Primary and secondary tuberculosis preventive treatment in HIV clinics: simulating alternative strategies.

BACKGROUND

Isoniazid preventive treatment (IPT) has been recommended for human immunodeficiency virus (HIV) infected individuals.

OBJECTIVE/

DESIGN

We used a mathematical model to simulate the benefits and risks of preventive treatment delivered through antiretroviral (ARV) clinics using clinical data from Botswana.

RESULTS

Preventive treatment was found to reduce the incidence of tuberculosis (TB) by at least 12 cases per 100000 population per year versus the scenario without such treatment over a 50-year simulation. Isoniazid (INH) resistant TB was observed to increase by <1% per year, even when using pessimistic assumptions about resistance emergence. The use of tuberculin skin testing had little impact as a screening procedure, while secondary treatment was observed to nearly double the impact of a preventive treatment program. Regardless of whether or not preventive treatment was implemented, INH-resistant TB rose in the context of increasing HIV prevalence, but was minimally amplified by preventive treatment itself.

CONCLUSIONS

IPT programs implemented through ARV clinics may be effective at reducing TB incidence. The resistance contribution of IPT appears unlikely to supersede its overall incidence and mortality benefits.