Dengue epidemics have been reported in Brazil since 1985. The scenery has worsened in the last decade because several serotypes are circulating and producing a hyper-endemic situation, with an increase of DHF/DSS cases as well as the number of fatalities. Herein, we report dengue virus surveillance in mosquitoes using a Flavivirus genus-specific RT-Hemi-Nested-PCR assay. The mosquitoes (Culicidae, n = 1700) collected in the Northeast, Southeast and South of Brazil, between 1999 and 2005, were grouped into 154 pools. Putative genomes of DENV-1, -2 and -3 were detected in 6 mosquito pools (3.8%). One amplicon of putative DENV-1 was detected in a pool of Haemagogus leucocelaenus suggesting that this virus could be involved in a sylvatic cycle. DENV-3 was found infecting 3 pools of larvae of Aedes albopictus and the nucleotide sequence of one of these viruses was identified as DENV-3 of genotype III, phylogenetically related to other DENV-3 isolated in Brazil. This is the first report of a nucleotide sequence of DENV-3 from larvae of Aedes albopictus.

Seven individuals living in a town in the Southwest of Bahia developed sudden signs of cardiac and systemic impairment, with lethality of 28.6%. Serological tests were positive at least in one test in the five patients examined. Forty percent of the Triatoma sordida mynphs found inside or around Trypanosoma cruzi were found by blood culturig in there out five cases the homes of these cases were positive for Trypanosoma cruzi. Transmission probably occurred through consumption of water contaminated with triatomine feces. These findings emphasize the necessity to evaluation the importance of vectors like Triatoma sordida in maintaining the endemicity of this disease. Key

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.

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.

Abstract. The phylogenetic position of Triatoma sherlocki within triatomines group was inferred by analyzing mtDNA fragments of Cyt B and 16S ribosomal RNA by using maximum parsimony and Bayesian analysis. Despite being differentiated from members of the T. brasiliensis complex on morphologic grounds, molecular phylogenetic analysis suggests T. sherlocki is a member of this complex; moreover, it was placed as a sister species of T. melanica . These suggestions were supported by robust credibility rates. Hence, we show evidence for the paraphyletic group of the " Triatoma brasiliensis complex," which should be composed of T. brasiliensis brasiliensis , T. brasiliensis macromelasoma , T. juazeirensis , T. melanica , and T. sherlocki .

SUMMARYA study was conducted of the biological, morphological and molecular characters of 3 strains of Trypanosoma cruzi (SI5, SI8 and SIGR3) isolated from specimens of Triatoma sordida collected in Santo Inácio and a domestic cat. In order to carry out the study, the following parameters were evaluated: pre-patent period, parasitaemia curves, morphology of the parasites, mortality rates, histopathological lesions and molecular typing. The strains presented variable pre-patent periods, low parasitaemia and no animal mortality. The morphological study of trypomastigotes showed a predominance of intermediate-width and short-length forms, as well as low nuclear index. Epimastigotes presented a low nuclear index, intermediate-width forms in strains SI5 and SI8, and large-width forms in SIGR3. A shorter length could be noted in strains SI8 and SIGR3, whereas SI5 displayed an intermediate length. The histopathological study did not detect amastigote nests in tissues. The amplification of the divergent domain of 24Sα rRNA, HSP60 and GPI genes of strains SI5, SI8 and SIGR3 classified the 3 strains into Group II. Biological parameters made it possible to classify the strains isolated in Santo Inácio (BA) into Biodeme III, Zymodeme 1 and Group II of T. cruzi.

BackgroundThe 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.MethodsTriatominae 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.ResultsIn 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.ConclusionsSynanthropic 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.

OBJECTIVECollection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains.METHODSFirst, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice.RESULTSSix triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) and T. sordida (460), and two in cities in Rio Grande do Sul, namely T. circummaculata (11) and T. rubrovaria (115). Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one), T. lenti (one), T. rubrovaria (16) and T. sordida (10). Their index of natural infection by T. cruzi was 6.4%.CONCLUSIONSThe isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship.