What is the first-line treatment for latent tuberculosis infection?

The first-line treatment for latent tuberculosis infection is isoniazid for 9 months. This approach is widely adopted because isoniazid has been shown to effectively reduce the risk of developing active tuberculosis in individuals with latent TB, which is characterized by the presence of Mycobacterium tuberculosis without clinical symptoms or transmission.

Isoniazid works by inhibiting the synthesis of mycolic acids, which are essential components of the bacterial cell wall. The 9-month duration of isoniazid treatment has been supported by research demonstrating its efficacy in both preventing the progression to active disease and reducing transmission risk. It is essential to identify and treat latent tuberculosis, especially in at-risk populations, to control and eliminate tuberculosis as a public health issue.

Other options, while they have their indications in the treatment of active tuberculosis or other bacterial infections, are not suitable for the treatment of latent TB. For instance, rifampicin is often used in active TB regimens, and pyrazinamide and ethambutol are commonly included in multi-drug treatment for active TB. However, they are not the preferred agents for latent infection therapy, where isoniazid's long-term effectiveness has been clearly established.