Isoniazid preventive therapy (IPT) is the administration of isoniazid (INH) to people with latent tuberculosis (TB) infection (LTBI) to prevent progression to active TB disease. Despite being life-saving for human immunodeficiency virus (HIV)-infected persons who do not have active TB, IPT is poorly implemented globally due to misconceptions shared by healthcare providers and policy makers. However, amongst HIV-infected patients especially those living in resource-limited settings with a high burden of TB, available evidence speaks for IPT: Among HIV-infected persons, active TB- the major contraindication to IPT, can be excluded with symptom screening; chest X-ray and tuberculin skin testing are unreliable and often lead to logistic delays resulting in increased numbers of people with LTBI progressing to active TB; the use of IPT has not been found to increase the risk of the development of INH mono-resistance; IPT is cost-effective and cheaper than the cost of treating cases of active TB that would develop without IPT; ART and IPT have an additive effect on the prevention of TB, and both are safe and beneficial even in children. In order to sustain the recorded gains from ART scale-up and to further reduce TB-related morbidity and mortality, more efforts are needed to scale-up IPT implementation globally.
Keywords: Chemoprophylaxis; Human immunodeficiency virus; Isoniazid preventive therapy; Tuberculosis.