Drug susceptibility of Mycobacterium tuberculosis in HIV-infected and -uninfected Ethiopians and its impact on outcome after 24 months of follow-up

From a prospective cohort study on tuberculosis/human immunodeficiency virus (TB/HIV) interaction in Addis Ababa, Ethiopia, drug susceptibility results were available for 94 TB patients (46% HIV-infected). Resistance to one or more drug(s) was detected in 21 (22.3%) and multidrug resistance in five (5.3%) patients. Occurrence of resistance was not related to HIV status or outcome after 24 months of follow-up. However, among HIV-infected TB patients who died during follow-up, survival time in those with a resistant Mycobacterium tuberculosis strain was significantly shorter compared to those with a sensitive strain (6 vs. 13 months). Early detection of drug resistance and timely treatment change can therefore have a positive impact on survival in HIV-infected TB patients.

Analysis of the population structure of Mycobacterium tuberculosis in Ethiopia, Tunisia, and The Netherlands: usefulness of DNA typing for global tuberculosis epidemiology

The genetic heterogeneity among Mycobacterium tuberculosis isolates from 501 patients in Ethiopia, Tunisia, and the Netherlands was compared by analysis of DNA polymorphism driven by insertion element IS6110. The percentage of isolates displaying two or more identical patterns differed greatly in the three countries: It was highest among Tunisian isolates and lowest in Dutch isolates. In contrast to isolates from Dutch subjects infected with M. tuberculosis, the majority of strains from Ethiopia and Tunisia were from a few families of genetically highly related strains. Furthermore, little overlap was observed among isolates from the three countries, indicating strict isolation of the bacterial reservoirs in the countries. A few strains from the Netherlands matched strains from Ethiopia and Tunisia. Those strains were invariably isolated from refugees, immigrants, or persons who visited Ethiopia or Tunisia.