A nationwide incident has been announced by health officials in England after the poliovirus was discovered in sewage.
Polio is a life-threatening disease caused by the poliovirus that is transmitted from person to person but can also be spread through food and feces.
The virus was identified in London sewage samples between February and May 2022, according to the UK Health Security Agency.
Paralysis can occur in the most severe cases — but for most people who contract it, the symptoms feel flu-like.
According to the World Health Organization (WHO), there are three types of wild poliovirus. Two of these (WPV2 and WPV3) have been eradicated while global efforts to eliminate WPV1 are ongoing.
In 2022, polio will be recorded as a persistent endemic in only two countries: Pakistan and Afghanistan.
However, the recent detection of wild polio outside of endemic countries in Malawi “demonstrates the continued risk of international spread of the disease,” WHO said.
Here are the countries affected by polio outbreaks in 2022:
In June 2022, Pakistan’s wild polio cases surged as eight cases were reported in the North Waziristan district bordering Afghanistan during the month.
Prior to this outbreak, the country had 15 months of quiet on the polio front. The last time a child was paralyzed was in January 2021.
The national eradication program said all of the children confirmed to have polio belong to a region where there are “high rejection rates of finger-tagging without vaccination during campaigns.”
An analysis by the WHO found that continued resistance to polio vaccines by some communities “still poses challenges, including some security issues with reports of attacks on police and soldiers,” increasing the risk of the virus spreading.
So far this year, only one case of wild polio has been detected in Afghanistan, while four cases were recorded in 2021 – up from 56 cases in 2020.
In November 2021, WHO and UNICEF launched a four-day polio immunization campaign in the country, targeting 9.9 million children under the age of five.
Musa Joya (Kabul University of Medical Sciences, Kabul, Afghanistan) tells The Lancet Microbe that children in Afghanistan are vulnerable to contracting and spreading the poliovirus because they do not have access to clean water and toilets equipped with soap and water.
He added that the “traditional, social and economic behaviors of Afghans -[eg,] a large number of people living together, eating together and sharing their food [from] a plate – increases the risk [of polio infection]“.
On January 31, 2022, the virus was detected in the South African country after a child under the age of five was infected.
The Global Polio Eradication Initiative (GPEI) said the case was “genetically linked” to wild polio, which was discovered in Pakistan’s southern province of Sindh in 2019.
Before that, the last clinically confirmed case of polio was reported in Malawi in 1992. This was also the first case of wild poliovirus to be reported on the continent in more than five years.
On August 25, 2020, the African region was certified wild poliovirus free.
The landmark statement was credited to the Kick Polio Out of Africa campaign, launched by Nelson Mandela in 1996 at a time when 75,000 children a year were paralyzed by the virus.
However, the region is still battling another form of polio, circulating vaccine-derived poliovirus (cVDPV).
CVDPV type 2 (cVDPV2) is the most common, with 959 cases worldwide in 2020, threatening polio eradication efforts.
They are a rare, mutant version of the virus – typically found in underimmunized communities with poor sanitation – derived from the live oral polio vaccine (OPV).