BackgroundPhylogeographic composition of M. tuberculosis populations reveals associations between lineages and human populations that might have implications for the development of strategies to control the disease. In Latin America, lineage 4 or the Euro-American, is predominant with considerable variations among and within countries. In Colombia, although few studies from specific localities have revealed differences in M. tuberculosis populations, there are still areas of the country where this information is lacking, as is a comparison of Colombian isolates with those from the rest of the world.Principal FindingsA total of 414 M. tuberculosis isolates from adult pulmonary tuberculosis cases from three Colombian states were studied. Isolates were genotyped using IS6110-restriction fragment length polymorphism (RFLP), spoligotyping, and 24-locus Mycobacterial interspersed repetitive units variable number tandem repeats (MIRU-VNTRs). SIT42 (LAM9) and SIT62 (H1) represented 53.3% of isolates, followed by 8.21% SIT50 (H3), 5.07% SIT53 (T1), and 3.14% SIT727 (H1). Composite spoligotyping and 24-locus MIRU- VNTR minimum spanning tree analysis suggest a recent expansion of SIT42 and SIT62 evolved originally from SIT53 (T1). The proportion of Haarlem sublineage (44.3%) was significantly higher than that in neighboring countries. Associations were found between M. tuberculosis MDR and SIT45 (H1), as well as HIV-positive serology with SIT727 (H1) and SIT53 (T1).ConclusionsThis study showed the population structure of M. tuberculosis in several regions from Colombia with a dominance of the LAM and Haarlem sublineages, particularly in two major urban settings (Medellín and Cali). Dominant spoligotypes were LAM9 (SIT 42) and Haarlem (SIT62). The proportion of the Haarlem sublineage was higher in Colombia compared to that in neighboring countries, suggesting particular conditions of co-evolution with the corresponding human population that favor the success of this sublineage.
Several genomes of different Mycobacterium tuberculosis isolates have been completely sequenced around the world. The genomic information obtained have shown higher diversity than originally thought and specific adaptations to different human populations. Within this work, we sequenced the genome of one Colombian M. tuberculosis virulent isolate. Genomic comparison against the reference genome of H37Rv and other strains showed multiple deletion and insertions that ranged between a few bases to thousands. Excluding PPE and PG-PGRS genes, 430 proteins present changes in at least 1 amino acid. Also, novel positions of the IS6110 mobile element were identified. This isolate is also characterized by a large genomic deletion of 3.6 kb, leading to the loss and modification of the dosR regulon genes, Rv1996 and Rv1997. To our knowledge, this is the first report of the genome sequence of a Latin American M. tuberculosis clinical isolate.
Background The introduction in 2006 of the rapid HIV test by BCN Checkpoint in a non‐clinical setting has been a successful step forwards in the uptake of testing. Nevertheless, HIV serostatus should be reported as HIV positive only when a reactive result has been tested again using a different assay (WHO guidelines 2015). The standard confirmation test has been the Western Blot (WB) test. However confirmation results take around 7 days to come back. Aims This study explores the possibility of Point of Care PCR testing for a same‐day confirmation. Materials and Methods Between March 2015 and September 2016 a POC PCR test (Xpert® HIV‐1 Qual) was performed in parallel to the Western Blot test after a reactive HIV rapid test (Alere Determine™ HIV‐1/2 Ag/Ab Combo and Alere™ HIV Combo). HIV confirmed positive cases received emotional support by peers, were informed and prepared for treatment initiation and rapidly linked to HIV clinic. Results During the study period 11 455 tests were performed to 7163 clients. A total of 249 reactive rapid HIV tests were found. For analysis a total of 33 cases were excluded due to the lack of PCR and/or WB test. Results of comparison of the 216 cases showed 194 concordant positive confirmations and 14 concordant negative results. In three cases PCR was positive and WB negative. In five cases PCR was negative and WB positive. Conclusion The POC PCR assay is easy to use and feasible in a community‐based center. Reducing time for confirmation to 90 min has been possible in 91.2% (197/216) of cases with positive PCR result. In cases of a negative PCR result an additional test (WB, Elisa or PCR quantitative) was needed to distinguish false positive results (6.5%) from viral load results below level of detection (2.3%). Clients expressed satisfaction with same‐day confirmation and less anxiety.
Morbidity and mortality caused by tuberculosis are increased in most of the Latin-American indigenous communities. Factors that could explain this situation are poverty and limited health services access due to social conflicts and geographical isolation. We determined the frequency of tuberculosis in Colombian indigenous communities and described their knowledge related to transmission and control. We developed a descriptive study and health survey. Interviews were performed to find ancestral knowledge about tuberculosis. Sputum samples from patients with respiratory symptoms were analyzed. 10 indigenous communities were studied, which tuberculosis incidence was 291/100,000. Communities believe that tuberculosis is a body and spirit disease, which transmission is by direct contact or by witchcraft. Tuberculosis incidence in the studied communities was ninefold higher than that of the general population from Antioquia Department. Knowledge exchange could facilitate the community empowerment and implementation of educational activities which might improve the control of the disease.
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