Seroepidemiological Study on Trend of Helicobacter pylori Infection Rate in a small population

我们对少数人群幽门螺杆菌感染率的变化趋势进行了血清流行病学研究。我们收集了1987、1988、1992、1993和1997年某小城镇约6000名30岁及以上居民的血清样本，并将其保存在冰柜中。用EIA法检测血清中幽门螺杆菌Ig-G抗体。以Ig-G抗体水平1+或以上判断幽门螺杆菌感染阳性。1988、1992和1993年的幽门螺杆菌感染率均低于1987和1997年。这可能是由于冷冻前的准备工作不充分或冷冻期间的状况不佳所致。在1987年和1997年，男性的发病率都高于女性。除1987年和1997年80岁或以上的老年人外，按年龄划分的比率均随年龄增长而增加。出生队列分析也显示了同样的现象。从1987年到1997年，同一年龄组的特定年龄比率略有下降。在1987年和1997年测量的533名居民中，持续阳性率约为70%，持续阴性率约为20%。血清阳转率约为5%，阴转率约为6%。研究区只有一家区域医院，医生在这10年里没有对幽门螺杆菌感染的患者进行根除治疗。这表明成年居民中存在幽门螺杆菌感染的自发血清转换，尽管在人群中所占比例很小。

We conducted a seroepidemiological study on trend of Helicobacter pylori infection rate in a small population. We collected serum samples from about 6,000 residents whose age were 30 years old or older in a small town in 1987,1988,1992,1993 and 1997 and had stored in freezers. We measured Ig-G antibody of Helicobacter pylori of the sera by EIA method. Positive Helicobacter pylori infection was judged by the Ig-G antibody level of 1+ or more. Helicobacter pylori infection rates in 1988,1992 and 1993 were lower than those in 1987 and 1997. This might be due to the poor preparation before freezing or poor condition during the freezing period. The rates in males were higher than in females in both 1987 and 1997. The age-specific rates increased with age except for those in 80 years old or more in both 1987 and 1997. Birth cohort analysis showed the same phenomenon. The age specific rates in same age groups slightly decreased from 1987 through 1997. Among 533 residents measured in both 1987 and 1997, the persistent positive rate was about 70% and the persistent negative was about 20%. The positive sero-conversion rate was about 5% and the negative was about 6%. There is only a regional hospital in the study area and physicians did not conduct the eradication therapy for patients with Helicobacter pylori infection in these 10 years. These suggest that there is a spontaneous sero-conversion of Helicobacter pylori infection among adult residents, though the proportion in population is small.