Bacteremic disseminated tuberculosis in sub-saharan Africa: a prospective cohort study

Abstract

Background: Disseminated tuberculosis is a major health problem in countries where generalized human immunodeficiency virus (HIV) infection epidemics coincide with high tuberculosis incidence rates; data are limited on patient outcomes beyond the inpatient period.

Methods: We enrolled consecutive eligible febrile inpatients in Moshi, Tanzania, from 10 March 2006 through 28 August 2010; those with Mycobacterium tuberculosis bacteremia were followed up monthly for 12 months. Survival, predictors of bacteremic disseminated tuberculosis, and predictors of death were assessed. Antiretroviral therapy (ART) and tuberculosis treatment were provided.

Results: A total of 508 participants were enrolled; 29 (5.7%) had M. tuberculosis isolated by blood culture. The median age of all study participants was 37.4 years (range, 13.6-104.8 years). Cough lasting >1 month (odds ratio [OR], 13.5; P< .001), fever lasting >1 month (OR, 7.8; P = .001), weight loss of >10% (OR, 10.0; P = .001), lymphadenopathy (OR 6.8; P = .002), HIV infection (OR, undefined; P < .001), and lower CD4 cell count and total lymphocyte count were associated with bacteremic disseminated tuberculosis. Fifty percent of participants with M. tuberculosis bacteremia died within 36 days of enrollment. Lower CD4 cell count (OR, 0.88; P = .049) and lower total lymphocyte count (OR, 0.76; P = .050) were associated with death. Magnitude of mycobacteremia tended to be higher among those with lower CD4 cell counts, but did not predict death.

Conclusions: In the era of free ART and access to tuberculosis treatment, almost one half of patients with M. tuberculosis bacteremia may die within a month of hospitalization. Simple clinical assessments can help to identify those with the condition. Advanced immunosuppression predicts death. Efforts should focus on early diagnosis and treatment of HIV infection, tuberculosis, and disseminated disease.

Figure 1.

Survival curve of participants with bacteremic disseminated tuberculosis, Kilimanjaro Christian Medical Centre and Mawenzi Regional Hospital, 2006–2010 (n = 29).

Figure 2.

Number of Mycobacterium tuberculosis colony-forming units per milliliter by CD4-positive T-lymphocyte count among participants with bacteremic disseminated tuberculosis, Kilimanjaro Christian Medical Centre and Mawenzi Regional Hospital, 2006–2010 (n = 9). Abbreviation: CFU, colony-forming unit.