VOA常速英語(yǔ):專家研發(fā)非洲撒哈拉沙漠以南地區(qū)抗毒蛇血清

Thousands of people in sub-Saharan Africa die or are disabled each year due to poisonous snake bites. Scientists in Britain are working to develop a serum that will counteract the venom from all sub-Saharan poisonous snake bites.

The Puff adder is only one of many venomous snakes native to sub-Saharan Africa.

Dr. Robert Harrison, of the Liverpool School of Tropical Medicine, says every year, puff adders and the other snakes kill about 32,000 people.

“It's not only that; other people who survive the bite - about 100,000 of them - are living with severe disabled limbs or legs, just really very disabling conditions,” he said.

The current method of producing anti-venom - starting with the venom itself - is time-consuming and costly, and the serum must be refrigerated. Victims have to be treated multiple times and there are possible side-effects. With the price of about $140 per single dose, the full treatment may cost more than $500, which makes it unaffordable for most rural Africans.

In addition, because of the way they're produced, current serums counteract poison from only one species, or a few related ones, so doctors must determine what snake bit the victim.

The anti-venom developed by scientists at the Liverpool School of Tropical Medicine specifically for Nigeria, proved to be cheap, safe and effective.

Harrison says his team is using it as a basis for developing universal anti-venom applicable to all venomous snakes in sub-Saharan Africa.

“We're going to do that by identifying the proteins that are unique to all the other species," he said. "And taking these unique proteins. i.e. different from the Source Scale Viper, the Puff Adder or the Spitting Cobra, and add that to the venoms of the original three.”

For this purpose the lab is regularly extracting venom from 450 snakes belonging to 21 of the most deadly species of sub-Saharan African snakes.

Scientists say the universal anti-venom will be more affordable than current serums and will be effective much longer.

Target date for the ultimate test - after a year of storage at room temperature - is set for July 2018.