Epidemiological study ofviral acute respiratory infections in Vietnam

1.研究背景：热带和亚热带国家的流感病毒感染仍然是一个令人担忧的问题，而新型流感病毒在中国历史上也曾发生过，因此与中国接壤的越南的流感监测非常重要.目的：1）流行病学研究在越南作为一个热带和亚热带国家的流感病毒感染和早期捕获的新型流感感染的监测网络的建立，2）耐金刚烷胺的流感病毒的流行病学研究，3）未知病原的急性呼吸道综合征的流行病学研究，4）在越南未来的流感疫苗接种计划的基础研究。结果：通过实验室人力资源的开发，建立了以河内、胡志明、芽庄、太原等城市为中心的全国性监测网络。越南发生了高致病性H5 N1禽流感疫情，我们的对口机构为控制疫情做出了贡献。 关于我们 呼吸综合征主要由流感病毒、腺病毒、肠道病毒和RS病毒引起，流行病学背景尚不清楚。与其他热带和亚热带国家一样，流感感染全年都有两个高峰，即6月至9月和12月至2月。这些观察结果表明，3月至5月期间，在开始爆发之前，接种疫苗是合适的。2005年，日本、美国和大洋洲等地发现了具有HA基因双突变（S 193 F和D225 N，Clade N）的金刚烷胺耐药H3 N2流行株。然而，M基因的进化模式被证明是非线性的，与HA和NA基因的进化模式无关。H3 N2病毒Hal基因片段的遗传漂变，尤其是抗原位点的遗传漂变，在A/H3 N2病毒中比在A/H1N1病毒中发生得更频繁。因此，我们可以得出结论，由于流感病毒全年传播，我们强调在热带和亚热带地区进行监测的重要性，因为在热带和亚热带地区，新毒株的出现可能比在温带地区更早被发现。少

1. Background:Influenza virus infections in tropical and subtropical countries remain to be um-fear, and as new type of influenza virus occurred historically in China, influenza surveillance in Vietnam bordering on China was quite important.2. Objective:1) Epidemiological study of influenza virus infections in Vietnam as a tropical and subtropical country and early catch of new type of influenza infection by establishing of surveillance net work, 2) epidemiological study of amantadine resistant influenza viruses, 3) epidemiological study of unknown pathogenic acute respiratory syndrome, 4) basic study for future influenza vaccination program in Vietnam.3. Results:We could establish a nationwide surveillance network tied with Hanoi, Ho Chi Minh, Nha Trang, and Tay Nguyen cities in conjunction with development of laboratory human resources. High pathogenic avian influenzas H5N1 outbreak occurred in Vietnam and our counterpart institutions were contributed to control this outbreak.Acute r … More espiratory syndrome, which epidemiological background remained to be unknown, was caused by mainly influenza viruses, adenoviruses, enteroviruses, and RS virus. Influenza infections occurred throughout year with two peaks, June-September and December-February, as in other tropical and subtropical countries. These observations suggest that the time during March to May, before starting outbreak is suitable it vaccination. High prevalence of amantadine resistant H3N2 with dual mutations of HA genes (S 193F and D225N, Clade N) was found in 2005, as in Japan, USA, and Oceania.Pylogenetic analysis of individual gene segments revealed that the HA and the NA genes of the influenza A viruses evolved in as sequential way. However, the evolutionary pattern of the M gene proved to be nonlinear and was not linked with that of the HA and NA genes. Genetic drift in Hal segments, especially in antigenic sites of A/H3N2 viruses, occurred more frequently in A/H3N2 viruses than it did in A/H1N1 viruses.Thus, we can conclude that as influenza viruses circulate throughout the year, we emphasize the importance of surveillance in tropical and subtropical zones, where the emergence of new strains may be detected earlier than it is in the temperate zones. Less