RESUMEN
To investigate the molecular epidemiology of Taiwanese Echovirus 30 (E-30) strains, we analyzed the 876 bp sequence of the VP1 gene from 32 Taiwanese strains isolated in 1988-2008, 498 reference sequences, and one Echovirus 21 strain as the out-group. Phylogenetic analysis detected six E-30 genotypes (designated GI-GVI) that had circulated globally during the past five decades. The genotypes varied widely in geographic distribution and circulation half-life. The GI, GII, and GV were ancient genotypes in which the first strains emerged in the 1950s. The GIII was a reemerging genotype, in which strains had first appeared in Colombia in 1995 before reemerging in the New Independent States (NIS) in 2003. The GIV, an emerging genotype that recently appeared in Asia in 2003, was closely related to the ancient genotypes. The GVI was the circulating genotype, which included eight clusters (A-H) that had circulated since 1967. No GVI-A, C, D, or E strains have been identified during the past 10 years. The GVI-B first appeared in China in 1984 and later in Russia and Asia in the 2000s. The GVI-F, G, and H strains, which comprised the prevalent clusters, had been dominant in Asia Pacific area, globally, and Europe, respectively. Taiwanese strains were classified into GVI-D (1988-1989), GVI-F (1993-2004), and GVI-G (1993-2008). The quiescence period of E-30 is longer in Taiwan (5-8 years) than in other countries (3-5 years).
Asunto(s)
Infecciones por Echovirus/epidemiología , Enterovirus Humano B/genética , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Niño , Preescolar , Femenino , Genes Virales , Humanos , Masculino , Epidemiología Molecular , Datos de Secuencia Molecular , Filogenia , ARN Viral/genética , Taiwán/epidemiologíaRESUMEN
In Taiwan, enterovirus 71 (EV71) has played an important role in severe enterovirus-related cases every year since the devastating outbreak in 1998. Three genogroups A, B, C occur worldwide; with the B and C genogroups being subdivided into B1-B4 and C1-C4 subgenogroups respectively. To understand the mutation of the EV71 genogroup in Taiwan before and after 1998, a total of 54 worldwide strains were studied including 41 Taiwanese strains obtained in 1986 and 1998-2004. A fragment of 207 bp of the VP4 region was amplified and sequenced. Genetic analysis was performed using MEGA software (version 3.0) for the nucleotide sequence alignment and phylogenetic analysis. In Taiwan, the subgenogroup B1 was predominant before 1998 while subgenogroup C2 was the major etiologic group in 1998 outbreak. A minor etiologic group outbreak in 1998, subgenogroup B4, became predominant during the period from 1999 to 2003. In this study, subgenogroup C4 emerged and became predominant in 2004 in Taiwan. The nucleotide differences between B1 and C2, C2 and B4, B4 and C4 were 20%-26%, 19%-27%, 18%-22%, respectively. Nucleotide sequence alignment revealed 67 substitutions. Most of the substitutions (62/67) were silent mutations. This is the first report about the emergence of EV71 subgenogroup C4 in Taiwan.