The arthropod-borne Mayaro virus (MAYV) causes ‘Mayaro fever’, a disease of medical significance, primarily affecting individuals in permanent contact with forested areas in tropical South America. Recently, MAYV has attracted attention due to its likely urbanization. Currently, there are no licensed drugs against most mosquito-transmitted viruses. Here, we investigated the in vitro anti-MAYV activity of the flavonoids quercetin and its derivatives from the Brazilian shrub Bauhinia longifolia (Bong.) Steud.

Background: The arthropod-borne Mayaro virus (MAYV) causes “Mayaro fever,” a disease of medical significance, primarily affecting individuals in permanent contact with forested areas in tropical South America. Recently, MAYV has attracted attention due to its likely urbanization. There are currently no licensed drugs against most mosquito-transmitted viruses. Punica granatum (pomegranate) fruits cultivated in Brazil have been subjected to phytochemical investigation for the identification and isolation of antiviral compounds. In the present study, we explored the antiviral activity of pomegranate extracts in Vero cells infected with Mayaro virus. Methods: The ethanol extract and punicalagin of pomegranate were extracted solely from the shell and purified by chromatographic fractionation, and were chemically identified using spectroscopic techniques. The cytotoxicity of the purified compounds was measured by the dye uptake assay, while their antiviral activity was evaluated by a virus yield inhibition assay. Results: Pomegranate ethanol extract (CC₅₀ = 588.9, IC₅₀ = 12.3) and a fraction containing punicalagin as major compound (CC₅₀ = 441.5, IC₅₀ = 28.2) were shown to have antiviral activity (SI 49 and 16, respectively) against Mayaro virus, an alphavirus. Immunofluorescence analysis showed the virucidal effect of pomegranate extract, and transmission electron microscopy (TEM) revealed damage in viral particles treated with this extract. Conclusions: The P. granatum extract is a promising source of antiviral compounds against the alphavirus MAYV and represents an excellent candidate for future studies with other enveloped RNA viruses. Graphical

The SARS-CoV-2 responsible for the ongoing COVID pandemic reveals particular evolutionary dynamics and an extensive polymorphism, mainly in Spike gene. Monitoring the S gene mutations is crucial for successful controlling measures and detecting variants that can evade vaccine immunity. Even after the costs reduction resulting from the pandemic, the new generation sequencing methodologies remain unavailable to a large number of scientific groups. Therefore, to support the urgent surveillance of SARS-CoV-2 S gene, this work describes a new feasible protocol for complete nucleotide sequencing of the S gene using the Sanger technique. Such a methodology could be easily adopted by any laboratory with experience in sequencing, adding to effective surveillance of SARS-CoV-2 spreading and evolution.

Using collection methods for Aedes adults as surveillance tools provides reliable indices and arbovirus detection possibilities. This study compared the effectiveness of different methods for collecting Ae. aegypti and Ae. albopictus and detecting arboviruses circulating in field-caught female specimens. Collection sites were defined in urban, peri-urban, and rural landscapes in two Brazilian cities. Collections were performed using Adultraps (ADT), BG-Sentinel (BGS), CDC-like traps (CDC), and indoor (ASP-I) and outdoor (ASP-O) aspiration during the rainy and dry seasons of 2015 and 2016. Generalized linear mixed models were used to model the effectiveness of each collection method. A total of 434 Ae. aegypti and 393 Ae. albopictus were collected. In total, 64 Ae. aegypti and sixteen Ae. albopictus female pools were tested for DENV, CHIKV, ZIKV, or YFV; none were positive. Positivity and density were linear at low densities (<1 specimen); thereafter, the relationship became non-linear. For Ae. aegypti, ADT and CDC were less effective, and ASP-I and ASP-O were as effective as BGS. For Ae. albopictus, all collection methods were less effective than BGS. This study highlights the need for an integrated surveillance method as an effective tool for monitoring Aedes vectors.

Resumo: A circulação simultânea da dengue, Zika e chikungunya impõe desafios importantes para o Brasil, que em decorrência das mudanças climáticas e outros fatores associados, estas arboviroses podem expor mais de 2 bilhões de pessoas no mundo, segundo a Organização Mundial da Saúde. A principal estratégia dos programas de controle do Aedes aegypti baseia-se no Levantamento de Índice Rápido para o Ae. aegypti (LIRAa), um inquérito amostral no qual o Índice de Infestação Predial (IIP) obtido é utilizado para priorizar áreas de intervenção. Neste estudo, analisou-se o desempenho do LIRAa quanto à sua sensibilidade na previsão de epidemias de dengue em municípios do Estado do Rio de Janeiro, em anos considerados epidêmicos. Foram obtidas as taxas de incidência (TI) por município nos anos de 2011, 2012, 2013, 2015 e 2016, e os IIP de outubro dos anos anteriores. Foram elaborados diagramas de dispersão, visando à análise exploratória e à visualização gráfica da relação entre as referidas variáveis, assim como análises de correlação de Spearman entre o IIP e o Índice de Breteau (IB) de cada ano, a fim de estimar a qualidade do LIRAa. A análise comparativa dos valores dos IIP e as respectivas TI no período indicou correlação significativa entre estas variáveis apenas em 2011/2012 (rs = 0,479; p < 0,01). Adicionalmente, foi observada correlação entre os IIP e IB. É urgente repensar os parâmetros estabelecidos pela metodologia LIRAa e investir em metodologias alternativas de vigilância entomoepidemiológica, que mensurem de forma confiável o risco de transmissão no território e assim delinear estratégias mais efetivas para o controle dessas arboviroses.

Brazilian traditional medicine has explored the antiviral properties of many plant extracts, including those from the Brazilian pepper tree, Schinus terebinthifolius. In the present study, we investigated the chemical composition and anti-mayaro virus (MAYV) activity of S. terebinthifolius fruit. Extensive virucidal activity (more than 95%) was detected for the ethyl acetate extract and the isolated biflavonoids. From the ethyl acetate extract of Schinus terebinthifolius fruits, two bioflavonoids were isolated ((2S, 2″S)-2,3,2″,3″-tetrahydroamentoflavone and agathisflavone), which showed strong virucidal activity against Mayaro virus. Furthermore, several other compounds like terpenes and phenolics were identified by hyphenated techniques (GC–MS, LC–MS and HPLC–UV), as well as by mass spectrometry. Immunofluorescence assay confirmed antiviral activity and transmission electron microscopy revealed damage in viral particles treated with biflavonoids. The data suggest the direct action of the extract and the biflavonoids on the virus particles. The biflavonoids tetrahydroamentoflavone and agathisflavone had strong virucidal activity and reduced MAYV infection.