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 COVID19. 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.