On July 28 2023, two separate news alerts reported disease outbreaks due to circulating vaccine-derived poliovirus type 2 (cVDPV2) in the United Republic of Tanzania and Kenya.
In Tanzania, the Ministry of Health reported the detection of cVDPV2 on July 4, 2023. The virus was found in a patient with acute flaccid paralysis (AFP) in the Rukwa region, in the southwestern part of the country, near Lake Tanganyika and the Zambian border. Genetic analysis indicated a close link with the cVDPV2 strain circulating in South Kivu, Democratic Republic of the Congo (DRC).
Experts are currently conducting field investigations to strengthen AFP surveillance and identify potential areas with populations with a low immunisation profile. The overall risk at the national level is considered high due to sub-optimal surveillance performance and low vaccination coverage, compounded by population movements across neighbouring countries.
In Kenya, on July 11, 2023, the World Health Organization (WHO) received an official report regarding cVDPV2 detection in two AFP cases and two asymptomatic children from Hagadera refugee camp. This camp is one of the largest in the world with over 100,000 refugees. Genetic sequencing revealed a genetic linkage to the cVDPV2 circulating in Banadir, Somalia.
The overall risk at the national level in Kenya is also being described as high due to the crowded living conditions in the refugee camp, high rates of malnutrition, and inadequate water and sanitation facilities, as well as frequent population movements with Somalia.
Efforts to control and contain the spread of cVDPV2 in both countries are ongoing.