Variations in genome fragments coding for RNA polymerase in human and simian hepatitis A viruses

AbstractThe genome of hepatitis A virus (HAV) isolated from spontaneously infected African vervet monkey (Cercopithecus aethiops) has been cloned and partially sequenced. Comparison of genome fragments (1248 and 162 bp) from the 3D (RNA polymerase) region with the corresponding parts of human HAV genomes revealed a high degree of heterogeneity: there were altogether 257 nucleotide changes leading to 44 substitutions in predicted amino acid sequence, i.e. 89% amino acid identity. This divergence is considered to be significantly greater than genomic variations usually found among human HAV strains, where amino acid identity in the 3D region is over 98%

Taxonomy of the caliciviruses

The International Committee on Taxonomy of Viruses (ICTV) has recently approved several proposals submitted by the present Caliciviridae Study Group. These proposals include the division of the family into 4 new genera designated Lagovirus, Vesivirus, "Norwalk-like viruses (NLVs), and "Sapporo-like viruses (SLVs); the latter 2 genera were assigned temporary names until acceptable names can be determined by the scientific community. The genera have been further divided into the following species: Feline calicivirus and Vesicular exanthema of swine virus (genus Vesivirus), Rabbit hemorrhagic disease virus and European brown hare syndrome virus (genus Lagovirus), Norwalk virus (genus NLV), and Sapporo virus (genus SLV). In addition, the ICTV approved a proposal to remove the hepatitis E virus from the Caliciviridae into an "unassigned classification status

Seroprevalence for hepatitis E virus (HEV) infection among volunteer blood donors of the Regional Blood Bank of Londrina, State of Paraná , Brazil Soroprevalência da infecção pelo virus da hepatite E (VHE) em candidatos a doadores de sangue voluntários do Hemocentro Regional de Londrina, Londrina, Estado do Paraná, Brasil

A cross-sectional study was carried out among 996 volunteer blood donors enrolled from May 1999 to December 1999 to determine the seroprevalence of hepatitis E virus (HEV) infection among volunteer blood donors of the Regional Blood Bank of Londrina, State of Paraná, Brazil, and to evaluate whether the rate of seroprevalence of IgG anti-HEV antibodies is associated with sociodemographic variables and with seropositivity for hepatitis A virus (HAV) infection. All participants answered the questionnaire regarding the sociodemographic characterisitcs. Serum samples were tested for IgG antibodies to HEV (anti-HEV) by an enzyme linked immunoassay (ELISA). All serum samples positive for anti-HEV IgG and 237 serum samples negative for anti-HEV were also assayed for IgG anti-HAV antibodies by ELISA. Anti-HEV IgG was confirmed in 23/996 samples, resulting in a seroprevalence of 2.3% for HEV infection, similar to previous results obtained in developed countries. No significant association was found between the presence of anti-HEV IgG antibodies and the sociodemographic variables including gender, age, educational level, rural or urban areas, source of water, and sewer system (p > 0.05). Also, no association with seropositivity for anti-HAV IgG antibodies was observed (p > 0.05). Although this study revealed a low seroprevalence of HEV infection in the population evaluated, the results showed that this virus is circulating among the population from Londrina, South Brazil, and point out the need of further studies to define the clinical and epidemiological importance of HEV infection and to identify additional risk factors involved in the epidemiology and pathogenesis of this infection in this population.<br>Os objetivos do estudo foram determinar a soroprevalência da infecção pelo vírus da hepatite E (VHE) em candidatos a doadores de sangue voluntários do Hemocentro Regional de Londrina, Paraná, e avaliar se essa soroprevalência está associada com variáveis socio-demográficas e com o índice de soropositividade para hepatite por vírus A (VHA). Foi realizado estudo transversal para determinar a taxa de soroprevalência da infecção pelo VHE em 996 candidatos a doadores de sangue. Todos os participantes responderam um questionário sobre características sociodemográficas. A pesquisa de anticorpos específicos IgG anti-VHE foi realizada por método de enzimaimunoensaio (ELISA). Todas as amostras soropositivas para IgG anti-VHE e 237 amostras soronegativas para IgG anti-VHE foram submetidas também à pesquisa de IgG anti-VHA por ELISA. Entre as 996 amostras de soro analisadas, anticorpos IgG anti-VHE foram detectados em 23 amostras, resultando em uma soroprevalência de 2,3% (IC 95%: 1,5 - 3,5), semelhante aos resultados de estudos realizados em países desenvolvidos. Não houve associação entre o índice de soropositividade de IgG anti-VHE e as variáveis sociodemográficas (sexo, idade, escolaridade, procedência, fonte de água e origem dos dejetos); também não se detectou associação entre soropositividade para IgG anti-VHE com soropositividade para IgG anti-VHA. Os resultados obtidos sugerem que, embora tenha se observado uma baixa prevalência da infecção pelo VHE na população analisada, verificou-se que existe circulação do VHE no município de Londrina e que estudos posteriores são necessários para definir a importância clínica e epidemiológica da infecção pelo VHE nesse município bem como identificar outros possíveis fatores de risco envolvidos na epidemiologia da infecção pelo VHE