The spread of polio across international borders has become a global public health emergency, the World Health Organization said Monday.
The agency called for three countries, Pakistan, Cameroon, and Syria, to take measures to stop the international spread of the virus. WHO said it's especially important that residents and longtime visitors to those countries be vaccinated for polio before traveling and that they carry proof of vaccination.
The alert comes amid recent reports that polio has spread from Pakistan to Afghanistan, from Cameroon to Equatorial Guinea and from Syria to Iraq.
"If unchecked, this situation could result in failure to eradicate globally one of the world's most serious vaccine preventable diseases," WHO said in a statement.
Ten countries have polio within their borders and all should step up efforts to contain and control outbreaks, WHO says. The affected countries include Ethiopia, Somalia, Nigeria and Israel – though the virus has only been found in sewage and stool samples in Israel, according to a previous WHO report.
WHO reported 413 cases of polio worldwide in 2013. The disease was once thought nearly eradicated. The recent re-emergence has been linked to thwarted vaccination campaigns in conflict zones such as Pakistan and Syria.
The USA has been polio-free since 1979, according to the Centers for Disease Control and Prevention. But vaccination remains crucial and travelers to countries with polio outbreaks may need booster doses, the agency says.