The World Health Organization says it believes polio has erupted in war-torn Syria, a dire development in the fight to eradicate the disease.
The Geneva-based agency says a cluster of more than 10 paralysis cases have been detected in Deir Al Zour province in eastern Syria, a contested area of the country.
The WHO's senior official for polio eradication says initial tests indicate polio is the cause, and efforts to address what could be a crisis situation are being geared up.
Dr. Bruce Aylward says the potential exists for a large scale outbreak that will take some time to bring under control.
That's because the collapse of health services during the civil war has meant there are young children in Syria who haven't been vaccinated.
Final confirmation may take a few more days, but Aylward says the WHO is assuming the worst.
"This quacks like a duck, looks like a duck — you've got to plan as though it's a duck," Aylward, the WHO's assistant director-general for polio, emergencies and country collaboration, said from Geneva late Saturday.
"We think that there's a high probability that this is real."
The unwelcome development is the latest setback for the global effort to eradicate polio, already 13 years behind schedule and billions of dollars over original cost estimates.
While polio remains endemic — meaning transmission has never been stopped — in only Pakistan, Afghanistan and Nigeria, several countries this year have seen spread of polio resume as a result of imported viruses. Among them is Somalia, where polio vaccination efforts were abandoned for four years because of conflict in the southern part of the country.
Conflict and disease outbreaks often go hand and hand. In Syria, the job of extinguishing this outbreak will likely be substantial, Aylward acknowledges.
"The potential is ... to have a large scale outbreak with a couple of hundred cases that takes some time to get back under control, very definitely," he says.
"If these cases are confirmed we're going to need six months of almost monthly campaigns to try and shut this down. "