Polio Outbreaks - Article

[Guest guest]

Nevermind the earlier post - found it... Here comes the next Polio Drive

initiative...

http://www.iht.com/articles/ap/2008/04/21/africa/AF-MED-Nigeria-Polio-Problems.p\

hp

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, are usually stamped out within months.

But in Nigeria, the outbreak caused by the vaccine has been ongoing since

2005. Low immunization rates, a weak health system and vaccine rumors have

fueled a worrying spike in the numbers of paralyzed children.

Some experts worry 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 year, there have been 106 recorded cases so far, according to new figures

released by the World Health Organization 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 paralyzed by a

mutated virus from the oral polio vaccine, health officials have had to use

three different vaccines to control the viruses.

The vaccine-sparked outbreak has struck more than 100 children so far,

including eight this year. For every paralyzed child, there are about 1,000

others infected and spreading the highly infectious and sometimes fatal disease.

Such outbreaks only happen when immunization rates are low.

The oral polio vaccine contains a weakened virus. In rare instances, as the

virus passes through children who have not been immunized, it changes into a

form dangerous enough to ignite new outbreaks.

An injectable polio vaccine is used in the West that does not cause outbreaks,

but it is 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 requires more vaccine.

Nearly all of the children paralyzed by polio are 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

immunization campaign was part of a U.S.-led plot to render Nigerian Muslims

infertile or infect them with AIDS.

While Nigerian authorities formally reversed the vaccine boycott, the health

system remains weak and there are lingering fears that the vaccine is a Western

plot to sterilize Muslims.

Up to 30 percent of children in the north have never had a single dose of

polio vaccine, according to WHO.

When doctors attempt to eradicate a disease, more than 90 percent of a

population must be immunized, and about four doses of polio vaccine are needed

in Nigeria for children to be protected.

" Our main problem is operational, " Aylward said. " Most kids just lie beyond

the reach of the Health Ministry. "

Aylward said that vaccine-sparked outbreaks are much easier to contain than

those caused by wild viruses. Similar outbreaks have happened elsewhere,

including China, Indonesia and Madagascar. In Egypt, a vaccine-caused outbreak

lasted about a decade.

In a report to be submitted to the World Health Assembly in May, WHO's ruling

body, the agency states that the annual risk of a vaccine-caused outbreak ranges

from 60 to 95 percent as long as the world continues to use the oral vaccine.

Some experts wonder if the world's reliance on the oral vaccine may ultimately

produce more problems as the globe edges toward eradication of polio.

" It is a worry because we've seen these outbreaks happen in a number of

countries, " said Olen Kew, a polio virologist at the U.S. Centers for Disease

Control and Prevention. " But we are aware of the risks and trying to deal with

the difficulties. "

Countries with little or no polio may also take a medical gamble by deciding

to spend their money elsewhere.

" As countries slip back on their polio vaccination, they become ripe for

outbreaks, " said Dr. Neal Halsey, a polio and vaccine safety expert at the s

Hopkins Bloomberg School of Public Health.

Halsey and others think using the injectable vaccine, in addition to the oral

vaccine, might solve the problem. WHO has acknowledged that countries must stop

using the oral vaccine as soon as possible because of its risks (the vaccine

also causes about 250 to 500 cases of polio a year), but says more research is

needed.

In the meantime, officials say that the large numbers of unvaccinated children

in Nigeria make the entire world vulnerable to polio. While much progress has

been made in the other three countries where polio is endemic — Afghanistan,

Pakistan, and India — the surge in cases in Nigeria could undo all of that.

" The outbreak in Nigeria is a shared global problem, " Aylward said. " Until it

is stopped in Nigeria, we are all at risk. "