, it is often eaten raw. The package did state that the product should be heat treated before consumption.

Previous outbreak
A decade ago there was an outbreak of shigellosis linked to imported sugar peas in Norway, Denmark and Sweden.

In May 2009, Norwegian officials identified a possible outbreak of Shigella sonnei infection involving four cases and five suspected infections in two separate households. One sample from an unopened package of sugar peas imported from Kenya in one household was positive for Shigella sonnei.

In May and June 2009 in Sweden an outbreak involved 47 suspected cases of whom 35 were laboratory confirmed. The epidemiological investigation based on patient interviews pointed to sugar snaps from Kenya as the source but Shigella was not detected in product samples.

The outbreak involved 10 people in Denmark in April and May 2009. The likely source was fresh, raw sugar peas imported from Africa, based on interviews with patients and the Norwegian outbreak.

Shigellosis is caused by infection with the bacterium Shigella. In Norway, the disease usually occurs after infection abroad, especially Egypt and Asia. Domestic infections can happen, either as secondary cases to people infected abroad or because of imported, contaminated foodstuffs.

The most common symptoms are diarrhea, headache, stomach pain, nausea and fever. They usually begin one to two days after eating contaminated food and last five to seven days.

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