The World Health Organisation (WHO) on 5 May 2014 declared outbreak of polio as a World Health Emergency after detecting new cases of polio across borders from countries like Syria and Pakistan.
WHO recommended citizens of affected countries travelling abroad to carry a vaccination certificate.
As per the WHO, the virus is considered endemic in only three countries: Afghanistan, Nigeria and Pakistan.
Although, WHO has also listed Equatorial Guinea, Ethiopia, Iraq, Israel and Somalia as countries among posing an ongoing risk for new wild poliovirus exportations in 2014.
As per WHO, Syria which was polio-free for 14 years was re-infected with the virus from Pakistan.
It is only the second time in the WHO's history it has made such a declaration, the first being during the swine flu pandemic of 2009.
WHO recorded 417 cases of polio worldwide in 2013, while till April 2014, it had already recorded 68 cases. Between January 2014 and April 2014, three new importations of the virus were detected, from Pakistan to Afghanistan, Syria to Iraq and Cameroon to Equatorial Guinea.
Polio is a crippling and potentially fatal viral disease that mainly affects children under the age of five.
The virus is transmitted through contaminated food and water, and multiplies in the intestine. It can then invade the nervous system, causing paralysis in one in every 200 infections. It is capable of causing death within hours.
Where: Across the world
When: 5 May 2014