Nakajima S, Nakamura K, Nishikawa F, Nakajima K
Institute of Public Health, Tokyo, Japan.
Epidemiol Infect. 1991 Apr;106(2):383-95. doi: 10.1017/s0950268800048536.
From January 1985 to March 1989, off-season viruses of H1N1 and H3N2 subtypes of influenza A viruses were isolated on five occasions in Japan. The HA gene sequences of the influenza A(H1N1) and A(H3N2) viruses isolated in Japan from 1985-9 were analysed and the phylogenetic tree for each subtype virus was constructed to determine any genetic relationship between viruses isolated in off-seasons and the epidemic viruses of the following influenza seasons. In one instance with H1N1 viruses in 1986 and in two instances with H3N2 viruses in 1985 and 1987, the spring isolates were genetically close to some of the winter isolates and were considered to be the parental viruses of the following influenza seasons. However, even in these cases, influenza viruses of the same subtype with different lineages co-circulated in Japan.
1985年1月至1989年3月期间,甲型流感病毒H1N1和H3N2亚型的非流行季病毒在日本被分离出5次。对1985 - 1989年在日本分离出的甲型流感病毒H1N1和H3N2病毒的血凝素(HA)基因序列进行了分析,并构建了每种亚型病毒的系统发育树,以确定非流行季分离出的病毒与随后流感季节的流行病毒之间的遗传关系。1986年在H1N1病毒的一个实例中,以及1985年和1987年在H3N2病毒的两个实例中,春季分离株在基因上与一些冬季分离株接近,并被认为是随后流感季节的亲本病毒。然而,即使在这些情况下,不同谱系的同一亚型流感病毒也在日本共同流行。