Tuberculosis chemotherapy and sputum conversion among HIV-seropositive and HIV-seronegative patients in south-eastern Uganda

Abstract

Objective: To investigate if there is a difference in response to tuberculosis treatment between HIV seronegative and HIV seropositive patients following two months of intensive phase tuberculosis treatment.

Design: Prospective cohort study.

Setting: St. Francis Leprosy Centre, south-east Uganda.

Subjects: Four hundred fifty seven patients with never previously treated sputum smear-positive tuberculosis admitted during a two-year period in 1991/1993.

Intervention: Intensive phase treatment with streptomycin, isoniazid, rifampicin and pyrazinamide.

Main outcome measures: Sputum conversion from a positive to a negative smear at eight weeks of treatment.

Results: HIV seropositivity prevalence was 28%. Among HIV seronegative patients, conversion to a negative smear status occurred in 76% persons compared to 78% in HIV seropositive patients. This difference was not statistically significant (OR = 0.9; 95% CI, 0.6-1.5). HIV seropositive patients, however, were more likely to die (p = 0.017). A high prevalence of resistance to isoniazid and streptomycin was found. Isoniazid resistance was more likely in HIV seronegative patients with M. tuberculosis strains compared to HIV seropositive persons (p < 0.005). Initial resistance to antituberculosis drugs did not have a significant effect on smear conversion.

Conclusion: This study demonstrates that HIV-seropositive status is not a principal factor in delaying sputum conversion among patients receiving intensive phase tuberculosis treatment.

PIP: A prospective cohort study was undertaken to investigate the response of HIV-seropositive and -seronegative patients at St. Francis Leprosy Center, southeastern Uganda, to tuberculosis chemotherapy. The study population included 457 patients without a history of prior tuberculosis therapy between 1991 and 1993. The subjects were exposed to an intensive phase therapy of rifampicin, streptomycin, isoniazid, and pyrazinamide. After the treatment, sputum culture and sensitivity tests were conducted. Findings showed that 77% of the patients who never received tuberculosis treatment in the past converted to a negative smear status after the 8-week treatment. There was no significant difference in sputum conversion rates between HIV-seropositive and -seronegative patients. The study also revealed that HIV seropositivity prevalence was 28%. Among HIV-seronegative patients, conversion to a negative smear status occurred in 76% compared to 78% HIV-seropositive patients. Moreover, a significant number of HIV-seronegative patients died during the initial course of the therapy. Also, a high prevalence of isoniazid and streptomycin resistance was noted; however, this result never affected the conversions of smears. In conclusion, the study clearly demonstrates that other factors outside the seropositive status may be the principal causes of the delay in sputum conversion among patients receiving intensive tuberculosis chemotherapy.