Epidemiological study ofviral acute respiratory infections in Vietnam

1.背景：热带、亚热带国家流感病毒感染仍令人担忧，而由于中国历史上曾发生新型流感病毒，与中国接壤的越南流感监测相当重要。目的：1)越南作为热带和亚热带国家的流感病毒感染的流行病学研究，通过建立监测网络，早期发现新型流感感染；2)金刚烷胺耐药流感病毒的流行病学研究；3)未知致病的急性呼吸综合征的流行病学研究；4)越南未来流感疫苗接种的基础研究。结果：结合实验室人力资源开发，可建立与河内、胡志明、芽庄、泰阮市相结合的全国性监测网络。越南发生高致病性禽流感H5N1疫情，我们的对口机构参与了控制疫情。急性r…更多的呼吸道综合征是由流感病毒、腺病毒、肠道病毒和RS病毒引起的，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，分别是6-9月和12-2月。这些观察结果表明，在3月至5月期间开始暴发之前的时间是接种疫苗的合适时间。2005年，在日本、美国和大洋洲发现了具有双重HA基因突变(S 193F和D225N，Clade N)的金刚烷胺耐药H3N2的高发流行。对单个基因片段的热源分析表明，甲型流感病毒的HA和NA基因是按顺序进化的。然而，M基因的进化模式被证明是非线性的，并且与HA和NA基因的进化模式不连锁。与甲型H1N1流感病毒相比，甲型H3N2型流感病毒HA1片段，尤其是A/H3N2型病毒抗原位点的基因漂移发生的频率更高。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监测的重要性，因为那里可能比温带地区更早发现新毒株。较少

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