Thursday, May 12, 2005

Polio cases mount in previously infection-free nations


Polio cases mount in previously infection-free nations

GENEVA (AP) — The spread of polio in Yemen and Indonesia is adding new urgency to attempts to contain the disease in countries previously believed to be polio-free, the U.N. health agency said Wednesday.

The outbreak has grown to 63 cases in Yemen, while two more cases were confirmed in Indonesia, bringing the total there to six since May 3, the World Health Organization said.

Six million doses of vaccine are on their way to Yemen for a second round of immunizations and a vaccination campaign is under way in Indonesia, but experts expect several more polio cases to emerge before the outbreaks are contained.

"The more countries that are free of the disease, the greater the risk is that we will have sporadic outbreaks," said Oliver Rosenbauer, spokesman for the WHO's polio eradication program.

This happens because polio immunization campaigns often stop once the disease has been beaten. That leaves babies vulnerable to infections brought into the country.

And while the outbreaks in Yemen and Indonesia can be halted through immunization drives, it could be devastating if the virus were to reach Somalia, where a lack of security would make it difficult to conduct a vaccination campaign, Rosenbauer said.

"We have already seen polio reintroduced in Ethiopia," he said. "If it spreads to Somalia, it will be a problem because it is logistically very, very challenging there."

Yemen remains the area of highest concern for the moment. The number of cases could top 100 before the next phase of vaccinations takes place this month, Rosenbauer said.

Ideally, four doses should be given in the first year of life. However, during outbreaks, health authorities launch three rounds of vaccinations for all children under 5. The doses are given once every four to six weeks.

About 35% of children become immune to the disease after one dose of the vaccine, but for the others, exposure to the virus in between vaccinations is dangerous.

Yemen completed a first round of vaccinations in mid-April and will embark on the second wave in late May. Because the span between the doses cannot be shortened, experts expect more cases to emerge.

In Indonesia, the first round of vaccination is just starting.

Yemen and Indonesia are the latest of 16 previously polio-free countries that have reported new cases since 2003 after a vaccine boycott in Nigeria was blamed for causing an outbreak that spread the disease to other countries. Yemen's outbreak was first reported April 22.

Hard-line Islamic clerics in northern Nigeria led the immunization boycott, claiming the polio vaccine was part of a U.S.-led plot to render Nigeria's Muslims infertile or infect them with AIDS. Vaccination programs restarted in Nigeria in July 2004 after local officials ended the 11-month boycott.

Last year, some 1,267 people were infected in the world — 792 of them in Nigeria. The total new cases in 2005 stands at 198, according to WHO, with Nigeria and Yemen listed as the worst-affected countries.

Polio comes from dirty water and usually infects young children, attacking the nervous system and causing paralysis, muscular atrophy, deformation and sometimes death.

When WHO launched its anti-polio campaign in 1988, the worldwide case count was more than 350,000 annually. WHO hopes to eradicate the disease globally by the end of 2005.