Is Africa truly free of wild polio?
n August 2020, the World Health Organization (WHO) certified the African region as wild polio-free after four years without a case on the continent. The announcement came after Nigeria, which has long battled challenges such as vaccine hesistance, political instability, ethnic violence and rough terrain with regard to eradication of the disease, became the last African country to be declared wild polio-free. Less than a decade ago, it accounted for more than half of all global cases. The last case of wild polio in Nigeria was reported in 2016.
Polio, or poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person’s spinal cord, causing paralysis. In the early 20th century, polio was one of the most feared diseases in industrialised countries, paralysing hundreds of thousands of children every year. Soon after the introduction of effective vaccines in the 1950s and 1960s, polio was controlled and practically eliminated as a public health problem in those countries.
It took somewhat longer for polio to be recognised as a problem in the developing world. Lameness surveys during the 1970s revealed that the disease was also prevalent in developing countries. As a result, during the 1970s, routine immunisation was introduced worldwide as part of national immunisation programs, helping to control the disease in many developing countries.
Rotary International launched a global effort to immunise the world’s children against polio in 1985. The establishment of the Global Polio Eradication Initiative (GPEI) followed in 1988. These efforts led to a 99% decline in the global incidence of polio. However, social, cultural, religious, and political factors hindered the eradication of wild polio in Nigeria.
The controversy surrounding the safety of the oral polio vaccination in northern Nigeria contributed immensely to the delay that led to continued infectivity of children with the poliovirus. Some of the delays to eradication were attributable to eccentric views upheld by parents who refused vaccination for their children due to religious, traditional, and superstitious beliefs. That is beside the initial vaccine boycott following rumors of contaminants likely to be carcinogenic and general misunderstanding about the possibility of developing polio after vaccination. Additionally, there was a lack of community involvement, information dissemination and disregard for cultural beliefs and norms.
Polio eradication in Nigeria took so long because challenges such as political instability, ethnic violence and rough terrain persist. The Boko Haram insurgency claimed the lives of nine polio vaccinators in high-risk northern Nigeria. The supplementary implementation activities in localised areas continue to be inefficient, while antivaccine sentiments still echo within the communities. Furthermore, children who live in border settlements are known to carry a different strain of poliovirus. That highlights the possibility of cross-border spread. In these hard-to-reach areas, only about 53% of children aged 12 -23 months received three doses of the polio vaccination.
But we must pause to ask: how accurate is the data regarding wild polio in Africa? Four cases of wild poliovirus infection (WPV1) were detected in July 2016 in a remote and security-challenged area of Borno State in northeastern Nigeria. This discovery was made two years after the WHO removed Nigeria from the list of polio-endemic countries and put Nigeria back on the list as having a strain of WPV1 that was in circulation but was undetected since 2011. In 2012, cases appeared in three countries that had reported eradication. The virus strain involved was determined to have been imported from Nigeria.
Also, an initiative created by a coalition between the national polio program and the Nigerian military to reach inaccessible areas named Reaching Every Settlement Initiative was able to provide immunisations to approximately 99.6% of all partially accessible settlements at least once by February 2020. This means that some children are yet to be reached.
Concerning laboratory poliovirus containment, the destruction of all potentially infectious poliovirus substances has taken place in all 47 African countries where cases were present. In 2018 South Africa received an initial ertificate of participation per the Containment Certification Scheme to retain poliovirus infectious materials in their laboratories. Some laboratories opt to retain infectious agents for the purpose of research. The certificate of participation is only awarded to facilities in countries that have demonstrated compliance with the required safeguards for the containment of polioviruses.
Hopefully, there will not be a repeat of the case of Dr Henry Bedson who, in 1978, stored the smallpox virus in his laboratory at the University of Birmingham that led to the death of a medical photographer. Janet Parker, who occupied the darkroom above the laboratory, was infected with the smallpox virus two years after its eradication. This tragedy underscores the dangers of stored viruses due to their inadvertent potential to cause harm.
It is important to remember that polio anywhere is polio everywhere.
Despite interventions with childhood immunisations, sub-Saharan Africa still records over two million deaths from vaccine preventable diseases (VPDs) annually. Nigeria remains a contributor to global childhood deaths. Although significant factors such as child, parental, socioeconomic and political barriers continue to impede immunisation programs, applying the aggressive approach taken on polio to other VPDs will increase access to routine immunisations.
A synergistic strategy is necessary to address the peculiarities of the region, that will assure progress towards the prevention of the mortality and morbidity associated with polio and VPDs. As seen with polio eradication programs, continuous, tenacious and concerted efforts will be needed to ensure the success and efficacy of public health programs.
The opinions expressed in this article are those of the author(s) and do not necessarily reflect the views of SAIIA.
(Main image: UNICEF health consultant Hadiza Waya tries to immunise a child during vaccination campaign against polio at Hotoro-Kudu, Nassarawa district of Kano in northwest Nigeria, on 22 April 2017. The World Health Organization said 116 million children are to receive polio vaccines in 13 countries in west and central Africa as part of efforts to eradicate the disease on the continent. - Pius Utomi Ekpei/AFP via Getty Images)