Making history: from a public health emergency to a polio-free world.

declared the second-ever public health emergency of international concern. Polio is the emergency – a disease again posing a public health risk to countries around the world and requiring a coordinated international response. 1 For some, this declaration seemed a paradox. Polio is nearly eradicated. The virus that once paralysed over 1000 children a day in more than 125 countries paralysed just over one child a day in eight countries in 2013. Two of the three countries that have never stopped polio – Afghanistan and Nige-ria – overcame tremendous difficulties to achieve a greater than 50% reduction in cases in 2013 and have kept their case counts in the single digits so far in 2014. 2 On 27 March 2014, India and the entire WHO South East Asia Region were certified polio-free , bringing to 80% the proportion of the world's population that now lives in regions entirely free of indigenous wild polioviruses. It is also increasingly likely that two of the three strains of wild poliovirus have been wiped out. Type 2 virus was last detected in India in 1999 and the type 3 virus has not been detected anywhere in the world since a child in Nigeria was paralysed by the virus in November 2012. Overall, the world remains largely on track to achieve all four of the ambitious objectives set out in the Polio eradication and endgame strategic plan 3 – the Global Polio Eradication Initiative's strategy to end all polio, everywhere, by 2018. However, this progress could still be undone. Although closer than ever to eradication in 2012, polio made a disturbing comeback in 2013. Both the number of children paralysed by the virus and the number of polio-infected countries nearly doubled. 2 Much of the increase in cases was the result of the international spread of the virus into areas that had long been polio-free. In the first four months of 2014, during what is traditionally the low season for polio transmission, wild poliovirus had already spread internationally in three major epidemiologic zones, thousands of kilometres apart. In Central Asia, the virus spread from Pakistan to Afghanistan; in the Middle East, from the Syrian Arab Republic to Iraq; 5 and in Central Africa, from Cameroon to Equatorial Guinea. The Emergency Committee convened by WHO under the International Health Regulations concluded that, if left unchecked, this situation could result " in failure to eradicate globally one …