MOSCOW, May 7. /TASS/. No cases of hepatitis of unknown origin in children have been identified in Russia so far and the risk of the disease being brought from other countries is tiny, the head of the scientific center for the prevention and control of AIDS at the Central Research Institute of Epidemiology under the consumer rights watchdog Rospotrebnadzor, Vadim Pokrovsky, told the media on Friday.

"In Russia, no cases of hepatitis of unknown etiology in children have been detected so far. The risk the disease may be brought from other countries is small, since contacts with most countries where cases of this infection have been detected are limited," he said.

Pokrovsky stressed that the cause of the disease remained unclear. It may be a result of a combination of several factors, for example, some kind of infection, "which occasionally causes liver damage," and some toxic product, he said. Together they may produce such an unusual effect, Pokrovsky speculated.

"It is not ruled out that the causes of this disease vary from country to country," he said. An epidemiological study will help answer the question about the cause of the hepatitis cases, he stressed.

On May 4, the World Health Organization’s Senior Scientist Philippa Easterbrook said that more than 220 cases of acute hepatitis of unknown origin in children had been exposed. The WHO continues to probe into all infectious and non-infectious causes of the disease, she said.