RESUMO
Enterovirus 71 (EV71), first isolated in 1969, has been responsible for numerous outbreaks of hand, foot and mouth disease (HFMD) with a small proportion of cases associated with neurological disease. Since 1997 there has been a significant increase in both the prevalence and virulence of EV71 in the Asia-Pacific region. We have examined the genetic diversity of EV71 in a large Australian city (Sydney N.S.W.) over a nineteen-year period. We determined the VP1 gene sequence of forty-eight EV71 strains isolated between 1983 and 2001. Analysis by molecular phylogeny revealed the presence of four subgenogroups B2, B4, C1 and C2. The results indicate that the major lineage circulating in Sydney N.S.W. was subgenogroup C1 with a recent switch in dominance to B4 in 2000 and 2001.
Assuntos
Enterovirus Humano A/classificação , Enterovirus Humano A/genética , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologia , Austrália/epidemiologia , Enterovirus Humano A/isolamento & purificação , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/virologia , Humanos , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , População Urbana , Proteínas Estruturais Virais/química , Proteínas Estruturais Virais/genéticaRESUMO
Human enterovirus 71 (EV71) (genus Enterovirus, family Picornaviridae) has been responsible for sporadic cases and outbreaks of hand-foot-and-mouth disease (HFMD), aseptic meningitis, encephalitis and poliomyelitis-like disease in Europe, the U.S.A., Australia and Asia. Recently, there has been an increase in EV71 activity in the Asia-Pacific region, with many outbreaks of HFMD associated with brainstem encephalitis manifesting as neurogenic pulmonary oedema with a high case fatality rate. In 1997, and again in 2000, EV71 outbreaks occurred in peninsular Malaysia. Variations in VP1 gene sequences have been shown to divide all known EV71 field isolates into three distinct genogroups (A, B and C). Consequently we examined the VP1 gene sequences of 43 EV71 strains isolated in peninsular Malaysia between 1997 and 2000 in order to determine the genogroup prevalence over the period. In this study we show that four subgenogroups (B3, B4, C1 and C2) of EV71 circulated in peninsular Malaysia between 1997 and 2000. Subgenogroups B3, B4 and C1 have been identified as the primary cause of the outbreaks of EV71 in peninsular Malaysia. Subgenogroup C1 also displayed endemic circulation from 1997 to 2000 and subgenogroup C2 was present at a low level during the 1997 outbreak.
