LONDON -- Raising a worldwide alarm, the World Health Organization announced Monday that spread of polio is an international public health emergency that could grow in the next few months and unravel the nearly three-decade effort to eradicate the crippling disease.
The agency described current polio outbreaks in Asia, Africa and the Middle East as an "extraordinary event" that required a coordinated international response. It was the first-ever international alert on polio.
"Until it is eradicated, polio will continue to spread internationally, find and paralyze susceptible kids," Dr. Bruce Aylward, who leads WHO's polio efforts, said during a press briefing.
Polio usually strikes children under five and is most often spread via infected water. There is no specific cure, but several vaccines exist.
Experts are particularly concerned that the virus continues to pop up in countries that were 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 the traditionally low season for polio spreading, leaving experts worried that cases could spike in the coming months.
Last week, WHO convened an emergency committee to decide whether the current polio outbreaks -- in at least 10 countries in Asia, the Middle East and Africa -- merit the declaration of an international health emergency.
Monday's decision means numerous measures will be adopted, including requiring people from countries exporting polio cases to have a certificate of polio vaccination before being able to travel internationally. Those measures will be reviewed in three months, WHO said.
At 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 a wider outbreak across the region. The virus has also been identified in the sewage system in Israel, the West Bank and Gaza, although no cases have been spotted.
In February, WHO found that 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 called the situation in Pakistan "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. There is some distrust of polio vaccinations in Pakistan since American forces located Osama bin Laden there using information gained in part under the guise of polio vaccinations.
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 accept that polio may not be eradicated, 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."
But Aylward said WHO and its partners aren't yet considering pushing back their latest deadline -- by 2018 -- to eradicate polio.
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."