Number of polio cases in Yemen and Indonesia on rise

The spread of polio in Yemen and Indonesia is adding new urgency to attempts to contain the disease, the U.N. health agency said Wednesday. The outbreak has grown to 63 cases in Yemen, while two more cases were confirmed in Indonesia.

The new cases are from a neighbouring village as the index case. Also confirmed today are six additional ‘positive contact’ cases, from the same village as the index case, bringing the total number of ‘positive contact’ cases to 14.

A ‘contact case’ is the positive isolation of wild poliovirus from stool samples collected from a healthy child.

During a polio outbreak, stool samples are frequently collected from healthy children in and around an affected area - this helps to determine the extent of wild poliovirus circulation in the immediate environment.

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.

Epidemiologists expected that the total number of cases will exceed 100, before the outbreak is stopped. Yemen had been polio-free since disease surveillance began in 1996.

Polio mainly affects young children and can cause irreversible paralysis.
Health officials realize they are now in a race against time to immunize millions of children before they contract the crippling and sometimes deadly disease.

Concern is particularly high to protect the Horn of Africa, where weak health systems, low levels of routine immunization and hampered access to all populations due to civil conflict means children in this area are at particular risk of potential spread of polio.

“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,�? said Oliver Rosenbauer, spokesman for the WHO’s polio eradication program.

“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 percent 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.

To ensure the necessary polio campaigns are implemented in endemic and high-risk countries, a global funding gap of US$ 50 million must urgently be filled by July. An additional US$ 200 million is needed for 2006 activities.