和谐英语

VOA常速英语:British Scientists Develop One-Hour TB Test

2010-09-16来源:和谐英语

British scientists say they have found a way to diagnose tuberculosis in an hour.

Alasdair Reid is an advisor on HIV and Tuberculosis (TB) at UNAIDS. He says diagnosing TB quickly will revolutionize the fight against the illness.

"It will save time for laboratory staff who have to spend hours each day looking at slides to try and find tuberculosis," said Reid.  "It will reduce the risk of death amongst people suffering from tuberculosis because they will be diagnosed and treated very quickly."

According to the World Health Organization (WHO), TB killed over 1 million people in 2008.

Before now, the only reliable way to test for tuberculosis was to take molecules out of a patient and grow a culture from this sample in order to identify if the TB bacteria was present - a process that takes up to eight weeks.

Another method was to identify a particular chemical marker, but scientists found this unreliable because it doesn't pick up all types of TB.

Now, they've found a way to zoom in and look for a particular molecule of DNA which would show if TB is present. They say this can be done in one hour, a change they say could dramatically reduce the number of TB cases worldwide.

People living with HIV are particularly vulnerable to the disease, says Reid. One in four AIDS deaths, he says, are due to tuberculosis.

"To have a new test that can accurately diagnose tuberculosis in a person living with HIV within an hour is the holy grail of tuberculosis control," added Reid.

TB is spreading fastest in South East Asia. It's also a growing problem in sub-Saharan Africa, the part of the world hit hardest by HIV.

"Tuberculosis is very much a disease of poverty, poor housing, poor nutrition," explained Reid.  "So tuberculosis tends to be focused in under resourced parts of the world."

According to the World Health Organization, around one-third of people around the world carry TB bacteria. Of those, only between 5-10 percent become sick or infectious.

The test has been developed by Britain's Health Protection Agency. It says the test will undergo trials before going on the market, a process that could take up to two years. 

A United States journal recently published details of a TB test that it says can produce a diagnosis in less than two hours.