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Golub, Jonathan Ea; Saraceni, Valeriab; Cavalcante, Solange Cb,c; Pacheco,
Antonio Gb,c; Moulton, Lawrence Ha; King, Bonnie Sa; Efron, Annea; Moore,
Richard Da; Chaisson, Richard Ea; Durovni, Betinab,c

From the aCenter for Tuberculosis Research and Departments of Medicine and
International Health, Johns Hopkins University, Baltimore, Maryland, USA

bMunicipal Health Secretariat, Rio de Janeiro, Brazil

cFiocruz, Rio de Janeiro and Federal University of Rio de Janeiro, Rio de
Janeiro, Brazil.

Abstract


Background: Tuberculosis is a common complication and leading cause of death in
HIV infection. Antiretroviral therapy (ART) lowers the risk of tuberculosis, but
may not be sufficient to control HIV-related tuberculosis. Isoniazid preventive
therapy (IPT) reduces tuberculosis incidence significantly, but is not widely
used.

Methods: We analysed tuberculosis incidence in 11 026 HIV-infected patients
receiving medical care at 29 public clinics in Rio de Janeiro, Brazil, between 1
September 2003 and 1 September 2005. Data were collected through a retrospective
medical record review. We determined rates of tuberculosis in patients who
received neither ART nor IPT, only ART, only IPT, or both ART and IPT.

Results: The overall tuberculosis incidence was 2.28 cases/100 person-years (PY)
[95% confidence interval (CI) 2.06-2.52]. Among patients who received neither
ART nor IPT, incidence was 4.01/100 PY. Patients who received ART had an
incidence of 1.90/100 PY (95% CI 1.66-2.17) and those treated with IPT had a
rate of 1.27/100 PY (95% CI 0.41-2.95). The incidence among patients who
received ART and IPT was 0.80/100 PY (95% CI 0.38-1.47). Multivariate Cox
proportional hazards modeling revealed a 76% reduction in tuberculosis risk
among patients receiving both ART and IPT (adjusted relative hazard 0.24; P <
0.001) after adjusting for age, previous tuberculosis diagnosis, and CD4 cell
counts at baseline.

Conclusion: The use of both IPT and ART in HIV-infected patients is associated
with significantly reduced tuberculosis incidence. In conjunction with expanded
access to ART, the wider use of IPT in patients with HIV will improve
tuberculosis control in high burden areas.