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We describe the circulation of Saint Louis encephalitis virus (SLEV) in two Brazilian States during outbreaks of Dengue and Zika viruses. We detected the virus in a patient from Araraquara, State of São Paulo, and in patients and in a mosquito pool of Culex quinquefasciatus from Sinop, State of Mato Grosso. Phylogenetic analysis grouped samples from this study within genotype V, which are closely related to other strains that previously circulated in other parts of the country. Genotype V seems to have established circulation in Brazil. Highlights: During epidemics of DENV and ZIKV, we detected SLEV in human and mosquito samples from two different Brazilian States;SLEV detected in our samples belong to Genotype V of the virus;The detection of SLEV was only possible because there were active arbovirus surveillance protocols in both areas; [ABSTRACT FROM AUTHOR]

Background: Increased levels of inflammatory cytokines are associated with severe dengue evolution, but the source of such hypercytokinemia is elusive. We investigated the contribution of innate lymphocytes, innate lymphoid cells (ILCs), and natural killer (NK) cells in cytokine production in early dengue infection.Methods: Peripheral blood mononuclear cells of individuals with dengue without warning signs (DWS-) and dengue with warning signs and severe dengue (SD) presentation combined (DWS+) were obtained between 2 and 7 days since fever onset and submitted to flow cytometry without specific antigen stimulation to evaluate cytokines in ILC and NK cell subpopulations.Results: ILCs and NK cells were found to be important sources of cytokines during dengue. ILCs of the DWS+/SD group displayed higher production of interferon gamma (IFN-γ) and interleukin (IL) 4/IL-13 when compared to DWS- individuals. On the other hand, NK Eomes+ cells of DWS- patients displayed higher IFN-γ production levels compared with the DWS+/SD group. Interestingly, when NK cells were identified by CD56 expression, DWS+/SD displayed higher frequency of IL-17 production compared with the DWS- group.Conclusions: These results indicate that ILCs and NK cells are important sources of inflammatory cytokines during acute dengue infection and display distinct profiles associated with different clinical forms. [ABSTRACT FROM AUTHOR]

Enterovirus (EV) is commonly associated with central nervous system (CNS) syndromes. Recently, gastroenteric viruses, including rotavirus (RVA), human astrovirus (HAstV), and norovirus (NoV), have also been associated with CNS neurological disorders. The aim of the present study was to investigate the presence of EV, RVA, HAst, and NoV associated to CNS infections with undiagnosed etiology in Northwest region of São Paulo State, Brazil, and to conduct the molecular characterization of the positive samples detected. A total of 288 cerebrospinal fluid samples collected from July to December 2017 were tested for EV and NoV by quantitative real‐time polymerase chain reaction (RT‐qPCR), HAstV by conventional RT‐PCR, and RVA by enzyme‐linked immunosorbent assay. Positive‐EV samples were inoculated in cells lines, amplified by RT‐PCR and sequenced. RVA, NoV, and HAstV were not detected. EV infection was detected in 5.5% (16/288), and five samples successful genotyped: echovirus 3 (E3) (1/5), coxsackie virus A6 (CVA6) (1/5), and coxsackie virus B4 (CVB4) (3/5). Meningitis was the main syndrome observed (12/16; 75%). CVA6, CVB4, and E3 were identified associated with aseptic meningitis. Reports of CVA6 associated with aseptic meningitis are rare, E3 had not been previously reported in Brazil, and epidemiological data on CVB4 in the country is virtually unknown. The present investigation illustrates the circulation of diverse EV types in a small regional sample set and in a short period of time, highlighting the importance of an active EV surveillance system in CNS infections. Enhanced understanding of undiagnosed CNS infections will assist in public health and health care planning. Highlights: EV was found in 5.5% of previously undiagnosed CNS infectionsRare Echovirus 3 identified for the first time in BrazilEV exhibit epidemiological importance in aseptic meningitis casesAn EV surveillance system in CNS infections is required to monitor circulating species and types [ABSTRACT FROM AUTHOR]