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.