RESUMO
Machupo virus and Chapare virus are members of the Tacaribe serocomplex (virus family Arenaviridae) and etiological agents of hemorrhagic fever in humans in Bolivia. The nucleotide sequences of the complete Z genes, a large fragment of the RNA-dependent RNA polymerase genes, the complete glycoprotein precursor genes, and the complete nucleocapsid protein genes of 8 strains of Machupo virus were determined to increase our knowledge of the genetic diversity among the Bolivian arenaviruses. The results of analyses of the predicted amino acid sequences of the glycoproteins of the Machupo virus strains and Chapare virus strain 200001071 indicated that immune plasma from hemorrhagic fever cases caused by Machupo virus may prove beneficial in the treatment of Bolivian hemorrhagic fever but not hemorrhagic fever caused by Chapare virus.
Assuntos
Arenavirus do Novo Mundo/genética , Variação Genética , RNA Viral/genética , Sequência de Aminoácidos , Animais , Infecções por Arenaviridae/virologia , Arenavirus do Novo Mundo/classificação , Bolívia , Chlorocebus aethiops , Evolução Molecular , Glicoproteínas/genética , Febre Hemorrágica Americana/virologia , Humanos , Proteínas do Nucleocapsídeo/genética , Filogenia , RNA Polimerase Dependente de RNA/genética , Alinhamento de Sequência , Análise de Sequência de RNA , Especificidade da Espécie , Células Vero , Proteínas do Envelope Viral/genéticaRESUMO
The results of analyses of Z, RNA-dependent RNA polymerase, glycoprotein precursor, and nucleocapsid protein gene sequence data suggested that Guanarito virus was the most common cause of Venezuelan hemorrhagic fever in a 7-year period in the 1990s and that the evolution of Pirital virus in association with Sigmodon alstoni (Alston's cotton rat) has occurred at a significantly higher rate than the evolution of Guanarito virus in association with Zygodontomys brevicauda (short-tailed cane mouse) on the plains of western Venezuela. The results of analyses of the primary structures of the glycoproteins of the 8 strains of Guanarito virus isolated from humans suggested that these strains would be highly cross-reactive in neutralization assays. Thus, passive antibody therapy may prove beneficial in the treatment of human disease caused by strains of Guanarito virus that are enzootic in the region in which Venezuelan hemorrhagic fever is endemic.
Assuntos
Infecções por Arenaviridae/virologia , Arenavirus do Novo Mundo/classificação , Arenavirus do Novo Mundo/genética , Polimorfismo Genético , Animais , Infecções por Arenaviridae/epidemiologia , Arenavirus do Novo Mundo/isolamento & purificação , Humanos , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Sigmodontinae/virologia , Venezuela/epidemiologia , Proteínas não Estruturais Virais/genética , Proteínas Estruturais Virais/genéticaRESUMO
A small focus of hemorrhagic fever (HF) cases occurred near Cochabamba, Bolivia, in December 2003 and January 2004. Specimens were available from only one fatal case, which had a clinical course that included fever, headache, arthralgia, myalgia, and vomiting with subsequent deterioration and multiple hemorrhagic signs. A non-cytopathic virus was isolated from two of the patient serum samples, and identified as an arenavirus by IFA staining with a rabbit polyvalent antiserum raised against South American arenaviruses known to be associated with HF (Guanarito, Machupo, and Sabiá). RT-PCR analysis and subsequent analysis of the complete virus S and L RNA segment sequences identified the virus as a member of the New World Clade B arenaviruses, which includes all the pathogenic South American arenaviruses. The virus was shown to be most closely related to Sabiá virus, but with 26% and 30% nucleotide difference in the S and L segments, and 26%, 28%, 15% and 22% amino acid differences for the L, Z, N, and GP proteins, respectively, indicating the virus represents a newly discovered arenavirus, for which we propose the name Chapare virus. In conclusion, two different arenaviruses, Machupo and Chapare, can be associated with severe HF cases in Bolivia.
Assuntos
Arenavirus do Novo Mundo/isolamento & purificação , Febre Hemorrágica Americana/virologia , Adulto , Arenavirus do Novo Mundo/classificação , Arenavirus do Novo Mundo/genética , Bolívia , Análise por Conglomerados , Diagnóstico Diferencial , Evolução Fatal , Genoma Viral , Febre Hemorrágica Americana/diagnóstico , Humanos , Masculino , Filogenia , RNA Viral/genética , Análise de Sequência , Homologia de Sequência de Aminoácidos , Dengue Grave/diagnóstico , Proteínas Virais , Febre Amarela/diagnósticoRESUMO
An outbreak of hantavirus pulmonary syndrome occurred in the province of Los Santos, Panama, in late 1999 and early 2000. Eleven cases were identified; 9 were confirmed by serology. Three cases were fatal; however, no confirmed case-patient died. Case-neighborhood serologic surveys resulted in an overall hantavirus antibody prevalence of 13% among household and neighborhood members from the outbreak foci. Epidemiologic investigations did not suggest person-to-person transmission of hantavirus infection. By use of Sin Nombre virus antigen, hantavirus antibodies were detected in Oligoryzomys fulvescens and Zygodontomys brevicauda cherriei. This outbreak resulted in the first documented cases of human hantavirus infections in Central America.