Asymptomatic Tuberculosis: Prevalence, Relevance, Biology, Diagnosis, and Treatment

Abstract

Tuberculosis (TB) care and prevention have long relied on the assumption that individuals with the disease will seek care once they become aware of symptoms. However, national prevalence surveys show that nearly half of bacteriologically confirmed TB cases report no symptoms at screening, challenging this paradigm. The World Health Organization (WHO) now recognizes asymptomatic TB as part of the disease spectrum and promotes symptom-agnostic screening strategies to identify and treat these individuals. Evidence suggests that asymptomatic TB could be contributing to transmission, although further research is needed. While defining symptom status remains imprecise, individuals with asymptomatic TB present distinct diagnostic and treatment challenges. Asymptomatic pulmonary TB typically involves more limited disease, lower bacillary burden, and difficulty producing sputum, reducing the sensitivity of current sputum-based tests. Novel diagnostic approaches, including alternative sampling and molecular tools, are under development. Treatment uptake and adherence are another concern, as individuals feel well and derive no immediate symptomatic benefit, increasing the risk of poor initiation and completion. Addressing these gaps through improved diagnostics, shorter and better-tolerated regimens, and enhanced treatment support is essential. Recognizing and targeting asymptomatic TB is critical to interrupt transmission and accelerate progress toward global TB elimination.