The spread of polio is an international public health emergency that could grow in coming months and ultimately unravel the nearly three-decade effort to eradicate the crippling disease, the World Health Organization said Monday.
The agency described the ongoing polio outbreaks in Asia, Africa and the Middle East as an "extraordinary event" requiring a coordinated international response.
"Until it is eradicated, polio will continue to spread internationally, find and paralyze susceptible kids," said Dr. Bruce Aylward, who leads WHO's polio efforts, during a press briefing.
Polio usually strikes children under five and is most often spread via infected water. There is no specific treatment or cure, but several vaccines exist.
Experts are particularly concerned the virus continues to pop up in countries previously free of the disease, such as Syria, Somalia and Iraq - where civil war or unrest complicates efforts to contain the virus. That spread has happened during what has traditionally been the low season of polio spread, leaving experts worried that cases could spike even further in the coming months.
Last week, WHO convened an emergency committee to decide whether the ongoing polio outbreaks - in at least 10 countries in Asia, the Middle East and Africa - merit the declaration of an international health emergency.
Declaring polio to be an international public health emergency means numerous measures will be adopted, including requiring people from countries currently exporting cases to have a certificate of polio vaccination before being able to travel internationally. Those measures will be reviewed in three months, WHO said.
As of the end of April, there were 68 confirmed polio cases, compared with just 24 at the same time last year. In 2013, polio reappeared in Syria, sparking fears the civil unrest there could ignite wider outbreaks across the region; the virus has also been identified in the sewage system in Israel, the West Bank and Gaza though no cases have been spotted.
In February, WHO found polio had also returned to Iraq. It is already circulating in eight other countries: Pakistan, Nigeria, Ethiopia, Afghanistan, Equatorial Guinea, Cameroon, Somalia and Kenya.
An independent monitoring board set up by WHO to assess progress in eradicating polio has described the problems as "unprecedented" and said the situation in Pakistan was "a powder keg." Dozens of Pakistani polio workers have been killed in the last two years and the vast majority of new cases are in Pakistan.
Officials also worry countries torn by conflict, such as Ukraine, Sudan and the Central African Republic, are rife for polio reinfection.
Some critics say it may even be time to pull the plug on polio eradication, since the deadline to wipe out the disease has already been missed several times. The ongoing effort costs about $1 billion a year.
"For the past two years, problems have steadily, and now rapidly mounted," said Dr. Donald A. Henderson, in an email. Henderson led WHO's initiative to get rid of smallpox, the only disease ever to have been eradicated. "It is becoming apparent that there are too many problems (for the polio eradication effort) to overcome, however many resources are assigned."
Aylward said WHO and its partners aren't yet considering pushing back their latest deadline to eradicate polio - by 2018.
Still, the independent board monitoring the progress being made on polio is not so convinced and has called for the program to be completely overhauled.
"Few involved in (polio eradication) can give a clear account of how decisions are made," concluded a recent report by the group. "If a billion-dollar global business missed its major goal several times, it would be inconceivable that it would not revisit and revise its organizational and decision-making structure."