Splaine M, Lintott A P, Angulo J J
J Hyg (Lond). 1974 Aug;73(1):15-26. doi: 10.1017/s0022172400023780.
The co-ordinates of the dwellings where cases of variola minor (alastrim) occurred during a small epidemic were used in a worked example of contour mapping of disease spread. The contoured variable was the date of onset, relative to an arbitrary base date, of the case introducing the disease into each of twenty-two households. Three contour maps prepared with slightly different computer programmes or dates exhibited similar concentric loops whose centres were close to the first infected household. The average rate of spread of the disease was estimated by regression of the number of days to onset of the first case in the household on the average distance from an arbitrary origin to the relevant contour line. The calculated average rate of spread was 1.22 metres per day. An additional map was contoured using the cumulative number of cases as the contoured variable, relative to the onset of the example epidemic.
在一个小型天花（类天花）疫情期间，将出现轻型天花病例的住所坐标用于疾病传播等高线绘图的一个实例中。绘制等高线的变量是疾病传入二十二户家庭中每户的病例相对于任意基准日期的发病日期。用稍有不同的计算机程序或日期绘制的三张等高线地图呈现出相似的同心环，其中心靠近首个受感染家庭。通过将每户首个病例发病天数对从任意原点到相关等高线的平均距离进行回归，估算出疾病的平均传播速度。计算得出的平均传播速度为每天1.22米。使用病例累计数作为等高线变量，相对于该例疫情的发病情况绘制了一张附加地图。
