(updates paragraph 6)

RIGA, March 31 (LETA) - The Children's Clinical University Hospital in Riga is currently treating 22 children for E.coli infection, the hospital's spokeswoman Ilze Olsteina informed LETA on Monday.

The situation at the hospital remains changeable - while some children sickened by the Shiga toxin producing E. coli (STEC) infection are being admitted to the hospital, some others are being released to continue recovering from the illness at home, said Olsteina.

The hospital's representative noted that the condition of ten hospitalized children is serious, while one child, who has been placed in the intensive care unit (ICU), is gravely ill.

All the hospitalized children are being closely monitored.

Since the start of the E.coli outbreak, four children have been released from the hospital and are recuperating at home.

The CDC has so far recorded 40 cases of E.coli infection, including two cases in adults. The cases E. coli infection have been recorded in Riga, Salaspils Municipality, Adazi Municipality, Dienvidkurzeme Municipality, Ropazi Municipality, Kekava Municipality and Cesis.

As reported, the Centre for Disease Prevention and Control (CDC) in cooperation with the Food and Veterinary Service continues an epidemiological investigation to establish the source of the bacteria. The CDC also works with the affected preschool institutions and family physicians observing children with severe symptoms of intestinal infection.

After inspections at several schools, preschool institutions and youth centers, the Food and Veterinary Service established that all these institutions had received food products or catering services from Zaks-2 company or Garbridis general partnership, which is comprised of Zaks-2 and Deliment. The companies' key owner is Zanna Gajevska.

Zaks-2 technologist Ilona Dreimane told LETA that the company is cooperating with the CDC and the Food and Veterinary Service to detect the cause of the infection and curb its spread.

The CDC explains that all humans and animals have bacteria called Escherichia coli (E. coli), or intestinal bacteria, in their gut. They are part of our normal bacterial flora and are usually harmless. However, there are particular strains of E. coli that can produce toxins or poisonous substances and cause serious illness.

These strains are called STEC/VTEC (Shiga toxin or verotoxin-producing E. coli). They can cause severe, bloody diarrhea, leading in some cases to acute kidney failure, in which case the patients require intensive care.

The main reservoir for these strains is herbivorous animals, especially cattle. The causative agent is excreted from the animal or from the human body in feces. Humans can become infected by eating contaminated food, undercooked beef, uncooked milk, unwashed or unprocessed fruit or vegetables. Transmission from person to person is also possible.

Last year, 42 cases of this infection were reported in Latvia, and 18 cases have been reported so far this year. On average, four to five cases of this infection are reported in Latvia per month, according to the CDC.