Isoniazid preventive therapy lowered the risk of tuberculosis more than 25% in a large cluster-randomized trial of HIV-positive people in Rio de Janeiro, Brazil. Isoniazid cut the risk of TB or death 30%.
Therapy to prevent TB in HIV-positive people is effective but remains sporadically implemented in regions with moderate or high TB burden. To test the widespread use of isoniazid preventive therapy in HIV-positive people of Rio de Janeiro, researchers conducted this cluster-randomized trial at 29 HIV clinics from September 2005 through August 2009. Antiretroviral therapy is free to eligible patients in Brazil.
HIV clinic staff were trained in TB screening, tuberculin skin testing, and use of isoniazid preventive therapy. The investigators randomly assigned two clinics to start the isoniazid intervention every 2 months. They compared TB incidence and death in periods with and without the isoniazid intervention.
Among 17,413 people in care at the HIV clinics, 12,816 were eligible for isoniazid preventive therapy. During the study period, TB developed in 475 people and 838 died. After the intervention began, the rate of tuberculin skin testing rose from 19 to 59 per 100 person-years overall and from 36 to 144 per 100 person-years in people eligible for isoniazid preventive therapy.
In the period without the intervention, TB was diagnosed in 221 people for an incidence of 1.31 per 100 person-years. With the intervention there were 254 TB diagnoses for an incidence of 1.10 per 100 person-years.
Statistical analysis adjusted for age, gender, initial CD4 count, and use of antiretroviral therapy determined that isoniazid preventive therapy lowered the risk of TB slightly more than 25% (adjusted hazard ratio 0.73, 95% confidence interval 0.54 to 0.99), while lowering the risk of TB or death about 30% (adjusted hazard ratio 0.69, 95% confidence interval 0.57 to 0.83).
The researchers conclude that “scale-up of [TB] preventive therapy for HIV-infected patients in settings of moderate tuberculosis incidence is achievable and should be widely implemented in Brazil and elsewhere.”
Source: Betina Durovni, Valeria Saraceni, Lawrence H. Moulton, Antonio G. Pacheco, Solange C. Cavalcante, Bonnie S. King, Silvia Cohn, Anne Efron, Richard E. Chaisson, Jonathan E. Golub. Effect of improved tuberculosis screening and isoniazid preventive therapy on incidence of tuberculosis and death in patients with HIV in clinics in Rio de Janeiro, Brazil: a stepped wedge, cluster-randomised trial. Lancet Infectious Diseases. 2013; 13: 852-858.
For the study abstract
(Downloading the complete article requires a subscription to Lancet Infectious Diseases or an online payment; the abstract is free.)
For trial details at ClinicalTrials.gov
Source: IAS