New Device Detects Tuberculosis in Exhaled Breath

A New Breakthrough in Tuberculosis Detection

Swedish scientists have made a significant advancement in the fight against tuberculosis (TB) by developing a new device capable of detecting TB DNA in exhaled air. This innovative method could serve as a valuable alternative when traditional sputum samples are hard to collect, potentially transforming how the disease is diagnosed.

Tuberculosis, an airborne illness, is typically diagnosed through the analysis of sputum — the mucus that is coughed up from the lungs. However, many patients struggle to produce sufficient sputum, which complicates the diagnostic process. The newly developed technique, named TB Hotspot detectOR (THOR), offers a promising solution by capturing aerosols from a person’s breath using electrostatic sampling. These samples are then analyzed using the same molecular test that is commonly used for sputum, known as Xpert MTB/RIF Ultra.

Researchers from the Karolinska Institutet explored whether individuals with TB release genetic material from the bacteria directly into the air when they breathe. Jay Achar, a researcher from the institute’s Department of Global Public Health, expressed optimism about the results, especially in regions where sputum collection poses challenges.

The findings, published in Open Forum Infectious Diseases, were based on a study involving 137 adults with TB at primary healthcare centers in South Africa. The device successfully detected TB DNA in exhaled air in 47% of participants who also had positive sputum tests. Among those with high bacterial loads in their sputum, the detection rate increased to 57%. The method demonstrated a specificity of 77%, indicating that it accurately identified individuals without TB in most cases.

In addition to testing individual samples, researchers also found TB DNA in 30% of environmental air samples collected from clinic rooms, even after thorough cleaning. This discovery highlights the sensitivity of the method and raises concerns about the potential for airborne transmission in healthcare settings.

This study represents a crucial step forward in understanding how TB spreads and improving early detection of infectious individuals, particularly in areas where obtaining sputum samples is challenging. The research also revealed some trends: higher detection rates were associated with men who had heavy bacterial loads in their sputum, while patients with fever were slightly less likely to test positive in air samples.

Key Findings and Implications

• THOR Device: The THOR device uses electrostatic sampling to capture aerosols from exhaled air, making it possible to detect TB DNA without relying on sputum samples.
• Sensitivity and Specificity: The method showed a sensitivity of 47% among participants with positive sputum tests and 57% among those with high bacterial loads. Its specificity was 77%, meaning it correctly identified most individuals without TB.
• Environmental Air Samples: Researchers found TB DNA in 30% of air samples from clinic rooms, emphasizing the need for improved infection control measures in healthcare facilities.
• Demographic Trends: Men with heavy bacterial loads had higher detection rates, while patients with fever were less likely to test positive in air samples.

Future Prospects

The development of this technology could significantly impact TB diagnosis, especially in resource-limited settings where sputum collection is often impractical. By providing an alternative method, the THOR device has the potential to improve early detection and reduce the spread of the disease. Further research will be needed to refine the technology and assess its effectiveness in different populations and environments.

As the global health community continues to seek better tools for combating TB, innovations like the THOR device offer hope for more efficient and accessible diagnostic methods. With continued investment and research, such advancements could play a critical role in the fight against one of the world’s oldest and most persistent diseases.