The Role of GeneXpert® for Tuberculosis Diagnostics in Brazil: An Examination from a Historical and Epidemiological Perspective.

The rapid molecular test (RMT) performed on the GeneXpert® system is widely used as a control strategy and surveillance technique for tuberculosis (TB). In the region of the Americas, TB incidence is slowly increasing owing to an upward trend in Brazil, which is among the high TB-burden countries (HBCs), ranking in the 19th position. In this context, we aimed to (i) describe the implementation and history of RMT-TB (Xpert® MTB/RIF and Xpert® MTB/RIF Ultra) in Brazil; (ii) to evaluate the national RMT laboratory distribution, TB, and resistance to RIF detection by RMT; and (iii) to correlate these data with Brazilian TB incidence. The quantitative data of Xpert® MTB/RIF and Xpert® MTB/RIF Ultra assays performed in the pulmonary TB investigation from 2014 to 2020 were provided by the Brazilian Ministry of Health. A spatial visualization using ArcGIS software was performed. The Southeast region constituted about half of the RMT laboratories-from 39.4% to 45.9% of the total value over the five regions. Regarding the federal units, the São Paulo state alone represented from 20.2% to 34.1% (5.0 to 8.5 times the value) of RMT laboratories over the years observed. There were significant differences (p < 0.0001) in the frequency of RMT laboratories between all years of the historical series. There was an unequal distribution of RMT laboratories between Brazilian regions and federal units. This alerts us for the surveillance of rapid molecular detection of TB in different parts of the country, with the possibility of improving the distribution of tests in areas of higher incidence in order to achieve the level of disease control recommended by national and worldwide authorities.

Molecular epidemiology of Mycobacterium tuberculosis in Brazil before the whole genome sequencing era: a literature review.

Molecular-typing can help in unraveling epidemiological scenarios and improvement for disease control strategies. A literature review of Mycobacterium tuberculosis transmission in Brazil through genotyping on 56 studies published from 1996-2019 was performed. The clustering rate for mycobacterial interspersed repetitive units - variable tandem repeats (MIRU-VNTR) of 1,613 isolates were: 73%, 33% and 28% based on 12, 15 and 24-loci, respectively; while for RFLP-IS6110 were: 84% among prison population in Rio de Janeiro, 69% among multidrug-resistant isolates in Rio Grande do Sul, and 56.2% in general population in São Paulo. These findings could improve tuberculosis (TB) surveillance and set up a solid basis to build a database of Mycobacterium genomes.

A Clinical-Epidemiological and Geospatial Study of Tuberculosis in a Neglected Area in the Amazonian Region Highlights the Urgent Need for Control Measures.

Tuberculosis (TB) is an infectious communicable disease, which despite global efforts, still needs special attention in regions with difficult access. This study aims to describe the spatial and epidemiological trends of TB incidences from 2013 to 2018 in Marajó Island, the Amazonian region, Pará, Brazil. We have obtained secondary data from the Brazilian TB databases and performed geospatial and statistical analyses on the data for new TB cases, relapses, and re-admissions. From 2013 to 2018, 749 new cases were reported, in which the diagnostics (culture) was not performed for 652 (87.2%) patient samples, the drug resistance test (DST) was performed for nine (1.2%) samples, and one (0.13%) was multidrug-resistant TB (MDR-TB). The rapid molecular testing (RMT) was performed on 40 (5.3%) patient samples, with results indicating that eight (20%) were susceptible to rifampicin and two (5%) were rifampicin resistant. Overall, the cure rate was 449 (66.7%), while relapses and re-admissions were 41 and 44, respectively. On the geospatial distribution, the municipality of Soure stands out with a high number of incidences, relapses, and re-admissions. Spatially, the eight MDR cases were randomly distributed. Our data highlight the urgent need for TB control measures in this region, by introducing the Xpert-Ultra® MTB/RIF (Cepheid, Sunnyvale, CA, USA) and Ogawa-Kudoh.

Molecular epidemiology of Mycobacterium tuberculosis in Brazil before the whole genome sequencing era: a literature review

Molecular-typing can help in unraveling epidemiological scenarios and improvement for disease control strategies. A literature review of Mycobacterium tuberculosis transmission in Brazil through genotyping on 56 studies published from 1996-2019 was performed. The clustering rate for mycobacterial interspersed repetitive units - variable tandem repeats (MIRU-VNTR) of 1,613 isolates were: 73%, 33% and 28% based on 12, 15 and 24-loci, respectively; while for RFLP-IS6110 were: 84% among prison population in Rio de Janeiro, 69% among multidrug-resistant isolates in Rio Grande do Sul, and 56.2% in general population in São Paulo. These findings could improve tuberculosis (TB) surveillance and set up a solid basis to build a database of Mycobacterium genomes.

Maintenance of Mycobacterium tuberculosis on glass beads.

The intent of this study was to estimate the shelf life of Mycobacterium tuberculosis strains, and to observe the loss of viability in some of them from year to year. From 2000 to 2004, 10,015 cultures of M. tuberculosis were preserved by freezing on glass beads at -70 degrees C. With the expectation that the loss of viability might be around 5-10%/yr of storage, 730 strains were analyzed in order to establish the prevalence of recovery within a 5% margin of error. This study shows that 94% of the strains preserved at -70 degrees C on glass beads could be recovered within 30 days. The recovery rates for drug-susceptible and drug-resistant strains showed no significant differences. The growth rates and the number of strains that showed abundant growth before the 30th day of incubation represent important features, since the subculture of a strain preserved for future use ought to quickly produce abundant growth in order to avoid misinterpretation of the tests. Our experience indicates that storage of M. tuberculosis on glass beads at -70 degrees C is a suitable procedure for an active culture collection in a public health laboratory like ours, where maintenance of M. tuberculosis cultures is a complementary activity and must be quick, practical, effective, and economical.