应用圆形分布探讨流行性脑脊髓膜炎发病季节性

为探讨流行性脑脊髓膜炎发病季节性,笔者对常德市１９５９～１９９０年流脑发病资料进行了圆形分布分析。结果表明：流行性脑脊髓膜炎发病具有明显的季节性,３２年中有２８年发病高峰日在３月份,有２６年９５％的流行期始于上年１０月份以后,终止于当年６月份以前,年发病率与圆形分布ｒ值呈正相关,与角的标准差呈负相关,与平均角－α无相关。提示年发病率高低影响发病季节性强弱,而与发病高峰日的早晚无关。

A Study on Seasonal Variation of Epidemic Cerebrospinal Meningitis with Circular Distribution Method

In order to study the seasonal variation of epidemic cerebrospinal meningitis (ECM) incidence, the data of ECM incidence during the period 1959~1990 in Changde City were analysed with circular distribution method. The result showed that the seasonal variation was obvious. In 28 of these 32 years, the highest peak of the ECM incidence occurred in March. In 26 years, 95% of epidemic periods began from October to June of the next year. The annual incidence rate had positive corretation with the r value of circular distribution, negative correlation with angular deviation and no correlation with mean angle a. It is concluded that the annual incidence rate concerns with the seasonal variation and does not concern with the date of the highest peak.