Why is the WHO declaring a polio global health emergency?

Child given an oral vaccine

Briefing: Crippling disease is making a comeback – and the World Health Organisation wants money to wipe it out for good

LAST UPDATED AT 11:20 ON Thu 24 May 2012

AS THE World Health Assembly convenes this week in Geneva, one item high on the agenda will be polio – and the World Health Organisation is expected to declare a global health emergency for the disease.

The offensive to wipe out polio began over 50 years ago, as ambitious an undertaking as the campaign to eradicate another health menace, smallpox. The WHO certified the eradication of smallpox in 1979 - one of only two infectious diseases to have been eradicated by humans, the other being rinderpest, a cattle disease, which was successfully wiped out in 2011.

So why now, after over 60 years of vaccination programmes, is the WHO declaring a global health warning for polio?

WHAT IS POLIO?
Poliomyelitis, often called polio or infantile paralysis, is an acute viral disease which spreads when a person eats or drinks food or water contaminated with infected faecal matter. Ninety per cent of polio infections cause no symptoms at all if the virus enters the blood stream. However, in the central nervous system, the virus destroys motor neurons, leading to muscle weakness and flaccid paralysis.

IS THERE AN EFFECTIVE VACCINE FOR THE DISEASE?
Yes. Following huge epidemics of the disease between 1910 and 1945 two vaccines were developed, one by Jonas Salk and the other by Albert Sabin. In 1955 an injected vaccine was launched and this was followed in 1962 by an oral vaccine.

HOW DO THE VACCINES WORK?
Polio vaccines are extremely effective because they interrupt the person-to-person transmission of the disease. As the polio virus cannot survive in the external environment for any extended period of time, vaccination means the virus has nowhere to thrive, and it dies.

HAS GLOBAL VACCINATION BEEN EFFECTIVE?
Highly effective. In the past fifty years vaccination programmes have eliminated polio from most of the countries in the world and reduced worldwide incidence of the disease from an estimated 350,000 cases in 1988 to just 1,652 cases in 2007.

WHERE DOES POLIO STILL EXIST?
The disease is now found in only three countries: Pakistan, Afghanistan and Nigeria. However, The Daily Telegraph reports that 2011 saw a surge of the disease in these countries, with 650 reported cases. In March this year the WHO warned of a potential health emergency in Pakistan because health teams failed to reach areas where outbreaks of polio had been reported.

WHY IS THE WHO DECLARING A POLIO EMERGENCY?
Sona Bari, spokesperson on polio for the WHO, says the world faces a "now or never" moment. "We are so close to totally eradicating the disease but we really are at a tipping point between success and failure," she says.

WHAT IS THIS 'TIPPING POINT'?
Failing to stamp out polio in the next few years could see as many as 200,000 children crippled in the next decade as efforts to eradicate polio stall. Ban Ki-moon, talking to the Los Angeles Times, said recently: "The world is now populated by a generation which has never been exposed to polio, nor been vaccinated. When the virus strikes under these conditions the effects can be devastating."

WHY HAVE VACCINATION PROGRAMMES STALLED?
One reason is funding. The Global Polio Eradication Initiative has only half of the $2 billion it needs to procure vaccines and deploy staff to the last bastions of the disease. The WHO global emergency declaration, expected this week, is intended to attract funds, and also allow polio-free countries to vaccinate people arriving at airport terminals from affected countries.

WHAT ARE THE OBSTACLES TO VACCINATION PROGRAMMES?
There are logistical problems in Nigeria, with a fragmented healthcare system that makes it difficult to deliver vaccines. In Afghanistan and Pakistan, ongoing conflicts often put children out of the reach of health workers. In Pakistan, hard-line Muslims even spread rumours that the vaccine is part of an American plot to make Muslims infertile. The CIA also used a fake hepatitis programme to get information about Osama bin Laden, which has caused deep suspicion of health workers bearing vaccines.

SO THIS EMERGENCY IS NOT ABOUT A POLIO EPIDEMIC?
No. The emergency declaration is a call-to-arms for a funding push, which could offer a real chance to wipe out polio forever. But the vaccination programme has also been boosted through educating people: hard-line religious leaders like Sami ul-Haq (known as the father of the Taliban in Pakistan), have launched immunisation drives, declaring polio vaccination "very much Islamic". WHO teams are now trying to reach an estimated 50,000 children in war zones. Dr Nima Abid, head of the WHO's polio efforts in Afghanistan, says: "We are talking about eradication. Not just control. So we have to reach these children." · 

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