Tuberculosis (TB) is the most common opportunistic infection with a high mortality rate among HIV-infected individuals. The risk of TB in HIV-infected persons continues to increase as HIV disease progresses and immunity decreases. There are persons who are HIV negative but are at risk of developing TB disease by virtue of having immunosuppression from medications or disease. It has been found that a vast majority of people infected with TB do not have no signs or symptoms of TB but are at high risk of active TB disease when the immune system becomes compromised. This state is known as Latent TB infection (LTBI) and is defined as ‘a state of persistent immune response to stimulation by Mycobacterium tuberculosis antigens with no evidence of clinically manifest active TB(1).
TB Preventive Therapy (TPT) is the administration of one or more anti-tuberculous drugs to individuals with latent TB infection to prevent progression to active disease. WHO recommends the use of Isoniazid for 6 months in resource-limited settings for the prevention of TB in at risk populations living in high TB incidence, prevalence and transmission settings. The use of Isoniazid is one of the ways in which active TB disease is prevented among at-risk populations in high TB incidence settings.
Others include Rifampicin and Isoniazid taken daily for 3 months and Rifapentine plus Isoniazid weekly for 3 months.