The World Health Organisation says cases of vaccine-derived poliovirus have been detected in Burundi and the Democratic Republic of Congo.
Vaccine-derived poliovirus found in Burundi, DR Congo
Health officials in Burundi and the Democratic Republic of Congo have detected cases of vaccine-derived poliovirus, the World Health Organisation and Global Polio Eradication Initiative say.
The WHO said the Burundian government had declared the detection of the virus a public health emergency after cases were confirmed in an unvaccinated four-year-old boy in Isale district in western Burundi and two other children who were his contacts.
Five other samples from environmental surveillance of waste water confirmed the presence of circulating poliovirus type 2 in Burundi, the WHO added in a statement.
Circulating poliovirus type 2 is different to wild poliovirus, with infections occurring when a weakened strain of poliovirus contained in the oral polio vaccine circulates among under-immunised populations for long periods.