用马尔科夫链对四川省城乡居民甲肝流行模式的研究

目的：探讨我省城乡居民甲肝流行模式，为我省甲肝流行趋势的预测和甲肝预防提供科学依据。方法：多阶段整群系统随机抽样法共计调查我省城乡居民3041人。用ELISA法检测HAV感染标志物（抗－HAV）。资料分析采用随机过程方法－两状态非齐次马尔科夫链。结果：抗－HAV阳性率城市和农村分别为72．99％和80．83％。城市人群总体MRR高达211．71，农村人群为153．17。MRRt以每5岁划分年龄组，城市人群除5－岁年龄组外，35岁以前各组MRRt均大于10，且接近20年年龄组主要集中在1－、15－和20－岁年龄组。农村人群只有11岁以前两组MRRt高于10，且随年龄增大呈下降趋势。结论：城市居民因感染HAV所承受的疾病负荷大于农村居民，其高危年龄为1－25岁。故应在该年龄组人群中实施有计划的免疫预防措施，以减少发病和控制流行。农村居民HAV感染的高危年龄发生在儿童期早期，故在农村应密切监测甲肝流行趋势，及时发现和控制可能发生的流行。

A STUDY ON EPIDEMIC MODE OF HEPATITIS A VIRUS INFECTION IN SICHUAN USING MARKOVCHAIN

Objective:To investigate the trend of hepatitis A virus infection in Sichuan and take a scientific information for HAV prevention.Methods:Using stratified mulitistage random cluster sampling,3041 serum samples were collected.Anti HAV were screened by ELISA.A stochastic model,the two state markov chain,was applied to HAV seroprevalence date by age group.Results:The anti HAV positive rate in urban and rural areas were 72 99% and 80 83% respectively.The total MRR in urban and rural areas were 211 71 and 153 17,respectively.Conclusions:The disease burden in urban was greater than that in rural.Prevention and control of HAV must be strengthened in high risk population.