Study randomized clinics to use Xpert or fluorescence microscopy for patients newly diagnosed with HIV showing TB symptoms
Among patients newly diagnosed with HIV and showing signs of tuberculosis disease, death rates in the year that followed were 22 percent lower among those in rural clinics assigned to use the Xpert point-of-care TB diagnostic tool, as opposed to those in rural clinics using smear microscopy aided by fluorescent dye. Among patients with advanced HIV, the use of Xpert doubled the proportion of people diagnosed with tuberculosis, and was linked to a 57 percent reduction in deaths from all causes, according to the study, reported in Clinical Infectious Diseases.
Xpert, a rapid diagnostic tool for identifying not only TB, but drug-resistance in patients, was first recommended by the World Health Organization for diagnosing tuberculosis in people with HIV in 2010. The disease can be difficult to diagnose by examining sputum under a microscope among people living with HIV, who can be vulnerable to tuberculosis outside the lungs.
The authors of the report note that a study in South Africa has shown that the use of Xpert led to significant increases in same-day TB diagnoses, while a study in Brazil has shown the diagnostic tool shortened the time to treatment for the disease. But, while an estimated 8 percent or more of people beginning antiretroviral treatment in sub-Saharan Africa die within the year that follows, with tuberculosis the leading cause of death among people with HIV (as well as, with HIV, the leading infectious cause of death worldwide), no study has measured the impact of the rapid and accurate diagnostic tool on mortality from all causes among people with HIV, the authors note. Determining how many of the deaths that did take place during the study were caused by tuberculosis was not possible, the authors write.
They note that challenges to using the device included unreliable electricity sources, training staff to use the machine and the cost of the cartridges. Researchers installed solar panels at some clinics to make Xpert use possible during the study. But, they note, the tool can be operated accurately by trained nurses, and a newer more portable, battery operated version of the machine will help to overcome infrastructure challenges.