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From VOA Learning English, |
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this is the Health Report. |
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Scientists are working on ways to |
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stop a disease |
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that threatens one-fifth of the world's population. |
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Over 120 million people |
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are infected with lymphatic filariasis, |
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also known as elephantiasis. |
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The disease is found mainly in Southeast Asia and Africa. |
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It effects the lymphatic system |
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which is a major part |
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of the body's natural defense for fighting disease. |
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Elephantiasis can cause swelling |
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or enlargement of skin and tissue. |
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The cause is a tiny worm |
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that enters and lives in lymphatic tubes |
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for six to eight years. |
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Scientists say |
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they have been able to demonstrate |
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that the most common cause of elephantiasis |
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can be stopped. |
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They are urging those at risk |
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to sleep under nets |
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treated with chemicals |
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that kill a common insect - the mosquitoes. |
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Lisa Reimer teaches at the Liverpool School |
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of Tropical Medicine. |
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She formerly served in Papua New Guinea, |
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as part of the team studying the disease. |
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The team involved researchers from Papua New Guinea, |
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Britain, Australia and the United States. |
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Doctor Reimer says |
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she was surprised at how effective |
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anti-malaria bed nets covered with insecticide |
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could be at fighting the disease. |
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"Filariasis is only picked up |
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by mosquitoes late in the evening, |
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so this is the time |
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when people are more likely to be protected |
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by their bed nets. |
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So we found that bed net use actually |
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is a greater barrier against |
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filariasis transmission |
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whereas malaria transmission may still be occurring |
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outside the times when the user is under the net." |
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Doctors normally use drugs to fight the disease. |
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Ms Reimer says doctors in Papua New Guinea |
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gave the drugs to people of five villages. |
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She says this treatment nearly ended |
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the threat from the worm to humans, |
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but the drugs didn't stop the threat from mosquitoes. |
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The treated nets |
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block female mosquitoes from securing blood, |
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which is necessary for them to reproduce. |
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The insecticide also cuts the life of the insects in half. |
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"If we can reduce mosquito-biting rates |
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then we're able to increase the thresholds |
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below which the disease prevalence will move to zero. |
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So by controlling mosquitoes we're making the targets |
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for the mass drug administration more obtainable." |
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The World Health Organization (WHO) has |
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set a goal of stopping lymphatic filariasis |
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as a public health problem by the year 2020. |
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The WHO estimates that 1.4 billion people |
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in 73 countries are at risk of the disease. |
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Children are often infected, |
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but they do not show signs of the disease |
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until later in life. |
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And that's the Health Report from VOA Learning English. |
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I'm Bob Doughty. |
