Assessing the vulnerability of Brazilian municipalities to the vectorial transmission of Trypanosoma cruzi using multi-criteria decision analysis.

Despite the dramatic reduction in Trypanosoma cruzi vectorial transmission in Brazil, acute cases of Chagas disease (CD) continue to be recorded. The identification of areas with greater vulnerability to the occurrence of vector-borne CD is essential to prevention, control, and surveillance activities. In the current study, data on the occurrence of domiciliated triatomines in Brazil (non-Amazonian regions) between 2007 and 2011 were analyzed. Municipalities' vulnerability was assessed based on socioeconomic, demographic, entomological, and environmental indicators using multi-criteria decision analysis (MCDA). Overall, 2275 municipalities were positive for at least one of the six triatomine species analyzed (Panstrongylus megistus, Triatoma infestans, Triatoma brasiliensis, Triatoma pseudomaculata, Triatoma rubrovaria, and Triatoma sordida). The municipalities that were most vulnerable to vector-borne CD were mainly in the northeast region and exhibited a higher occurrence of domiciliated triatomines, lower socioeconomic levels, and more extensive anthropized areas. Most of the 39 new vector-borne CD cases confirmed between 2001 and 2012 in non-Amazonian regions occurred within the more vulnerable municipalities. Thus, MCDA can help to identify the states and municipalities that are most vulnerable to the transmission of T. cruzi by domiciliated triatomines, which is critical for directing adequate surveillance, prevention, and control activities. The methodological approach and results presented here can be used to enhance CD surveillance in Brazil.

[Evaluation of the impact of vector control of Chagas disease through serological testing in Mambaí/Buritinópolis, Goiás State]. / Avaliação do impacto das ações de controle vetorial da doença de Chagas através do inquérito sorológico em Mambaí/Buritinópolis, Goiás.

In 1999, we performed serological and entomological surveys to evaluate the impact of vectorial control measures against transmission of Chagas' disease in the endemic area of Mambaí and Buritinópolis (GO). A census was undertaken of the population, after which the entomological survey was performed regarding the dwelling units and serological evaluation of the human population. Blood samples were collected by digital puncture in filter paper. The first serologic test performed to detect antibodies against Trypanosoma cruzi was the indirect immunofluorescence test (IFI) with (1/2)0 positive dilution as cut-off point and, positive samples were further evaluated with indirect hemagglutination reaction (HAI). The prevalence of positive IFI reactions was 12.3% (95%CL: 11.5-13.2). Triatoma infestans was not found within the dwellings. The absence of infection among individuals younger than 14 years and, the absence of T. infestans during the last entomological survey demonstrates the success of the control program of Chagas' disease in the studied area where the vectorial transmission can be considered to have been interrupted.

Avaliação do impacto das açoes de controle vetorial da doença de Chagas atravÚs do inquérito sorológico em Mambaí/Buritinópolis, Goiás / Evaluation of the impact of vector control of Chagas disease through serological testing in Mambaí/Buritinópolis, Goiás State

In 1999, we performed serological and entomological surveys to evaluate the impact of vectorial control measures against transmission of Chagas' disease in the endemic area of MambaÝ and Buritinópolis (GO). A census was undertaken of the population, after which the entomological survey was performed regarding the dwelling units and serological evaluation of the human population. Blood samples were collected by digital puncture in filter paper. The first serologic test performed to detect antibodies against Trypanosoma cruzi was the indirect immunofluorescence test (IFI) with (1/2)0 positive dilution as cut-off point and, positive samples were further evaluated with indirect hemagglutination reaction (HAI). The prevalence of positive IFI reactions was 12.3 (95CL: 11.5-13.2). Triatoma infestans was not found within the dwellings. The absence of infection among individuals younger than 14 years and, the absence of T. infestans during the last entomological survey demonstrates the success of the control program of Chagas' disease in the studied area where the vectorial transmission can be considered to have been interrupted.

Pesquisas prioritárias sobre doença de Chagas na Amazônia: agenda de curto-médio prazo / Priority researches on Chagas' disease in the Amazonia Region: a short-medium term schedule

Na programaçao da V Jornada de Diagnostico, Tratamento e Controle de Doencas Tropicais do Baixo Amazonas, em face ao crescente interesse que a doença de Chagas vem despertando na regiao, foi levada a cabo uma extensa e rica reuniao cientifica sobre os diversos aspectos da tripanossomíase americana na Amazonia. Como objetivo central destas atividades, buscou-se proporcionar informaçóes atualizadas e elevar o conhecimento técnico, despertando para a pesquisa e favorecendo o intercâmbio científico entre os diferentes profissionais, setores e instituições envolvidos com o tema. De modo geral, os relatos reiteraram a existência de uma 'enzootia peculiar e com particularidades sub-regionais em toda a Amazonia, com ampla dispersáo de vetores silvestres e do agente etiológico, este geralmente classificado como do zimodema Z1 (Miles)...

O controle de triatoma brasiliensis e triatoma pseudomaculata / Control of triatoma brasiliensis and triatoma pseudomaculata

Avaliação do controle físico, pela melhoria habitacional, e caracterização do ambiente peridomiciliar mais e menos favorável à persistência da infestação ou reinfestação por triatoma brasiliensis e triatoma pseudomaculata

Monitoring the domiciliary and peridomiciliary invasion process of Triatoma rubrovaria in the State of Rio Grande do Sul, Brazil

The presence of Triatoma rubrovaria in Brazil has only been confirmed in the States of Paraná and Rio Grande do Sul (RS), where it is found naturally infected with Trypanosoma cruzi. In the wild environment it occurs in rocky habitats and has an eclectic diet, feeding from cockroaches, reptiles and mammals. Data from the Chagas Disease Control Program obtained by the Fundaçao Nacional de Saúde, between 1975 and 1997, indicate a growing domiciliary and peridomiciliary invasion of T. rubrovaria in RS, where it has become the most frequently Triatominae species captured in this state since the control of Triatoma infestans. In order to monitor this process, we analyzed collection data derived from 22 years of control campaigns against T. infestans. Collection data for triatomines from domestic habitats show an inverse relationship, with high numbers of T. infestans and low numbers of T. rubrovaria during 1976-1987, compared to the following ten years, 1986-1997, when the number of T. infestans dropped drastically and that of T. rubrovaria increased. There are no consistent indications of intradomiciliary colonization by T. rubrovaria, since only low numbers of nymphs have been captured in the intradomiciliary ecotopes. Nevertheless, this species appears to have preadaptive characteristics for anthropic ecotopes, and should be kept under constant epidemiological surveillance

Eliminacion de la transmission vectorial de la enfermedad de Chagas en Brasil / Elimination of vectorial transmission of Chagas disease in Brazil

El control de la transmisión vectorial de la enfermedad de Chagas en el Brasil fue sistematizado y estructurado en forma de programa de alcance nacional a partir del año 1975, cuando instrumentamos, a partir de las investigaciones entomológicas y sero-epidemiológicas, normas que sirvieron para delimitar el área de riesgo de transmisión vectorial en el país y orientar las intervenciones de control químico en las poblaciones domiciliarias del vector. Los autores presentan, aquí, los datos de base, recogidos a través de estas investigaciones que son cotejadas con los datos actuales. La evaluación revela la virtual interrupción de la transmisión de Triatoma infestans y la posibilidad de transmisión, en niveles poco importantes, con especies de vector nativas de diferentes áreas del país. Se enfatiza la importancia de mantener acciones de vigilancia entomológica con caráter permanente, con el objetivo de prevenir el restablecimiento de la transmisión. (AU)

Eliminacion de la transmission vectorial de la enfermedad de Chagas en Brasil / Elimination of vectorial transmission of Chagas disease in Brazil

El control de la transmisión vectorial de la enfermedad de Chagas en el Brasil fue sistematizado y estructurado en forma de programa de alcance nacional a partir del año 1975, cuando instrumentamos, a partir de las investigaciones entomológicas y sero-epidemiológicas, normas que sirvieron para delimitar el área de riesgo de transmisión vectorial en el país y orientar las intervenciones de control químico en las poblaciones domiciliarias del vector. Los autores presentan, aquí, los datos de base, recogidos a través de estas investigaciones que son cotejadas con los datos actuales. La evaluación revela la virtual interrupción de la transmisión de Triatoma infestans y la posibilidad de transmisión, en niveles poco importantes, con especies de vector nativas de diferentes áreas del país. Se enfatiza la importancia de mantener acciones de vigilancia entomológica con caráter permanente, con el objetivo de prevenir el restablecimiento de la transmisión.