A high-risk Zika and dengue transmission hub: virus detections in mosquitoes at a Brazilian university campus.

BACKGROUND: Zika virus (ZIKV) and dengue virus (DENV) are mosquito-borne flaviviruses prevalent throughout tropical regions. Currently, management of ZIKV and DENV centers on control of the primary vector Aedes aegypti. This vector is highly anthropophilic and is therefore prevalent throughout densely urbanised landscapes. A new passive trap for gravid Ae. aegypti (Gravid Aedes Trap - GAT) was developed for mosquito surveillance. Here the different killing agents and the level of transmission of arboviruses that may occur in mosquitoes sampled by GATs are assessed for the first time. METHODS: Gravid Aedes traps (GATs) were deployed at the Federal University of Minas Gerais campus, in Belo Horizonte, Brazil to sample Ae. aegypti. Three different killing agents were evaluated within the GATs: sticky cards, long-lasting insecticide-impregnated nets (LLINs) and canola oil. Traps were monitored weekly for 14 weeks then mosquito specimens were identified to the species level and Ae. aegypti catches were pooled and submitted to qRT-PCR assays for to DENV and ZIKV virus detection, followed by Bayesian phylogenetic analysis of the ZIKV. Additionally, comparisons of means were performed on transformed weekly catch data (P = 0.05, t-tests) with the stats package of the R statistical software. RESULTS: In total, 1506 female Ae. aegypti were captured using GATs, with traps using sticky cards catching more mosquito than those using either LLINs or canola oil. Both ZIKV and DENV were detected in Ae. aegypti females captured over several weeks suggesting that this highly populated university campus may have served as a significant transmission hub. The infection rate for ZIKV was present in seven (8.5%) pools from four weeks while DENV was detected in four (4.9%) pools from four weeks. Phylogenetic analysis of ZIKV classified the strain as Asian genotype. CONCLUSIONS: The Federal University of Minas Gerais and similar organizations must strongly consider monitoring Ae. aegypti populations and reinforcing personal protection of staff and students during seasons of high mosquito activity.

Vector competence of Brazilian Aedes aegypti and Ae. albopictus for a Brazilian yellow fever virus isolate.

Because the potential urban yellow fever (YF) mosquito vectors Aedes aegypti and Ae. albopictus are at historical highs in Brazil, both in terms of density and geographical range, we assessed the risk of an urban YF epidemic in Brazil. We evaluated and confirmed in a laboratory setting the vector competence of Brazilian Ae. aegypti for a currently circulating strain of YF virus, and investigated the potential for Brazilian Ae. albopictus to transmit YF.

[Periodicity of capture of the Anopheles darlingi Root (Diptera: Culicidae) in Porto Velho, Rondônia, Brazil]. / Periodicidade de captura de Anopheles darlingi Root (Diptera: Culicidae) em Porto Velho, RO.

Anopheles darlingi Root is the principal malaria vector in Amazonia region. The objectives of this work were to study the periodicity of Anopheles darlingi Root, the host preference for peri or extra-domestic environments and the parous rate in four field sites in Porto Velho (RO) by human-landing. All of the Anopheles specimens collected were identified, but only A. darlingi was dissected for the parous study. The results showed that human-landing colleted a total of 985 anophelines, with A. darlingi (972) being the most abundant species. Female mosquitoes were more abundant at extra-domestic environments in two of the locations studied (São João e Candeias do Jamari) (P < 0.05). The parous rate was 96% and no periodicity was observed for captures of females of A. darlingi in the field sites.

Evaluation of the sticky MosquiTRAP for detecting Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) during the dry season in Belo Horizonte, Minas Gerais, Brazil.

MosquiTRAP is a sticky trap specifically designed to capture gravid females of Aedes aegypti (L.) and allows the identification of the mosquito in the field during the inspection of the trap. This study aims to compare this sticky trap to larval and ovitrap surveys for field monitoring of A. aegypti during the dry season. The study was conducted from March to June of 2003 in 20 blocks of the district of Itapoã, Belo Horizonte, MG. The traps were monitored every week while the larval survey was conducted on a monthly basis. The larval index: Premise Index (PI) and Breteau Index (BI) had equal values throughout the experiment (1.72 in the first two months and zero in the last two). The container index (CI) during the first two months was 0.09 and 0.1%, respectively and zero in the last two. The Ovitrap Positive Index (OPI) ranged from 16.7 to 76.9%, and the MosquiTRAP Positive Index (MPI) ranged from 0 to 31.5%. The Egg Density Index (EDI) ranged from 26.6 to 82.8, while the Adult Density Index ranged from 0 to 1.6 throughout the experiment. Temperature and rainfall did not affect the Positive and Density Indices, although these environmental variables seemed to have affected the larvae indices. Although the MosquiTRAP caught a low number of Aedes mosquitoes during the study, it was more sensitive than the larval survey to detect the presence of Aedes mosquitoes.

Periodicidade de captura de Anopheles darlingi Root (Diptera: Culicidae) em Porto Velho, RO / Periodicity of capture of the Anopheles darlingi Root (Diptera: Culicidae) in Porto Velho, Rondônia, Brazil

Anopheles darlingi Root é o principal vetor de malária na Amazônia brasileira. Os objetivos deste trabalho foram avaliar a periodicidade de captura, a preferência por peri ou extradomicílio e a taxa de paridade de A. darlingi em quatro localidades em Porto Velho, RO, utilizando a atração humana. Todos os anofelinos capturados foram identificados e A. darlingi foi dissecada para caracterização da paridade. Do total de 985 anofelinos coletados, 972 eram A. darlingi. O número de fêmeas foi significativamente maior no extradomicílio em duas das localidades estudadas (São João e Candeias do Jamari) (P < 0,05). A taxa de paridade foi de 96 por cento e não foi observado horário preferencial para captura de fêmeas de A. darlingi nas localidades estudadas.

Anopheles darlingi Root is the principal malaria vector in Amazonia region. The objectives of this work were to study the periodicity of Anopheles darlingi Root, the host preference for peri or extra-domestic environments and the parous rate in four field sites in Porto Velho (RO) by human-landing. All of the Anopheles specimens collected were identified, but only A. darlingi was dissected for the parous study. The results showed that human-landing colleted a total of 985 anophelines, with A. darlingi (972) being the most abundant species. Female mosquitoes were more abundant at extra-domestic environments in two of the locations studied (São João e Candeias do Jamari) (P < 0.05). The parous rate was 96 percent and no periodicity was observed for captures of females of A. darlingi in the field sites.

Evaluation of the sticky MosquiTRAP™ for detecting Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) during the dry season in Belo Horizonte, Minas Gerais, Brazil

MosquiTRAP™ is a sticky trap specifically designed to capture gravid females of Aedes aegypti (L.) and allows the identification of the mosquito in the field during the inspection of the trap. This study aims to compare this sticky trap to larval and ovitrap surveys for field monitoring of A. aegypti during the dry season. The study was conducted from March to June of 2003 in 20 blocks of the district of Itapoã, Belo Horizonte, MG. The traps were monitored every week while the larval survey was conducted on a monthly basis. The larval index: Premise Index (PI) and Breteau Index (BI) had equal values throughout the experiment (1.72 in the first two months and zero in the last two). The container index (CI) during the first two months was 0.09 and 0.1 percent, respectively and zero in the last two. The Ovitrap Positive Index (OPI) ranged from 16.7 to 76.9 percent, and the MosquiTRAP Positive Index (MPI) ranged from 0 to 31.5 percent. The Egg Density Index (EDI) ranged from 26.6 to 82.8, while the Adult Density Index ranged from 0 to 1.6 throughout the experiment. Temperature and rainfall did not affect the Positive and Density Indices, although these environmental variables seemed to have affected the larvae indices. Although the MosquiTRAP caught a low number of Aedes mosquitoes during the study, it was more sensitive than the larval survey to detect the presence of Aedes mosquitoes.

MosquiTRAP é uma armadilha desenvolvida para a captura de fêmeas grávidas de Aedes aegypti (L.) e permite a identificação do mosquito em campo, durante a vistoria da armadilha. O objetivo desse estudo foi comparar essa armadilha com a pesquisa larvária e a ovitrampa para o monitoramento do A. aegypti em campo durante a estação seca. O trabalho foi realizado de março a junho 2003 em 20 quarteirões no bairro Itapoã, Belo Horizonte (MG). O monitoramento das armadilhas foi semanal e a pesquisa larvária foi realizada mensalmente. O índice Predial (IP) e o índice de Breteau (IB) apresentaram valores iguais durante todo o experimento (1,72 nos primeiros dois meses e zero nos dois últimos) e o índice de Recipiente (IR) nos dois primeiros meses foi de 0,09 e 0,1 por cento respectivamente e nos dois últimos foi zero. O índice de Positividade de Ovitrampa (IPO) variou de 16,7 a 76,9 por cento e o índice de Positividade de MosquiTRAP (IPM) variou de 0 a 31,5 por cento. O índice de Densidade de Ovos (IDO) variou de 26,6 a 82,8 enquanto o índice de Densidade de Adultos (IDA) variou de 0 a 1,6 durante todo o experimento. A temperatura e a precipitação não influenciaram os índices de Positividade e de Densidade, mas parecem ter influenciado os índices larvários. Apesar de a MosquiTRAP ter coletado um número pequeno de Aedes, observou-se que ela foi mais sensível para detectar a presença de Aedes do que a pesquisa larvária.

Malária em Minas Gerais, Brasil, no período 1980-1992 / Malaria in the State of Minas Gerais, Brazil, 1980-1992

A análise epidemiológica da malária em Minas Gerais mostra a necessidade de divulgaçäo permanente da situaçäo da transmissäo da doença, de forma a contribuir para a suspeita clínica em casos febris e para o diagnóstico precoce. A divulgaçäo das informaçöes técnicas sobre a malária visa ao melhor desempenho dos serviços de saúde locais, a fim de controlar os casos detectados e diminuir as taxas de morbi-mortalidade. Considera-se ser importante a manutençäo de sistema organizado e ativo de vigilância epidemiológica de malária,mesmo em áreas endêmicas.