More than 30 people are sick in Sweden and several other European countries from a rare strain of Salmonella. Officials will not say what other countries are involved or how many people are sick outside Sweden.

Since the middle of September, 33 Salmonella Mikawasima infections have been linked by whole genome sequencing in Sweden. WGS analysis also allowed a connection to be made with illnesses reported in other EU countries.

The source of infection is not yet known but is believed to be a food product distributed to a number of European countries.

A spokesperson for the European Centre for Disease Prevention and Control (ECDC) would not tell Food Safety News which other countries have reported illnesses and how many people are affected.

“We can confirm there is an ongoing investigation of Salmonella Mikawasima cases in several EU countries, which has been identified through exceedance analysis and whole genome sequencings. ECDC is currently collecting further epidemiological and WGS information from the countries to assess the extent of this event,” according to the ECDC spokesperson.

Those sick in Sweden live across 12 counties. The most recent known date of illness onset is Oct. 24. Patients have been reported in all age groups with a range of 4 to 89 years old. Slightly more women than men have fallen ill.

Rare strain but infections rising
The number of Salmonella Mikawasima cases in Sweden is usually low at one to two per year.

Affected local infection protection units, Livsmedelsverket (Swedish Food Agency) and Folkhälsomyndigheten (Public Health Agency of Sweden) are investigating the outbreak in Sweden to identify the source of infection.

Sweden is also investigating another foodborne outbreak with 25 people sick from Salmonella Newport. Symptom onset dates range from Aug. 16 to Oct. 12 and people aged 1 to 82 years old have been affected.

Last year, about 50 people in five European countries fell ill with the rare strain of Salmonella. It is not yet clear if the incidents are connected.

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

There was also an increase in the number of Salmonella Mikawasima infections in several EU countries in 2013. There has been an upward trend in cases in Europe since 2009.

About Salmonella infections
Food that is contaminated with Salmonella bacteria usually does not look, smell or taste spoiled. Anyone can become sick with a Salmonella infection, but infants, children, seniors and people with weakened immune systems are at higher risk of serious illness because their immune systems are fragile, according to the CDC.

Anyone who has symptoms of Salmonella infection should seek medical attention. Sick people should tell their doctors about the possible exposure to Salmonella bacteria because special tests are necessary to diagnose salmonellosis. Salmonella infection symptoms can mimic other illnesses, frequently leading to misdiagnosis.

Symptoms of Salmonella infection can include diarrhea, abdominal cramps, and fever within 12 to 72 hours after eating contaminated food. Otherwise healthy adults are usually sick for four to seven days. In some cases, however, diarrhea may be so severe that patients need to be hospitalized. 

Older adults, children, pregnant women and people with weakened immune systems, such as cancer patients, are more likely to develop a severe illness and serious, sometimes life-threatening conditions.

It is possible for some people to be infected with the bacteria and to not get sick or show any symptoms, but to still be able to spread the infection to others.

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