High Frequencies of kdr Mutation and Chikungunya Infection in Aedes aegypti Population from Minas Gerais, Brazil.

The Chikungunya virus (CHIKV) presents global health challenges, with Brazil experiencing outbreaks since its introduction in 2014. In 2023, following a CHIKV outbreak in Minas Gerais (MG), social media was used to optimize an entomological survey aimed at identifying vectors and viral lineages and assessing insecticide resistance. Following Instagram posts, residents with suspected CHIKV infection were able to schedule mosquito aspirations. In total, 421 mosquitoes (165 Aedes aegypti and 256 Culex quinquefasciatus) were captured from 40 households in Salinas city (MG) and tested for the Dengue, Zika, and Chikungunya viruses through RT-qPCR. Twelve of 57 pools (10 Ae. aegypti and two Cx. quinquefasciatus) tested positive for CHIKV RNA. Viral RNA was also detected in the heads of nine Ae. aegypti, indicating viral dissemination but not in Cx. quinquefasciatus. Genome sequencing yielded the first near-complete genome from the 2023 outbreak, unveiling that the CHIKV strain belonged to the East/Central/South African (ECSA) genotype. Additionally, genetic analyses revealed high frequencies of kdr alleles, including in CHIKV-infected mosquitoes, suggesting resistance to pyrethroid insecticides in this Ae. aegypti population. Social media was important for guiding mosquito-capture efforts in CHIKV transmission hotspots, thus optimizing the opportunity for viral detection. These findings emphasize the urgent need for innovative vector studies and control strategies, as well as interdisciplinary approaches in public health interventions.

Essential oil and fenchone extracted from Tetradenia riparia (Hochstetter.) Codd (Lamiaceae) induce oxidative stress in Culex quinquefasciatus larvae (Diptera: Culicidae) without causing lethal effects on non-target animals.

We investigated the larvicidal activity of the essential oil (EO) from Tetradenia riparia and its majority compound fenchone for controlling Culex quinquefasciatus larvae, focusing on reactive oxygen and nitrogen species (RONS), catalase (CAT), glutathione S-transferase (GST), acetylcholinesterase (AChE) activities, and total thiol content as oxidative stress indicators. Moreover, the lethal effect of EO and fenchone was evaluated against Anisops bouvieri, Diplonychus indicus, Danio rerio, and Paracheirodon axelrodi. The EO and fenchone (5 to 25 µg/mL) showed larvicidal activity (LC50 from 16.05 to 18.94 µg/mL), followed by an overproduction of RONS, and changes in the activity of CAT, GST, AChE, and total thiol content. The Kaplan-Meier followed by Log-rank (Mantel-Cox) analyses showed a 100% survival rate for A. bouvieri, D. indicus, D. rerio, and P. axelrodi when exposed to EO and fenchone (262.6 and 302.60 µg/mL), while α-cypermethrin (0.25 µg/mL) was extremely toxic to these non-target animals, causing 100% of death. These findings emphasize that the EO from T. riparia and fenchone serve as suitable larvicides for controlling C. quinquefasciatus larvae, without imposing lethal effects on the non-target animals investigated.

Ilheus Virus (ILHV) Resistance in Culex quinquefasciatus from the Northern Region of Brazil.

BACKGROUND: Orthoflavivirus ilheusense (ILHV) is a member of the Flaviviridae family. It was first isolated in 1944 from pools of Aedes serratus and Psorophora ferox mosquitoes; however, it has also been detected in species of the genus Culex, such as Cx. portesi and Cx. coronator. The objective of this study was to examine the vector competence of Cx. quinquefasciatus mosquitoes to ILHV infection and the subsequent transmission of the virus through their saliva during feeding on blood. METHODS: F1 generation females of Cx. quinquefasciatus (Ananindeua/PA) were orally infected with goose blood infected with strain BeH7445, and body, head and saliva samples were analyzed at 7, 14, and 21 dpi using the techniques of virus isolation in cells and indirect immunofluorescence. RESULTS: The presence of ILHV was not detected in the body and head samples of Cx. quinquefasciatus females at any of the three dpi's analyzed, indicating that the lineage of mosquitoes analyzed was resistant to ILHV. CONCLUSIONS: According to the results obtained in this study, the species Cx. quinquefasciatus proved resistant to ILHV, regardless of the virus titers to which it was exposed, which suggests the possibility that this species does not act as a vector in the ILHV transmission cycle.

New artificial hematophagy system with attractive polymeric biofilm for maintenance of Culex quinquefasciatus (Diptera: Culicidae) in the laboratory.

BACKGROUND: Maintaining mosquito colonies in the laboratory requires a blood supply so that females' oocytes can mature and oviposition can take place. In this study, a new artificial hematophagy system for colonization and maintenance of Culex quinquefasciatus in the laboratory was developed and tested. METHODS: We developed an attractive polymeric biofilm including 25% L-lactic acid for use as a membrane in an artificial hematophagy system and compared the feeding rate of females with Parafilm-M®. We also evaluated the oviposition rate, larval survival and adult emergence of females fed through the attractive biofilm. RESULTS: The average percentage of female Cx. quinquefasciatus fed through the attractive biofilm was 87%, while only 20% became engorged with Parafilm-M® (p < 0.0001). Feeding through the attractive biofilm developed in this study produced high levels of evaluated biological parameters; the percentage of egg laying by females that underwent artificial hematophagy through the biofilm was 90%, with an average of 158 eggs per raft. From these eggs, 97% of the larvae hatched, of which 95% reached the pupal stage. The adult emergence rate corresponded to 93% of pupae. CONCLUSIONS: Insects fed with attractant through the biofilm system had a higher engorgement rate compared to those fed through Parafilm-M®. Our study is preliminary and suggests that polymeric biofilm has great potential for artificially feeding mosquitoes in the laboratory. Based on this research, new studies will be carried out with biofilm and different systems.

Exploring the range of Culex mosquitoes in Western Argentinean Patagonia, unveiling the presence of Culex pipiens bioform pipiens in South America.

Culicids in Argentinean Patagonia are characterized by low species diversity and adaptation to extreme environmental conditions, yet few studies have been conducted in the region. To further assess the occurrence of Culicidae in Western Patagonia, and in particular the presence of Culex pipiens bioforms at the southernmost extent of their distribution, immature and adult specimens were collected aboveground across various land uses located in shrubland, steppe, and deciduous forest between 38.96 and 46.55°S. Mosquitoes were reported at 35 of the 105 inspected sites. Five species from the genus Culex were identified, all of which were present in the steppe and the forest, while only Cx. apicinus and members of the Cx. pipiens complex were collected in the shrubland. Within the latter, a total of 150 specimens were molecularly identified by PCR amplification of Ace-2 and CQ11 loci. The first-to-date occurrence of bioform pipiens in South America is reported, along with the first records of Cx. quinquefasciatus signatures in Patagonia. In addition, the distribution of Cx. acharistus and Cx. dolosus as south as Santa Cruz province is expanded, and the first record of Cx. eduardoi in Río Negro province is provided. Immature specimens of Cx. pipiens were conspicuous in human-made aquatic habitats (both containers and in the ground), while Cx. acharistus was more prominent in artificial containers and Cx. eduardoi was mainly in ground habitats, either natural or human-made. These findings provide valuable insights into the distribution and ecological roles of these mosquito species in a region of extreme environmental conditions.

Unveil the sugar diet and associated environmental compounds in the crop of the mosquito Culex pipiens.

Culex pipiens (Linnaeus, 1758) mosquitoes search plant sources of sugars to cope with the energetic demand of various physiological processes. The crop as part of the digestive system is devoted to the storage of sugar-based meal obtained from various nectars sources. The profiling of sugars and metabolites in the Culex pipiens' crop is scarce, and only few studies used Liquid Chromatography - Mass Spectrometry (LC-MS), which provides broad detection for biomonitoring environmental substances and even contaminants in the sugar diet of mosquitoes populations. Therefore, sugar and metabolite profiling were performed on crops obtained from mosquitoes exposed to plant nectar under laboratory or natural conditions by Ultra High-Performance LC-MS (UHPLC-MS). This method allowed us a precise quantitative and qualitative identification of sugar diet and associated environmental compounds in the crop of the mosquito C. pipiens. Under laboratory condition, mosquitoes were allowed to feed on either glucose solution, commercially-available flowers or field collected flowers. In addition, we collected mosquitoes from the field to compare those crop metabolomes with metabolome patterns occurring after nectar feeding in the lab. The sugar quantities and quality obtained from the crops of mosquitoes collected in the field were similar to those crops obtained from mosquitoes that fed on commercially-available flowers and from field collected flowers with a limit of detection of 10 µg/L for sucrose, glucose and sucrose. Next to sugar compounds, we identified 2 types of amino acids, 12 natural products, and 9 pesticides. Next to the diversity of sugar compounds, we could confirm that secondary metabolites and environmental pollutants are typically up taken from floral nectar sources by C. pipiens. The in-depth knowledge on mosquito-plant interactions may inspire the development and further optimization of mosquito trap systems and arboviral surveillance systems.

Emergence of genotype III St. Louis encephalitis virus in the western United States potentially linked to a wetland in Argentina.

St. Louis encephalitis virus (SLEV) is endemic in the Americas and its transmission networks involve Culex mosquitoes and avian species. In 2015, a human encephalitis outbreak took place in Arizona and California, indicating the re-emergence of this pathogen in the US. Viral strains isolated in that outbreak belong to genotype III SLEV previously detected only in South America. In this study, genotype III SLEV was detected in mosquitoes collected in Mar Chiquita Lagoon (Córdoba, Argentina), an overwintering site for numerous migratory bird species. The genotype III SLEV sequence detected in this site shares the closest known ancestor with those introduced in Arizona in 2015. Our results highlight the potential significance of wetlands as key sites for arbovirus maintenance and emergence.

Bacterial community associated with Culex quinquefasciatus Say, 1823 (Diptera: Culicidae) from an urban area in the Amazon, Brazil

ABSTRACT The emergence of insecticide resistance in different mosquito populations underscores the pressing need for alternative approaches to control vector-borne diseases. Among several technological strategies, the employment of bacterial symbionts, such as the Wolbachia pipientis strains wMel and wAlbB to inhibit the ability of Aedes aegypti (Linnaeus, 1762) to transmit dengue and Zika viruses in endemic regions worldwide is promising. This investigation examines both the bacterial diversity associated with Culex quinquefasciatus and the genetic diversity of Wolbachia in females collected in Coari, Amazonas State, Brazil. Both 16S rRNA and Wolbachia surface protein (wsp) gene sequences were generated and examined. Proteobacteria was the dominant phylum. Wolbachia was the predominant genus, followed by Providencia, unclassified Erwiniaceae, and Acinetobacter. The presence of Delftia in Cx. quinquefasciatus need further investigations to identify the strains and if any of them can inhibit the transmission of arboviruses by this mosquito. Wolbachia 16S rRNA sequences were detected in all samples analyzed. The wsp sequences from Coari specimens were identified as Wolbachia wPip strain of the supergroup B. These sequences are identical and share 100% similarity with those of other Cx. quinquefasciatus populations from Brazil. Our findings suggest the hypothesis of previous studies that the Wolbachia invasion in Cx. quinquefasciatus was recent.

West Nile virus in Mexico: Why vectors matter for explaining the current absence of epidemics.

Since 2002, West Nile Virus (WNV) has been reported in 18 states in Mexico, either by PCR or serological testing. However, it is believed that the virus is present in more states. Only four states (out of 32) have reported confirmed human cases, and one state has serological evidence. In the country, WNV is present in mainly horses and birds, but its presence extends to crocodiles, felines, canines, swines, donkeys, caprines, antilopes, cattle, bats, and camelids. Positive mosquito species include Aedes and Culex spp. Different hypotheses have been proposed to explain the absence of WNV epidemics in Latin America. Since some regions of Mexico and the United States share ecological and climatic conditions, these hypotheses may not be sufficient to account for the absence of WNV outbreaks or epidemics. This paper discusses the proposed ideas and attempts to contextualize them for Mexico, particularly for the U.S.-Mexico border, where WNV infections have been reported in humans, horses, and mosquitoes. We propose that integration of urban ecology and entomology knowledge is needed to better understand the absence of WN cases in Mexico.

Blood meal sources of mosquitoes (Diptera: Culicidae) in domestic and open green environments from two urbanisations of temperate Argentina.

Understanding the blood-feeding patterns of mosquitoes is essential for evaluating their potential as disease vectors, especially in urban areas where mosquitoes coexist with humans, domestic animals and wildlife. This study aimed to bridge a substantial gap in regional knowledge by identifying the blood meal sources of field-collected mosquitoes in domestic and open green environments from two urbanisations of temperate Argentina, the Área Metropolitana de Buenos Aires (AMBA) and Tandil, using molecular techniques. Female mosquitoes were collected from November 2019 to March 2020 and April-May 2021. A bipartite network analysis was performed for each environment and urbanisation. A total of 103 blood meals from Aedes (2 species) and Culex (7 species) were identified. Among these, five mammal and 18 bird species were recognised as hosts. Aedes mosquitoes exclusively fed on mammals, while Culex mosquitoes exhibited a broader host range including both birds and mammals. In AMBA, the open green environments were composed by more mosquito species than the domestic environments, while both presented similar numbers of vertebrate species. In contrast, in open green environments from Tandil only blood-fed Aedes albifasciatus were collected. For open green environments of AMBA and domestic environments of Tandil, results suggested some degree of host selection. For the three main vectors of diseases in the region, Aedes aegypti, Ae. albifasciatus and Culex pipiens molestus, we present the first molecular evidence of human blood meals in South America. Epidemiological significance of the present findings is discussed.

Species diversity pattern of mosquitoes (Diptera: Culicidae) breeding in different permanent, temporary and natural container habitats of Peshawar, KP Pakistan / Padrão de diversidade de espécies de mosquitos (Dípteros: Culicidae) reproduzidos em diferentes habitats permanentes, naturais temporárias e contentores de Peshawar, KP Paquistão

To determine the species composition, relative abundance and seasonal variation of different mosquitoes Genera (Aedes, Anopheles, Armigeres, Culex, and Culiseta) in different habitats the present research work was carried out in Entomology Research Laboratory of The University of Peshawar. Sampling performed from variety of permanent and temporary breeding habitats was carried out on monthly basis from targeted breeding sites for two consecutive years through dipping method. Species diversity in the survey sites was noted. Collection from these seventeen various types of potential larval habitats, yielded a total of 42,430 immature constituting 41,556 larvae and 874 pupae. Among these only 19,651 adult mosquitoes emerged comprising 11,512 female and 8,139 male mosquitoes. 78% (n= 15333) of mosquito larvae were from permanent and 22% (n=4318) were from temporary breeding sites. This study showed that Peshawar valley harbours 15 species from the genera Aedes, Anopheles, Armigeres, Culex and Culiseta. When the density of each species was examined, Culex quinquifasciatus was found to be dominant (79%) and constant in distribution. Among the temporary habitats Aedes albopictus was found as the most prevalent species particularly from tree holes and water cisterns. The highest intensity of mosquitoes was in June (2243 emerged adults) and November (2667 emerged adults) while the lowest was in January (203 emerged adults). A perfect positive correlation (r = +0.8) was found between temperature and population of mosquitoes (df 10 and α 0.05). The species diversity index for mosquitoes remained between 0.12 and 1.76. The Margalef's richness components was noticeably low for bamboo traps (0.2) and fairly high for rice fields, Percolating water and Animal tracks (1.3) which shows the abundance of mosquito species in these habitats. Similarly Pielou's Evenness was highest for bamboo traps (E=1) showing species uniform distribution. Animal tracks were presumed not only the diverse habitat rather also possessed high value for species richness and species evenness. Temperature, rainfall, humidity and other related attributes responsible for species variation and abundance need to be analysed further to pave way for controlling vector species in their oviposition targeted sites.

Para determinar a composição de espécies, abundância relativa e variação sazonal de diferentes gêneros de mosquitos (Aedes, Anopheles, Armigeres, Culex e Culiseta) em diferentes habitats, o presente trabalho foi realizado no Laboratório de Pesquisa em Entomologia da Universidade de Peshawar. A amostragem coletada a partir de uma variedade de habitats de reprodução permanentes e temporários foi realizada mensalmente a partir de locais de reprodução alvo por 2 anos consecutivos através do método de imersão. A diversidade de espécies nos locais de pesquisa foi anotada. A coleta desses 17 tipos diferentes de habitats larvais potenciais rendeu um total de 42.430 imaturos, constituindo 41.556 larvas e 874 pupas. Destes, emergiram apenas 19.651 mosquitos adultos, sendo 11.512 fêmeas e 8.139 machos. 78% (n = 15333) das larvas do mosquito eram de criadouros permanentes e 22% (n = 4318) de criadouros temporários. Este estudo mostrou que o vale de Peshawar abriga 15 espécies dos gêneros Aedes, Anopheles, Armigeres, Culex e Culiseta. Quando a densidade de cada espécie foi examinada, Culex quinquifasciatus foi considerado dominante (79%) e constante na distribuição. Entre os habitats temporários, o Aedes albopictus foi encontrado como a espécie mais prevalente, principalmente em ocos de árvores e cisternas de água. A maior intensidade de mosquitos foi em junho (2.243 adultos emergidos) e novembro (2.667 adultos emergidos), enquanto a menor foi em janeiro (203 adultos emergidos). Uma correlação positiva perfeita (r = +0,8) foi encontrada entre temperatura e população de mosquitos (DF 10 e α 0,05). O índice de diversidade de espécies de mosquitos permaneceu entre 0,12 e 1,76. Os componentes de riqueza de Margalef foram visivelmente baixos para armadilhas de bambu (0,2) e razoavelmente altos para campos de arroz, água percolada e rastros de animais (1,3), o que mostra a abundância de espécies de mosquitos nesses habitats. Da mesma forma, a uniformidade de Pielou foi maior para armadilhas de bambu (E = 1), mostrando distribuição uniforme das espécies. As pegadas de animais foram presumidas não apenas como habitat diverso, mas também possuíam alto valor para riqueza e uniformidade de espécies. Temperatura, chuva, umidade e outros atributos relacionados responsáveis pela variação e abundância das espécies precisam ser analisados mais a fundo para abrir caminho para o controle de espécies de vetores em seus locais de oviposição alvo.

Mosquitoes (Diptera: Culicidae) of the Amazonian savannas of French Guiana with a description of two new species.

Amazonian savannas are among the most noteworthy landscape components of the coastal plain of French Guiana. Although they cover only 0.22% of the territory, they bring together a large part of the animal and plant diversity of this overseas region of France. This article outlines the results of the first study dedicated to mosquitoes (Diptera: Culicidae) of Amazonian savannas. Samplings were conducted in eight independent savannas evenly distributed along a transect of 170 km on the coastal plain of French Guiana. A total of 50 mosquito species were recorded, which is about 20% of the culicid fauna currently known in French Guiana. Among them, Culex (Melanoconion) organaboensis sp. nov. and Cx. (Mel.) zabanicus sp. nov. are newly described based on both morphological features of the male genitalia and a DNA barcode obtained from type specimens. Diagnostic characters to assist their identification are provided and their placement within the infrasubgeneric classification of the subgenus Melanoconion is discussed.

A nationwide epidemiological and geodemographic analysis of lymphatic filariasis in Ecuador: a neglected and often forgotten disease in Ecuador.

Introduction: Lymphatic filariasis (LF) is a neglected parasitic disease transmitted by mosquitoes and affecting the lymphatic system. The aim of this study was to analyze the epidemiological and sociodemographic characteristics of patients with LF during the last 11 years of available data in Ecuador. Methods: A 11-year nationwide analysis of hospital admission and in-hospital mortality based on the National Institute of Statistics and Census (INEC) data was conducted in Ecuador from 2011 to 2021. The International Classification of Diseases 10th Revision (ICD-10) code for filariasis (ICD: B74) was used to retrieve information on severe LF as a proxy for incidence among 221 Ecuadorian cities. Results: A total of 26 hospital admissions and 3 deaths due to LF were registered. The highest mortality rate was found in populations over 80 years. Men accounted for 62.5% (n = 17) of total number of cases with an average incidence rate of 1.7 cases per/1,000,000, while females accounted for 34.6% (n = 9), representing 1 case per/1,000,000 woman. Cities located at lower altitude (459/1,000,000) reported higher incidence rates than those located at higher altitudes (7.4/1,000,000). Conclusion: This is the first study on LF in Ecuador. Although, Ecuador is not considered endemic for LF, we found evidence of the presence of this disease in recent years. The implementation and improvement of an adequate integrated epidemiological surveillance system will allow early identification of cases and therefore their respective treatment.

Genus Culex Linnaeus, 1758 (Diptera: Culicidae) as an Important Potential Arbovirus Vector in Brazil: An Integrative Review.

The genus Culex has 817 species subdivided into 28 subgenera. It has a cosmopolitan distribution, being most abundant in countries with a tropical climate. Understanding the ecology and diversity of viruses circulating in the species of this genus is important for understanding their role as arbovirus vectors in Brazil. To conduct an integrative review to identify the importance of the Culex genus as arbovirus vectors in Brazil. A search was carried out for scientific papers in the PubMed, BVSalud, Patuá-IEC and International Catalogue of Arboviruses: including certain other viruses of vertebrates databases. 36 publications describing arbovirus detections in Culex mosquitoes collected in the field in Brazil were evaluated. A total of 42 arbovirus species were detected, as well as studies analyzing the vector competence of C. quinquefasciatus for the transmission of four different arboviruses. The study of the Culex genus and its role as a vector of arboviruses in Brazil is essential for understanding transmission cycles, with the main aim of reducing cases of human infection. Thus, entomovirological surveillance guides the implementation of actions to detect circulating arboviruses among vectors to anticipate measures aimed at preventing or reducing the risk of arbovirus outbreaks in the country.

Daytime Resting Activity of Aedes Aegypti and Culex Quinquefasciatus Populations in Northern Mexico.

Aedes aegypti and Culex quinquefasciatus are disease vectors distributed throughout much of the world and are responsible for a high burden of vector-borne disease, which has increased during the last 2 decades. Most pathogens vectored by these mosquitoes do not have therapeutic remedies; thus, combating these diseases is dependent upon vector control. Improvements in vector control strategies are urgently needed, but these hinge on understanding the biology and ecology of Ae. aegypti and Cx. quinquefasciatus. Both species have been extensively investigated, but further knowledge on diel resting activity of these vectors can improve vector surveillance and control tools for targeting resting vector populations. From April to December 2021, we determined outdoor daytime resting habits of Ae. aegypti and Cx. quinquefasciatus male, female, and blood-fed female populations in Reynosa, Mexico, using large red odor-baited wooden box traps. The daytime resting activity for Ae. aegypti males, females, and blood-fed females was restricted to a period between 0900 h and 1300 h, with a peak at 0900 h, while the resting activity of Cx. quinquefasciatus male, female, and blood-fed females was between 0700 h and 1100 h, with a peak at 0700 h. A generalized additive model was developed to relate relative humidity and temperature to resting Cx. quinquefasciatus and Ae. aegypti male, female, and blood-fed populations caught in traps. This study advances the understanding of outdoor resting behavior for 2 important vector mosquito species and discusses future studies to fill additional knowledge gaps.

Culicidae assemblages of artificial containers and possible biotic interactions affecting Aedes albopictus (Diptera: Culicidae) in Argentina.

In Argentina, the distribution of Aedes albopictus (Skuse) is limited to two provinces with a subtropical climate and few records. This study aims to describe and compare assemblies of Culicidae that breed in artificial containers in two areas with different degrees of urbanisation where Ae. albopictus is present and to evaluate possible biotic interactions. We sampled container larval habitats of an urban (Eldorado city) and a rural environment (Colonia Aurora village). We performed generalized linear mixed models to evaluate which variables (containers characteristics or environment) are associated with the presence and abundance of Ae. albopictus, Aedes aegypti Linneaus and Culex quinquefasciatus Say, and the presence of mosquito predators (Lutzia bigoti (Bellardi) and Toxorhynchites spp.). Also, the relationship between the most abundant species was quantified in each environment using Hurlbert's C8 association coefficient. Ae. aegypti was the most abundant species in the urban environment, while Cx. quinquefasciatus and Ae. albopictus were the most abundant in the rural area. Predators were more present in the rural environment and affected the abundance of Aedes mosquitoes. Regarding the C8 index, Ae. aegypti was negatively associated with Ae. albopictus in the urban area, whereas in the rural area these species presented a significantly positive relationship. These results show that in urban environments the high abundance of Ae. aegypti could be affecting the Asian tiger mosquito as evidenced by local studies of food larval competition. Also a greater presence of predators could be affecting Ae. albopictus in rural environments.

Host-mosquito interactions in rural and urban equestrian facilities from temperate Argentina.

Targeted vector surveillance informed by data on mosquito biting patterns can help limit arboviral zoonotic diseases. To characterise host-biting networks in rural and urban equestrian facilities from temperate Argentina, adult resting mosquitoes were collected (December 2018-April 2019) with a battery-powered aspirator. Engorged females were sorted to species, and their blood source was identified using molecular techniques. Bipartite network analysis was performed for rural and urban matrices. A total of 177 bloodmeals from 11 mosquito species of Aedes and Culex were identified, with seven mammal and 17 bird species recognised as hosts. Mammals represented 61% of the total feeds, mainly horse, dog and sheep; the best represented avian hosts were Columbiformes. Aedes species and Culex maxi fed only on mammals, while most other Culex species presented a wide range of hosts. The rural network had more nodes and interactions than its urban counterpart, both with some degree of host selection and aggregated patterns according to network indices. Culex quinquefasciatus was the strongest species in both networks, whereas Culex apicinus and Culex dolosus had a prominent role in the rural network. Bipartite network analysis will contribute to understanding the effects of urbanisation in the dynamics of vector-borne diseases.

Vector Competence of Culex quinquefasciatus from Brazil for West Nile Virus.

West Nile virus is characterized as a neurotropic pathogen, which can cause West Nile fever and is transmitted by mosquitoes of the genus Culex. In 2018, the Instituto Evandro Chagas performed the first isolation of a WNV strain in Brazil from a horse brain sample. The present study aimed to evaluate the susceptibility of orally infected Cx. quinquefasciatus from the Amazon region of Brazil to become infected and transmit the WNV strain isolated in 2018. Oral infection was performed with blood meal artificially infected with WNV, followed by analysis of infection, dissemination, and transmission rates, as well as viral titers of body, head, and saliva samples. At the 21st dpi, the infection rate was 100%, the dissemination rate was 80%, and the transmission rate was 77%. These results indicate that Cx. quinquefasciatus is susceptible to oral infection by the Brazilian strain of WNV and may act as a possible vector of the virus since it was detected in saliva from the 21st dpi.

First Isolation and Genome Sequence Analysis of West Nile Virus in Mosquitoes in Brazil.

West Nile virus is a flavivirus transmitted by mosquitoes, mainly of the genus Culex. In Brazil, serological studies have already indicated the circulation of the virus since 2003, with the first human case detected in 2014. The objective of the present paper is to report the first isolation of WNV in a Culex (Melanoconion) mosquito. Arthropods were collected by protected human attraction and CDC light bait, and taxonomically identified and analyzed by viral isolation, complement fixation and genomic sequencing tests. WNV was isolated from samples of Culex (Melanoconion) mosquitoes, and the sequencing analysis demonstrated that the isolated strain belonged to lineage 1a. The finding of the present study presents the first evidence of the isolation and genome sequencing of WNV in arthropods in Brazil.

Manifestaciones oculares producidas por la larva del Culex quinquefaciatus / Ocular manifestations produced by the larva of Culex quinquefaciatus

Las enfermedades transmitidas por vectores registran altas tasas de morbilidad y mortalidad para las personas. Los vectores biológicos son aquellos organismos capaces de transportar y transmitir un patógeno a otro organismo animal u hombre. Los más comunes son los insectos. El Culex quinquefaciatus es un vector de importantes enfermedades. Tiene un amplio desarrollo en nuestro país por las condiciones favorables climatológicas para su reproducción. El objetivo de este estudio fue presentar un caso portador de una larva de mosquito. Se describen las características más importantes del cuadro clínico, su diagnóstico, manejo. Las manifestaciones oculares secundarias a la infección por el mosquito C. quiquefasciatus en nuestro país son poco frecuentes, gracias a la campaña de erradicación del Aedes Aegiyptis en Cuba. En nuestro caso, se debió a las malas condiciones higiénicas del paciente y a la mala disposición de los desechos líquidos. Tal ambiente favoreció el depósito del huevo del mosquito en el ojo del paciente y que se desarrollara hasta la larva en el espacio subconjuntival del mismo(AU)

Vector-borne diseases have high morbidity and mortality rates for people. Biological vectors are those organisms capable of transporting and transmitting a pathogen to another animal organism or man, the most common being insects. Culex quinquefaciatus is a vector of important diseases, it is widely developed in our country due to the favorable weather conditions for its reproduction. A case carrying a mosquito larva is presented. The most important characteristics of the clinical picture, its diagnosis and management are described. Ocular manifestations secondary to infection by the Cx quiquefasciatus mosquito in our country are rare. Thanks to the campaign to eradicate Aedes Aegiyptis in Cuba. In our case, it was due to poor hygienic conditions of the patient and poor disposal of liquid waste. What favored the deposit of the mosquito egg in the patient's eye and that it developed into a larva in its subconjunctival space(AU)