2006年VOA标准英语-Researchers in Niger Prepare for Battle Against（在线收听）

By Naomi Schwarz
Dakar
27 October 2006

Africa's Sahel region, stretching from Senegal to Ethiopia, along the southern edge of the Sahara, has been called the "meningitis belt."  More than half the world's cases of the disease occur there. Researchers in Niger are trying out a combination of high-tech and low-tech approaches to fight the disease.

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A woman is vaccinated against meningitis in Niger

The disease lives harmlessly in many people, in their throat or nose. But once it enters the blood stream, symptoms appear, and 70 percent of those who do not receive treatment will die.

Suzanne Chanteau, director of the Meningitis research program at the Niger-based Center for Health and Medical Research, known as CERMES, says residents in the Sahel are particularly at risk for the disease, which causes swelling of a lining of the brain.

"There is a hypothesis that the low humidity in this region and also maybe the dust winds are favorable conditions for the development of infection of the throat by viralogical organism or bacteriological organism responsible for meningitis," she noted.

Scientists hypothesize that these dry and dusty conditions irritate the fragile skin that lines the nose and throat, giving the bacteria an opening directly into the blood stream.

When patients are diagnosed and treated promptly, 90 percent recover fully.  But there are several different strains of meningitis, and doctors need to know which one has infected their patients.

An old test required highly-trained technicians to analyze a bacteria culture in pristine lab conditions. It also required that the bacteria sample be refrigerated.

This was a significant obstacle, Chanteau says.

"All the countries in the meningitis belt lack laboratories, so they cannot cultivate the bacteria on site," she explaine.  "That is why a rapid test that can be performed by nurses is necessary."

Chanteau and her colleagues developed such a test. In the simple procedure, the health worker takes a sample of spinal fluid from the patient, and inserts a specially treated dipstick, which shows results in 10 minutes.

The team at CERMES created a separate dipstick test for each of the four most prevalent forms of meningitis.

"We believe that there will be two kinds of effects," she said.  "The first one is on the individual level. The diagnosis of meningococcal infection will help the health staff to select appropriate antibiotic treatment. And the second, maybe the most important impact is that, at the beginning of an epidemic, the doctors will be able to know what is the serogroup of meningococci responsible for the outbreak and they can apply the control measure very quickly, instead of waiting for one team from the capital coming to make the diagnosis."

But to identify potential outbreaks before they occur, another member of Chanteau's team is looking to satellite imagery.

Isabelle Jeanne, a doctor and head of the Global Information Systems unit at CERMES, tracks dust storms from space and analyzes their atmospheric conditions.

"We want to have atmospheric conditions categorized and say if it is these conditions, there is favorable conditions to have meningitis or not," she explained.  "And these conditions are not favorable for meningitis."

If she is successful, she will be able to use current satellite data to see where the next dust storm will hit. With this advance warning, health workers could target anti-meningitis efforts to the areas most likely to be affected.