Fast track — ArticlesEffect of highly active antiretroviral therapy on incidence of tuberculosis in South Africa: a cohort study
Introduction
More than 70% of the 36·1 million HIV-1-infected individuals worldwide live in sub-Saharan Africa, and a high proportion of these are co-infected with tuberculosis.1, 2 An accelerated course of HIV-1 infection after the onset of tuberculosis has been reported in many studies.3, 4, 5, 6
Tuberculosis is the leading cause of morbidity and mortality among HIV-1-infected patients in sub-Saharan Africa.7, 8, 9 Unlike other HIV-1-related opportunistic infections, tuberculosis occurs at all levels of CD4 count,9, 10, 11 is infectious, and its prevention is a major public-health priority.
Tuberculosis control programmes based on passive case finding and treatment of sputum-smear-positive disease by short-courses of directly observed chemotherapy (DOTS) have been successful in developed countries. However, these strategies have failed to achieve similar success in countries with high burdens of HIV-1 infection.12, 13 Consequently, WHO has formulated a strategic framework aimed at functional integration of control programmes for tuberculosis and HIV/AIDS.14
The survival benefits associated with highly active antiretroviral therapy (HAART) are well documented; however, studies assessing the effect of HAART on tuberculosis have shown variable results. Although some studies have shown that HAART can reduce the risk of tuberculosis by more than 80%,15, 16, 17 others have reported no significant reduction.18, 19 No similar studies have been done in sub-Saharan Africa because only a tiny minority of the population presently has access to HAART. The UN has mobilised the Great Global Alliance to facilitate increased access to antiretroviral therapy in resource-limited settings.20
We did an observational study to compare the risk of tuberculosis in indigent cohorts of HIV-1-infected patients without access to HAART and in those receiving this treatment through participation in phase III randomised trials at a public health-care facility in Cape Town, South Africa.
Section snippets
Patients
New Somerset Hospital HIV Clinic, University of Cape Town, South Africa, is a major public health-care facility dedicated to HIV-1-infected patients in Cape Town. It was established in 1986, and serves largely indigent patients who are referred to the clinic from a wide range of primary health-care facilities in Cape Town. Antiretroviral therapy is not available in the public sector in South Africa, and patients access HAART through participation in clinical trials. Patients who expressed
Results
1085 patients in the non-HAART cohort and 270 patients in the HAART cohort were studied. 315 patients were excluded from the non-HAART cohort: 79 were on antiretroviral monotherapy or dual therapy, isoniazid prophylaxis, or both; 222 presented with tuberculosis at their initial clinic visit; and 14 incident cases received tuberculosis chemotherapy but did not meet the tuberculosis case definition. The remaining 770 patients were included in the analysis. Of the 270 patients recruited in the
Discussion
We have shown a substantial reduction in tuberculosis incidence attributable to HAART in HIV-1-infected individuals in sub-Saharan Africa. This study differs from previous reports because the high frequency of tuberculosis in our cohort allowed quantification of the protective effect of HAART at the different stages of HIV-1 disease. The effect of HAART was significant across all the baseline immunological, clinical, and socioeconomic variables in our cohort, except in patients with CD4 counts
References (26)
- et al.
Response to treatment, mortality, and CD4 lymphocyte counts in HIV-infected persons with tuberculosis in Abidjan, Cote d'Ivoire
Lancet
(1995) - et al.
Spectrum of immunodeficiency in HIV-1-infected patients with pulmonary tuberculosis in Zaire
Lancet
(1993) - et al.
Deaths from tuberculosis in sub-Saharan African countries with a high prevalence of HIV-1
Lancet
(2001) - et al.
Randomised trial of isoniazid versus rifampicin and pyrazinamide for prevention of tuberculosis in HIV-1 infection
Lancet
(1998) AIDS epidemic update, December 2000
(2000)- et al.
Global burden of tuberculosis: estimated incidence, prevalence, and mortality by country
JAMA
(1999) - et al.
Association between tuberculosis and HIV disease progression in a high tuberculosis prevalence area
Int Tuberc Lung Dis
(2001) - et al.
Impact of pulmonary tuberculosis on survival of HIV-infected adults: a prospective epidemiologic study in Uganda
AIDS
(2000) - et al.
Progression of human immunodeficiency virus in patients with tuberculosis disease
Am J Epidemiol
(1997) - et al.
Accelerated course of human immunodeficiency virus infection after tuberculosis
Am J Respir Crit Care Med
(1995)
Tuberculosis and HIV infection in sub-Saharan Africa
JAMA
HIV-related morbidity and mortality in sub-Saharan Africa: opportunities for prevention
AIDS
Tuberculosis should not be considered an AIDS-defining illness in areas with a high tuberculosis prevalence
Int Tuberc Lung Dis
Cited by (516)
Incidence and predictors of tuberculosis among children on antiretroviral therapy at northeast Ethiopia comprehensive specialized hospitals, 2022; A multicenter retrospective follow-up study
2022, HeliyonCitation Excerpt :This study determined that the overall incidence rate of tuberculosis among children receiving ART in the comprehensive specialized hospitals in northeast Ethiopia was 2.0 (95% CI: 1.5–2.6) per 100 person-years. This result was similar to that of research conducted in Ethiopia's northwest [18] and SNNPR regions [25] and in South Africa [26]. It could be due to shared socioeconomic and demographic factors, HIV treatment facilities, and HIV treatment recommendations.
Incidence and risk factors for tuberculosis among people living with HIV in Bangui: A cohort study
2022, Public Health in PracticeHIV treatment and worker absenteeism: Quasi-experimental evidence from a large-scale health program in South Africa
2021, Journal of Health EconomicsPrevalence of positive IGRAs and innate immune system in HIV-infected individuals in Japan
2021, Journal of Infection and Chemotherapy