Genetic patterns, sublineages and dynamics of tuberculosis transmission in Cuba, a low burden country

Abstract

Context: In Cuba, a country with a low incidence of tuberculosis (TB), there is no information on the dynamics of transmission of the disease for two decades. Aims: Determine the genetic patterns and sublineages of Mycobacterium tuberculosis complex (MTBC) isolates circulating in 2009 and their relationship with the epidemiological data of the patients. Settings and Design: A retrospective descriptive study was carried out in Cuba with 178 MTBC isolates. Methods and Material: Spoligotyping and mycobacterial interspersed repetitive unit variable number tandem repeat (MIRU-VNTR) typing with 24 loci were performed. Statistical analysis used: Nonparametric methods, analysis of variance and homogeneity test, using the statistical package Statgraphics Plus version 2.1 were used. Results: Spoligotyping produced 39 spoligotypes. The S, Beijing, LAM and Haarlem sublineages prevailed. The clustering rate was 75.84% and the Hunter-Gaston discriminatory index (HGDI): 0.8734. MIRU-VNTR typing with 24 loci defined 154 genetic patterns: six grouped 30 isolates and 148 showed unique patterns. The clustering rate was 14.60% and the HGDI: 0.9926. There was a predominance of sublineages by region: S, Beijing and LAM in the West, Center and East, respectively. Conclusions: The dynamics of TB transmission in Cuba in 2009 is reported, inferring that this occurs in a limited manner and belonging to risk groups does not favor transmission. It serves to evaluate a megaproject of the Global Fund to reduce the transmission of TB in this country. The population genetic structure of MTBC resembles that of an Ibero-American country, with the exception of the high frequency of the Beijing and S sublineages.