Polio outbreaks in Cameroon following the COVID-19 pandemic

Abstract

Polio is an infectious and disabling life-threatening disease caused by the poliovirus. This disease is prevented through vaccination. Though this viral infection has been eliminated in most parts of the world, a few countries are still endemic to wild poliovirus. In 2020, the World Health Organization (WHO) African Region, including Cameroon, was certified free of wild poliovirus. Some countries recurrently report circulating vaccine-derived poliovirus cases (cVDPV) despite recorded achievements. Also, the risk of importing poliovirus from endemic settings remains, particularly in the context of coronavirus disease (COVID-19). This study aimed to assess the state of polio in Cameroon and identify the situation during COVID-19. A data review was conducted from February to March 2023. Data on polio cases and vaccination coverage per region of Cameroon were reviewed from 2014 to 2022. Data were analyzed with Microsoft Excel, and the results were presented as proportions. The last wild poliovirus was reported in Cameroon in 2014, and the country benefitted from a response. No case of poliovirus was detected in the country from 2015 to 2018. After that, an increasing number of type two cVDPV were reported across 50% of the country's regions from 2019 to 2022. The outbreaks benefitted from responses with various oral polio vaccines, including the type two novel oral polio vaccine (nOPV-2). Though wild polioviruses have been eliminated in most countries, including Cameroon, cVDPV remains a significant problem. There is an urgent need to strengthen disease surveillance and vaccination to prevent cVDPV-2 in this country, particularly in the COVID-19 context.