Tackling return of wild polio

Recently, the Ministry of Health announced the first case of polio in the past 30 years. How is the world uniting to fight a possible resurgence of the cripling disease?

A case of wild poliovirus type one was reported in a three-year-old girl experiencing paralysis in Lilongwe, Malawi.

This is the first case of wild poliovirus reported in Africa in five years. Following a lengthy surveillance process, the continent was declared free of the disease in 2020.

“The last case of wild polio virus in Africa was identified in northern Nigeria in 2016 and globally there were only five cases in 2021. Any case of wild polio virus is a significant event and we will mobilize all resources to support the country’s response,” Dr Modjirom Ndoutabe, polio coordinator in the World Health Organisation (WHO) Regional Office for Africa told Al Jazeera.

WHO said it is supporting Malawi’s health authorities to carry out a risk assessment and outbreak response, including supplemental immunisation.

Malawi has not reported a case of wild poliovirus since 1992, thanks to a mass campaign to kick out the crippling disease.

Minister of Health Khumbize Kandodo Chiponda said the government is confident of containing the outbreak and has already started taking steps in line with WHO guidelines.

Her statement reads: “The first step is declaring this as a Public Health Emergency. There will be emergency operations committee meetings and a risk assessment of the situation will be done with support from our partners such as the WHO.”

 “We will also work very closely with our neighboring countries, as diseases know no borders … The ministry would like to assure the nation that the situation is under control.”

Imported strain

Wild polio is endemic in only Afghanistan and Pakistan.

Laboratory results showed that the strain found in the child in Malawi is linked to a strain of polio circulating in Sindh Province, Pakistan.

Since the case is imported, the African continent is still considered free of wild poliovirus.

The girl experienced the onset of paralysis last November and samples of her stool were collected.  These samples were sequenced at the National Institute for Communicable Diseases in South Africa in February. The results were then confirmed by the US Centres for Disease Control and Prevention.

President Lazarus Chakwera said he had directed Chaponda to declare a public health emergency because “it is a threat to our country’s status as a polio-free nation”.

Matshidiso Moeti, the WHO’s regional director for Africa, said as long as wild polio exists anywhere in the world, all countries remain at risk of importation of the virus.

 “Following the detection of wild polio in Malawi, we’re taking urgent measures to forestall its potential spread,” she said.

Global fight

Since 1988, worldwide cases of the polio virus have dropped by 99 percent, from more than 350 000 to just five cases in Afghanistan and Pakistan last year, according to the Global Polio Eradication Initiative (GPEI) data.

Billionaire philanthropist Bill Gates, who was on his first visit to Pakistan, said continuing and sustained polio vaccination efforts in the two countries were likely to determine whether the world would be able to completely eradicate the virus.

The polio eradication initiative said it is working with health authorities to begin vaccination efforts in the sub-region to prevent the spread of the virus and ramp up surveillance efforts.

Reads a statement issued by GPEI: “Detection of [wild poliovirus type 1] outside the world’s two remaining endemic countries, Pakistan and Afghanistan, is a serious concern and underscores the importance of prioritising polio immunisation activities.

“Until polio is fully eradicated, all countries remain at risk of importation and must maintain high vaccination coverage to protect all children from polio.”

According to the think tank, the polio eradication programme has seen importations from endemic countries to regions that have been certified wild poliovirus-free in the past “and has moved quickly to successfully stop transmission of the virus in these areas”.

Vaccine-derived strain

Africa was declared free of wild polio in August 2020 and the WHO said that the new case did not affect that status.

Beyond wild poliovirus, the continent still struggles with “circulating vaccine-derived polioviruses,” or cVDPV — a different category of virus that can cause polio.

The vaccine-derived strain is linked to environmental contamination.

If a child is immunised through the oral poliovirus vaccine, remnants of the weakened poliovirus can leave the child’s body through feces, which can enter the surrounding environment.—Devex and The Natio