Incidence and Risk Factors of Tuberculosis in Human Immunodeficiency Virus-Infected Patients in Korea

Shin, Hyoung Shik; Kim, Ui Seok; Kim, Nam Joong; Oh, Myoung Don; Choe, Kangwon

Abstract

BACKGROUND: Tuberculosis is the most frequent opportunistic infection in HIV-infected patients in Korea. We examined the incidence and risk factors for tuberculosis in HIV-infected patients.
METHODS
We reviewed the medical records of 143 HIV-infected patients between January 1988 and June 1997 at the Seoul National University Hospita The incidence of tuberculosis was determined by the number of new tuberculosis per 100 patients divided by a total duration of follow-up (cases/100 person- years). The incidence of tuberculosis was analyzed with respect to CD4+ lymphocyte count, status of tuberculin skin reaction, and status of delayed hypersensitivity skin reaction.
RESULTS
The total duration of follow-up was 229.6 person-years. During follow-up, 22 patients developed tuberculosis [9.6 cases per 100 person-years (95% CI, 6.0 to 14.5)]. The incidence of tuberculosis according to sex and transmission route showed no significant difference. Tuberculosis occurred more frequently in patients with minimum CD4+ T lympho-cyte counts of less than 200 cells/mm3 (14.2 cases/100 person-years) than in those with higher T lymphocyte counts (3.9 cases/100 person-years) [relative risk, 4.02 (95% CI 1.32 to 12.5), P=0.009]. The incidence of tuberculosis was higher among tuberculin- positive patients [17.0 cases/100 person-years (95% CI, 9.0 to 29.0)] than among tuberculin-negative [8.0 cases/100 person-years (95% CI, 3.2 to 16.6)], but the difference was not statistically significant [relative risk, 2.35 (95% CI, 0.88 to 6.26, P=0.078)]. The rate of tuberculosis in patients with negative delayed hypersensitivity test was not significantly different from that in patients with positive results (P=0.510).
CONCLUSION
The incidence of tuberculosis was 9.6 cases per 100 person-years. CD4+ lymphocyte count (<200 cells/mm3) was the most useful predictor for the development of tuberculosis in HIV patients in Korea.