UNITED NATIONS — The World Health Organization said Tuesday it has confirmed Syria’s first polio outbreak since 1999, putting all of the Middle East at high risk of a revival of the crippling infectious virus.

Twenty-two children in northeastern Deir Ezzour province, near Syria’s border with Iraq, were reported on Oct. 17 to have become paralyzed and traces of the wild polio virus were found in samples taken from 10 victims, WHO spokesman Oliver Rosenbauer told reporters Tuesday in Geneva.

Polio is a scourge that was recorded in ancient Egyptian paintings and carvings, and it paralyzed President Franklin D. Roosevelt. It’s a “communicable disease and with population movements it could travel to other areas,” Rosenbauer said, warning of the high risk of a regional spread. The virus invades the nervous system to cause irreversible paralysis within hours.

More than 4,000 Syrians surge daily into neighboring countries to flee the 2½-year-old civil war, according to the U.N. refugee agency.

The outbreak in Syria adds to recent discoveries of the polio virus in Israeli sewage systems, setting back the World Health Organization’s $5.5 billion initiative to make the world polio-free by 2018.

While global cases of polio had dropped to 223 in 2012 from 350,000 in 1988, they rose this year to 301, according to the United Nations agency’s data. Although Nigeria, Pakistan and Afghanistan remained the only countries where polio is endemic, discovery of the virus in Israel earlier this year raised concerns of a possible spread in the Mideast and Europe.

Most of the 22 children in Syria were younger than 2 years old and weren’t immunized against the disease or lacked the full dosage of vaccine. Immunization rates in Syria dropped to 68 percent in 2012 from 91 percent in 2010, as violence weakened the nation’s infrastructure and health systems, Glenn Thomas, also a WHO spokesman, said in an email.

There’s no cure for polio, and it can be prevented only through immunization. It is transmitted through contaminated food and water and mainly affects children younger than 5 years old. Syria has more than 3 million children in that age group, according to the UN.