Studying how tuberculosis without symptoms spreads to close contacts
Looks at whether people with symptom-free tuberculosis pass it to those around them.
Plain-language title generated from the registry record
Registry title: Questioning the Epidemiology of Asymptomatic TB
Key facts
- Where
- Manhiça, MozambiqueSee the site
Where in Mozambique
- Centro de Investigação em Saúde de Manhiça (CISM)Manhiça, MozambiqueTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Barcelona Institute for Global Health
- Trial code
- NCT07312266
- Record updated
- 31 December 2025
- Original description
Tuberculosis (TB) remains one of the world's leading causes of morbidity and mortality. Current TB control strategies focus largely on the binary paradigm of TB, which tackle Mtb infection and the symptomatic stages of the disease as the major drivers of the TB epidemic. However, prevalence surveys have shown that about 50% of cases in which Mycobacterium tuberculosis is isolated from sputum but do not report having symptoms. Therefore, asymptomatic TB may play an important role in TB transmission. However, no field study has demonstrated direct transmission from a subclinical TB case to a confirmed secondary case.Read full original descriptionShow less
Questioning the Epidemiology of Asymptomatic TB
Tuberculosis (TB) remains one of the world's leading causes of morbidity and mortality. Current TB control strategies focus largely on the binary paradigm of TB, which tackle Mtb infection and the symptomatic stages of the disease as the major drivers of the TB epidemic. However, prevalence surveys have shown that about 50% of cases in which Mycobacterium tuberculosis is isolated from sputum but do not report having symptoms. Therefore, asymptomatic TB may play an important role in TB transmission. However, no field study has demonstrated direct transmission from a subclinical TB case to a confirmed secondary case.
TB-QUEST is an ERC-funded epidemiological field study that aims to provide direct evidence of effective transmission from asymptomatic TB cases to their close contacts using advanced genomic methods, and to better characterize the asymptomatic stage of TB within the natural history of disease.
Inclusion: 18 years of age or older; Documented HIV infection; Presenting at a health facility for routine HIV care; On ART for less than 6 months; No evidence of viral suppression; Documented CD4 count >350 copies/ul; TB-suggestive x-ray; Verified absence of fever and cough, as ascertained through the symptom trackers; Contacts:.
Exclusion: Currently taking anti-tuberculosis treatment or preventive TB treatment; History of TB treatment in the last 12 months; Pregnant women; Refusal to provide consent for study procedures; Contra-indication to any sampling procedure required by the study; Study 3 will utilize additional inclusion criteria:; Plans to migrate in the next 12 months; Pregnant women; Contacts with co-prevalent TB identified at baseline.
Index cases:.