LONDON (AP) — Burundi health officials have declared a vaccine-linked polio outbreak, the first time the paralytic disease has been detected in the East African country in more than three decades.
Polio was diagnosed in an unvaccinated four-year-old boy in the western part of the country and two other children who were contacts of the child, Burundi authorities confirmed in a statement on Friday. Officials also found traces of the virus in sewage samples, confirming polio was circulating.
The virus that made the children sick was found to be a mutated strain of polio that initially came from an oral vaccine.
The government of Burundi has declared the polio outbreak a national public health emergency and plans to launch an immunization campaign within weeks, aimed at protecting all children up to the age of seven.
“We are supporting national efforts to increase polio vaccination to ensure that no child is lost and faces the debilitating impact of polio,” said Dr. Matshidiso Moeti, WHO director for Africa.
The outbreak is another setback for the global polio eradication effort spearheaded by the World Health Organization and its partners, which began in 1988 and initially aimed to eradicate the disease within a dozen years.
Polio is a highly infectious disease that is spread primarily through water and typically affects children under five years of age. There is no treatment. While the oral vaccine used in the global effort to eradicate the disease is highly effective, it requires four doses.
The oral vaccine can also cause polio in about 2-4 children per 2 million doses. In extremely rare cases, the weakened virus can also sometimes mutate into a more dangerous form and trigger outbreaks, especially in places with poor sanitation and low levels of vaccination.
In recent years, the oral polio vaccine has caused many more cases of polio than the wild polio virus. Last year, cases linked to the oral vaccine occurred in wealthy countries including Britain, Israel and the United States for the first time in years.
Officials began rolling out a new oral polio vaccine last year that they hoped would be less likely to mutate into a version capable of triggering new outbreaks. But the outbreak in Burundi – as well as six cases in Congo – was found to have been triggered by the new oral vaccine.
Across Africa, more than 400 cases of polio last year were linked to the oral vaccine, including Congo, Nigeria, Ethiopia and Zambia.
The disease also remains stubbornly entrenched in Pakistan and Afghanistan, where transmission has never been interrupted.