Nigeria, 1 of 3 remaining polio-endemic countries including Afghanistan and Pakistan, marked its first year without a case of polio on July 24, 2015. With no cases of polio being reported in a little more than a year in Somalia, the entire continent of Africa marks 1 year with no polio cases being reported (http://bit.ly/1IWLEUf).
Nigeria and the other countries in the World Health Organization’s African region must pass 2 more years without reporting a case of polio to be declared polio-free. To achieve this goal, these African countries need to maintain high-quality surveillance and vaccination efforts. The wild polio virus can persist in infected people who exhibit no symptoms of the disease but who shed virus into the environment through their stools. For this reason, testing of sewage systems can help identify areas where polio might linger so that officials can mount a targeted immunization campaign.
Friedrich MJ. Nigeria May Be Next Country to Eliminate Polio. JAMA. 2015;314(15):1553. doi:10.1001/jama.2015.12546