Diversity of biting midges Culicoides (Diptera: Ceratopogonidae), potential vectors of disease, in different environments in an Amazonian rural settlement, Brazil

The Culicoides transmit a variety of pathogens. Our aim was to survey the Culicoides species occurring in an Amazonian rural settlement, comparing abundance, richness, and diversity in different environments. METHODS: Culicoides were captured using CDC light traps. The Shannon-Wiener (H') and Rényi indices were used to compare species diversity and evenness between environments, the equitability (J') index was used to calculate the uniformity of distribution among species, and similarity was estimated using the Jaccard similarity index. A permutational multivariate analysis of variance was applied to assess the influence of environment on species composition. A non-metric dimensional scale was used to represent the diversity profiles of each environment in a multidimensional space. RESULTS: 6.078 Culicoides were captured, representing 84 species (45 valid species/39 morphotypes). H' values showed the following gradient: forest > capoeira > peridomicile > forest edge. The equitability J' was greater in capoeira and forests compared to peridomiciles and the forest edge. The population compositions of each environment differed statistically, but rarefaction estimates indicate that environments of the same type possessed similar levels of richness. Species of medical and veterinary importance were found primarily in peridomiciles: C. paraensis, vector of Oropouche virus; C. insignis and C. pusillus, vectors of Bluetongue virus; C. filariferus, C. flavivenula, C. foxi, and C. ignacioi, found carrying Leishmania DNA. CONCLUSIONS: This study indicates that diversity was higher in natural environments than in anthropized environments, while abundance and richness were highest in the most anthropized environment. These findings suggest that strictly wild Culicoides can adapt to anthropized environments

Impacto da pandemia de COVID-19 nas doenças respiratórias: Um estudo sobre bronquite e bronquiolite aguda em crianças na região norte do Brasil

Respiratory diseases constitute a diverse set of conditions that affect the respiratory system, playing a significant role in healthcare systems. Bronchitis and acute bronchiolitis are two respiratory conditions that significantly impact lung health, especially in young children and some vulnerable groups. The association between bronchitis, acute bronchiolitis and COVID-19 is significant due to the similarities in the respiratory symptoms of these conditions. Both involve inflammation of the airways, resulting in coughing and difficulty breathing. Therefore, it is important to analyse epidemiological profiles before and after the pandemic and understand the impact of the pandemic on hospitalization and deaths associated with bronchitis and bronchiolitis. The main objective of this article was to analyse the prevalence and epidemiological profile of hospitalizations and deaths caused by bronchitis and acute bronchiolitis in children living in the Northern region of Brazil. This is a quantitative, retrospective study that analysed the number of hospitalizations and deaths due to bronchitis and acute bronchiolitis in the North region based on public data from the Hospital Information System (SIH) of the Unified Health System (SUS). During the analysis period, the number of hospitalizations decreased by 6%, but the number of deaths increased significantly. The state of Pará has the highest number of hospitalizations, and the state of Amazonas has the highest mortality rate. Both predominate in children under 1 year of age. Additionally, hospital spending increased by 32% during the COVID-19 pandemic. The significant incidence of bronchitis and acute bronchiolitis in children under one year of age stands out as a primary concern for child health. The inherent vulnerability of this age group, combined with frequent exposure to infectious agents, highlights the need for more effective preventive approaches and management strategies.As doenças respiratórias constituem um conjunto diversificado de condições que afetam o sistema respiratório, desempenhando um papel significativo nos sistemas de saúde. A bronquite e bronquiolite aguda são duas condições respiratórias que impactam significativamente a saúde pulmonar, especialmente em crianças pequenas e em alguns grupos vulneráveis. A associação entre bronquite, bronquiolite aguda e COVID-19 é significativa devido às semelhanças nos sintomas respiratórios dessas condições. Ambos envolvem inflamação das vias respiratórias, resultando em tosse e dificuldade respiratória. Dessa forma, é importante analisar perfis epidemiológicos antes e depois da pandemia e compreender o impacto da pandemia na hospitalização e óbitos associados à bronquite e bronquiolite. O objetivo principal deste artigo foi analisar a prevalência e o perfil epidemiológico das internações e óbitos causados por bronquite e bronquiolite aguda em crianças residentes na região Norte do Brasil. Trata-se de um estudo quantitativo, retrospectivo, que analisou o número de internações e óbitos por bronquites e bronquiolite aguda na região Norte com base em dados públicos do Sistema de Informações Hospitalares (SIH) do Sistema Único de Saúde (SUS). Durante o período de análise, o número de hospitalizações diminuiu 6%, mas o número de mortes aumentou significativamente. O estado do Pará tem o maior número de internações, e o estado do Amazonas tem a maior taxa de mortalidade. Ambos predominam em crianças menores de 1 ano. Além disso, os gastos hospitalares aumentaram 32% durante a pandemia de COVID-19. A significativa incidência de bronquites e bronquiolite aguda em crianças com menos de um ano destaca-se como uma preocupação primordial para a saúde infantil. A vulnerabilidade inerente a esse grupo etário, combinada com a exposição frequente a agentes infecciosos, evidencia a necessidade de abordagens preventivas e estratégias de manejo mais eficazes

Distribution and diversity of mosquitoes and Oropouche-like virus infection rates in an Amazonian rural settlement.

Mosquito diversity and disease transmission are influenced by landscape modifications, i.e., vectors and pathogens previously found only in forests are now found close to human environments due to anthropic changes. This study determined the diversity and distribution of mosquitoes in forest environments in order to analyze the potential vectors of Amazonian forest arboviruses. Mosquitoes were collected by 1) vertical stratification from forest canopy and ground areas using Hooper Pugedo (HP) light traps and human attraction and 2) horizontal stratification using HP light traps in peridomicile, forest edge, and forest environments near the Rio Pardo rural settlement, Amazonas, Brazil. A total of 3,750 mosquitoes were collected, representing 46 species. 3,139 individuals representing 46 species were sampled by vertical stratification. Both the Shannon-Weaver diversity index (H') and equitability (J') were higher in the canopy than on the ground. 611 individuals representing 13 species were sampled by horizontal stratification. H' decreased in the following order: forest edge > forest > peridomicile, and J' was greater at the forest edge and smaller in the peridomicile environment. Moreover, H' was higher for the human attraction collection method than the HP traps. A total of 671 pools were analyzed by RT-qPCR; three species were positive for Oropouche-like viruses (Ochlerotatus serratus, Psorophora cingulata, and Haemagogus tropicalis) and the minimum infection rate was 0.8%. The composition of mosquito species did not differ significantly between anthropic and forest environments in Rio Pardo. Some mosquito species, due to their abundance, dispersion in the three environments, and record of natural infection, were hypothesized to participate in the arbovirus transmission cycle in this Amazonian rural settlement

First evidence of Zika virus venereal transmission in Aedes aegypti mosquitoes

<div><p> BACKGROUND Aedes aegypti is considered the main Zika virus (ZIKV) vector, and is thought to be responsible for the 2015-2016 outbreak in Brazil. Zika positive Ae. aegypti males collected in the field suggest that vertical and/or venereal transmission of ZIKV may occur. OBJECTIVES In this study, we aimed to demonstrate that venereal transmission of ZIKV by Ae. aegypti can occur under laboratory conditions. METHODS Ae. aegypti collected in the city of Manaus, confirmed as negative for Zika, Dengue and Chikungunya virus by reverse transcription real-time polymerase chain reaction (RT-qPCR) (AaM3V- strain), were reared under laboratory conditions and used for the experiments. The ZIKV used in this study was isolated from a patient presenting with symptoms; ZIKV was confirmed by RT-qPCR. Experiment 1: virgin male mosquitoes of AaM3V- strain were intrathoracically inoculated with a ZIKV suspension; four days after injection, they were transferred to a cage containing virgin females of AaM3V- strain and left to copulate for five days. Experiment 2: virgin female mosquitoes of AaM3V- strain were orally infected with a ZIKV suspension by blood feeding membrane assay; nine days after blood feeding, they were placed in cages with Ae. aegypti AaM3V- virgin males and left to copulate for four days. After copulation, all mosquitoes were individually evaluated for viral infection by RT-qPCR. FINDINGS The mean infection rate in Experiment 1 and Experiment 2 was 45% and 35%, respectively. In both experiments, cycle threshold values ranged from 13 to 35, indicating the presence of viral genomes. MAIN CONCLUSION Ae. aegypti males intrathoracically inoculated with a ZIKV suspension are infected and can transmit the virus to uninfected females by mating. Moreover, Ae. aegypti females orally infected with a ZIKV suspension can transmit the virus to uninfected males by copulation. This study shows that ZIKV infection of Ae. aegypti mosquitoes occurs not only during blood feeding, but also during copulation.</p></div