A recent study from Karolinska Institutet has evaluated a new rapid test for detecting latent tuberculosis infection, showing potential benefits for use in areas with limited resources. The research was published in Clinical Infectious Diseases.
Tuberculosis continues to be one of the most lethal infectious diseases globally. Early detection and preventive treatment of individuals with latent infection are essential steps to reduce new cases and prevent the spread of active disease.
The standard method for diagnosing latent tuberculosis is the QuantiFERON-TB Gold Plus laboratory test, which requires several processing steps, takes up to two days for results, and depends on advanced laboratory facilities and skilled personnel. These requirements make it difficult to implement in high-prevalence regions lacking such infrastructure.
Researchers at Karolinska Institutet, working with colleagues in Vietnam, compared QuantiFERON-TB Gold Plus to TB-Feron, a point-of-care test that delivers results within 15 minutes without needing specialized laboratories or staff.
The study involved 345 adults in Hanoi, Vietnam. Participants were grouped as people with confirmed tuberculosis, household contacts of those with infectious tuberculosis, and individuals without known exposure. Each participant was tested using both TB-Feron and QuantiFERON-TB Gold Plus.
TB-Feron demonstrated a sensitivity of 88 percent in identifying expected positive cases, while QuantiFERON-TB Gold Plus showed a slightly higher sensitivity at 92 percent. However, TB-Feron’s specificity—its ability to correctly identify healthy individuals—was lower at 70 percent compared to 96 percent for the established laboratory test.
For household contacts of infected patients, there was good agreement between the two tests; 92 percent concordance was observed for positive samples. The study also found no systematic differences when comparing TB-Feron results obtained by different groups of laboratory staff, suggesting reliable reproducibility.
"This test can help more people with latent tuberculosis to be detected and receive preventive treatment, especially in rural areas in countries with limited resources," said Lina Davies Forsman, last author and researcher at Karolinska Institutet.
