海南省1985～1993年脊髓灰质炎流行野毒株的分析

ANALYSIS OF THE WILD TYPE POLIOVIRUS EPIDEMICSTRAINS IN HAINAN PROVINCE, 1985-1993

海南省１９８５－１９９３年经历了４次较大的脊髓灰质炎（脊灰）流行，年发病数分别为７２５例（１９８５年）１９７例（１９８９年；６４例（１９９０年）和６５例（１９９３）年．历年流行的野毒株均为脊灰Ｉ型病毒．对历年来分离的病毒株先用ＰＣＲ－ＲＦＬＰ法选出有代表性的毒株，再将这些病毒株ＶＰ１基因的部份片段做核酸序列分析，并与非流物年分离的毒株作相应的比较。结果显示，每次较大流行年的分离毒株与上一次流行的代表株相比较，其核苷酸均有效大的改变，说明当脊灰新的基因型出现时便在本省有一次较大的流行，对新的基因型脊灰病毒的由来，结合全国脊灰病毒的分子流行病学资料进行了讨论。

From 1985 to 1993, there were four outbreaks of poliomyelitis in Hainan Province. 725 cases were reported in 1985, 197 cases in 1989, 64 cases in 1990 and 65 cases in 1993. All the wild epidemic strains were type 1 polioviruses. Several representative epidemic strains were selected by PCR-RFLP method, 300 nucleotides in VP1 coding region (nucleotides 2480 - 2779) of each representative strains were compared with each other by se- quence analysis. It showed clearly that each outbreak was caused by a wild type 1 poliovirus with new genotype. The sequence diversity of the epidemic strains in 1985 and 1989 was 18%, that of the epidemic strains in 1989 and 1990 was 17.7%, in 1990 and 1993 was 10.3%. This suggested there would be an outbreak when the poliovirus with new genotype circulated in the province. Based on the molecular epidemiological data of poliovirus in the whole nation, we discussed the origin of the wild type polioviurs with the new genotype.