RESUMO
We aimed to describe the landscape, including molecular, epidemiological, and clinical aspects of CHIKV infections in the Ribeirao Preto region, an area endemic to dengue. We randomly screened 3744 plasma samples that had undergone DENV diagnosis to evaluate CHIKV-RNA using an in-house RT-PCR assay. Positive samples were followed clinically, and RNA samples were submitted to whole genome sequencing. Seventeen cases (0.5 %) were positive for CHIKV-RNA despite being negative for DENV-RNA. Notably, half of the patients experienced prolonged arthralgia lasting more than 90 days. Compared with the healthy control group, leukopenia and thrombocytopenia were observed in all CHIKV-positive individuals with statistically significant P values (P < 0.0001 and P = 0.0003, respectively). The genomic analysis revealed that the CHIKV strains being studied are classified within the East-Central-South-African (ECSA) genotype. This analysis identified new mutations, E1: K211E and E2: V264A, while the previously known mutation E1: A226V was not detected among these strains. This study highlights the need for epidemiological surveillance and preparedness for potential CHIKV epidemics in Brazil, particularly where other arboviruses co-circulate.
Assuntos
Febre de Chikungunya , Vírus Chikungunya , Dengue , Genótipo , RNA Viral , Humanos , Brasil/epidemiologia , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/sangue , Febre de Chikungunya/virologia , Vírus Chikungunya/genética , Vírus Chikungunya/isolamento & purificação , Dengue/epidemiologia , Dengue/virologia , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , RNA Viral/genética , Adulto Jovem , Doenças Endêmicas , Adolescente , Sequenciamento Completo do Genoma , Idoso , Criança , Filogenia , Mutação , Pré-Escolar , Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Vírus da Dengue/classificação , Trombocitopenia/epidemiologia , Trombocitopenia/virologiaRESUMO
After the Zika virus (ZIKV) epidemic in the Americas in 2016, both Zika and dengue incidence declined to record lows in many countries in 2017-2018, but in 2019 dengue resurged in Brazil, causing ~2.1 million cases. In this study we use epidemiological, climatological and genomic data to investigate dengue dynamics in recent years in Brazil. First, we estimate dengue virus force of infection (FOI) and model mosquito-borne transmission suitability since the early 2000s. Our estimates reveal that DENV transmission was low in 2017-2018, despite conditions being suitable for viral spread. Our study also shows a marked decline in dengue susceptibility between 2002 and 2019, which could explain the synchronous decline of dengue in the country, partially as a result of protective immunity from prior ZIKV and/or DENV infections. Furthermore, we performed phylogeographic analyses using 69 newly sequenced genomes of dengue virus serotype 1 and 2 from Brazil, and found that the outbreaks in 2018-2019 were caused by local DENV lineages that persisted for 5-10 years, circulating cryptically before and after the Zika epidemic. We hypothesize that DENV lineages may circulate at low transmission levels for many years, until local conditions are suitable for higher transmission, when they cause major outbreaks.
Assuntos
Vírus da Dengue/imunologia , Dengue/epidemiologia , Suscetibilidade a Doenças/imunologia , Epidemias/estatística & dados numéricos , Infecção por Zika virus/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Brasil/epidemiologia , Criança , Pré-Escolar , Dengue/imunologia , Dengue/transmissão , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Epidemias/prevenção & controle , Monitoramento Epidemiológico , Feminino , Genoma Viral/genética , Humanos , Imunidade Heteróloga , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , Mosquitos Vetores/virologia , Filogeografia , Sorotipagem , Adulto Jovem , Zika virus/imunologia , Infecção por Zika virus/epidemiologiaRESUMO
A total of 126 coagulase-negative staphylococci strains (CNS) were isolated from blood samples and from the intravenous catheters and cerebrospinal fluid of 103 patients admitted to the University Hospital of Ribeirão Preto. Staphylococcus epidermidis (68.2 percent), S. haemolyticus (11.1 percent) and S. hominis (3.2 percent) were the most frequent species. The last two CNS showed greater resistance to antimicrobial agents than S. epidermidis. CNS were the agents of infection in 10.7 percent of the patients and the agents of intravenous catheter colonization in 18.4 percent of the cases