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Background: Neglected tropical diseases are a growing threat to global health, and endemic Chagas disease has emerged as one of the most important health problems in America. The main strategy to prevent Trypanosoma cruzi transmission is chemical control of vectors. This study presents a descriptive analysis of synanthropic triatomines before and after the implementation of a vector-control program in Bahia, Brazil. Methods: Descriptive analysis and geospatial statistics were performed on triatomine data, (1) the relative abundance and (2) proportional spatial distribution, from Bahia during two periods: (A) 1957 to 1971 and (B) 2006 to 2019. Results: We observed a decrease in the relative abundance of Panstrongylus megistus (A: n=22.032, 61.9%; B: n=1.842, 1.0%) and Triatoma infestans (A: n=1.310, 3.7%; B: n=763, 0.43%), as well as an increase in the relative abundance of T. sordida (A: n=8.314, 23.4%, B: n=146.901, 81.6%) and T. pseudomaculata (A: n=894, 2.5%, B: n=16.717, 9.3%). Conclusions: Our results indicate a clear reduction in the occurrence of P. megistus and T. infestans (last record in 2015) and an increase in the relative abundance and geographical distribution of T. sordida and T. pseudomaculata after 40 years of the vector-control program. The high frequency of other triatomine species in the municipalities of the state of Bahia and their abundance in recent years highlight the need to reinforce permanent entomological surveillance actions to prevent Chagas disease.

Six to seven million people worldwide are estimated to be infected with Trypanosoma cruzi, the etiologic agent of Chagas disease transmitted mainly by triatomines. Triatoma bahiensis was recently collected in the Brazilian state of Bahia and revalidated using different approaches. The main criterion used to define a “good” biological species is reproductive isolation, so we evaluated the cytogenetics of first-generation (F1) hybrids resulting from the experimental cross between T. bahiensis females and Triatoma lenti males to possibly characterize the postzygotic isolation associated with the hybrid breakdown. All cells analyzed presented a karyotype of 2n = 22 and a pair of univalent autosomes. This chromosome behavior represents hybrid collapse and underscores the specific status of T. bahiensis. Thus, we have characterized the presence of the hybrid collapse phenomenon in an experimental cross, and we confirm the specific status of T. bahiensis, thus contributing to the Triatominae taxonomy.

Background The identification of Trypanosoma cruzi and blood-meal sources in synanthropic triatomines is important to assess the potential risk of Chagas disease transmission. We identified T. cruzi infection and blood-meal sources of triatomines caught in and around houses in the state of Bahia, northeastern Brazil, and mapped the occurrence of infected triatomines that fed on humans and domestic animals. Methods Triatominae bugs were manually captured by trained agents from the Epidemiologic Surveillance team of Bahia State Health Service between 2013 and 2014. We applied conventional PCR to detect T. cruzi and blood-meal sources (dog, cat, human and bird) in a randomized sample of triatomines. We mapped triatomine distribution and analyzed vector hotspots with kernel density spatial analysis. Results In total, 5906 triatomines comprising 15 species were collected from 127 out of 417 municipalities in Bahia. The molecular analyses of 695 triatomines revealed a ~10% T. cruzi infection rate, which was highest in the T. brasiliensis species complex. Most bugs were found to have fed on birds (74.2%), and other blood-meal sources included dogs (6%), cats (0.6%) and humans (1%). Trypanosoma cruzi-infected triatomines that fed on humans were detected inside houses. Spatial analysis showed a wide distribution of T. cruzi-infected triatomines throughout Bahia; triatomines that fed on dogs, humans, and cats were observed mainly in the northeast region. Conclusions Synanthropic triatomines have a wide distribution and maintain the potential risk of T. cruzi transmission to humans and domestic animals in Bahia. Ten species were recorded inside houses, mainly Triatoma sordida, T. pseudomaculata, and the T. brasiliensis species complex. Molecular and spatial analysis are useful to reveal T. cruzi infection and blood-meal sources in synanthropic triatomines, identifying areas with ongoing threat for parasite transmission and improving entomological surveillance strategies.

Made available in DSpace on 2014-12-03T13:11:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-04-01Bitstream added on 2014-12-03T13:22:29Z : No. of bitstreams: 1 WOS000335107100009.pdf: 551403 bytes, checksum: 231bd25534bd4a2116671aa577882b62 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Multiple fragments of mitochondrial DNA genes (cytochrome b, cytochrome oxidase I, and 16S rDNA) were used to evaluate the phylogenetic relationships among Triatoma melanocephala, Triatoma tibiamaculata, Triatoma vitticeps, and other members of Triatoma brasiliensis subcomplex under a Bayesian framework and maximum parsimony criterion. With the addition of new sequences of T. tibiamaculata and T. vitticeps, Triatoma juazeirensis, Triatoma melanica and the newly sequenced T. melanocephala, the three first sylvatic species, T. melanocephala, T. tibiamaculata and T. vitticeps, were strongly recovered into a clade separate from the other with the remaining Triatoma species from South America, such as the members of T. brasiliensis subcomplex. Panstrongylus megistus was recovered as a sister to T. tibiamaculata, whereas T. vitticeps was a sister to T. melanocephala. This study revealed the non-monophyly of the T. brasiliensis subcomplex, and the polyphyly of Triatoma was reinforced by the placement of these three sylvatic species with Dipetalogaster, Meccus, Mepraia, and Panstrongylus. The results herein shown highlight the need of generic revision in Triatomini. (C) 2014 The Authors. Published by Elsevier B.V. Sao Paulo State Univ UNESP, Sch Pharmaceut Sci, Dept Biol Sci, Araraquara, SP, Brazil Univ Fed Rio de Janeiro, Inst Biol, Dept Zool, Rio De Janeiro, RJ, Brazil Secretaria Saude Estado Bahia, Programa Controle Dengue Itabuna, Salvador, BA, Brazil Sao Paulo State Univ UNESP, Sch Pharmaceut Sci, Dept Biol Sci, Araraquara, SP, Brazil FAPESP: 10/50355-1 FAPESP: 10/17027-0 FAPESP: 11/22378 CAPES: 23038.005285/2011-12

Triatomine surveillance in rural areas, artificial ecotypes, and natural ecotopes of the cities of Caturama, Ibipitanga, Macaubas, and Seabra in the south-central region of the Brazilian state of Bahia was carried out between 2008 and 2013. Natural infection by Trypanosoma cruzi was evaluated in the specimens collected to monitor vectors of Chagas disease. A total of 1,357 specimens were collected, and four species were identified: Triatoma sordida (83%), Triatoma lenti (16.4%), Triatoma pseudomaculata (0.5%), and Panstrongylus geniculatus (0.1%). Triatoma sordida was found in four cities, only 0.7% in intradomiciliary environments. Triatoma lenti was found only in Macaubas; 8.5% were found in intradomiciliary environments, 88.3% in peridomiciliary environments, and 3.1% in sylvatic environments. Natural infection by T. cruzi was 0.5% for T. sordida and 3.1% T. lenti. All of these cases were found in peridomiciliary environments of Macaubas. As the results show, triatomines were found in intradomiciliary environments in three cities that were surveyed in the south-central region of the state of Bahia. Thus, an epidemiologic survey should be performed to avoid the risk of transmission to the population.

Made available in DSpace on 2015-02-02T12:39:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-08-01Bitstream added on 2015-02-02T13:08:18Z : No. of bitstreams: 1 S0037-86822014000400513.pdf: 1589420 bytes, checksum: a221c6c33f0106a5842db613ac096b8a (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Introduction Chagas disease transmitted by the Triatoma infestans was eradicated from Brazil in 2006. However, reports of triatomine foci threaten the control of Chagas disease. The goal of this study was to determine T. infestans foci in the City of Ibipeba, State of Bahia.Methods Triatominae specimens were collected in Ibipeba and entomologic indicators were calculated using indices of domiciliary infestation, density, and colonization.Results T. infestans foci was discovery in Ibipeba, State of Bahia. Approximately 95% of the specimens were discovered inside dwellings, of which 34% were T. infestans. This species was also discovered forming a colony in tree bark in the peridomicile.Conclusions Triatoma infestans foci in peridomestic ecotopes in Ibipeba, BA, indicate increased the risk of transmission Chagas disease. Secretaria da Saúde do Estado da Bahia Diretoria de Vigilância Epidemiológica Universidade Estadual Paulista Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista Faculdade de Ciências Farmacêuticas

Triatoma bahiensis Sherlock & Serafim, 1967, T. lenti Sherlock & Serafim, 1967, and T. pessoai Sherlock & Serafim, 1967 were described based on material collected in the Brazilian state of Bahia. These species were later included in the T. brasiliensis complex based on their geographic distribution. Triatoma bahiensis and T. pessoai were subsequently synonymized with T. lenti. However, the phylogenetic position of T. lenti within the T. brasiliensis complex has remained doubtful. This study aims to assess the taxonomic status of T. bahiensis and to infer the phylogenetic relationships between T. lenti, T. bahiensis and the other members of the T. brasiliensis species complex. The identities of the species in concern were confirmed by comparisons with high resolution photos of the respective type materials; lectotypes are designated for T. pessoai and T. bahiensis. Morphological, morphometric, molecular, and cytogenetic approaches as well as experimental crosses were used. The low viability of experimental crosses combined with morphological and morphometric data allow the differentiation of T. bahiensis and T. lenti. Pairwise cyt b sequence divergence between T. lenti and T. bahiensis was 2.5%. Cytogenetic and molecular analyses grouped T. lenti and T. bahiensis as members of the T. brasiliensis complex. These results revalidate the specific status of T. bahiensis.

Triatoma melanocephala Neiva & Pinto is found in the Brazilian states of Bahia, Paraiba, Pernambuco, Rio Grande do Norte, and Sergipe. In addition to the species' specific description, eight other articles on this insect were found in the literature. In this study, data was obtained on the morphology, morphometry, and life cycle of T. melanocephala, since this vector is of epidemiological and taxonomic importance. The specimens studied were obtained from a colony that has been kept at the Triatomine Insectarium of the College of Pharmaceutical Sciences of Sao Paulo State University's in Brazil. The morphological studies were performed using scanning electron microscopy. These studies characterized the eggs, the external adult female genitalia, and the ninth ventral abdominal segments of male and female nymphs. The morphometric studies characterized the five nymphal instars and the adult stage by measuring the head, thorax, abdomen, antennae, and mouthparts parameters. The life cycle of T. melanocephala was developed starting by 15 couples in the fifth instar. They were fed on Swiss mice every two weeks and observed daily. During daily observation, minimum temperature, maximum temperature, and relative humidity of the laboratory were measured. The results of the biological, morphometric, and morphological studies have increased the knowledge available on T. melanocephala.