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目的 了解近几年流感病毒在深圳地区活动的特点及甲３（Ｈ３Ｎ２） 亚型毒株ＨＡ１ 基因演变概况。方法 病毒分离采用常规的鸡胚双腔接种，毒株检定用常量半加敏ＨＩ测定。新鲜收获含病毒粒的鸡胚尿囊液用来提取ＲＮＡ，经逆转录合成ｃＤＮＡ，经聚合酶链反应（ＰＣＲ） 扩增，产物纯化，采用双脱氧链末端终止法进行核苷酸序列测定。结果 近几年来深圳地区流感活动概况与全国情况相一致：在人群中仍同时流行Ｈ３Ｎ２，Ｈ１Ｎ１ 亚型和乙型毒株，当甲型毒株活动减弱时，乙型毒株活动就增强，反之，甲型毒株增强时，乙型毒株就减弱。随着时间的推移，Ｈ３Ｎ２ 亚型毒株ＨＡ１ 基因不断地发生点突变，这种突变严重受人群免疫压力所影响，１９９６ 年的毒株与１９９５ 的毒株相比，不仅氨基酸替换点中多数是位于抗原决定簇区或受体结合部位上，并增加两个糖基化位点，故导致Ｈ３Ｎ２ 毒株於１９９６ 年活动明显增强。结论 近来在深圳地区人群中仍同时流行着Ｈ３Ｎ２，Ｈ１Ｎ１ 亚型和乙型流感病毒。然而，不同年其优势毒株是不一样的。１９９６ 年Ｈ３Ｎ２ 毒株活动增强是由于其ＨＡ１ 区氨基酸序列发生替换所造成。
Objective To understand the characteristics of influenza virus activity in Shenzhen in recent years and the evolution of HA1 gene of H3N2 subtype strain. Methods Viruses were isolated by routine double-chamber chick embryo inoculation. The strains were assayed by semi-sensitized HI. Freshly harvested chicken embryo allantoic fluid containing virus particles was used to extract RNA, cDNA was synthesized by reverse transcription, amplified by polymerase chain reaction (PCR) and the product was purified. The nucleotide sequence was determined by dideoxy chain termination method. Results In recent years, the general situation of influenza in Shenzhen was consistent with the national situation: H3N2, H1N1 subtype and type B virus were still prevailing in the population. When the activity of type A virus decreased, the activity of type B virus strain increased. When the type A strain is enhanced, the type B strain is weakened. Over time, HA1 gene of the H3N2 subtype strain is continuously mutated point by point, and this mutation is severely affected by the immune pressure of the population. Compared with the strain of 1995, the strain of 1996 is not only the majority of the amino acid replacement points Located in the antigenic determinant region or receptor binding sites, and increase the two glycosylation sites, resulting in H3N2 strains significantly increased activity in 1996. Conclusions Recently, H3N2, H1N1 subtype and influenza B virus are still prevailing in Shenzhen area. However, the dominant strains in different years are different. The increased activity of H3N2 strains in 1996 was due to the replacement of the amino acid sequence of HA1.