Britain issued a travel warning to Israel and the West Bank after traces of the polio virus were found in sewage both in Israeli and Palestinian Authority areas earlier this summer. Britain’s National Health Service recommended that those traveling to Israel should make sure they have been vaccinated against the virus sometime in the past 10 years.

Health authorities believe the potentially deadly, paralysis-inducing virus first arrived in Israel in February, crossing the border from Egypt to the southern Bedouin city of Rahat. It was first detected in Rahat’s sewage in late May, and since then has spread to much of the rest of the country.

In August, the Israeli Health Ministry launched a nationwide vaccination campaign among Israeli children that has seen over 242,000 inoculated. There have been no reported incidents of the paralytic disease caused by the virus.

The travel warning, issued by the British National Travel Health Network and Centre, reminds “UK residents to make sure they are up-to-date with routine immunizations,” adding that those traveling to the area “should also make sure they have had a polio containing vaccine in the past 10 years.” The warning concludes by affirming that “the Israeli health authorities are monitoring the situation closely.”

Britain’s travel warning echoes a similar announcement issued by the World Health Organization in July, which warned of a medium to high likelihood of the virus spreading from Israel overseas, and cautioned those traveling to Israel to make sure they were properly vaccinated before visiting the country.

Times of Israel staff contributed to this report.