There’s reason for both optimism and deep concern on World Polio Day, 24 October: global polio numbers have fallen over decades, but new outbreaks continue to fester, raising questions about eradication efforts in countries where humanitarian access is a problem.
First, the good news: a global commission announced today that one of three strains of the wild poliovirus has been eradicated. The type 3 strain was last spotted in Nigeria in 2012. It’s part of a decades long drop in polio worldwide, from some 350,000 cases of wild poliovirus in 1988 to double digit figures of the remaining type 1 wild poliovirus today.
The bad news: there has been a recent surge in polio, fuelled by dozens of cases of wild poliovirus in Pakistan and Afghanistan. There are also unexpected new outbreaks of vaccine derived strains rare mutations that affect under immunised populations in at least 14 other countries this year. Some of these hadn’t seen polio for years, including Ghana and the Philippines, which both announced outbreaks in September. And, in some cases, vaccine derived polio strains have leapt across borders from Nigeria to its neighbours and from Somalia to Ethiopia.
The risk of new outbreaks in new countries is considered extremely high, even probable, a World Health Organisation committee on polio said this month.
While public health messaging has often brimmed with optimism that polio is on the brink of defeat, there are worries among health experts behind the scenes. In its biannual meetings in October, the WHO’s expert advisory group on vaccines and immunisation said it had serious concerns about the overall state of eradication efforts, citing an inability to control outbreaks in Africa and Asia.
Source: The New Humanitarian