Two people have died in Finland as investigations into a Shiga toxin-producing E. coli (STEC) outbreak continue.

The National Institute for Health and Welfare (THL) has received nine reports of suspected E. coli outbreaks from across Finland from June to August. Seven E. coli O103 outbreaks reported to the agency from municipalities in different parts of the country belong to the same incident.

Updating a previous report, the agency said the start date of the epidemic has been set as the end of July. This is defined based on typing of patient isolates. In THL’s laboratory from July 27 to Aug. 24, there were 57 E. coli O103 cases with the Shiga toxin 1 (stx1) gene recorded. Of these, 40 clustered based on whole genome sequencing (WGS) indicating they could be from the same source.

Women are slightly more affected than men. The median age is 37 years old and the range is 2 to 97 years of age.

Deaths and hospitalizations reported
Two adults were diagnosed with hemolytic uremic syndrome (HUS) and have died. Both were susceptible to infections due to old age or underlying disease. Hemolytic uremic syndrome without a finding of E. coli is not reportable in Finland but mentioning of HUS can be lacking in E. coli notifications. Of the interviewed E. coli O103 patients in 2001 to 2020, none were reported with HUS.

The majority of the 33 people interviewed in the current outbreak mentioned symptoms including diarrhea. More than a third of them have been hospitalized. Most had eaten outside the home before becoming ill.

The Finnish Food Authority (Ruokavirasto) and local food control authorities are tracing potential sources of infection based on information provided in the interviews.

An outbreak notification has also been sent to the European Centre for Disease Prevention and Control (ECDC) to see if other countries have reported related infections.

Since 2016, an average of 200 E. coli infections have been reported to the Infectious Diseases Register in Finland each year. More than half of these come from abroad.

E. coli O103 is one of the more common types of the pathogen found in patients in Finland. It has previously been detected in cattle and raw milk and caused an outbreak in 2014 traced to contaminated water.

About E. coli infections
Anyone who has developed symptoms of E. coli infection should seek medical attention and tell their doctor about their possible exposure to the bacteria. Specific tests are required to diagnose the infections, which can mimic other illnesses.

The symptoms of E. coli infections vary for each person but often include severe stomach cramps and diarrhea, which is often bloody. Some patients may also have a fever. Most patients recover within five to seven days. Others can develop severe or life-threatening symptoms and complications, according to the U.S. Centers for Disease Control and Prevention (CDC).

About 5 to 10 percent of those diagnosed with E. coli infections develop a potentially life-threatening kidney failure complication, known as a hemolytic uremic syndrome (HUS). Symptoms of HUS include fever, abdominal pain, feeling very tired, decreased frequency of urination, small unexplained bruises or bleeding, and pallor.

Many people with HUS recover within a few weeks, but some suffer permanent injuries or death. This condition can occur among people of any age but is most common in children younger than five years old because of their immature immune systems, older adults because of deteriorating immune systems, and people with compromised immune systems such as cancer patients.

People who experience HUS symptoms should immediately seek emergency medical care. People with HUS will likely be hospitalized because the condition can cause other serious and ongoing problems such as hypertension, chronic kidney disease, brain damage, and neurologic problems.

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