Cryptic circulation of chikungunya virus in São Jose do Rio Preto, Brazil, 2015-2019.

BACKGROUND: Chikungunya virus (CHIKV) has spread across Brazil with varying incidence rates depending on the affected areas. Due to cocirculation of arboviruses and overlapping disease symptoms, CHIKV infection may be underdiagnosed. To understand the lack of CHIKV epidemics in São José do Rio Preto (SJdRP), São Paulo (SP), Brazil, we evaluated viral circulation by investigating anti-CHIKV IgG seroconversion in a prospective study of asymptomatic individuals and detecting anti-CHIKV IgM in individuals suspected of dengue infection, as well as CHIKV presence in Aedes mosquitoes. The opportunity to assess two different groups (symptomatic and asymptomatic) exposed at the same geographic region aimed to broaden the possibility of identifying the viral circulation, which had been previously considered absent. METHODOLOGY/PRINCIPAL FINDINGS: Based on a prospective population study model and demographic characteristics (sex and age), we analyzed the anti-CHIKV IgG seroconversion rate in 341 subjects by ELISA over four years. The seroprevalence increased from 0.35% in the first year to 2.3% after 3 years of follow-up. Additionally, we investigated 497 samples from a blood panel collected from dengue-suspected individuals during the 2019 dengue outbreak in SJdRP. In total, 4.4% were positive for anti-CHIKV IgM, and 8.6% were positive for IgG. To exclude alphavirus cross-reactivity, we evaluated the presence of anti-Mayaro virus (MAYV) IgG by ELISA, and the positivity rate was 0.3% in the population study and 0.8% in the blood panel samples. In CHIKV and MAYV plaque reduction neutralization tests (PRNTs), the positivity rate for CHIKV-neutralizing antibodies in these ELISA-positive samples was 46.7%, while no MAYV-neutralizing antibodies were detected. Genomic sequencing and phylogenetic analysis revealed CHIKV genotype ECSA in São José do Rio Preto, SP. Finally, mosquitoes collected to complement human surveillance revealed CHIKV positivity of 2.76% of A. aegypti and 9.09% of A. albopictus (although it was far less abundant than A. aegypti) by RT-qPCR. CONCLUSIONS/SIGNIFICANCE: Our data suggest cryptic CHIKV circulation in SJdRP detected by continual active surveillance. These low levels, but increasing, of viral circulation highlight the possibility of CHIKV outbreaks, as there is a large naïve population. Improved knowledge of the epidemiological situation might aid in outbreaks prevention.

Antiviral Activity of Quercetin Hydrate against Zika Virus.

Zika virus (ZIKV) has re-emerged in recent decades, leading to outbreaks of Zika fever in Africa, Asia, and Central and South America. Despite its drastic re-emergence and clinical impact, no vaccines or antiviral compounds are available to prevent or control ZIKV infection. This study evaluated the potential antiviral activity of quercetin hydrate against ZIKV infection and demonstrated that this substance inhibits virus particle production in A549 and Vero cells under different treatment conditions. In vitro antiviral activity was long-lasting (still observed 72 h post-infection), suggesting that quercetin hydrate affects multiple rounds of ZIKV replication. Molecular docking indicates that quercetin hydrate can efficiently interact with the specific allosteric binding site cavity of the NS2B-NS3 proteases and NS1-dimer. These results identify quercetin as a potential compound to combat ZIKV infection in vitro.

Caffeic Acid Has Antiviral Activity against Ilhéus Virus In Vitro.

Ilhéus virus (ILHV) is a neglected mosquito-borne flavivirus. ILHV infection may lead to Ilhéus fever, an emerging febrile disease like dengue fever with the potential to evolve into a severe neurological disease characterized by meningoencephalitis; no specific treatments are available for this disease. This study assessed the antiviral properties of caffeic acid, an abundant component of plant-based food products that is also compatible with the socioeconomic limitations associated with this neglected infectious disease. The in vitro activity of caffeic acid on ILHV replication was investigated in Vero and A549 cell lines using plaque assays, quantitative RT-PCR, and immunofluorescence assays. We observed that 500 µM caffeic acid was virucidal against ILHV. Molecular docking indicated that caffeic acid might interact with an allosteric binding site on the envelope protein.

Eficácia do uso do álcool etílico 70% na antissépsia da pele antes da coleta de sangue / Efficacy of 70% ethyl alcohol use o9n skin antissepsia before blood collection

Objetivo ­ Quantificar a presença de agentes da flora microbiana da pele de usuários da sala de coleta de uma unidade básica de saúde ­ UBS, assim como verificar a eficácia da antissepsia da pele com o uso do álcool etílico 70% prévia à coleta de sangue. Métodos ­ A coleta da região antecubital do braço dos 40 pacientes selecionados aleatoriamente, foi realizada antes e após antissepsia do local com álcool etílico 70%, com auxílio de um swab embebido em solução fisiológica estéril para posterior transporte e processamento o qual foi realizado no laboratório escola da Universidade Paulista UNIP, campus JK, São José do Rio Preto. Resultados ­ Das 80 amostras (40 antes da antissepsia e 40 depois da antissepsia) coletadas, foi observada uma redução de 87,01% do número de colônias de micro-organismos identificados como cocos e bacilos Gram-positivos, catalase positivos. Conclusão ­ Os resultados da pesquisa permitem concluir que o álcool etílico a 70% é eficaz na antissepsia da pele e que a antissepsia com álcool etílico 70% reduz a flora microbiana da pele conferindo maior segurança e liberdade de riscos ao procedimento prévio à coleta de sangue.

Objective ­ To quantify the presence of agents of the microbial flora of the skin of patients in the collection room of a hospital (UBS) as well as to verify the efficacy of skin antisepsis with the use of 70% ethyl alcohol prior to blood collection. Methods ­ The collection of the antecubital region of the arm of the 40 randomly selected patients was performed before and after site antisepsis with 70% ethyl alcohol, with the aid of a swab soaked in sterile solution for subsequent transportation and processing, which was performed in the laboratory University of São Paulo UNIP, JK campus, São José do Rio Preto. Results ­ From the 80 samples (40 before antisepsis and 40 after antisepsis) collected, a reduction of 87.01% in the number of colonies of microorganisms identified as cocci and gram positive bacilli, catalase positive, was observed. Conclusion ­ The results of the research allow us to conclude that 70% ethyl alcohol is effective in antisepsis of the skin and that antisepsis with 70% ethyl alcohol reduces the microbial flora of the skin giving greater safety and reduced risk to the procedure prior to blood collection