Impact of isoniazid preventive therapy for HIV-infected adults in Rio de Janeiro, Brazil: an epidemiological model.
BACKGROUND
The potential epidemiological impact of isoniazid preventive therapy (IPT), delivered at levels that could be feasibly scaled up among people living with HIV (PLHIV) in modern, moderate-burden settings, remains uncertain.


METHODS
We used routine surveillance and implementation data from a cluster-randomized trial of IPT among HIV-infected clinic patients with good access to antiretroviral therapy in Rio de Janeiro, Brazil, to populate a parsimonious transmission model of tuberculosis (TB)/HIV. We modeled IPT delivery as a constant process capturing a proportion of the eligible population every year. We projected feasible reductions in TB incidence and mortality in the general population and among PLHIV specifically at the end of 5 years after implementing an IPT program.


RESULTS
Data on time to IPT fit an exponential curve well, suggesting that IPT was delivered at a rate covering 20% (95% confidence interval: 16% to 24%) of the 2500 eligible individuals each year. By the end of year 5 after modeled program rollout, IPT had reduced TB incidence by 3.0% [95% uncertainty range (UR): 1.6% to 7.2%] in the general population and by 15.6% (95% UR: 15.5% to 36.5%) among PLHIV. Corresponding reductions in TB mortality were 4.0% (95% UR: 2.2% to 10.3%) and 14.3% (14.6% to 33.7%). Results were robust to wide variations in parameter values on sensitivity analysis.


CONCLUSIONS
TB screening and IPT delivery can substantially reduce TB incidence and mortality among PLHIV in urban, moderate-burden settings. In such settings, IPT can be an important component of a multi-faceted strategy to feasibly reduce the burden of TB in PLHIV.
*Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD; †Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; ‡Subsecretariat for Primary Care, Surveillance, and Health Promotion, Municipal Health Secretariat, Rio de Janeiro, Brazil; §Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; ‖Program of Scientific Computing, Fiocruz, Rio de Janeiro, Brazil; ¶Evandro Chagas Institute of Clinical Research, Fiocruz, Rio de Janeiro, Brazil; and #Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
David W
DW
Dowdy
Jonathan E
JE
Golub
Valeria
V
Saraceni
Lawrence H
LH
Moulton
Solange C
SC
Cavalcante
Silvia
S
Cohn
Antonio G
AG
Pacheco
Richard E
RE
Chaisson
Betina
B
Durovni
D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D000995:Antitubercular Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001938:Brazil / Q000453:epidemiology; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy* / Q000635:transmission; D006801:Humans; D007538:Isoniazid / Q000008:administration & dosage / Q000494:pharmacology*; D008875:Middle Aged; D014376:Tuberculosis / Q000517:prevention & control* / Q000635:transmission; D014505:Urban Population; D055815:Young Adult
D019380:Anti-HIV Agents; D000995:Antitubercular Agents; D007538:Isoniazid