While the world’s eyes and headlines are focused on the comparatively recent COVID-19 disease, news of spread in Africa of polio tends, tends to be buried. However, as the excerpted article from the Sudanese website Dabanga explains, nine cases of polio have been detected in Sudan. And it is not just Sudan experiencing polio outbreaks. So far this year there have been 133 cases in 14 African countries.

When there is news from Africa this year regarding polio, it is often declaring the eradication of the disease on the continent. This seeming contradiction—the eradication of a disease that is still spreading—can be explained by examining the virus that causes the paralyzing disease and the vaccine against it in more depth. The polio that was eradicated from Africa was caused by the “wild type” virus, meaning it was naturally occurring. Actually there are three “wild types” of poliovirus—called serotypes 1, 2, and 3—and it is these that have purportedly been successfully eliminated from Africa, mostly through the use of vaccination.

Many of the vaccines used contain a weakened version of one or more of the serotypes. Unfortunately, on rare occasions a weakened form can revert back to one that can paralyze. That reverted form, which is called a vaccine-derived poliovirus, can spread to other individuals who were not vaccinated. Those 133 cases in Africa this year are from vaccine-derived poliovirus type 2.

The worldwide campaign to totally eradicate polio has suffered several setbacks, including the inability to vaccinate in regions held by terrorists. In 2020, as described in this and other articles, an additional problem has arisen in the form of COVID-19, which has diverted public health resources from combating polio. As the article emphasizes, if preventive immunization campaigns are not restarted soon, the result could be bleak, with the possibility of significantly more cases occurring in Sudan and other African countries, and health care systems already struggling with COVID-19 straining even more under the additional pressure.

Across the African continent, 133 type 2 [polio] cases in 14 countries have been reported in 2020, significantly higher than 47 this time last year.

Source: “Nine new polio cases confirmed by Sudan MoH,” Dabanga (Sudan), 14 August 2020. https://www.dabangasudan.org/en/all-news/article/nine-new-polio-cases-confirmed-by-sudan-moh

Ethiopia, Chad, and the Central African Republic have reported vaccine-derived poliovirus type 2 (cVDPV2) cases this year. Chad has reported 62 cVDPV2 cases in 2020. Across the African continent, 133 type 2 cases in 14 countries have been reported in 2020, significantly higher than 47 this time last year.

Polio cases are surging in many countries, and models paint a “pretty bleak picture” if campaigns don’t restart soon, said Michel Zaffran, Director of the Polio Eradication Programme at the World Health Organization, last month: “For now, countries will only be responding to outbreaks; preventive campaigns remain on hold.”

In “urgent” recommendations in late May, the Global Polio Eradication Initiative said it expected circulation of polioviruses “to increase exponentially during the upcoming high season,” raising the possibility of “uncontrolled multi-country outbreaks.”

Hits: 0