Highlights
- HIV testing coverage among household contacts of tuberculosis (TB) patients averaged 72.9%, but exhibited significant variability (0% to 100%) across different settings.
- The pooled HIV positivity rate among these contacts was 5.9%, rising to 9.7% in countries with a national adult HIV prevalence of 10% or higher.
- Systematic HIV testing during TB contact investigation represents a high-yield opportunity for early HIV diagnosis and linkage to care.
- Barriers to testing include social stigma, logistical constraints, and gaps in provider motivation, which must be addressed to optimize integrated screening programs.
Background: The TB-HIV Syndemic and the Screening Gap
The intersection of Human Immunodeficiency Virus (HIV) and tuberculosis (TB) remains one of the most formidable challenges in global public health. Individuals living with HIV are at a significantly higher risk of developing active TB, and TB remains the leading cause of death among people living with HIV. While the World Health Organization (WHO) has long advocated for integrated services, implementation in the field often remains siloed. Systematic screening of household contacts—those living in the same residence as a person with bacteriologically confirmed TB—is a cornerstone of TB control. This strategy offers a unique window of opportunity to identify not only secondary TB cases but also individuals with undiagnosed HIV infection.
Despite the theoretical benefits, the actual uptake and yield of HIV testing during these household visits have been poorly quantified globally. Understanding the coverage (who gets tested) and the positivity (who tests positive) is essential for health policy experts and clinicians to justify the resource allocation required for integrated screening. This systematic review and meta-analysis by Scott et al., published in The Lancet Global Health, provides the most comprehensive data to date on this critical intervention.
Study Design and Methodology
For this systematic review and meta-analysis (PROSPERO: CRD42024471979), researchers conducted a rigorous search of MEDLINE, Embase, Global Health, and Africa Wide databases, covering the period from January 1, 2000, to June 24, 2025. The study focused on household contacts of individuals with TB in high-TB-burden settings. The primary analysis specifically targeted contacts without a known HIV diagnosis at the time of screening.
The researchers extracted data on two primary outcomes: coverage (the proportion of eligible contacts who received an HIV test) and positivity (the proportion of those tested who were newly diagnosed with HIV). Pooled proportions were calculated using random-effects meta-analysis to account for expected heterogeneity between studies. Furthermore, the team performed meta-regression to explore how national HIV prevalence, the time period of the study, and participant age influenced these outcomes. To provide a holistic view, qualitative reports were also summarized to identify the facilitators and barriers to testing through the lens of the COM-B (Capability, Opportunity, Motivation, and Behavior) framework.
Key Findings: Yield and Coverage Analysis
Quantitative Results
The search identified 31 quantitative studies involving 110,090 people. For the primary analysis, 17 studies (40,407 people) were included after excluding those with previously known HIV status. The results revealed a pooled HIV testing coverage of 72.9% (95% CI 60.3–83.9). While this figure suggests a reasonable level of implementation, the range was stark—from 0% in some settings to 100% in others—indicating that the success of integrated screening is highly dependent on local infrastructure and program commitment.
The most compelling finding was the HIV positivity rate. The pooled positivity was 5.9% (95% CI 3.6–8.8). To put this in perspective, this yield is substantially higher than most general population testing initiatives. In high-prevalence settings (national adult HIV prevalence ≥10%), the positivity rate jumped to 9.7% (95% CI 5.8–14.5). These figures underscore that household contacts of TB patients are an exceptionally high-risk group for HIV, likely due to shared socio-economic risk factors and the biological interplay between the two pathogens.
Qualitative Insights
Seven qualitative studies provided context to the numerical data. Using the COM-B model, the researchers identified several key themes:
- Capability: Contacts needed adequate knowledge about the benefits of knowing their HIV status, while providers required training on how to offer testing sensitively within a home environment.
- Opportunity: Home-based testing was generally seen as a facilitator because it reduced travel costs and time. However, the lack of privacy in crowded households and the intermittent supply of test kits served as major barriers.
- Motivation: Stigma remains a powerful deterrent. Many contacts feared that an HIV diagnosis would lead to social isolation. Conversely, the desire to remain healthy for one’s family acted as a strong motivator for those who accepted testing.
Clinical and Policy Implications
The high positivity rate found in this meta-analysis suggests that every TB household contact investigation should, by default, include an offer of HIV testing. For clinicians, this means that the discovery of a TB index case should trigger a comprehensive family-centered health assessment. For policy experts, the data supports the integration of HIV and TB funding streams at the community level. If nearly 10% of contacts in high-prevalence areas are testing positive, failing to test during a TB visit is a significant missed opportunity for the “95-95-95” targets.
Furthermore, the variability in coverage suggests that current guidelines are not being consistently applied. Health systems must move beyond simply recommending testing to active monitoring and evaluation. Routine TB program indicators should include HIV testing coverage and yield among contacts to ensure accountability and identify sites requiring additional support.
Expert Commentary and Limitations
While the study presents a strong case for integrated testing, several limitations must be considered. The high degree of heterogeneity (I² > 90%) in the meta-analysis suggests that a single “pooled” number might not reflect the reality of every specific district. Factors such as local stigma, the specific model of home-based care, and the prevalence of undiagnosed HIV in the broader community all play roles. Additionally, the study focused on testing, but the subsequent linkage to Antiretroviral Therapy (ART) was not always documented in the included literature. Finding a positive case is only the first step; ensuring they start and stay on treatment is the ultimate goal.
Clinicians should also be aware that a negative HIV test at the time of TB contact screening does not preclude future risk. In high-incidence settings, these individuals might benefit from discussions regarding Pre-Exposure Prophylaxis (PrEP), further cementing the household visit as a comprehensive sexual health opportunity.
Conclusion
The systematic review by Scott and colleagues clarifies that HIV testing during TB household contact screening is not just a secondary task—it is a high-yield clinical necessity. With a positivity rate of nearly 6% overall and nearly 10% in high-prevalence regions, the efficiency of this screening strategy is undeniable. To close the remaining gaps, programs must focus on the “Opportunity” and “Motivation” pillars of the COM-B model, ensuring that test kits are available and that testing is delivered in a way that minimizes stigma and maximizes privacy. Monitoring the implementation of HIV testing within routine TB programs should become a standard practice in high-burden settings.
References
1. Scott P, Elsayedkarar M, Marambire E, et al. HIV testing during systematic screening for tuberculosis among household contacts in high-tuberculosis burden settings: a systematic review and meta-analysis. Lancet Glob Health. 2026;14(1):e81-e91. doi:10.1016/S2214-109X(25)00437-1.
2. World Health Organization. WHO consolidated guidelines on tuberculosis: module 2: screening – systematic screening for tuberculosis disease. Geneva: World Health Organization; 2021.
3. UNAIDS. 95-95-95: Empowering people to know their HIV status, access treatment and reach viral suppression. 2020.
Funding
This study was supported by the National Institute for Health and Care Research (NIHR) and the Wellcome Trust.