The dengue virus (DENV), of the genus Flavivirus (Flaviviridae), has four antigenically distinct serotypes, of which DENV-3 is classified into five genotypes. Here, we describe the detection of DENV-3 genotype I in sera of a Brazilian patient travelling from Singapore to Rio de Janeiro, Brazil, by using multiplex real-time RT-PCR, DNA sequencing of the whole envelope protein gene, and phylogenetic analysis. The virus shares ancestry with those identified in Bali, Indonesia, in 2015. It is possible that arboviruses such as Chikungunya ECSA genotype, DENV-4 genotype I, and Zika were introduced in Brazil from other continents during the multiple international events hosted by the country over the last four years, including World Youth Day, the Soccer World Cup, and the Summer Olympics.

Chikungunya virus (CHIKV) is a mosquito-borne pathogen that emerged in Brazil by late 2014. In the country, two CHIKV foci characterized by the East/Central/South Africa and Asian genotypes, were established in North and Northeast regions. We characterized, by phylogenetic analyses of full and partial genomes, CHIKV from Rio de Janeiro state (2014-2015). These CHIKV strains belong to the Asian genotype, which is the determinant of the current Northern Brazilian focus, even though the genome sequence presents particular single nucleotide variations. This study provides the first genetic characterisation of CHIKV in Rio de Janeiro and highlights the potential impact of human mobility in the spread of an arthropod-borne virus.

The aim of this study was to evaluate the effects of dengue virus infection during pregnancy and its correlation with low birth weight, prematurity, and asphyxia. A non-concurrent cohort study reveals the association of dengue during pregnancy with prematurity and low birth weight, when birth occurred during the maternal-fetal viremia period (p = 0.016 and p < 0.0001, respectively).

Parvovirus B19 (B19V) infects individuals worldwide and is associated with an ample range of pathologies and clinical manifestations. B19V is classified into three distinct genotypes, all identified in Brazil. Here, we report a complete sequence of a B19V genotype 1A that was obtained by high-throughput metagenomic sequencing. This genome provides information that will contribute to the studies on B19V epidemiology and evolution.

The Pantanal hosts diverse wildlife species and therefore is a hotspot for arbovirus studies in South America. A serosurvey for Mayaro virus (MAYV), eastern (EEEV), western (WEEV) and Venezuelan (VEEV) equine encephalitis viruses was conducted with 237 sheep, 87 free-ranging caimans and 748 equids, including 37 collected from a ranch where a neurologic disorder outbreak had been recently reported. Sera were tested for specific viral antibodies using plaque-reduction neutralisation test. From a total of 748 equids, of which 264 were immunised with vaccine composed of EEEV and WEEV and 484 had no history of immunisation, 10 (1.3%) were seropositive for MAYV and two (0.3%) for VEEV using criteria of a ≥ 4-fold antibody titre difference. Among the 484 equids without history of immunisation, 48 (9.9%) were seropositive for EEEV and four (0.8%) for WEEV using the same criteria. Among the sheep, five were sero- positive for equine encephalitis alphaviruses, with one (0.4%) for EEEV, one (0.4%) for WEEV and three (1.3%) for VEEV. Regarding free-ranging caimans, one (1.1%) and three (3.4%), respectively, had low titres for neutralising antibodies to VEEV and undetermined alphaviruses. The neurological disorder outbreak could not be linked to the alphaviruses tested. Our findings represent strong evidence that MAYV and all equine encephalitis alphaviruses circulated in the Pantanal.

INTRODUÇÃO: Analisar prospectivamente a disfunção hepática e a evolução dos sinais e sintomas em pacientes adultos com dengue durante um período de dois meses. MÉTODOS: Realizamos um estudo prospectivo em Campos dos Goytacazes, Rio de Janeiro, Brasil, de janeiro a julho de 2008. Foi avaliada a evolução das manifestações clínicas e laboratoriais em 90 pacientes adultos com dengue, em um período de dois meses. Vinte controles foram arrolados para análise da função hepática. Em ambos os grupos foram realizadas coletas de dados e sangue nos primeiros cinco dias da doença, e aos 8, 15, 30 e 60 dias após o início da doença. Foram excluídos pacientes com hepatite B, hepatite C, gestantes e aqueles sabidamente soropositivos para HIV. RESULTADOS: No final do segundo mês do início da dengue, 33,3% (30/90) dos pacientes apresentaram persistência de pelo menos um sinal ou sintoma. Estavam presentes no final do segundo mês 57,7% (15/26) dos sinais ou sintomas. Os maiores percentuais de persistência foram: artralgia, adinamia, fraqueza, fadiga, anorexia, alteração do paladar e queda de cabelo. A infecção prévia pelo vírus da dengue (DENV) não predispôs a uma maior duração dos sintomas. Da função hepática, observamos alterações relevantes somente nos níveis das transaminases, que em alguns casos permaneceram elevados até o final do segundo mês. Os níveis de ALT ultrapassaram os de AST na convalescença. Homens apresentaram níveis mais elevados de transaminases quando comparados aos de mulheres. CONCLUSÕES: Dengue apresenta grande número de sintomas e transaminases elevadas no final do segundo mês de doença.

INTRODUCTION: To analyze the liver dysfunction and evolution of signs and symptoms in adult dengue patients during a two-month follow-up period. METHODS: A prospective cohort study was conducted in Campos dos Goytacazes, Rio de Janeiro, Brazil, from January to July, 2008. The evolution of laboratory and clinical manifestations of 90 adult dengue patients was evaluated in five scheduled visits within a two-month follow-up period. Twenty controls were enrolled for the analysis of liver function. Patients with hepatitis B, hepatitis C, those known to be human immunodeficiency virus (HIV) seropositive and pregnant women were excluded from the study. RESULTS: At the end of the second month following diagnosis, we observed that symptoms persisted in 33.3% (30/90) of dengue patients. We also observed that, 57.7% (15/26) of the symptoms persisted at the end of the second month. The most persistent symptoms were arthralgia, fatigue, weakness, adynamia, anorexia, taste alteration, and hair loss. Prior dengue virus (DENV) infection did not predispose patients to a longer duration of symptoms. Among hepatic functions, transaminases had the most remarkable elevation and in some cases remained elevated up to the second month after the disease onset. Alanine aminotransferase (ALT) levels overcame aspartate aminotransferase (AST) during the convalescent period. Male patients were more severely affected than females. CONCLUSIONS: Dengue fever may present a wide number of symptoms and elevated liver transaminases at the end of the second month.

In Niterói, state of Rio de Janeiro, dengue virus type 4 (DENV-4) was isolated for the first time in March 2011. We analysed the laboratory findings of the first cases and evaluated the use of molecular techniques for the detection of DENV-4 in Aedes aegypti that were field-caught. Conventional reverse transcriptase-polymerase chain reaction (RT-PCR) and SimplexaTM Dengue real-time RT-PCR confirmed DENV-4 infection in all cases. Additionally, DENV-4 was confirmed in a female Ae. aegypti with 1.08 x 10³ copies/mL of virus, as determined by quantitative real-time RT-PCR. This is the first time the SimplexaTM Dengue real-time assay has been used for the classification of cases of infection and for entomological investigations. The use of these molecular techniques was shown to be important for the surveillance of dengue in humans and vectors.

Antes diagnosticado na África e na Ásia, o vírus Chikungunya foi detectado nos últimos três anos, no Caribe, na Itália, na França e nos Estados Unidos. Relatamos o primeiro caso do Rio de Janeiro, Brasil, em 2010.

Initially diagnosed in Africa and Asia, the Chikungunya virus has been detected in the last three years in the Caribbean, Italy, France, and the United States of America. Herein, we report the first case for Rio de Janeiro, Brazil, in 2010.

Despite evidence of West Nile virus (WNV) activity in Colombia, Venezuela and Argentina, this virus has not been reported in most South American countries. In February 2009, we commenced an investigation for WNV in mosquitoes, horses and caimans from the Pantanal, Central-West Brazil. The sera of 168 horses and 30 caimans were initially tested using a flaviviruses-specific epitope-blocking enzyme-linked immunosorbent assay (blocking ELISA) for the detection of flavivirus-reactive antibodies. The seropositive samples were further tested using a plaque-reduction neutralisation test (PRNT90) for WNV and its most closely-related flaviviruses that circulate in Brazil to confirm the detection of specific virus-neutralising antibodies. Of the 93 (55.4%) blocking ELISA-seropositive horse serum samples, five (3%) were seropositive for WNV, nine (5.4%) were seropositive for St. Louis encephalitis virus, 18 (10.7%) were seropositive for Ilheus virus, three (1.8%) were seropositive for Cacipacore virus and none were seropositive for Rocio virus using PRNT90, with a criteria of > four-fold antibody titre difference. All caimans were negative for flaviviruses-specific antibodies using the blocking ELISA. No virus genome was detected from caiman blood or mosquito samples. The present study is the first report of confirmed serological evidence of WNV activity in Brazil.

Circulation of a new dengue virus (DENV)-3 genotype was recently described in Brazil and Colombia, but the precise classification of this genotype has been controversial. Here we perform phylogenetic and nucleotide-distance analyses of the envelope gene, which support the subdivision of DENV-3 strains into five distinct genotypes (GI to GV) and confirm the classification of the new South American genotype as GV. The extremely low genetic distances between Brazilian GV strains and the prototype Philippines/L11423 GV strain isolated in 1956 raise important questions regarding the origin of GV in South America.

Em Pernambuco, os primeiros casos de dengue ocorreram em 1987. Após intervalo de 7 anos sem casos autóctones, em 1995 ocorreu uma nova epidemia. Foram analisados aspectos relevantes das epidemias (1995-2006), utilizando-se dados epidemiológicos, clínicos e laboratoriais. Um total de 378.374 casos foi notificado, com 612 casos confirmados de febre hemorrágica do dengue e 33 óbitos. A taxa de mortalidade foi de 5.4%. A taxa de incidência aumentou de 134 para 1.438/100.000 habitantes, correspondente às epidemias pelos sorotipos 2 e 3, em 1995 e 2002, respectivamente. O dengue acometeu principalmente pessoas adultas (20-49 anos); 40,7% do sexo masculino e 59,3%, feminino. A partir de 2003, aumentou o número de casos em menores de 15 anos. Entre 225 casos de dengue hemorrágico, foram identificadas 42,7% e 57,3% infecções primárias e secundárias, respectivamente (p = 0.0279). Manifestações neurológicas também foram observadas. A partir de 2002, circularam os sorotipos 1, 2 e 3; predominando o sorotipo 3.

In Pernambuco, the first dengue cases occurred in 1987. After a seven-year interval without autochthonous cases, a new epidemic occurred in 1995. Important aspects of the dengue epidemics during the period 1995-2006 have been analyzed here, using epidemiological, clinical and laboratory data. A total of 378,374 cases were notified, with 612 confirmed cases of dengue hemorrhagic fever and 33 deaths. The mortality rate was 5.4%. The incidence rate increased from 134 to 1,438/100,000 inhabitants, corresponding to the epidemics due to serotypes 2 and 3, in 1995 and 2002, respectively. Dengue mainly affected adults (20-49 years); 40.7% were male and 59.3% were female. From 2003 onwards, the number of cases among individuals younger than 15 years old increased. Out of 225 dengue hemorrhagic fever cases, 42.7% primary and 57.3% secondary infections were identified (p = 0.0279). Neurological manifestations were also observed. From 2002 onwards, serotypes 1, 2 and 3 were circulating; serotype 3 was predominant.

A total of 4 243 049 dengue cases have been reported in Brazil between 1981 and 2006, including 5 817 cases of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) and a total of 338 fatal cases. Although all Brazilian regions have been affected, the Northeast and Southeast regions have registered the highest number of notifications. DENV-1 and DENV-4 were isolated for the first time in the Amazon region of Brazil in 1981 and 1982. The disease became a nationwide public health problem following outbreaks of DENV-1 and DENV-2 in the state of Rio de Janeiro in 1986 and 1990, respectively. The introduction of DENV-3 in 2000, also in the state of Rio de Janeiro, led to a severe epidemic with 288 245 reported dengue cases, including 91 deaths. Virus strains that were typed during the 2002 epidemic show that DENV-3 has displaced other dengue virus serotypes and entered new areas, a finding that warrants closer evaluation. Unusual clinical symptoms, including central nervous system involvement, have been observed in dengue patients in at least three regions of the country.

En Brasil se han notificado 4 243 049 casos de dengue entre 1981 y 2006, de ellos 5 817 casos de dengue hemorrágico/síndrome de choque por dengue (DH/SCD) y un total de 338 casos mortales. A pesar de que la enfermedad ha afectado a todas las regiones brasileñas, el mayor número de casos se ha notificado en las regiones nororiental y suroriental. Los virus del dengue (DENV) 1 y 4 se aislaron por primera vez en la región amazónica de Brasil en 1981 y 1982. La enfermedad se convirtió en un problema nacional de salud pública después de los brotes de DENV-1 y DENV-2 en el Estado de Río de Janeiro en 1986 y 1990, respectivamente. La introducción del DENV-3 en 2000, también en el Estado de Río de Janeiro, llevó a una grave epidemia con 288 245 casos notificados de dengue y 91 muertes. Las cepas del virus identificadas durante la epidemia de 2002 demostraron que el DENV-3 ha desplazado a los otros serotipos y se ha expandido a nuevas zonas, algo que merece una evaluación más profunda. En los pacientes con dengue de al menos tres regiones del país se han observado síntomas clínicos atípicos, entre ellos alteraciones del sistema nervioso central.

The objective of this study was to evaluate the impact of dengue virus infection on liver function by measuring aminotransferase in blood samples from patients serologically diagnosed by according to two MAC-ELISA protocols. Degrees of liver damage were classified according to aminotransferase levels: grade A - normal enzyme levels; grade B - increased levels of at least one of the enzymes; grade C - increased, with at least one of the enzymes being at levels higher than three times the upper reference values; grade D - acute hepatitis, with aminotransferase levels at least ten times their normal values. Of the 169 serologically confirmed cases of dengue at the dengue referral center in Campos dos Goytacazes in the state of Rio de Janeiro, Brazil, 65.1% had abnormal aminotransferase levels: 81 cases being classified as grade B, 25 as grade C and 3 as grade D. A further 34.9% of cases had normal enzyme levels and were classified as grade A. Liver damage is a common complication of dengue infection and aminotransferase levels are a valuable marker for monitoring these cases.

Histological and ultrastructural alterations in lung tissue of BALB/c mice infected with dengue virus serotype 2 (non-neuroadapted), by intraperitoneal and intravenous routes were analyzed. Lung tissues were processed following the standard techniques for photonic and electron transmission microscopies. Histopathological and ultrastructural studies showed interstitial pneumonia, characterized by the presence of mononuclear cells. In the mouse model, the dengue virus serotype 2 seems to led to a transient inflammatory process without extensive damage to the interalveolar septa, but caused focal alterations of the blood-exchange barrier. Endothelial cells of blood capillaries exhibited phyllopodia suggesting activation by presence of dengue virus. Morphometrical analysis of mast cells showed an expressive increase of the number of these cells in peribronchiolar spaces and adjacent areas to the interalveolar septa. Alveolar macrophages showed particles dengue virus-like inside rough endoplasmic reticulum and Golgi complex, suggesting viral replication. The tissue alterations observed in our experimental model were similar to the observed in human cases of dengue fever and dengue hemorrhagic fever. Our results show that BALB/c mice are permissive host for dengue virus serotype 2 replication and therefore provides an useful model to study of morphological aspects of dengue virus infection.

Dengue outbreaks have occurred in several regions in Brazil and cocirculating dengue virus type 1 (DENV-1), DENV-2, and DENV-3 have been frequently observed. Dual infection by DENV-2 and DENV-3 was identified by type-specific indirect immunofluorescence assay and confirmed by reverse transcription polymerase chain reaction in a patient in Ceará with a mild disease. This is the first documented case of simultaneous infection with DENV-2 and DENV-3 in Brazil. Sequencing confirmed DENV-2 and DENV-3 (South-East/American) genotype III and (SriLanka/India), genotype III respectively.