Cacipacore virus as an emergent mosquito-borne Flavivirus

Abstract INTRODUCTION: Cacipacore virus (CPCV), a possible bird-associated flavivirus, has yet to be detected in mosquitoes. Our purpose is examining CPCV in mosquitoes from the Amazon region of Brazil. METHODS: Approximately 3,253 Culicidae (grouped into 264 pools) were collected from the Amazon region during 2002-2006 and analyzed using a Flavivirus genus-specific reverse transcription- polymerase chain reaction followed by nested polymerase chain reaction assay and by nucleotide sequencing of amplicons. RESULTS: Nucleotide sequences from five mosquito samples showed high similarity to the those of CPCV originally isolated in the Amazon region. CONCLUSIONS: This is the first report of CPCV-infected mosquitoes which has implications on the arbovirus maintenance in nature and transmission to man.

Serologic survey of hantavirus in a rural population from the northern State of Mato Grosso, Brazil

INTRODUCTION: Hantavirus is a genus of ribonucleic acid (RNA) viruses included in the family Bunyaviridae. Hantaviruses are rodent-borne zoonoses that, in the last 18 years, became an emergent public health problem in the Americas, causing a severe cardiopulmonary syndrome. This disease has no specific treatment and has a high case fatality. The transmission of hantavirus to man occurs by inhaling aerosols of rodent excreta. The aim of this study was to determine the prevalence of antibodies to hantavirus in the population of the rural settlement of Tupã in the county of Marcelândia, state of Mato Grosso, Brazil. METHODS: The participants of the serologic survey were visited at their homes and selected randomly among the settlement population. Blood samples of the participants were collected by venopuncture. The serum samples were tested by an IgG-ELISA using an N recombinant protein of Araraquara hantavirus as antigen, using the protocol previously established by Figueiredo et al. RESULTS: IgG antibodies to hantavirus were detected in 7 (13%) of the 54 participants. The positivity was higher among men. It was observed that there was an association of seropositivity to hantavirus within the participants born in the south of Brazil. CONCLUSIONS: The results suggest that, in this rural area, everyone is exposed to the same risk of becoming infected with hantavirus, and, therefore, there is a need to intensify surveillance activities and education of the local people to prevent this viral infection.

Prevalence of serum antibodies to hantavirus in a rural population from the southern state of Santa Catarina, Brazil / Prevalência de anticorpos séricos para hantavírus em população rural do extremo sul do estado de Santa Catarina, Brasil

INTRODUCTION: Rodent-borne hantaviruses cause severe human diseases. We completed a serological survey of hantavirus infection in rural inhabitants of Turvo County, in the southern State of Santa Catarina, Brazil, in which seropositivity for hantavirus was correlated to previous disease in the participants. METHODS: The levels of IgG antibodies to hantavirus Araraquara in the sera of 257 individuals were determined using an immunoenzymatic assay. RESULTS: IgG antibodies to hantavirus were found in 2.3 percent of the participants. All seropositive participants reported previous disease with symptoms suggestive of hantavirus cardiopulmonary syndrome. CONCLUSIONS: Human infections causing unreported cardiopulmonary syndrome probably occur in the southern State of Santa Catarina.

INTRODUÇÃO: Hantaviroses são zoonoses de roedores silvestres que causam doenças graves em seres humanos. Este trabalho mostra inquérito sorológico para hantavírus em população rural e periurbana do município de Turvo, Estado de Santa Catarina e a correlação da presença de anticorpos anti-hantavírus com a história mórbida pregressa dos indivíduos. MÉTODOS: Investigaram-se os 257 participantes do estudo quanto à presença de anticorpos IgG séricos anti-hantavírus Araraquara, por método imunoenzimático. RESULTADOS: A prevalência de anticorpos anti-hantavírus na população foi de 2,3 por cento. Os soropositivos possuíam antecedente nosológico sugestivo de hantavirose pregressa. CONCLUSÕES: Os achados mostram a ocorrência de infecções por hantavírus no extremo sul de Santa Catarina.

Diagnosis of hantavirus infection in humans and rodents in Ribeirão Preto, State of São Paulo, Brazil / Diagnóstico de infecção por hantavírus em humanos e roedores em Ribeirão Preto, Estado de São Paulo

INTRODUCTION: Hantavirus pulmonary and cardiovascular syndrome (HPCS) is an emerging serious disease in the Americas. Hantaviruses (Bunyaviridae) are the causative agents of this syndrome and are mainly transmitted through inhalation of aerosols containing the excreta of wild rodents. In the Ribeirão Preto region (state of São Paulo, Brazil), HPCS has been reported since 1998, caused by the Araraquara virus (ARAV), for which Necromys lasiurus is the rodent reservoir. This study aimed to show diagnostic results relating to infection in humans and rodents, obtained at the Virology Research Center of the Ribeirão Preto School of Medicine, University of São Paulo, between 2005 and 2008. METHODS: HPCS was diagnosed by means of ELISA and/or RT-PCR in 11 (21.2 percent) out of 52 suspected cases, and 54.4 percent of these were fatal. Furthermore, 595 wild rodents (Necromys lasiurus, Akodon sp, Calomys tener and Oligoryzomys sp) were caught between 2005 and 2008. RESULTS: Fifteen (2.5 percent) of these rodents presented antibodies for hantavirus, as follows: Necromys lasiurus (4 percent), Calomys tener (1.9 percent) and Akodon sp (1.5 percent). Nucleotide sequences obtained through RT-PCR from one HPCS patient and one Calomys tener rodent were compared with hantavirus sequences from GenBank, which showed that both were homologous with ARAV. CONCLUSIONS: This work corroborates previous studies showing that ARAV is the hantavirus causing HPCS in the Ribeirão Preto region. It also shows that rodents infected with hantavirus represent a constant risk of transmission of this virus to man.

INTRODUÇÃO: A síndrome pulmonar e cardiovascular por hantavírus é uma doença grave emergente nas Américas. Os hantavírus, Bunyaviridae, são os agentes causadores desta síndrome, causadas, principalmente, pela inalação de aerossóis dos dejetos de roedores silvestres. Na região de Ribeirão Preto, a SPCVH, causada pelo vírus Araraquara, tem sido diagnosticada, desde 1998. O roedor-reservatório do ARAV é o Necromys lasiurus. Este tem como objetivo mostrar os resultados de diagnósticos da infecção de humanos e roedores obtidos no Centro de Pesquisa em Virologia da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, durante o período de 2005 a 2008. MÉTODOS: A síndrome pulmonar e cardiovascular por hantavírus foi diagnosticada, por ELISA e/ou RT-PCR, em 11 (21,2 por cento) dos 52 casos suspeitos e destes, 54,4 por cento foram casos fatais. Além disso, também, de 2005 a 2008, foram capturados 595 roedores silvestres, Necromys lasiurus, Akodon sp, Calomys tener e Oligoryzomys sp. RESULTADOS: Quinze (2,5 por cento) destes roedores apresentaram anticorpos para hantavírus. As soropositividades intraespécie ou gênero foram 4 por cento para Necromys lasiurus, 1,9 por cento para Calomys tener e 1,5 por cento para Akodon sp. Sequências nucleotídicas, obtidas pela RT-PCR de um paciente com SPCVH e de um roedor Calomys tener, foram comparadas com sequências de hantavírus do GenBank, o que mostrou que ambas tinham homologia com o ARAV. CONCLUSÕES: Este trabalho corrobora outros estudos que mostram que o ARAV é o hantavírus causador da SPCVH, na região de Ribeirão Preto, além de mostrar que roedores infectados por hantavírus representam um risco constante de transmissão desses vírus para o homem.