Subclinical tuberculosis among adults with HIV: Clinical features and outcomes in a South African cohort

Bajema, K. L., Bassett, I. V., Coleman, S. M., Ross, D., Freedberg, K. A., Wald, A. and Drain, P. K.

BACKGROUND: Subclinical tuberculosis is an asymptomatic disease phase with important relevance to persons living with HIV. We describe the prevalence, clinical characteristics, and risk of mortality for HIV-infected adults with subclinical tuberculosis.

METHODS: Untreated adults with HIV presenting for outpatient care in Durban, South Africa were screened for tuberculosis-related symptoms and had sputum tested by acid-fast bacilli smear and tuberculosis culture. Active tuberculosis and subclinical tuberculosis were defined as having any tuberculosis symptom or no tuberculosis symptoms with culture-positive sputum. We evaluated the association between tuberculosis disease category and 12-month survival using Cox regression, adjusting for age, sex, and CD4 count.

RESULTS: Among 654 participants, 96 were diagnosed with active tuberculosis disease and 28 with subclinical disease. The median CD4 count was 68 (interquartile range 39-161) cells/mm(3) in patients with active tuberculosis, 136 (72-312) cells/mm(3) in patients with subclinical disease, and 249 (125-394) cells/mm(3) in those without tuberculosis disease (P < 0.001). The proportion of smear positive cases did not differ significantly between the subclinical (29%) and active tuberculosis groups (14%, P 0.08). Risk of mortality was not increased in individuals with subclinical tuberculosis relative to no tuberculosis (adjusted hazard ratio 0.84, 95% confidence interval 0.26-2.73).

CONCLUSIONS: Nearly one-quarter of tuberculosis cases among HIV-infected adults were subclinical, which was characterized by an intermediate degree of immunosuppression. Although there was no significant difference in survival, anti-tuberculous treatment of subclinical cases was common. 

April 12, 2019
Year of publication
Resource types
Journal and research articles
subclinical TB, tuberculosis, co-infection

Similar Resources

We describe baseline characteristics, time to treatment initiation and interim patient outcomes at a decentralized, outpatient treatment site for rifampicin-resistant TB (RR-TB).
Treatment success rates of rifampicin resistant (RR)/multi-drug resistant (MDR) tuberculosis (TB) in South Africa range from 43–48%, falling short of the World Health Organization’s target of ≥75%. We present rates and assess predictors of attrition by 12 months on treatment.
Drug resistance is a challenge for the global control of tuberculosis. We examined mortality in patients with tuberculosis from high-burden countries, according to concordance or discordance of results from drug susceptibility testing done locally and in a reference laboratory.
The diagnostic accuracy of Xpert MTB/RIF is well documented, anticipated improvements in patient outcomes have not been clearly identified. We performed an individual patient data meta-analysis to examine improvements in patient outcomes associated with Xpert MTB/RIF.

This issue of the Southern African HIV Clinicians Society's "HIV Nursing Matters" online magazine focuses on vulnerable populations, including TB in prisons and intimate partner violence in the context of HIV.

This issue of the Southern African HIV Clinicians Society's "HIV Nursing Matters" online magazine focuses on key populations.


Attrition along the HIV care continuum slows gains in mitigating the South African HIV epidemic. Understanding population-level gaps in HIV identification, linkage, retention in care and viral suppression is critical to target programming.

Background: A fraction of HIV-diagnosed individuals promptly initiate antiretroviral therapy (ART).

According to the World Health Organization, South Africa ranks as one of the highest burden of TB, TB/HIV co-infection, and drug-resistant TB (DR-TB) countries.