New Method To Diagnose Tuberculosis

Tuberculosis (TB) is a infectious disease that mainly affects your lungs. The bacteria that cause tuberculosis, Mycobacterium tuberculosis, are spread from one person to another through air via coughs and sneezes. Tuberculosis used to be rare in developed countries, but infections began increasing in 1985, partly because of the emergence of HIV. HIV weakens the immune system, making it unable to fight TB.

Mycobacterium Tuberculosis
Although your body may harbor the bacteria that cause tuberculosis, your immune system usually can prevent you from becoming sick. For this reason, doctors make a distinction between latent and active TB. In latent TB, also called inactive TB,  you have a TB infection, but the bacteria remain in your body in an inactive state and cause no symptoms. This form isn't contagious, but it can turn into active TB, so treatment is important. An estimated 2 billion people have latent TB. Active TB makes you sick and can spread to others. It can occur in the few weeks after infection of the TB bacteria, or occur years later.

New Method To Diagnose

Researchers have now developed a new approach to the diagnosis of tuberculosis, reported in PeerJ. The method relies on sequencing of DNA extracted from sputum to detect and characterize the Mycobacterium Tuberculosis that cause TB, without the need for time-consuming culture of bacteria in the laboratory.

The team detected  sequences from the TB bacteria in all eight sputum samples they investigated and were able to assign the bacteria to a known lineage in seven of the samples. Two samples were found to contain sequences from Mycobacterium africanum, a variety of the TB bacterium that is particular to West Africa.

The research team aim to test the  technique on a variety of samples, and hope that it will help detect mixed infections caused by more than one kind of bacterium. However, it is still some time before it can be used as a routine diagnostic tool.