Entoepidemiology of Chagas disease in northwest São Paulo and cytogenetic analysis of its main vector, Triatoma sordida (Hemiptera: Triatominae).

One century after the discovery of Chagas disease, it is still considered as a major health problem, causing more deaths in the Americas than any other parasitic disease. The northwest region of São Paulo, a macro-region that includes cities with a high-quality of life, has particularly high rates of Chagas disease. Therefore, this study aimed to assess the number of patients with Chagas disease, and to identify the triatomine fauna in the northwest region of São Paulo State, and to cytogenetically analyze Triatoma sordida mutants, thus providing new knowledge to control these species and avoid possible infections by Chagas disease. A total of 700 Chagas patients of both genders and variable age, who were born in and residents of the northwest region of the State of São Paulo were recruited for this study. Regarding the entoepidemiological fauna, both T. sordida and Rhodnius neglectus were captured from 2004 to 2011 in the northwest region of the São Paulo; however, T. sordida was the predominant species. Some of these collected triatomines were infected by Trypanosoma cruzi in several developmental stages. Furthermore, the lactoacetic orcein method was used for cytogenetic analysis. Several abnormalities were observed during meiosis of the T. sordida mutants, including condensed chromosomes with no chiasma, chromatin bridges between the autosomes, and some non-pairing homologous chromosomes. Thus, our study suggests that Chagas disease is currently not under control in Brazil. Furthermore, we suggest that cryptic speciation may be occurring in populations of T. sordida of Brazil. Further studies are necessary to understand the mechanisms behind these phenomena.

[Detection of Aedes aegypti and Aedes albopictus, in an urban zone of the municipality of Catanduva, SP, after control of a Dengue epidemic]. / Detecção de Aedes aegypti e Aedes albopictus, na zona urbana do município de Catanduva-SP, após controle de epidemia de Dengue.

After the realization of control research that had in view the transmission of dengue virus, we started to monitor two kinds of entomological vigilance, Breteau Index and ovitrap. We intended to evaluate the necessary time elapsed before Aedes sp mosquitoes were again detected at the urban area of Catanduva s town (SP). The ovitraps showed positiveness for the Aedes aegypti two months after the control research, while the Breteau Index became positive only at the fourth month after the end of the referred research.

[Description of the colonization of Aedes albopictus (Diptera: culicidae) in the region of Saõ José do Rio Preto, SP, 1991-1994]. / Descrição da colonização de Aedes albopictus (Diptera: culicidae) na região de São José do Rio Preto, SP, 1991-1994.

This study aims to describe and analyze the colonization of Aedes albopictus whose presence was detected in 1991 in the area of Sào José do Rio. Preto already colonized by the Aedes aegypti. Year and month of occurrence, counties, composition and location of larval samples, kinds of containers, average number of larvae an Breteau Index bare been analyzed from the information obtained in measurements of larval density by Superintendência de Controle de Endemias (SUCEN). The presence of Aedes albopictus was ascertained in 34 towns up to December 1994. The colonization of the area by the mosquito is still reduced showing some differences in relation to Aedes aegypti such as greater ratio outdoors, occupying container in different proportions. The average number of Aedes albopictus larvae has had influence of larvae of another species. It has showed a seasonal behavior similar to Aedes aegypti and it has moved from east to west direction.