This review summarized trials evaluating the effects of interventions aiming to increase the diagnosis of tuberculosis and reduce the number of undiagnosed tuberculosis cases in communities. After searching for relevant trials up to 19 December 2016, we included 17 studies conducted in sub-Saharan Africa (nine studies), Asia (six studies), and South America (two studies).

Why does tuberculosis go undiagnosed and how might programmes improve this?

Tuberculosis is a chronic infectious disease that affects over 10 million people worldwide, with an estimated four million tuberculosis patients remaining undiagnosed each year. Interventions such as outreach tuberculosis screening with or without health promotion that actively screen for tuberculosis among individuals presenting with symptoms of tuberculosis, may increase detection of microbiologically confirmed tuberculosis cases. These interventions may improve treatment outcomes by increasing the number of tuberculosis patients who are cured and complete treatment. However, we do not know if these interventions reduce either tuberculosis treatment failure, or tuberculosis-associated death or long-term tuberculosis burden in moderate- and high-tuberculosis settings.

What the research says

House-to-house screening for active tuberculosis, and organizing tuberculosis diagnostic clinics nearer to where people live and work, may increase tuberculosis case detection in settings where the prevalence of undiagnosed disease is high (low-certainty evidence). These people may have higher levels of treatment success and lower levels of default from treatment (low-certainty evidence).

There was insufficient evidence to determine if health promotion activities alone increase tuberculosis case detection (very low-certainty evidence).

There was also insufficient evidence to determine if sustained improvements in case detection impact on long-term tuberculosis prevalence, as the only study to evaluate this found no effect after four years (very low-certainty evidence).