RESUMO
The role of rats in human hepatitis E virus (HEV) infections remains controversial. A genetically distinct HEV was recently isolated from rats in Germany, and its genome was sequenced. We have isolated a genetically similar HEV from urban rats in Los Angeles, California, USA, and characterized its ability to infect laboratory rats and nonhuman primates. Two strains of HEV were isolated from serum samples of 134 wild rats that had a seroprevalence of antibodies against HEV of ≈80%. Virus was transmissible to seronegative Sprague-Dawley rats, but transmission was spotty and magnitude and duration of infection were not robust. Viremia was higher in nude rats. Serologic analysis and reverse transcription PCR were comparably sensitive in detecting infection. The sequence of the Los Angeles virus was virtually identical to that of isolates from Germany. Rat HEV was not transmissible to rhesus monkeys, suggesting that it is not a source of human infection.
Assuntos
Vírus da Hepatite E/isolamento & purificação , Hepatite E/veterinária , Hepatite Viral Animal/virologia , Animais , Animais Selvagens/virologia , Sequência de Bases , Doenças Transmissíveis Emergentes/patologia , Doenças Transmissíveis Emergentes/transmissão , Doenças Transmissíveis Emergentes/veterinária , Doenças Transmissíveis Emergentes/virologia , DNA Viral/genética , Feminino , Hepatite E/patologia , Hepatite E/transmissão , Hepatite E/virologia , Vírus da Hepatite E/genética , Vírus da Hepatite E/patogenicidade , Hepatite Viral Animal/patologia , Hepatite Viral Animal/transmissão , Humanos , Fígado/patologia , Los Angeles , Macaca mulatta , Masculino , Ratos , Ratos Sprague-Dawley , Estudos Soroepidemiológicos , Zoonoses/transmissão , Zoonoses/virologiaRESUMO
A unique hepatitis E virus (HEV) strain was identified as the aetiological agent of acute hepatitis in a United States (US) patient who had recently returned from vacation in Thailand, a country in which HEV is endemic. Sequence comparison showed that this HEV strain was most similar, but not identical, to the swine and human HEV strains recovered in the US. Phylogenetic analysis revealed that this new HEV isolate was closer to genotype 3 strains than to the genotype 1 strains common in Asia. The fact that this HEV was closely related to strains recovered in countries where HEV is not endemic and was highly divergent from Asian HEV strains raises the questions of where the patient's infection was acquired and of whether strains are geographically as localized as once thought.
