Eurosurveillance reports today an outbreak of Shigella in Norway that sickened at least 46 people.

Two municipalities were involved. A large cluster (42 cases) was concentrated in north Norway, while a small cluster (4 cases) occurred in the south-east region. Epidemiological evidence and traceback investigations have linked the outbreak to the consumption of imported fresh basil. The product has been withdrawn from the market. No further cases have been reported since 25 October.

On 9 October 2011, the Department of Infectious Disease Epidemiology at the Norwegian Institute of Public Health was informed by the Municipal Medical Officer and the Local Food Safety Authority in Tromsø (northern Norway) about an unusually high number of cases of gastrointestinal disease caused by Shigella sonnei.

A delicatessen and catering company located in the centre of Tromsø received several complaints from customers who had fallen ill with gastrointestinal symptoms after having eaten food items from there.

On 14 October, a small cluster of cases who had not been to Tromsø were reported and the outbreak was classified as national.

An outbreak case was defined as a person with gastrointestinal symptoms with laboratory confirmed infection with S. sonnei with indistinguishable multiple-locus variable number of tandem repeats analysis (MLVA) profiles in Norway after 1 October 2011.

Traceback investigations of ingredients in the pesto served in Tromsø are still ongoing. The same distributer that provided the fresh basil to the catering company in Tromsø also delivered fresh basil to the restaurant implicated in the second cluster in south-east Norway. The distributor imported this herb from a country outside the European Union and has voluntarily withdrawn it from the market. The National Veterinary Institute analysed samples of pesto and other ingredients from the catering company in Tromsø. Samples available for analysis have been negative. An epidemic intelligence information system (EPIS) enquiry has been posted to determine whether other European countries have observed a similar increase in cases infected with S. sonnei. So far, no other countries have reported any recent increase in cases that can be linked to this outbreak.

Three small children from Oslo, Akershus and Østfold are in hospital with a serious kidney disease following an E. coli infection.

Oslo University Hospital (Oslo Universitetssykehus) authorities confirm two have developed the potentially fatal Haemolytic-uremic syndrome (H.U.S.), which can also give acute kidney failure and change blood chemistry.

The Institute of Public Health (Folkehelseinstituttet/FHI) says the third child, admitted to Ullevål Hospital, has also developed H.U.S. Medical staff at both hospitals are refusing to give details about their conditions.

The Foreigner reports that no further details were available at this time.
 

The Norwegian Institute of Public Health has confirmed a genetic match for an infection of E. coli O157 among three children who developed hemolytic uremic syndrome (HUS) this year.

The Institute reported this week,

“The first child became ill in January, the second in February and the third in March. In addition, a sibling of one of the children has also developed HUS, but it has not yet been confirmed whether this is the same bacterial strain.”

One of the four children—all of which are under the age of ten—has died.

The source of the outbreak has yet to be determined. County food safety officials are currently questioning the families of victims on the children's meals and testing leftover food, while federal officials are seeking information on any further possible cases (i.e. persons, and particularly children, with bloody diarrhea who test positive for enterohemorrhagic E. coli).

I wonder if they’ve looked into the families’ grocery store receipts?

A peer-reviewed article in the April 15 issue of Clinical Infectious Diseases reports that the source of a 2007 outbreak of E. coli in Denmark was found using credit card information.

Investigators had struggled to determine the source of a strain of E. coli O26 that infected 20 Danish children between February and May of 2007.

Flesh and Stone reports that when interviews failed to yield any likely suspect foods, investigators turned to shopping lists.

“Parents in seven families provided their credit card information and a list of supermarkets where they had shopped. The two supermarket chains that the parents had used most often agreed to help with the investigation. The stores searched their central computers for the precise amount paid and the date and the location of the shop.

“From there, investigators determined that five families had purchased the same brand of fermented, organic beef sausage. A sixth family was linked to the same sausage brand through shopping records provided by the kindergarten attended by two children who became infected with the same E. coli strain, STEC O26. An unopened sample of the sausage also tested positive for the strain.”

Authors of the CID article acknowledged that relying on memory to identify similarities among the diets of outbreak victims diets is often unsuccessful and found credit card information to be “a strong tool in the [current] investigation.”

Investigation of a similar outbreak of E. coli O157 in Iceland successfully used the same method some months later. It could be worth a try for Norway.
 

Norway's Food Safety Authority (Mattilsynet) says norovirus – originating in staff or cold food served at a hotel buffet or both -- swept through the Clarion Hotel Gardermoen, near Oslo's main airport, Saturday afternoon and evening.

The victims included members of a national diabetes foundation attending a conference and what was supposed to be the foundation's 60th anniversary party.

Instead, most of them wound up vomiting and suffering from acute diarrhea, especially serious ailments for diabetics. More than 30 were taken to hospital, and scores of other visitors at the hotel also fell ill, including hotel staff and members of a band hired in to play at the foundation's party.

Here’s another norovirus infosheet from the past with some tips. The originals can be found at foodsafetyinfosheets.ksu.edu