The World Health Organization, WHO, announced a polio epidemic in Mozambique on Wednesday after the virus was discovered in a child living in the northeastern Tete district, the country’s first case in nearly three decades.
The case, which follows an epidemic in Malawi in February, is the second imported case of wild poliovirus in southern Africa this year, according to the WHO. It was discovered in a child who began exhibiting paralysis near the end of March.
“The detection of another case of wild poliovirus in Africa is greatly concerning. It shows how dangerous this virus is and how quickly it can spread,” Matshidiso Moeti, the WHO’s regional director for Africa, said in a statement.
Polio infects the nerve system and can induce paralysis that is permanent within hours. It cannot be cured, but vaccination can prevent infection, and extensive national and regional immunization campaigns in newborns and children have resulted in a remarkable decline in cases worldwide in recent decades.
The WHO is backing large-scale vaccines aimed at millions of children in southern Africa in order to limit the virus’s spread on the continent, which was proclaimed free of indigenous wild polio in 2020 after eliminating all types of the virus in Africa.
The newly confirmed case, according to genomic sequencing, is connected to a strain that first circulated in Pakistan in 2019, identical to the one identified in Malawi this year.
Polioviruses can resurface and spread quickly in unprotected populations. Vaccine-derived polio can also occur in areas with low immunity and inadequate sanitation, because vaccinated people can excrete the virus, putting the unvaccinated at risk.
Polio has been around since ancient times. If someone had polio as a child or young adult but had kept or recovered some or all movement of weakened arms or legs, even to the point of being athletic afterward, they can risk becoming weaker in late adulthood. That is post-polio syndrome (PPS), a condition that can affect polio survivors decades after they recover from their initial poliovirus infection. Some PPS patients become wheelchair-bound when they had not been before.