Species composition and fauna distribution of mosquitoes (Diptera: Culicidae) and its importance for vector-borne diseases in a rural area of Central Western - Mato Grosso, Brazil

Abstract. This study describes ecological data obtained in a rural area in the State of Mato Grosso, including the insects belonging to the family Culicidae, especially those framed as potential vectors of tropical diseases. In 2015, we collected adult mosquitoes in fragments of forest in a rural area located in Mato Grosso Central West of Brazil. We captured 18,256 mosquitoes of the sub-families Culicinae and Anophelinae and have identified 34 species belonging to 12 genera: Aedes (1 species), Anopheles (8 species), Coquillettidia (1 species), Haemagogus (1 species), Culex (5 species), Psorophora  (5 species), Ochlerotatus (4 species), Deinocerites (1 species),  Mansonia (4 species), Sabethes (2 species), Limatus (1 species), Wyeomyia (1 species). The family Culicidae presented high richness and abundance, established by diversity indexes (Margalef α =3.26; Shannon H' = 2.09; Simpson D = 0.19) with dominance of the species Anopheles (Nyssorhyncus) darlingi Root (89.8%). This species has considerable epidemiological value, considered the main vector of malaria in Mato Grosso. Many species of mosquitoes are vectors of pathogens that cause disease in humans and domestic animals, transmitting pathogens including viruses (arboviruses), filaria worms (helminths) and protozoa. Composição de espécies e distribuição da fauna de mosquitos (Diptera: Culicidae) e sua importância para doenças transmitidas por vetores em uma área rural do centro-ocidental - Mato Grosso, Brasil Resumo. Este estudo descreve dados ecológicos de uma área rural do Estado de Mato Grosso e dos insetos da família Culicidae especialmente aqueles enquadrados como vetores potenciais de doenças tropicais. Em 2015, coletamos mosquitos adultos em fragmentos de floresta em localidades de áreas rurais no Mato Grosso região Centro Oeste do Brasil. Foram capturados 18.256 exemplares alados de mosquitos das subfamílias Culicinae e Anophelinae e identificadas 34 espécies pertencentes a 12 gêneros: Aedes (1 espécie), Anopheles (8 espécies), Coquillettidia (1 espécie), Haemagogus (1 espécie), Culex (5 espécies), Psorophora (5 espécies), Ochlerotatus (4 espécies), Deinocerites (1 espécie), Mansonia (4 espécies), Sabethes (2 espécies), Limatus (1 espécie), Wyeomyia (1 espécie). A família Culicidae apresentou alta riqueza e abundância, estabelecida por índices de diversidade (Margalef α = 3.26, Shannon H' = 2.09, Simpson D = 0.19) com predominância da espécie Anopheles (Nyssorhyncus)darlingi Root (89.8%). Esta espécie tem considerável valor epidemiológico, sendo considerada o principal vetor de malária em Mato Grosso. Muitas espécies de mosquitos são vetores de patógenos que causam doenças em humanos e animais domésticos, transmitindo patógenos incluindo vírus (arboviroses), filárias (helmintos) e protozoários

Natural transovarial transmission of dengue virus 4 in Aedes aegypti from Cuiabá, State of Mato Grosso, Brazil

INTRODUCTION: Dengue is the most prevalent arboviral disease in tropical areas. In Mato Grosso, outbreaks are reported every year, but studies on dengue in this state are scarce. METHODS: Natural transovarial infection of Aedes aegypti by a flavivirus was investigated in the Jardim Industriário neighborhood of Cuiabá, Mato Grosso. Eggs were collected with ovitraps during the dry, intermediate, and rainy seasons of 2012. After the eggs hatched and the larvae developed to adulthood, mosquitoes (n = 758) were identified and allocated to pools of 1-10 specimens according to the collection location, sex, and climatic period. After RNA extraction, multiplex semi-nested RT-PCR was performed to detect the four dengue virus (DENV) serotypes, yellow fever virus, West Nile virus and Saint Louis encephalitis virus. RESULTS: DENV-4 was the only flavivirus detected, and it was found in 8/50 pools (16.0%). Three of the positive pools contained females, and five contained males. Their nucleotide sequences presented 96-100% similarity with DENV-4 genotype II strains from Manaus, Amazonas. The minimum infection rate was 10.5 per 1000 specimens, and the maximum likelihood estimator of the infection rate was 11.6 (95% confidence interval: 4.8; 23.3). CONCLUSIONS: This study provides the first evidence of natural transovarial infection by DENV-4 in Ae. Aegypti in Mato Grosso, suggesting that this type of infection might serve as a mechanism of virus maintenance during interepidemic periods in Cuiabá, a city where dengue epidemics are reported every year. These results emphasize the need for efficient vector population control measures to prevent arbovirus outbreaks in the state

Detection of Oropouche virus segment S in patients and inCulex quinquefasciatus in the state of Mato Grosso, Brazil

This study aimed to investigate the circulation of Orthobunyavirus species in the state of Mato Grosso (MT) Brazil. During a dengue outbreak in 2011/2012, 529 serum samples were collected from patients with acute febrile illness with symptoms for up to five days and 387 pools of female Culex quinquefasciatuscaptured in 2013 were subjected to nested-reverse transcription-polymerase chain reaction for segment S of the Simbu serogroup followed by nucleotide sequencing and virus isolation in Vero cells. Patients (5/529; 0.9%) from Cuiabá (n = 3), Várzea Grande (n = 1) and Nova Mutum (n = 1) municipalities were positive for the S segment of Oropouche virus (OROV). Additionally, eight/387 Cx. quinquefasciatuspools were positive for the segment, with a minimum infection rate of 2.3. Phylogenetic analysis indicated that all the samples belong to the subgenotype Ia, presenting high homology with OROV strains obtained from humans and animals in the Brazilian Amazon. The present paper reports the first detection of an Orthobunyavirus, possibly OROV, in patients and in Cx. quinquefasciatus mosquitoes in MT. This finding reinforces the notion that arboviruses frequently reported in the Amazon Region circulate sporadically in MT during dengue outbreaks

Species composition and fauna distribution of mosquitoes (Diptera: Culicidae) and its importance for vector-borne diseases in a rural area of Central Western - Mato Grosso, Brazil

Este estudo descreve dados ecológicos de uma área rural do Estado de Mato Grosso e dos insetos da família Culicidae especialmente aqueles enquadrados como vetores potenciais de doenças tropicais. Em 2015, coletamos mosquitos adultos em fragmentos de floresta em localidades de áreas rurais no Mato Grosso região Centro Oeste do Brasil. Foram capturados 18.256 exemplares alados de mosquitos das subfamílias Culicinae e Anophelinae e identificadas 34 espécies pertencentes a 12 gêneros: Aedes (1 espécie), Anopheles (8 espécies), Coquillettidia (1 espécie), Haemagogus (1 espécie), Culex (5 espécies), Psorophora (5 espécies), Ochlerotatus (4 espécies), Deinocerites (1 espécie), Mansonia (4 espécies), Sabethes (2 espécies), Limatus (1 espécie), Wyeomyia (1 espécie). A família Culicidae apresentou alta riqueza e abundância, estabelecida por índices de diversidade (Margalef α = 3.26, Shannon H' = 2.09, Simpson D = 0.19) com predominância da espécie Anopheles (Nyssorhyncus)darlingi Root (89.8%). Esta espécie tem considerável valor epidemiológico, sendo considerada o principal vetor de malária em Mato Grosso. Muitas espécies de mosquitos são vetores de patógenos que causam doenças em humanos e animais domésticos, transmitindo patógenos incluindo vírus (arboviroses), filárias (helmintos) e protozoários.This study describes ecological data obtained in a rural area in the State of Mato Grosso, including the insects belonging to the family Culicidae, especially those framed as potential vectors of tropical diseases. In 2015, we collected adult mosquitoes in fragments of forest in a rural area located in Mato Grosso Central West of Brazil. We captured 18,256 mosquitoes of the sub-families Culicinae and Anophelinae and have identified 34 species belonging to 12 genera: Aedes (1 species), Anopheles (8 species), Coquillettidia (1 species), Haemagogus (1 species), Culex (5 species), Psorophora (5 species), Ochlerotatus (4 species), Deinocerites (1 species), Mansonia (4 species), Sabethes (2 species), Limatus (1 species), Wyeomyia (1 species). The family Culicidae presented high richness and abundance, established by diversity indexes (Margalef α =3.26; Shannon H' = 2.09; Simpson D = 0.19) with dominance of the species Anopheles (Nyssorhyncus) darlingi Root (89.8%). This species has considerable epidemiological value, considered the main vector of malaria in Mato Grosso. Many species of mosquitoes are vectors of pathogens that cause disease in humans and domestic animals, transmitting pathogens including viruses (arboviruses), filaria worms (helminths) and protozoa

Vírus da encefalite de Saint Louis em Mato Grosso, Centro-Oeste, Brasil

The dengue virus (DENV), which is frequently involved in large epidemics, and the yellow fever virus (YFV), which is responsible for sporadic sylvatic outbreaks, are considered the most important flaviviruses circulating in Brazil. Because of that, laboratorial diagnosis of acute undifferentiated febrile illness during epidemic periods is frequently directed towards these viruses, which may eventually hinder the detection of other circulating flaviviruses, including the Saint Louis encephalitis virus (SLEV), which is widely dispersed across the Americas. The aim of this study was to conduct a molecular investigation of 11 flaviviruses using 604 serum samples obtained from patients during a large dengue fever outbreak in the state of Mato Grosso (MT) between 2011 and 2012. Simultaneously, 3,433 female Culex spp. collected with Nasci aspirators in the city of Cuiabá, MT, in 2013, and allocated to 409 pools containing 1-10 mosquitoes, were also tested by multiplex semi-nested reverse transcription PCR for the same flaviviruses. SLEV was detected in three patients co-infected with DENV-4 from the cities of Cuiabá and Várzea Grande. One of them was a triple co-infection with DENV-1. None of them mentioned recent travel or access to sylvatic/rural regions, indicating that transmission might have occurred within the metropolitan area. Regarding mosquito samples, one pool containing one Culex quinquefasciatus female was positive for SLEV, with a minimum infection rate (MIR) of 0.29 per 1000 specimens of this species. Phylogenetic analysis indicates both human and mosquito SLEV cluster, with isolates from genotype V-A obtained from animals in the Amazon region, in the state of Pará. This is the first report of SLEV molecular identification in MT.O vírus da dengue (DENV), frequentemente envolvido em epidemias de grande proporção, e o vírus da febre amarela (YFV), responsável por surtos silvestres esporádicos, são considerados os flavivírus circulantes mais importantes no Brasil. Por este motivo, o diagnóstico laboratorial de doença febril aguda indiferenciada durante períodos epidêmicos é frequentemente direcionado para dengue e febre amarela no país, dificultando a detecção de outros arbovírus possivelmente circulantes, incluindo o vírus da encefalite de Saint Louis (SLEV), que é amplamente disperso nas Américas. O objetivo deste estudo foi investigar molecularmente a presença de 11 flavivírus no soro de 604 pacientes durante grande epidemia de dengue no estado de Mato Grosso (MT), Centro-Oeste do Brasil, entre 2011- 2012. Concomitantemente, 3.433 fêmeas de Culex spp. capturadas com aspirador de Nasci na cidade de Cuiabá, MT e alocadas em 409 pools com 1-10 mosquitos em 2013 foram testadas por multiplex seminested RT-PCR para os mesmos flavivírus. O SLEV foi detectado em três pacientes co-infectados com o DENV-4 das cidades de Cuiabá e Várzea Grande, MT. Um dos pacientes apresentava tripla co-infecção com DENV-1. Nenhum paciente referiu histórico recente de viagem ou acesso a áreas rurais/silvestres. Um pool contendo uma fêmea de Culex quinquefasciatus foi positivo para o SLEV, apresentando taxa de infecção mínima (MIR) de 0,29 por 1000 espécimes desta espécie. A análise filogenética indica que ambas as amostras formam um cluster com isolados do genótipo V-A do SLEV obtidos de animais na região amazônica do estado do Pará. Este é o primeiro relato de identificação molecular do SLEV no MT