[00:00.00]如果您也喜欢 恒星英语学习网 www.hxen.com 请与您的朋友分享...This is the VOA Special English [00:03.55]Health Report. [00:04.80]The World Health Organization [00:07.31]is urging health officials [00:09.62]to ban commonly-available [00:11.87]blood tests for tuberculosis. [00:14.61]W.H.O. officials made the call [00:18.30]after two studies found that results [00:21.55]from a commonly used test [00:23.80]are undependable and misleading. [00:27.45]The blood tests are low-cost [00:30.53]and produce fast results. [00:32.87]They are widely used [00:35.57]in developing countries, [00:37.06]especially India. [00:38.90]The Indian government says [00:42.12]the country [00:42.94]has more than two million [00:44.64]new cases of TB a year. [00:47.47]But, researchers say [00:50.21]the tests being sold [00:51.61]are dangerously inaccurate. [00:54.20]They say the results are wrong [00:56.56]in fifty percent of patients. [00:58.82]David Dowdy studies [01:01.66]infectious diseases [01:03.00]at the Johns Hopkins [01:05.30]Bloomberg School of Public Health [01:07.36]in Baltimore, Maryland. [01:09.05]He led one of the studies. [01:11.09]DAVID DOWDY: "These tests [01:12.68]are actively doing people harm [01:15.43]by causing them either [01:17.77]to take medicines [01:18.77]that they don't need [01:19.66]or delaying the diagnosis [01:21.56]that they actually do need, [01:23.61]to get better." [01:24.66]Traditional tests for TB [01:27.05]examine the sputum, [01:29.24]a material found [01:30.47]in a person's lungs. [01:31.78]Active TB is identified [01:35.17]if certain bacterium grows [01:37.41]in the test material. [01:39.81]However, these tests [01:42.21]take longer to carry out. [01:44.20]Dr. Dowdy says the blood tests [01:47.33]are widely used [01:48.72]because of the speed of results. [01:51.71]DAVID DOWDY: "What these tests do [01:53.70]is they measure antibodies [01:56.35]in the blood against TB [01:58.04]so anytime anyone has been [02:00.14]infected with TB at any time [02:03.60]in their life, [02:04.26]they will develop antibodies. [02:05.71]The problem is that one person's [02:08.35]antibodies are not [02:09.62]going to be the same [02:10.56]as another person's antibodies. [02:12.28]And we don't have a test yet [02:14.28]that can detect these antibodies [02:18.17]across the board." [02:19.11]The leader of the other study [02:21.60]was Madhukar Pai, [02:23.04]an epidemiologist [02:25.15]at McGill University [02:26.81]in Montreal, Canada. [02:28.59]He says the tests are usually [02:31.32]used by private medical centers [02:33.91]-- not government [02:35.53]TB control programs. [02:37.48]MADHUKAR PAI: "So these tests [02:38.85]are uniformly not used [02:41.01]in the developed world. [02:42.91]They are mostly used in countries [02:44.80]with weak regulation, [02:46.29]and lack of regulation [02:48.84]allows these sorts of tests [02:50.50]to be on the market and used freely." [02:53.20]Experts say the blood tests [02:55.41]are a big business [02:56.75]in developing countries, [02:58.50]worth millions of dollars a year. [03:01.38]The World Health Organization says [03:04.47]a million of the tests [03:06.11]are done every year. [03:07.61]But, the tests are not approved [03:10.50]by any recognized supervisory group. [03:13.83]Dr. Pai also says the WHO [03:18.06]is pushing scientists [03:19.71]to continue research for a quick test. [03:23.60]MADHUKAR PAI: "[Be]cause someday [03:24.89]we want a simple dipstick-like test [03:27.18]for TB, as we have for HIV and malaria. [03:29.92]But right now we don't have such a test [03:31.76]for TB for point of care use." [03:34.45]And that's the VOA Special English [03:37.75]Health report, [03:39.05]written by Caty Weaver, [03:40.70]with reporting from Jessica Berman [03:43.24]and Vidushi Sinha. [03:45.19]For more health news and to learn English, [03:48.14]go to www.hxen.com. [03:51.38]And follow us on Facebook [03:54.06]and Twitter at VOA Learning English. [03:57.01]I'm Christopher Cruise.如果您也喜欢 恒星英语学习网 www.hxen.com 请与您的朋友分享...