河北正定农村甲型肝炎的流行病学研究

An epidemiological study of hepatitis A in a Hebei rural area

目的 了解河北农村甲型肝炎 (甲肝 )在非流行期与流行期的流行强度、流行规律。方法 在正定的A乡 ,于 1990～ 1992年连续 3次普查 1985～ 1989年间出生的儿童甲型肝炎病毒 (HAV)的流行率 ,以及各年龄组HAV易感者的新感染率 (非流行期 ) ;对正定的B乡 ,于 1992年末对 1987～ 1991年出生的儿童普查HAV感染率。 3个月后 ,该乡发生甲肝流行 ,对流行期甲肝的流行特点进行了调查。结果 正定农村 1～ 8岁儿童HAV感染率从约 4%随年龄上升到约 90 % ;非流行期各年龄儿童易感者的HAV感染率为 7 3 %～ 33 3% ,年度间有波动。流行期HAV新感染率极高 ,除 1～岁组为 36 8%稍低外 ,其余均在 5 8 9%～ 81 1%之间 ,且无组间差异。儿童感染HAV以隐性过程为主 ,年龄较大者 ,呈现显性过程者所占比例亦高。结论 甲型肝炎在正定农村呈地方性流行 ,甲肝流行无须外来传染源的介入。流行期HAV在一定范围内迅速广泛传播。所以 ,我国北方农村儿童需要甲肝疫苗的保护。安全有效的甲肝疫苗会使我们比较容易地控制农村HAV的流行。

Objective To understand the HAV prevalence and epidemiological laws in Hebei rural area.Methods In Community A of Zhengding County,three cross-sectional investigations were consecutively made among 1～8 years old children in 3 years; and in Community B,the prevalence of HAV was investigated among 1～7 years old children before hand and three months later,there was an epidemic of hepatitis A in the community and we investigated it.Results In the rural area of Hebei,the infection rates of HAV changed from 4% to 90% for children aged 1 to 8 years old.During the non-epidemic period,there were about 7 3%～33 3% of infectious rate being infected every year,although there some fluctuations between different years.During the epidemic period,the HAV was widely spread and the infection rates raised as high as about 60% for susceptible children.For most children,they had a silent infection process which changed with age.The ratio of apparent to in apparent infection raised from 1∶10 4 to 1∶3 6 for 1 to 8 years old children.Conclusion Hepatitis A is an endemic disease in Zhending rural area and over 90% of children are infected with HAV before they were 10 years old.We need to use vaccine to protect the susceptible children in the area from suffering the disease,just as what we have done for some other infectious diseases.