New rapid test reliably detects tuberculosis

„Xpert MTB / RIF“ Detects illness quickly and accurately

29/10/2013

A newly developed test can quickly and reliably detect the dangerous lung disease tuberculosis, which, according to the World Health Organization (WHO), has infected 8.6 million people worldwide alone last year. This is the result of a South African study, which is currently published in the British journal "The Lancet". Because the course of the disease could not affect a quick detection but positive.

Test allows for faster treatment
A new test appears to be able to quickly and accurately identify the bacterial infectious disease tuberculosis (TB) that is found worldwide. To this realization, a team of South African scientists has come to Keertan Dheda from the University of Cape Town. It is the one of the California company „Cepheid“ developed rapid test called „Xpert MTB / RIF“, on an automated „Real-time polymerase chain reaction“ (real-time PCR) and can detect tuberculosis pathogens within two hours. The great advantage would be the researchers especially in the handling, because „Xpert MTB / RIF can also be administered by a nurse in a general outpatient clinic, which means more patients start treatment on the same day, more patients are treated with a positive bacterial culture, and less total treatment time“, the scientists in the trade magazine „The Lancet“.

83% of tuberculosis cases correctly diagnosed
The researchers had a total of 1502 patients with clinical suspected tuberculosis in South Africa, Zimbabwe, Zambia and Tanzania investigated for their study: In 758 subjects for the detection of the disease, a conventional microscopic analysis of the bronchial secretions (sputum examination) made in the other group (N = 744), however, the new test equipment was applied. The result: the new device showed a higher sensitivity than microscopy and diagnosed tuberculosis correctly in 83 percent of the cases - in conventional microscopy, however, it was only half, as the researchers write.

However, disease progression can not be positively influenced
Two and six months after the tests, the next tests were done. It finally showed that, despite the rapid and reliable diagnosis by the Xpert MTB / RIF in the further course of the disease, there were no differences between the two patient groups - neither with regard to the severity of the course nor with regard to the mortality rate. Instead, according to the researchers, even in both groups eight percent of the patients had died. Thus, "the possible long-term effect of this test is probably overestimated," according to the authors. According to Christian Wejse from the University of Aarhus in Denmark, it should also be considered whether the use of new, relatively expensive test makes sense, especially in poorer countries, because of "expensive equipment in health centers where the power can fail or in which Poorly trained and paid staff could be a tricky business“, said Wejse in a commentary on the South African study. (No)

Picture: Bernardo Peters-Velasquez