Tuberculosis is an airborne disease that is often diagnosed by analyzing sputum—mucus coughed up from the lungs. However, not all patients are able to produce sputum, which makes detection more difficult. In a new study, researchers tested whether DNA from the tuberculosis bacterium could be detected in exhaled air—known as aerosols—in people seeking care for respiratory symptoms.

The study was conducted at primary care clinics in South Africa and included 137 adult participants with tuberculosis. The researchers used a new device, TB Hotspot detectOR (THOR), which collects aerosols using electrostatic sampling. The samples were analyzed using the same technique as for sputum, Xpert MTB/RIF Ultra.