The impact of antiretroviral therapy and isoniazid preventive therapy on tuberculosis incidence in HIV-infected patients in Rio de Janeiro, Brazil.
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.


CONCLUSIONS
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.
Golub
Jonathan E
JE
Center for Tuberculosis Research, Johns Hopkins University, Baltimore, Maryland 21231, USA.
Saraceni
Valeria
V
Cavalcante
Solange C
SC
Pacheco
Antonio G
AG
Moulton
Lawrence H
LH
King
Bonnie S
BS
Efron
Anne
A
Moore
Richard D
RD
Chaisson
Richard E
RE
Durovni
Betina
B
D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D000995:Antitubercular Agents / Q000627:therapeutic use*; D001938:Brazil; D018791:CD4 Lymphocyte Count; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000382:microbiology; D015497:HIV-1; D006801:Humans; D015994:Incidence; D007538:Isoniazid / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D014376:Tuberculosis / Q000517:prevention & control*; D019562:Viral Load
D044966:Anti-Retroviral Agents; D000995:Antitubercular Agents; D007538:Isoniazid