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The Tendency and Rule of HCV Genotype Distribution Mode Changed in China

Author: HongGuoZuo
Tutor: MaoQing
School: Third Military Medical University
Course: Internal Medicine
Keywords: China hepatitis C virus Genotype epidemiology human immunodeficiency virus
CLC: R512.63
Type: Master's thesis
Year: 2011
Downloads: 103
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Abstract

Over 200 million patients infected with hapetitis C virus (HCV), while the prevalence of HCV in China increased very rapidly in recent years. Hepatic steatosis and hepatocellular carcinoma is frequent in those patients. It is very difficult to curb the spread of HCV, because of no effective vaccine. The progression and treatment outcome of HCV is related with HCV genotypes. To control this disease, many molecular epidemiological studies have been finished in many countries since 1990s.Series evidences suggested that distribution of HCV genotypes is associated with the high risk factors and geographical patterns. However recent researches argued that HCV genotypes distribution model also changed with the passage of time. Few surveys revealed that there might be difference in HCV genotypes distribution model between patients with human immunodeficiency virus (HIV)/HCV coinfection and HCV monoinfection. Study design:In order to conclude the rules of HCV genotype distribution mode changed in China, this research, composed with three parts reasonably, was carried out. Firstly, the results of all HCV molecular epidemiology researches performed in China after 1995 was analyzed. This systematic analysis summarized the change of HCV genotypes distribution mode in China, and identifid the major intrusion genotype. For proving this hypothesis, a survey on virus strain origin would be performed. Bioinformatics method was used to estimate the velocity of this intrusion genotype virus transmission as an experimental evidence.If HIV coinfection would impact on HCV spontaneous clearing, HCV epidemiological characteristics would be changed, because of the increasing of HIV coinfection in China. A meta-analysis was performed in the influence of HIV infection on spontaneous HCV clearance and related risks. Results:Part 1:Systematic Analysis of HCV Genotype Distribution in China There are three epidemic areas existed in China, areaⅠcontained Yunnan and Guangxi province. areaⅡcontained Xingjiang province and the middle and lower reaches of Changjiang River. areaⅢcontained the central and north part of China. Two periods were divided in about 1997 to 2000. In the second period, the percentage of HCV 2 genotype infection descend sharply, meanwhile, the percentage of HCV 6 genotype infection raised in Southern of China.Part 2:The Velocity of HCV Subtype 6a Transmission in Southwest China Most of HCV 6a strains distributed in Southwest China orgined in 1968, at last 4 epidemic strains existed. The earlier orgined strains could be isolated both in intravenous drug user (IDU) and non-IDU patients. After 1997, HCV 6a strains transmission in southwest China accelerated, and the trend intensified in 2007.Part 3:Influence of HIV coinfection on the epidemiological characteristics of HCV HIV coinfection could reduce the HCV spontaneous clearence rate, pooled RR =0.81(0.67, 0.97) p=0.022. Mela and IDUs had the more limited chance. HBV/HIV/HCV coinfected patients might have higher HCV spontaneous clearence rate. No associations were found between HCV spontaneous clearence and age, race, other HIV related risks (CD4+T, HIV RNA, HAART).Conclusions:In recent 15 years, the distribution of HCV genotype has been changed in China. Three epidemic areas existed. Two periods were divided. In the second period, the percentage of HCV 2 genotype infection descend sharply, meanwhile, the percentage of HCV 6 genotype infection raised in Southern of China. In part 2, a strong evidence was provided by a“molecular clock”phylogenetic analysis. HCV 6a subtype would be transmited stringendo in southwest China after 2007. However few researches concerned with HCV 6 virus. It should be enhanced in the future.Considered with the detrimental effection of HIV coinfected on spontaneous HCV clearance, HCV epidemiological characteristics would be changed, and the mode of HCV genotype distribution would be influenced, because of the increasing of HIV coinfection in China. The high-risk groups of HIV/HCV coinfection were IDUs, and related genotypes were 6 and 3. The increase of HIV/HCV coinfection would be the related risk of HCV genotype 6 virus transmited stringendo in China.

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CLC: > Medicine, health > Internal Medicine > Infectious disease > Viral infections > Viral Hepatitis > Hepatitis C (non- A non-B )
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