Study shows the high rates of subclinical TB infections in PLWHA

30 March 2022

A recent CAPRISA-led study highlighted the inadequacies of symptom-based TB screening in high TB-HIV burden settings resulting in the high incidence rates of recurrent subclinical TB in people living with HIV and AIDS (PLWHA).

The study, “Recurrent subclinical tuberculosis among ART accessing participants: Incidence, clinical course, and outcomes, published in the journal Clinical Infectious Diseases, set out to determine the incidence, progression, and outcomes of subclinical TB in anti-retroviral therapy (ART) accessing PLWHA with known previous successful TB treatment outcomes in South Africa.

A total of 402 adult participants living with HIV and AIDS were screened for TB with 3-monthly clinical and bacteriologic evaluation and bi-annual chest radiographs over 3 years. A total of 48/402 (11.9%) bacteriologically confirmed incident recurrent TB cases was identified, comprising 17/48 (35.4%) subclinical TB cases and 31/48 (64.5%) clinical TB cases. 

Age, sex, and body mass index (BMI) were similar among subclinical, clinical, and no TB groups. 

Incidence rates of recurrent TB overall; in clinical TB; and subclinical TB groups was 2.3 [95% CI: 1.7-3.0]; 1.5 [95% CI: 1.1-2.2]; and 0.9 [95% CI: 0.5-1.4] per 100 person-years, respectively. In the subclinical TB group, 14/17 (82.4%) was diagnosed by TB culture only, 11/17 (64.7%) received TB treatment, and 6/17 (35.3%) resolved TB spontaneously.

Undiagnosed asymptomatic subclinical tuberculosis (TB) remains a significant threat to global TB control and accounts for a substantial proportion of cases among people living with HIV/AIDS (PLWHA). The researchers called for an update of the symptom-based screening guidelines to control the scourge of TB infections in PLWHA.

For further reading see: Naidoo K, et al. Recurrent subclinical tuberculosis among ART accessing participants: Incidence, clinical course, and outcomes. Clin Infect Dis. 2022. doi: 10.1093/cid/ciac185.


Image: Undiagnosed asymptomatic subclinical TB remains a threat to global TB control. Photo credit: Adobe Stock