Around 50 people in five European countries have been struck down with a rare strain of Salmonella.

Salmonella Mikawasima has infected 15 people in Germany, 13 in Sweden, eight in both Denmark and the Czech Republic and six in Austria.

The Austrian Agency for Health and Food Safety (AGES) told Food Safety News that as illness was caused by a very rare serotype, the sudden accumulation indicates transmission through a foodstuff but there is currently no indication on the source of the outbreak.

The agency is investigating the suspected foodborne outbreak with the Federal Ministry of Labor, Social Affairs, Health and Consumer Protection (BMASGK), state authorities and the other EU member states concerned.

Luise Müller, an epidemiologist at the Statens Serum Institut in Denmark, confirmed to us that an investigation is ongoing.

“In Denmark, we have nine cases; three male and six females aged three to 97 years. They live across the whole country. They were ill from July 10 to August 8. Four cases were hospitalized. We are currently interviewing cases to reveal a hypotheses about the source of the outbreak,” she said.

A spokeswoman from the Public Health Agency of Sweden (Folkhälsomyndigheten) said the outbreak consists of 13 cases that cluster in whole genome sequencing and involves four counties in the country.

“The cases are between three and 81 years old, 30.8 percent of the cases are women and 69.2 percent are men. Onset of disease was between 18 July and 2 August,” she said.

“The number of Salmonella Mikawasima cases in Sweden is usually low, one to two per year, when there is no outbreak. The patients have been asked to answer a trawling questionnaire but we have no suspected vehicle at the moment.”

The European Centre for Disease Prevention and Control (ECDC) said an investigation is ongoing and any link with an increase from 2013 is not known.

From late September to November 2013, the United Kingdom observed a rise in Salmonella Mikawasima domestic cases with 75 laboratory reports. By the end of November 2013, five other EU member states reported an additional 42 cases in Denmark, Sweden, France, Germany and Spain.

Epidemiological and microbiological investigations at the time did not allow conclusions to be drawn on whether the cases were linked.

From 2007 to 2012, 671 cases were reported from EU and EEA countries to the European Surveillance System (TESSy) with a steady increase since 2009.

Norway reported an outbreak involving 13 people in late 2012 but the source was not found.

An outbreak of Salmonella Mikawasima in October 1992 was associated with nine cases in the South West Thames region of the UK and traced to kebabs.

According to the Centers for Disease Control and Prevention (CDC) in the United States, there have been 22 cases in the 10 years from 2006-2016.

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