Many people with tuberculosis (TB) do not feel unwell and do not present to health services with symptoms. People with such asymptomatic forms of TB (aTB) may only be identified during screening with so-called symptom-agnostic tools like chest X-ray or during TB prevalence surveys. Recent reviews found that about one half of people with TB detected by prevalence surveys had bacteriologically confirmed disease but reported no typical TB symptoms upon inquiry. More research is now ongoing to better characterize the full spectrum of TB, from infection to disease. 

Interest in aTB has increased in recent years as more emphasis is being placed on screening and earlier diagnosis. The World Health Organization’s End TB Strategy stresses the importance of TB screening and active case-finding for TB in the first component of its first pillar. In 2021, WHO released updated evidence-based recommendations for systematic TB screening, alongside an operational handbook and new tools to facilitate implementation.