It called outbreaks “an extraordinary event” requiring an “international response, and recommended citizens of affected countries, notably Pakistan, Syria and Cameroon, with the greatest risk of exporting the poliovirus, to carry a vaccination certification.
Afghanistan, Equatorial Guinea, Ethiopia, Iraq and Israel were also mentioned as “posing an ongoing risk” for spreading the virus. The only other time WHO made a similar declaration was in regard to an international swine flu pandemic in 2009.
“The conditions for a public health emergency have been met,” said Bruce Aylward, WHO Assistant Director General.
Polio typically affects children under five. The virus is transmitted through contaminated food and water, and can cause paralysis and death.
The virus is currently prevalent in only three countries – Pakistan, Afghanistan and Nigeria, but opposition to vaccination campaigns, particularly in Pakistan, have allowed it to spread to other countries. Syria, free of polio for 14 years, had the virus re-introduced from Pakistan.