RESUMO
BACKGROUND: Yellow fever (YF) is a severe, infectious, but non-communicable arboviral hemorrhagic disease. In the last decades, yellow fever virus (YFV) infections have been prevalent in endemic areas in Brazil, affecting human and non-human primate (NHP) populations. Monitoring of NHP infection started in 1999, and reports of epizootic diseases are considered important indicators of viral transmission, particularly in relation to the sylvatic cycle. This study presents the monitoring of YFV by real-time RT-PCR and the epidemiological findings related to the deaths of NHPs in the south-eastern states and in the north-eastern state of Bahia, during the outbreak of YF in Brazil during 2017 and 2018. METHODS: A total of 4198 samples from 2099 NHPs from south-eastern and north-eastern Brazilian states were analyzed by real-time reverse transcription polymerase chain reaction (rtRT-PCR). RESULTS: A total of 4198 samples from 2099 NHPs from south-eastern and north-eastern Brazilian states were collected between 2017 and 2018. The samples were subjected to molecular diagnostics for YFV detection using real-time reverse transcription polymerase chain reaction (rtRT-PCR) techniques. Epizootics were coincident with human YF cases. Furthermore, our results showed that the YF frequency was higher among marmosets (Callithrix sp.) than in previous reports. Viremia in species of the genus Alouatta and Callithrix differed greatly. DISCUSSION: Our results indicate a need for further investigation of the role of Callithrix spp. in the transmission cycles of YFV in Brazil. In particular, YFV transmission was observed in a region where viral circulation has not been recorded for decades and thus vaccination has not been previously recommended. CONCLUSIONS: This highlights the need to straighten epizootic surveillance and evaluate the extent of vaccination programmes in Brazil in previously considered "YFV-free" areas of the country.
Assuntos
Doenças dos Primatas/epidemiologia , Febre Amarela/veterinária , Alouatta/virologia , Animais , Brasil/epidemiologia , Callithrix/virologia , Surtos de Doenças , Humanos , Doenças dos Primatas/transmissão , Doenças dos Primatas/virologia , Febre Amarela/epidemiologia , Febre Amarela/virologia , Zoonoses/epidemiologia , Zoonoses/virologiaRESUMO
IMPORTANCE: Recent studies have reported an increase in the number of fetuses and neonates with microcephaly whose mothers were infected with the Zika virus (ZIKV) during pregnancy. To our knowledge, most reports to date have focused on select aspects of the maternal or fetal infection and fetal effects. OBJECTIVE: To describe the prenatal evolution and perinatal outcomes of 11 neonates who had developmental abnormalities and neurological damage associated with ZIKV infection in Brazil. DESIGN, SETTING, AND PARTICIPANTS: We observed 11 infants with congenital ZIKV infection from gestation to 6 months in the state of Paraíba, Brazil. Ten of 11 women included in this study presented with symptoms of ZIKV infection during the first half of pregnancy, and all 11 had laboratory evidence of the infection in several tissues by serology or polymerase chain reaction. Brain damage was confirmed through intrauterine ultrasonography and was complemented by magnetic resonance imaging. Histopathological analysis was performed on the placenta and brain tissue from infants who died. The ZIKV genome was investigated in several tissues and sequenced for further phylogenetic analysis. MAIN OUTCOMES AND MEASURES: Description of the major lesions caused by ZIKV congenital infection. RESULTS: Of the 11 infants, 7 (63.6%) were female, and the median (SD) maternal age at delivery was 25 (6) years. Three of 11 neonates died, giving a perinatal mortality rate of 27.3%. The median (SD) cephalic perimeter at birth was 31 (3) cm, a value lower than the limit to consider a microcephaly case. In all patients, neurological impairments were identified, including microcephaly, a reduction in cerebral volume, ventriculomegaly, cerebellar hypoplasia, lissencephaly with hydrocephalus, and fetal akinesia deformation sequence (ie, arthrogryposis). Results of limited testing for other causes of microcephaly, such as genetic disorders and viral and bacterial infections, were negative, and the ZIKV genome was found in both maternal and neonatal tissues (eg, amniotic fluid, cord blood, placenta, and brain). Phylogenetic analyses showed an intrahost virus variation with some polymorphisms in envelope genes associated with different tissues. CONCLUSIONS AND RELEVANCE: Combined findings from clinical, laboratory, imaging, and pathological examinations provided a more complete picture of the severe damage and developmental abnormalities caused by ZIKV infection than has been previously reported. The term congenital Zika syndrome is preferable to refer to these cases, as microcephaly is just one of the clinical signs of this congenital malformation disorder.
Assuntos
Artrogripose/etiologia , Hidrocefalia/etiologia , Malformações do Sistema Nervoso/etiologia , Complicações Infecciosas na Gravidez , Infecção por Zika virus/complicações , Zika virus , Anormalidades Múltiplas/etiologia , Brasil , Cerebelo/patologia , Cérebro/patologia , Feminino , Seguimentos , Humanos , Lactente , Morte do Lactente , Recém-Nascido , Lisencefalia/etiologia , Masculino , Microcefalia/etiologia , Morte Perinatal , Gravidez , Zika virus/genética , Zika virus/isolamento & purificação , Zika virus/patogenicidade , Infecção por Zika virus/congênitoRESUMO
BACKGROUND: The incidence of microcephaly in Brazil in 2015 was 20 times higher than in previous years. Congenital microcephaly is associated with genetic factors and several causative agents. Epidemiological data suggest that microcephaly cases in Brazil might be associated with the introduction of Zika virus. We aimed to detect and sequence the Zika virus genome in amniotic fluid samples of two pregnant women in Brazil whose fetuses were diagnosed with microcephaly. METHODS: In this case study, amniotic fluid samples from two pregnant women from the state of Paraíba in Brazil whose fetuses had been diagnosed with microcephaly were obtained, on the recommendation of the Brazilian health authorities, by ultrasound-guided transabdominal amniocentesis at 28 weeks' gestation. The women had presented at 18 weeks' and 10 weeks' gestation, respectively, with clinical manifestations that could have been symptoms of Zika virus infection, including fever, myalgia, and rash. After the amniotic fluid samples were centrifuged, DNA and RNA were extracted from the purified virus particles before the viral genome was identified by quantitative reverse transcription PCR and viral metagenomic next-generation sequencing. Phylogenetic reconstruction and investigation of recombination events were done by comparing the Brazilian Zika virus genome with sequences from other Zika strains and from flaviviruses that occur in similar regions in Brazil. FINDINGS: We detected the Zika virus genome in the amniotic fluid of both pregnant women. The virus was not detected in their urine or serum. Tests for dengue virus, chikungunya virus, Toxoplasma gondii, rubella virus, cytomegalovirus, herpes simplex virus, HIV, Treponema pallidum, and parvovirus B19 were all negative. After sequencing of the complete genome of the Brazilian Zika virus isolated from patient 1, phylogenetic analyses showed that the virus shares 97-100% of its genomic identity with lineages isolated during an outbreak in French Polynesia in 2013, and that in both envelope and NS5 genomic regions, it clustered with sequences from North and South America, southeast Asia, and the Pacific. After assessing the possibility of recombination events between the Zika virus and other flaviviruses, we ruled out the hypothesis that the Brazilian Zika virus genome is a recombinant strain with other mosquito-borne flaviviruses. INTERPRETATION: These findings strengthen the putative association between Zika virus and cases of microcephaly in neonates in Brazil. Moreover, our results suggest that the virus can cross the placental barrier. As a result, Zika virus should be considered as a potential infectious agent for human fetuses. Pathogenesis studies that confirm the tropism of Zika virus for neuronal cells are warranted. FUNDING: Consellho Nacional de Desenvolvimento e Pesquisa (CNPq), Fundação de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ).
Assuntos
Líquido Amniótico/virologia , Microcefalia/epidemiologia , Infecção por Zika virus/diagnóstico , Zika virus/isolamento & purificação , Brasil/epidemiologia , Surtos de Doenças , Feminino , Genoma Viral/genética , Idade Gestacional , Humanos , Recém-Nascido , Microcefalia/genética , Filogenia , Placenta/virologia , Gravidez , Complicações Infecciosas na Gravidez/virologia , RNA Viral/isolamento & purificação , Infecção por Zika virus/virologiaRESUMO
OBJECTIVE: To present results of virological surveillance and epidemiological aspects of dengue in the State of Rio Grande do Norte, Brazil. METHODS: A total of 1581 cases, reported from 2010 to 2012 at various health centres in the state, were analysed by viral isolation and/or RT-PCR for viral detection and typing. To identify whether different genotypes were circulating in the state during this period, sequencing of the complete E gene for DENV (1485 bp in length) was performed directly from patient serum samples. RESULTS: All four serotypes of dengue virus circulated in Rio Grande do Norte, with the introduction of DENV-4 in the state in 2011. In 2012, DENV-4 represented 100% of positive confirmed cases. 53.97% of cases occurred in Natal. Case numbers peaked in April (21%) and May (23%). Genetic characterisation of circulating strains confirmed the circulation of genotypes V, south-east Asian/American and II, respectively, for DENV-1, DENV-2 and DENV-4. CONCLUSIONS: This work furthers a better understanding of dengue viruses in the State of Rio Grande do Norte. Strengthening control efforts in the region is important considering the impact of dengue.
Assuntos
Vírus da Dengue/genética , Dengue/epidemiologia , Epidemias , Genótipo , Filogenia , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , Dengue/virologia , Surtos de Doenças , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Vigilância da População , Prevalência , Sorotipagem/métodos , Adulto JovemRESUMO
The wetlands of the Brazilian Pantanal host large concentrations of diverse wildlife species and hematophagous arthropods, conditions that favor the circulation of zoonotic arboviruses. A recent study from the Nhecolândia sub-region of Pantanal reported serological evidence of various flaviviruses, including West Nile virus and Ilheus virus (ILHV). According to the age of seropositive horses, at least three flaviviruses, including ILHV, circulated in the Brazilian Pantanal between 2005 and 2009. To extend this study, we collected 3,234 adult mosquitoes of 16 species during 2009 and 2010 in the same sub-region. Mosquito pool homogenates were assayed for infectious virus on C6/36 and Vero cell monolayers and also tested for flaviviral RNA by a group-specific real-time RT-PCR. One pool containing 50 non-engorged female specimens of Aedes scapularis tested positive for ILHV by culture and for ILHV RNA by real-time RT-PCR, indicating a minimum infection rate of 2.5 per 1000. Full-length genomic sequence exhibited 95% identity to the only full genome sequence available for ILHV. The present data confirm the circulation of ILHV in the Brazilian Pantanal.
Assuntos
Aedes/virologia , Flavivirus/isolamento & purificação , Animais , Brasil , Linhagem Celular , Análise por Conglomerados , Feminino , Flavivirus/genética , Dados de Sequência Molecular , Filogenia , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
BACKGROUND: Dengue is an acute febrile illness caused by an arbovirus that is endemic in more than 100 countries. Early diagnosis and adequate management are critical to reduce mortality. This study aims to identify clinical and hematological features that could be useful to discriminate dengue from other febrile illnesses (OFI) up to the third day of disease. METHODS: We conducted a sectional diagnostic study with patients aged 12 years or older who reported fever lasting up to three days, without any evident focus of infection, attending an outpatient clinic in the city of Rio de Janeiro, Brazil, between the years 2005 and 2008. Logistic regression analysis was used to identify symptoms, physical signs, and hematological features valid for dengue diagnosis. Receiver-operating characteristic (ROC) curve analyses were used to define the best cut-off and to compare the accuracy of generated models with the World Health Organization (WHO) criteria for probable dengue. RESULTS: Based on serological tests and virus genome detection by polymerase chain reaction (PCR), 69 patients were classified as dengue and 73 as non-dengue. Among clinical features, conjunctival redness and history of rash were independent predictors of dengue infection. A model including clinical and laboratory features (conjunctival redness and leukocyte counts) achieved a sensitivity of 81% and specificity of 71% and showed greater accuracy than the WHO criteria for probable dengue. CONCLUSIONS: We constructed a predictive model for early dengue diagnosis that was moderately accurate and performed better than the current WHO criteria for suspected dengue. Validation of this model in larger samples and in other sites should be attempted before it can be applied in endemic areas.
Assuntos
Dengue/diagnóstico , Febre/diagnóstico , Adulto , Diagnóstico Diferencial , Testes Diagnósticos de Rotina , Feminino , Humanos , Masculino , Razão de Chances , Curva ROC , Fatores de Tempo , Adulto JovemRESUMO
We examined levels of dengue virus type 3 (DENV-3) RNA in association with the type of infection (primary or secondary) in 42 patients with fatal and non-fatal outcomes in Rio de Janeiro, Brazil, 2002. Subjects with fatal outcomes had mean virus titers significantly higher than those who survived (12.5 vs. 7.9 log(10) RNA copies/ml). Because primary infections were confirmed among the fatal cases (52.1%), antibody-dependent enhancement alone did not explain all the cases of severe disease in this study population. These findings suggest that high levels of DENV-3 may have contributed to the severe form of dengue in Rio de Janeiro, 2002.
Assuntos
Vírus da Dengue/genética , Dengue/virologia , Anticorpos Facilitadores/imunologia , Brasil/epidemiologia , Dengue/epidemiologia , Dengue/mortalidade , Vírus da Dengue/classificação , Vírus da Dengue/imunologia , Surtos de Doenças , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G/sangue , RNA Viral/sangue , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
In this study, we revisited the phylogeography of the three of major DENV-3 genotypes and estimated its rate of evolution, based on the analysis of the envelope (E) gene of 200 strains isolated from 31 different countries around the world over a time period of 50 years (1956-2006). Our phylogenetic analysis revealed a geographical subdivision of DENV-3 population in several country-specific clades. Migration patterns of the main DENV-3 genotypes showed that genotype I was mainly circumspect to the maritime portion of Southeast-Asia and South Pacific, genotype II stayed within continental areas in South-East Asia, while genotype III spread across Asia, East Africa and into the Americas. No evidence for rampant co-circulation of distinct genotypes in a single locality was found, suggesting that some factors, other than geographic proximity, may limit the continual dispersion and reintroduction of new DENV-3 variants. Estimates of the evolutionary rate revealed no significant differences among major DENV-3 genotypes. The mean evolutionary rate of DENV-3 in areas with long-term endemic transmissions (i.e., Indonesia and Thailand) was similar to that observed in the Americas, which have been experiencing a more recent dengue spread. We estimated the origin of DENV-3 virus around 1890, and the emergence of current diversity of main DENV-3 genotypes between the middle 1960s and the middle 1970s, coinciding with human population growth, urbanization, and massive human movement, and with the description of the first cases of DENV-3 hemorrhagic fever in Asia.
Assuntos
Vírus da Dengue/genética , Dengue/virologia , Evolução Molecular , Filogenia , Proteínas do Envelope Viral/genética , América , Teorema de Bayes , Vírus da Dengue/classificação , Fluxo Gênico , Geografia , Humanos , Indonésia , Análise de Sequência de RNA , TailândiaRESUMO
BACKGROUND: Dengue virus pathogenesis is not yet fully understood and the identification of patients at high risk for developing severe disease forms is still a great challenge in dengue patient care. During the present study, we evaluated prospectively the potential of cytokines present in plasma from patients with dengue in stratifying disease severity. METHODS: Seventeen-cytokine multiplex fluorescent microbead immunoassay was used for the simultaneous detection in 59 dengue patients. GLM models using bimodal or Gaussian family were determined in order to associate cytokines with clinical manifestations and laboratory diagnosis. RESULTS: IL-1beta, IFN-gamma, IL-4, IL-6, IL-13, IL-7 and GM-CSF were significantly increased in patients with severe clinical manifestations (severe dengue) when compared to mild disease forms (mild dengue). In contrast, increased MIP-1beta levels were observed in patients with mild dengue. MIP-1beta was also associated with CD56+NK cell circulating rates. IL-1beta, IL-8, TNF-alpha and MCP-1 were associated with marked thrombocytopenia. Increased MCP-1 and GM-CSF levels correlated with hypotension. Moreover, MIP-1beta and IFN-gamma were independently associated with both dengue severity and disease outcome. CONCLUSION: Our data demonstrated that the use of a multiple cytokine assay platform was suitable for identifying distinct cytokine profiles associated with the dengue clinical manifestations and severity. MIP-beta is indicated for the first time as a good prognostic marker in contrast to IFN-gamma that was associated with disease severity.