Oyewale Tomori, Nigerian Academy of Science In 2012 Nigeria accounted for more than half of all polio cases worldwide. Within three years – and after a rigorous immunisation campaign involving more than 200 000 volunteers – the country was removed from the list of polio-endemic countries. Less than a year later two new cases of polio have been reported. This is a setback for a country that aimed to achieve polio free status by 2017. Professor Oyewale Tomori explains why Nigeria finds itself in this position.Why has there been a new outbreak of polio in Nigeria?Nigeria was removed from the list of polio endemic countries after a long and tortuous eradication campaign.But after attaining non-polio endemic status in September 2015, commitment waned and complacency set in. This was particularly evident at the levels of the national assembly, governors and local government area chairpersons. This complacency meant that polio eradication activities were no longer backed by adequate and timely counterpart funding at the state and local government area levels. This was despite a public and often vocal commitment to polio eradication from Nigeria’s President Muhammadu Buhari.As a result gaps remained in the quality of immunisation and surveillance activities. These were especially prominent in the country’s security compromised areas.The wild poliovirus (type 1) isolates were recovered from residents in Gwoza and Jere local government areas in Borno state in northern Nigeria. Genetic sequencing suggests these isolates are most closely linked to the wild poliovirus type 1 that was last detected in the state in 2011.How far back does this set Nigeria in its progress to eradicate polio?When Nigeria was removed from the list of polio-endemic countries in 2015 it meant this was the first time the country had managed to interrupt transmission of wild poliovirus. It needed to have no new cases of the wild poliovirus reported for three successive years to finally attain a polio free status by 2017.Countries have to go at least 12 months without a case before they can be considered for removal from the list of polio endemic countries. Polio-free status comes after three years without a case.Although Nigeria can no longer be considered a polio endemic country analysis shows that the 2016 isolate is closely linked to a 2011 isolate. This means we were unable to detect the transmission.The current outbreak has set Nigeria back by at least two years – provided that no wild polio virus is detected in the future.What has Boko Haram’s role been?The new polio cases in Nigeria were reported from children in areas of the country rendered inaccessible by Boko Haram insurgency.The insecurity seriously hampered effective routine and special immunisation activities.Many of the children in these areas could not be reached. So, vaccination programmes couldn’t be carried out.In addition, inaccessibility also made it difficult to effectively investigate reports of acute flaccid paralysis cases. Acute flaccid paralysis is weakness in the limbs in children under 15. This signals the onset of paralytic polio, with more serious symptoms such as loss of muscle reflexes, severe muscle pain and spasms and loose or floppy limbs that are often worse on one side of the body.Boko Haram has contributed significantly to the current situation by creating an environment of insecurity in the affected areas.What does Nigeria need to do now?The World Health Organisation has a set of International Health Regulations which guide countries on how to limit the spread of diseases and public health risks. The organisation’s emergency committee has deemed the international spread of poliovirus a public health emergency of international concern.Nigeria complied with the temporary recommendations issued under the regulations. This involved declaring the outbreak a national public health emergency.The Federal Minister of Health and stakeholders drew up an emergency plan. Three rounds of special immunisation campaigns were carried out in the affected and surrounding areas. This was a bid to ensure that the situation was contained.But the current security situation will adversely affect the implementation of the plan. The Ministry of Health will need to work closely with the country’s armed forces to ensure easy access and protection of health workers.I believe the situation is serious enough for the Presidential Task Force on Polio Eradication to be convened urgently. It must agree on the positive commitment and active involvement of national assembly members, state governors and local government area chairpersons. It must also maintain the essential support of traditional and religious leaders, women’s organisations and community leaders. These groups all have a role to play in making Nigeria a polio free country.Nigeria must focus on attaining polio free status over the next three years and concentrate less on prematurely celebrating victory.Nigeria was eagerly looking forward to 2017 as the year it would attain polio free status. The clock has now been set to 2019.Oyewale Tomori, President, Nigerian Academy of ScienceThis article was originally published on The Conversation. Read the original article.