Polio outbreak paralyzes 17 children in Syria: World Health Organization (WHO)

The file photo shows a child being vaccinated.

The World Health Organization (WHO) says a polio outbreak has paralyzed at least 17 Syrian children since March, calling the situation in the war-torn country "very serious."

"We are very much worried, because if there is one case of polio with a kid that is paralyzed, it is already an outbreak," WHO spokesman Tarim Jasarevic said at a press conference in the Swiss city of Geneva on Tuesday.

He added that for every polio-caused paralysis there are almost 200 children, who has been infected by the virus but exhibit no symptoms. "The virus is circulating. It is very serious," he said.

Less than two weeks ago, the UN agency for the first time announced two cases of polio-caused paralysis among Syrian children. It also said at the time that the Arab country had been hit by its first outbreak of the crippling illness since 2014. Polio mainly affects children under the age of five.

According to Jasarevic, the new cases all appeared between March 3 and May 23, but they were only just confirmed, since the process of determining with certainty that whether a case of acute flaccid paralysis was caused by polio can take up to as long as two months. He also warned that "more confirmations" would be expected.

Jasarevic added that all of the cases but one had been registered in the Mayadin district of the eastern province of Dayr al-Zawr, large part of which is currently under the control of the Takfiri Daesh terrorist group, and a siege of the capital Damascus has restricted access to basic goods, services and medicine for the inhabitants of the province.

One case of polio-caused paralysis surfaced in Raqqah, Daesh's de facto capital in the Middle Eastern country, he said.

According to Jasarevic, the WHO plans to bring in more of the polio vaccine, Oral polio vaccine (OPV), to get immunization levels high enough to ensure they can curb the outbreak. He also said that the agency intended to vaccinate over 400,000 children under five in Dayr al-Zawr.

Syria has been gripped by foreign-backed militancy since March 2011. In August last year, United Nations Special Envoy for Syria Staffan de Mistura estimated that to date over 400,000 people had been killed in the conflict.