Polio cases double in Nigeria
2008-04-21 13:27
London - Polio cases in Nigeria have nearly doubled this year as officials struggle to fight various natural strains of the virus and those unleashed by the vaccine itself.
Outbreaks linked to the vaccine, as opposed to the "wild", or naturally occurring, polio virus, were usually stamped out within months.
But in Nigeria, the outbreak caused by the vaccine had been ongoing since 2005. Low immunisation rates, a weak health system and vaccine rumours had fuelled a worrying spike in the numbers of paralysed children.
Some experts worry that the sudden jump in polio cases could complicate eradication efforts. Last year at this time, Nigeria had 54 reported cases caused by wild polio virus.
'This is a huge step backwards'
This year, there had been 106 recorded cases so far, according to new figures released by the World Health Organisation and its partners last week.
"This is a huge step backwards," said Oyewale Tomori, a polio expert at Redeemer's University in Nigeria. He said the last time the country had every type of polio was in 1999 and described the current situation as "hugely traumatic".
Since acknowledging last year that some Nigerian children were paralysed by a mutated virus from the oral polio vaccine, health officials had had to use three different vaccines to control the viruses.
The vaccine-sparked outbreak had struck more than 100 children so far, including eight this year. For every paralysed child, there were about 1 000 others infected and spreading the highly infectious and sometimes fatal disease. Such outbreaks only happen when immunisation rates are low.
Immunisation campaign
The oral polio vaccine contained a weakened virus. In rare instances, as the virus passes through children who had not been immunised, it changed into a form dangerous enough to ignite new outbreaks.
An injectable polio vaccine was used in the West that did not cause outbreaks, but it was more expensive and must be given by a doctor or nurse.
"There are just way too many kids in Nigeria who haven't been vaccinated and that's allowing the virus to spread," said Dr Bruce Aylward, director of WHO's polio department.
Ending the country's parallel polio outbreaks simply required more vaccine. Nearly all of the children paralysed by polio were in northern Nigeria, where a yearlong boycott of the vaccine in 2003 triggered an explosion of the disease, which was exported to more than two dozen countries worldwide.
Hard-line Nigerian Islamic clerics called for the boycott, claiming that an immunisation campaign was part of a United States-led plot to render Nigerian Muslims infertile or infect them with Aids.
While Nigerian authorities formally reversed the vaccine boycott, the health system remained weak and there were lingering fears that the vaccine was a Western plot to sterilise Muslims.
Up to 30% of children in the north had never had a single dose of polio vaccine, according to WHO.
- AP