Cape Town - HIV-positive people on antiretroviral therapy (ART) are less likely to contract tuberculosis, a study has found.

The review study, which was published in the open access journal PLoS Medicine this week, found that participants on ART had a 65 percent reduction in their risk of developing TB irrespective of their CD4 count.

The study, by a group of international researchers from the World Health Organisation (WHO), the UCT-based Desmond Tutu HIV Centre, the SA Centre for Epidemiological Modelling at Stellenbosch University and the London School of Hygiene and Tropical medicine, analysed 11 relevant studies from sub-Saharan Africa, South America, the Caribbean and Asia.

They found that HIV-positive people on ARVs had reduced their risk of contracting TB by 65 percent compared to those who were not on ART, while ART was also associated with a 57 percent reduction in TB among adults with a CD4 count of more than 350.

Currently WHO recommends ART from a CD4 count of 350 and below. The CD4 count is used to determine how well the immune system works. Previously, antiretroviral drugs were provided only if the count was less than 250.

One of the authors, Dr Amitabh Suthar, from the WHO, described the latest findings as “significant”.

He said they were consistent with studies on people from the developed countries.

“People who are HIV-positive are extremely susceptible to TB because the HI virus destroys the immune system cells that are necessary to combat TB infection.

“This review found that antiretroviral therapy is strongly associated with a reduction in TB incidence in adults with HIV across all CD4 counts,” Suthar said.

He said the latest finding needed to be considered not only by those who were living with the diseases, but also by healthcare providers, researchers and policy makers when weighing the benefits and risks of initiating ART. - Cape Argus