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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.

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Arbovirus infections are increasingly important causes of disease, whose spectrum of neurological manifestations are not fully known. This study sought to retrospectively assess the incidence of arboviruses in cerebrospinal fluid samples of patients with neurological symptoms to inform diagnosis of central and peripheral nervous system disorders. A total of 255 cerebrospinal fluid (CSF) samples collected from January 2016 to December 2017 were tested for dengue virus (DENV 1-4), Zika virus (ZIKV), and Chikungunya virus (CHIKV) in addition to other neurotropic arboviruses of interest, using genetic and serologic assays. Of the 255 CSF samples analyzed, 3.53% (09/255) were positive for arboviruses presenting mainly as meningitis, encephalitis, and cerebrovascular events, of which ZIKV was detected in 2.74% (7/255), DENV in 0.78% (2/255), in addition to an identified ILHV infection that was described previously. All the cases were detected in adults aged 18 to 74 years old. Our findings highlight the scientific and clinical importance of neurological syndromes associated with arboviruses and demonstrate the relevance of specific laboratory methods to achieve accurate diagnoses as well as highlight the true dimension of these diseases to ultimately improve public health planning and medical case management.

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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.

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Measles is an acute and highly contagious but vaccine-preventable infectious disease. Despite years of being considered eliminated, decreased vaccination rates have produced virus reemergence in several countries, including Brazil. Measles can be controlled through immunization programs, through which aim to achieve 95% coverage with two doses of the vaccine. Measles can also be controlled if suspected cases can be properly identified in order to contain outbreaks. This cross-sectional study determined the prevalence of measles antibodies and their correlation with rubella antibodies (resulting from the combination vaccine used in Brazil's public immunization program) in individuals aged higher 10 years old in São José do Rio Preto, São Paulo State, Brazil, participants of a prospective cohort of arbovirosis surveillance before virus reemergence in the country. Our findings presented that 32.9% of individuals aged 10-40 years old had not antibodies against measles; 39.3% of total individuals with documented evidence of measles vaccination did not have anti-measles IgG, though only 20.2% of individuals with documented evidence of rubella vaccination lacked anti-rubella IgG. Besides, the most of measles cases reported in the city, following the virus spreading in the country, occurred especially in groups defined by us as susceptible. Because the combination MMR vaccine is part of Brazil's national vaccine schedule, the possible reasons for this relatively high rate of seronegativity need to be investigated further, once that it reflects outbreak risk.

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Identificación precoz del sintomático respiratorio, para realizar su respectivo tratamiento específico, desarrollando planes de prevención y control de la tuberculosis, determinado a la vez la situación en la que se encuentra la población zafrera en los departamentos de Santa Cruz y Tarija

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INTRODUÇÃO: O aparecimento da co-infecção tuberculose/síndrome da imunodeficiência adquirida, o aumento de doenças por micobactérias não tuberculosas e as confusões que estas podem ter com as emergentes cepas multirresistentes exigem respostas laboratoriais mais rápidas e de melhor rendimento, não só com isolamento das micobactérias, mas também com a sua identificação. OBJETIVO: Estudo comparativo entre uma nova ferramenta de identificação molecular com sonda genética baseada na unidade 16S do gene rDNA do Mycobacterium tuberculosis (Accuprobe Gen Probe®, Gen Probe Inc.) e a metodologia clássica. MÉTODO: Foram selecionados 55 isolados do gênero Mycobacterium, mantidos em bacterioteca, obtidos de escarros de pacientes de uma unidade de referência para tuberculose. Foram feitos repiques em três tubos: um destinado à identificação genética, outro para realização dos testes clássicos (produção e acumulação da niacina, e crescimento em meio de Lowenstein-Jensen com agentes inibidores - ácido p-nitrobenzóico e hidrazida do ácido tiofeno-2-carboxílico), e outro reserva. RESULTADOS: A sonda identificou 51 amostras do complexo M. tuberculosis (uma associada ao M. kansasii) e 4 como micobactérias não tuberculosas, posteriormente identificadas como M. kansasii (3) e M. avium (1). Os métodos tradicionais identificaram 47 amostras como do complexo M. tuberculosis, 4 com perfil de micobactérias não tuberculosas (concordante com o obtido pela sondagem genética) e 4 provas inconclusivas, uma delas exatamente a que associava duas espécies de micobactérias. CONCLUSÃO: Os benefícios da técnica de biologia molecular justificam sua implantação e uso rotineiro, associado aos métodos clássicos, numa unidade com alta demanda e que atenda casos de tuberculose de alta complexidade.