IFN-α as a time-sensitive biomarker during Oropouche virus infection in early and late seroconverters.

In the present study, patients with acute OROV fever were classified as early seroconverters (IgM/IgG positive at baseline) or late seroconverters (IgM/IgG negative at baseline) and the timeline kinetics of the production of chemokines and cytokines were assessed at 1-3, 4-7, 8-10 and ≥11 days after patients have reported the first symptoms. Regardless immunoglobulin profile, all OROV fever patients presented higher levels of CXCL8, and IFN-α and lower levels of TNF and IL-10 at baseline as compared to healthy donors (HD). Lower levels of CCL2, CXCL10, and IFN-γ and higher levels of CCL2, CXCL10, IL-6, and IL-17A were detected in early and late seroconverters, respectively, as compared to HD. While early seroconverters presented the increasing levels of CCL2 along the timeline, late seroconverters displayed decreasing levels of CCL2, CXCL10, and IL-6 following days of disease onset. Noteworthy was that IFN-α was revealed as universal biomarker of human OROV fever, while CXCL8 & IL-5 and CXCL10 & IL-17 were consistently observed in early and late seroconverters, respectively. Thus, our results suggest that the production of IFN-α, CXCL10, and IL-17 precede the seroconversion bringing novel insights on the immunological events triggered by the OROV disease.

Polymorphism of DC-SIGN (CD209) promoter in association with clinical symptoms of dengue fever.

C-type lectin DC-SIGN receptor, encoded by CD209, plays a key role in the infection of dendritic cells by dengue virus (DENV). Because the -336A/G SNP (rs4804803) polymorphism in the promoter of CD209 modulates DC-SIGN expression, we investigated the putative association of this polymorphism with DENV infection and its pathogenesis. A control sample of 72 individuals, rigorously selected through a clinical investigation for absence of past dengue fever (DF) was compared to a sample of 168 patients (156 classical DF; 12 dengue hemorrhagic fever), all residents from Pará, Brazil. However, the prevalence of symptoms showed a trend higher in the AA genotype (Wilcoxon test; Z=2.02; p=0.04). Hence, our findings indicate that the G allele downregulates the spectrum of symptoms during the early acute phase of DENV infection, putatively decreasing the viremia, as suggested in the literature.

[Serological survey for arboviruses in Juruti, Pará State, Brazil]. / Vigilância sorológica para arbovírus em Juruti, Pará, Brasil.

This study aimed to measure the prevalence of antibodies to arboviruses in the area affected by the Juruti Project before local mining operations. A total of 1,597 human and 85 wild animal sera were examined, using the hemagglutination inhibition test against 19 antigens from the most prevalent arboviruses in the Brazilian Amazon and IgM-ELISA for dengue and yellow fever. Positive sera for Mayaro and Oropouche viruses were also tested by IgM-ELISA. Prevalence of hemagglutination inhibition antibodies to alphaviruses, flaviviruses, and orthobunyaviruses in humans was 28.7%, while for wild animals it was 8.2% for flaviviruses. Recent infections based on presence of IgM was confirmed for Mayaro (n = 5), Oropouche (n = 23), and dengue (n = 20). The results showed active circulation of the dengue, Mayaro, and Oropouche viruses in Juruti, as well as flaviviruses in wild animals, suggesting the circulation of these viruses in the Municipality of Juruti.

Vigilância sorológica para arbovírus em Juruti, Pará, Brasil / Serological survey for arboviruses in Juruti, Pará State, Brazil

O objetivo foi avaliar a prevalência de anticorpos para arbovírus na área de influência do Projeto Juruti antes da exploração mineral local. Foram examinados 1.597 soros humanos e 85 de animais silvestres. A pesquisa de anticorpos foi realizada pelo teste de inibição da hemaglutinação contra antígenos dos arbovírus mais prevalentes na Amazônia brasileira e IgM-ELISA para dengue e febre amarela. Soros humanos inibidores da hemaglutinação positivos para Mayaro e Oropouche foram também testados por IgM-ELISA. Anticorpos inibidores da hemaglutinação para alfavírus, orthobunyavirus e/ou flavivírus foram detectados, sendo 28,7 por cento reações monotípicas. Infecções recentes para Oropouche (n = 23), Mayaro (n = 5), e dengue (n = 20) foram confirmadas por IgM-ELISA. A prevalência de anticorpos inibidores da hemaglutinação em soros de animais silvestres foi de 8,2 por cento para flavivírus. Os resultados obtidos mostram que houve circulação ativa dos vírus Mayaro, Oropouche e dengue no período do estudo em humanos em Juruti, Pará, Brasil, e de diversos arbovírus em animais silvestres, indicando presença desses vírus em áreas do Município de Juruti.

This study aimed to measure the prevalence of antibodies to arboviruses in the area affected by the Juruti Project before local mining operations. A total of 1,597 human and 85 wild animal sera were examined, using the hemagglutination inhibition test against 19 antigens from the most prevalent arboviruses in the Brazilian Amazon and IgM-ELISA for dengue and yellow fever. Positive sera for Mayaro and Oropouche viruses were also tested by IgM-ELISA. Prevalence of hemagglutination inhibition antibodies to alphaviruses, flaviviruses, and orthobunyaviruses in humans was 28.7 percent, while for wild animals it was 8.2 percent for flaviviruses. Recent infections based on presence of IgM was confirmed for Mayaro (n = 5), Oropouche (n = 23), and dengue (n = 20). The results showed active circulation of the dengue, Mayaro, and Oropouche viruses in Juruti, as well as flaviviruses in wild animals, suggesting the circulation of these viruses in the Municipality of Juruti.