Update on the treatment of tuberculosis and latent tuberculosis infection

Tuberculosis (TB) has emerged as a global public health epidemic. Despite decreasing numbers of cases in the United States since 1992, TB remains a serious public health problem among certain patient populations and is highly prevalent in many urban areas. The responsibility for prescribing an appropriate drug regimen and ensuring that treatment is completed is assigned to the public health program or the clinician not to the patient. The initial prescribed regimen for the treatment of TB usually consists of 4 drugs: isoniazid, rifampin, pyrazinamide, and ethambutol. The minimum length for the treatment of drug-susceptible TB with a rifampin-based regimen is 6 to 9 months. Providing medications directly to the patient and watching him/ her swallow the anti-TB drugs, which is termed directly observed therapy, is recommended for all patients diagnosed with TB and can help ensure higher completion rates, prevent the emergence of drug resistant TB, and enhance TB control. There has been renewed interest in the treatment of those with latent TB infection as a TB-control strategy in the United States for eliminating the large reservoir of individuals at risk for progression to TB. The 2 broad categories of persons who should be tested for latent TB infection are those who are likely to have been recently infected (such as contacts to infectious TB cases) and persons who are at increased risk of progression to TB disease following infection with Mycobacterium tuberculosis (eg, human immunodeficiency virus infection and selected medical conditions; recent immigrants to the United States from high TB-burden countries). The preferred regimen for the treatment of latent TB infection is 9 months of isoniazid. There is now renewed interest in and great need for the development of new drugs to treat TB and latent TB infection.