Isoniazid preventive therapy and 4-year incidence of pulmonary tuberculosis among HIV-infected Thai patients.
METHODS
Human immunodeficiency virus (HIV) clinics at two Thai tertiary care medical centres.


OBJECTIVE
To evaluate the efficacy of tuberculin skin test (TST) guided isoniazid preventive therapy (IPT) in combination with antiretroviral therapy (ART) in the prevention of tuberculosis  (TB).


METHODS
A 4-year prospective comparative study of patients at two HIV clinics: one performed TST at enrolment and, if positive, prescribed IPT (IPT group), while the other did not perform TST (non-IPT group).


RESULTS
There were 200 patients included in each group. Baseline characteristics  and drop-out rates were similar in both groups. The incidence of pulmonary TB over 4 years was not significantly different between the IPT and non-IPT groups (0.80 cases vs. 1.76 per 100 person-years [py], P = 0.13). However, the incidence of pulmonary TB in the non-IPT group was significantly  higher during the first 6 months (8.60 vs. 0 cases/100 py, P = 0.01) and among patients with initial CD4 < 200 cells/l (9.41 vs. 0 cases/100 py, P = 0.02). The survival analyses demonstrated a protective effect of IPT (x(2) = 3.66, P = 0.04) for early TB.


CONCLUSIONS
Benefit of IPT plus ART was evident only in the first 6 months of care. These findings suggest that TST-guided IPT should be routinely provided for HIV-infected patients after initial entry into medical care.
Division of Infectious Diseases, Faculty of Medicine, Thammasat University Hospital, Pathumthani, Thailand.
T
T
Khawcharoenporn
A
A
Apisarnthanarak
W
W
Manosuthi
S
S
Sungkanuparph
L M
LM
Mundy
D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D000995:Antitubercular Agents / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy; D006801:Humans; D015994:Incidence; D007538:Isoniazid / Q000627:therapeutic use*; D008297:Male; D011446:Prospective Studies; D013785:Thailand / Q000453:epidemiology; D013997:Time Factors; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control*
D019380:Anti-HIV Agents; D000995:Antitubercular Agents; D007538:Isoniazid