Mortality in patients with HIV-1 and tuberculosis co-infection in Rio de Janeiro, Brazil - associated factors and causes of death

Abstract

Background: Tuberculosis is the most frequent opportunistic infection and the leading cause of death among persons living with HIV in several low and middle-income countries. Mortality rates during tuberculosis treatment and death causes among HIV-1/TB co-infected patients may differ based on the immunosuppression severity, timing of diagnosis and prompt initiation of tuberculosis and antiretroviral therapy.

Methods: This was a retrospective observational study conducted in the clinical cohort of patients with HIV-1/Aids of the National Institute of Infectious Diseases Evandro Chagas, Rio de Janeiro, Brazil. All HIV-1 infected patients who started combination antiretroviral therapy up to 30 days before or within 180 days after the start of tuberculosis treatment from 2000 to 2010 were eligible. Causes of death were categorized according to the "Coding Causes of Death in HIV" (CoDe) protocol. The Cox model was used to estimate the hazard ratio (HR) of selected mortality variables.

Results: A total of 310 patients were included. Sixty-four patients died during the study period. Mortality rate following tuberculosis treatment initiation was 44 per 100 person-years within the first 30 days, 28.1 per 100 person-years within 31 and 90 days, 6 per 100 person-years within 91 and 365 days and 1.6 per 100 person-years after 365 days. Death probability within one year from tuberculosis treatment initiation was approximately 13%. In the adjusted analysis the associated factors with mortality were: CD4 ≤ 50 cells/mm3 (HR: 3.10; 95% CI: 1.720 to 5.580; p = 0.00); mechanical ventilation (HR: 2.81; 95% CI: 1.170 to 6.760; p = 0.02); and disseminated tuberculosis (HR: 3.70; 95% CI: 1.290 to 10.590, p = 0.01). Invasive bacterial disease was the main immediate cause of death (46.9%).

Conclusion: Our results evidence the high morbidity and mortality among patients co-infected with HIV-1 and tuberculosis in Rio de Janeiro, Brazil. During the first year following tuberculosis diagnosis, mortality was the highest within the first 3 months, being invasive bacterial infection the major cause of death. In order to successfully intervene in this scenario, it is utterly necessary to address the social determinants of health contributing to the inequitable health care access faced by this population.

Keywords: Bacterial disease; Brazil; CoDe; Cohort study; HIV/Aids; Mortality; Tuberculosis.

Fig. 1

Flowchart of inclusion/exclusion criteria for HIV-1/TB co-infected patients, INI-Fiocruz Cohort, 2000–2010

Fig. 2

Kaplan-Meier survival curve after TB treatment initiation according to TB clinical presentation, n = 310, INI-Fiocruz cohort, 2000–2010