Molecular detection of mycobacterium tuberculosis complex species in triatomines found in urban households and Peridomiciles in a city with high prevalence of tuberculosis in Northeastern Brazil.

Background: Triatomine insects, native to northeastern Brazil, have been found in the urban peridomicile. The city of Sobral has a high number of tuberculosis cases and several triatomine species. This study investigates the presence of mycobacteria, particularly Mycobacterium tuberculosis complex (MTBC) species, in triatomines captured in the urban perimeter of Sobral. Methods: We analyzed 167 triatomines captured in urban households and peridomiciles of Sobral. Mycobacteria were identified by the PRA-hsp65 method followed by partial sequencing of the hsp65 and rpoB genes. The sequences confirmed as MTBC were also typed by mycobacterial interspersed repetitive units-variable number tandem repeats (MIRU-VNTR) and spoligotyping. Results: Triatoma brasiliensis (38.6%), Triatoma pseudomaculata (32.9%), Panstrongylus lutzi (24.3%) were the most frequently identified. In 51.1% (70/167) of them, species of the Mycobacteriaceae family were detected by PRA-hsp65; of these, 31.4% (22/70) were identified as belonging to MTBC species. Nine (12.9%) of the triatomine samples were confirmed by sequencing as belonging to MTBC species. MIRU-VNTR genotyping suggests that the presence of different MTBC sublines in the triatomines should be investigated. Conclusion: This is the first report of MTBC lineages in triatomine insects. These results indicate the migration and adaptation of these insects in an urban setting.

A social network approach for the study of leprosy transmission beyond the household.

BACKGROUND: Mycobacterium leprae was the first microorganism directly associated with a disease, however, there are still important gaps in our understanding of transmission. Although household contacts are prioritized, there is evidence of the importance of extrahousehold contacts. The goal of this article is to contribute to our understanding of the transmission of leprosy ex-household. METHODS: We compare co-location data of 397 leprosy cases and 211 controls drawn from the Centro de Dermatologia Sanitária D. Libânia in Fortaleza, Brazil. We collected lifetime geolocation data related to residence, school attendance and workplace and developed novel methods to establish a critical distance (Rc) for exposure and evaluated the potential for transmission for residence, school and workplace. RESULTS: Our methods provide different threshold values of distance for residence, school and workplace. Residence networks demonstrate an Rc of about 500 m. Cases cluster in workplaces as well. Schools do not cluster cases. CONCLUSIONS: Our novel network approach offers a promising opportunity to explore leprosy transmission. Our networks confirm the importance of coresidence, provide a boundary and suggest a role for transmission in workplaces. Schools, on the other hand, do not demonstrate a clustering of cases. Our findings may have programmatic relevance.