Reexamining how asymptomatic tuberculosis spreads

Questioning the Epidemiology of Asymptomatic TB

This project will test whether people with asymptomatic tuberculosis—particularly adults living with HIV—can pass TB to their household and close contacts.

Quick facts

• Study type: Observational
• Enrollment: 6770 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Barcelona Institute for Global Health (other)
• Locations: 1 site (Manhiça, Maputo Province)
• Trial ID: NCT07312266 on ClinicalTrials.gov

What this trial studies

TB-QUEST is a prospective epidemiological field project that enrolls adults living with HIV who attend routine care and have laboratory-confirmed but self-reported asymptomatic TB, together with their close household and community contacts. The study combines systematic symptom tracking, clinical and radiological assessment, and collection of respiratory and other samples. Advanced whole-genome sequencing and contact tracing will be used to seek direct genomic links between index asymptomatic cases and secondary cases among contacts. Follow-up over time will also characterize the clinical, immunological and radiological features of the asymptomatic stage within the natural history of TB.

Who should consider this trial

Good fit: Ideal candidates are adults (≥18) living with HIV who receive routine care at the Manhiça site and have laboratory evidence of TB without reported symptoms, plus their willing close household or community contacts of any age.

Not a fit: People already receiving anti-TB treatment or preventive therapy, pregnant women, those planning to migrate within 12 months, or individuals unable to undergo required sampling procedures are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, findings could change screening and prevention practices by identifying asymptomatic people who transmit TB and thereby reducing onward spread.

How similar studies have performed: To date no field study has demonstrated direct transmission from subclinical or asymptomatic TB cases, so this project uses genomic linkage methods to address a largely unproven but important transmission hypothesis.

Eligibility criteria

Index cases:

Inclusion Criteria:

1. 18 years of age or older
2. Documented HIV infection
3. Presenting at a health facility for routine HIV care

Exclusion Criteria:

1. History of TB treatment in the last 12 months
2. Pregnant women
3. Refusal to provide consent for study procedures
4. Contra-indication to any sampling procedure required by the study

Study 3 will utilize additional inclusion criteria:

Inclusion criteria:

1. On ART for less than 6 months
2. No evidence of viral suppression
3. Documented CD4 count \>350 copies/ul
4. TB-suggestive x-ray
5. Verified absence of fever and cough, as ascertained through the symptom trackers

Contacts:

Inclusion criteria: All close contacts (household and close community contacts) will be offered to participate in the study, regardless of age or HIV status.

Exclusion criteria:

1. Plans to migrate in the next 12 months
2. Pregnant women
3. Currently taking anti-tuberculosis treatment or preventive TB treatment
4. Contacts with co-prevalent TB identified at baseline

Where this trial is running

Manhiça, Maputo Province

• Centro de Investigação em Saúde de Manhiça (CISM) — Manhiça, Maputo Province, Mozambique (RECRUITING)

Study contacts

• Study coordinator: Alberto L. Garcia-Basteiro, MD

Conditions: Tuberculosis, HIV, Asymptomatic tuberculosis, Asymptomatic, Subclinical tuberculosis, Subclinical