At least four European countries have been affected by a Salmonella outbreak with investigators as yet unable to determine the source.

Thirteen people have fallen ill in Iceland, eight in Denmark, one in Sweden and an unknown number of people were also ill in the Netherlands and Belgium. The European Centre for Disease Prevention and Control (ECDC) was informed about the outbreak by national authorities.

In September in Iceland, there was an increase in reports of Salmonella infections. Further investigations found they were the same type of Salmonella typhimurium. Samples were sent to Statens Serum Institute (SSI) in Denmark for sequencing.

Situation in Iceland
Overall, 13 individuals were diagnosed with this type of Salmonella infection, including seven women and six men. The average age was 55 and the range was 21 to 72 years old, according to Iceland’s Directorate of Health.

onset of symptoms was from Aug. 4 to Sept. 2, but most became ill from Aug. 27 leading officials to believe that the outbreak has ended. These individuals lived across the country but mainly in the south-west of Iceland.

Telephone interviews were conducted with those infected and they were asked about risk factors and food consumption in the days before illness. However, the infection has not yet been traced to a specific food.

In September and October, three other people were diagnosed with Salmonella typhimurium in Iceland but sequencing revealed it was a different type than the outbreak strain. A sequencing device has also been bought making it possible to sequence microorganisms in the country in the future instead of sending samples abroad.

Icelandic cases are closely related to Salmonella typhimurium infections in the Netherlands, which were reported to the ECDC in September.

Several other countries have also recorded infections with the same strain, including Denmark and Belgium, but it is not known how many people are sick in total.

Denmark registered eight cases with sample dates from Aug. 27 to Oct. 5. The cases are from several regions in the country. Five are female and three are male in the age range from 20 to 76 years old. The investigation did not reveal any hypothesis to the source of infection.

Sweden has one case related to the outbreak. The patient is a 4-year-old girl with onset of disease in mid-September and no international travel history.

about Salmonella
Food contaminated with Salmonella bacteria does not usually look, smell, or taste spoiled. Anyone can become sick with a Salmonella infection. 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 developed symptoms of Salmonella food poisoning 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 require hospitalization.

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. Some people get infected without getting sick or showing any symptoms. However, they may still spread the infections to others.