At least three children have developed kidney failure after being diagnosed with E. coli infections that are linked to eating ice cream from a farm.

A cluster of infections due to Shiga toxin producing E. coli (STEC) O26:H11 has been traced to the tourist attraction Efstidalur II farm in Blaskogabyggd in the south of Iceland.

The 17 ill children are aged between 14 months to 12 years old. At least three of them developed hemolytic uremic syndrome (HUS), a severe condition associated with E. coli infections that causes kidney failure.

Around one third of employees at the farm have also been investigated but none tested positive for the bacterium.

It was initially suspected that children who fell ill after visiting the farm were infected because of contact with calves but further investigation found some children had no contact with this animal while nine had eaten ice cream and the tenth child was infected by a sibling.

Product testing of ice cream did not find the outbreak strain but samples were not the same as what the children had eaten as new product was being sold. An investigation found the E. coli strain that infected the children was also detected in feces from calves.

Officials from the Directorate of Health urged anyone who had visited the farm between June 10 and July 4,  and developed diarrhea within 10 days, to contact a doctor to be tested for the bacterium.

“After contact with animals, before eating or preparing food and especially after caring for individuals with diarrhea, hand-washing with soap and water is strongly recommended. Alcohol-based hand-sanitizer is an optional addition but may not be sufficient on its own against many causes of diarrhea,” added the agency.

The Icelandic Food and Veterinary Authority (Matvælastofnun) recently detected STEC in 30 percent of lamb samples and 11.5 percent of beef samples it tested.

Of 148 samples of Icelandic sheep meat, 44 samples were positive for STEC and in the 148 samples of domestic and foreign beef 17 samples were contaminated.

Symptoms of infections caused by STEC include abdominal cramps and diarrhea. The incubation period can range from three to eight days and many people recover within 10 days.