Asymptomatic tuberculosis more common in people living with HIV

A study, conducted in South Africa, has found that the incidence of subclinical (asymptomatic) tuberculosis is higher in people living with HIV and similar to that of those with clinical tuberculosis (TB). The study was published in Healio Magazine.

These findings have led experts in TB to believe that is now necessary to change TB screening guidelines, which up until now have been symptom-screening based.

Unidentified asymptomatic subclinical tuberculosis “remains a significant threat to global TB control and accounts for a substantial proportion of cases among people living with HIV/AIDS” says Doctor Kogieleum Naidoo, MBChB, PhD, clinical head of the HIV and TB treatment research program at the Centre for the AIDS Programme of Research in South Africa (CAPRISA).

Naidoo and his team followed 402 people living with HIV who had previous been treated for TB. The participants were screened for TB for 36 months.

During the study period, 12% of participants (48) showed a bacteriologically confirmed recurrence of TB:

• 35% (17) subclinical asymptomatic form
• 65% (31) clinical form

The study showed that age, gender, and body mass index were roughly the same amongst participants with both subclinical, clinical and no TB found.

In the subclinical group, 82% of patients were diagnosed by TB culture only, 65% received treatment for their TB, and 35% spontaneously cleared their TB.

The study’s authors say that their work “highlights the cyclical nature of TB disease progression and need for reconsideration of current TB screening and testing guidelines,” and that “the challenge of using TB symptoms alone for finding and treating TB cases is demonstrated, emphasising the importance of targeted universal TB screening, and testing among high-risk groups.”

Scientists from the Texas Institute of Biomedical Research were able recently able to improve the TB vaccine by applying a temporary blocking of interleukin-10 at the same time as the administration of the BCG vaccine. Work is continuing on this project.