气温对兰州市细菌性痢疾发病的滞后效应研究

目的：探讨日均气温对兰州市细菌性痢疾发病的影响及其滞后效应。方法：收集兰州市2008-2015年每日细菌性痢疾发病资料，结合同期气象资料，利用分布滞后非线性模型（distributed lag non-linear model，DLNM）分析日均气温与细菌性痢疾发病的关联性。结果：日均气温与细菌性痢疾发病的暴露-反应关系呈“J”型，最低发病温度为17 ℃，对不同性别、年龄人群高温效应影响均大于中间效应。高温效应和中间效应对男、女性人群均表现为急性作用，当天的效应值最高，随后波动下降，高温效应对女性影响更大。在不同年龄段人群中，0~3岁组人群的细菌性痢疾发病的高温效应和中间效应均最大；高温效应和中间效应对0~3岁、19~64岁人群均表现为急性作用，当天的效应值最高，随后波动下降，而≥65岁者当天发病，之后下降，再缓慢波动上升。相对于最低发病温度17 ℃，高温（32 ℃）和中间温度（26 ℃）均能增加细菌性痢疾发病的风险，以滞后14 d累计效应最大，在男性、女性、0~3岁、4~11岁、12~18岁、19~64岁、≥65岁人群中，中间温度对细菌性痢疾发病RR（95%CI）值分别为2.30（1.53~3.13）、2.45（1.65~3.30）、2.41（1.59~3.28）、2.54（1.40~3.79）、1.82（0.41~3.43）、1.98（1.11~2.93）、1.73（0.68~2.88），高温时RR（95%CI）值分别2.93（1.38~4.69）、3.08（1.48~4.9）、3.26（1.60~5.16）、3.12（1.06~5.56）、1.94（0.73~5.39）、2.31（0.54~4.36）、2.06（0.02~4.51）。结论：高温可显著增加细菌性痢疾的发病风险，女性和3岁以下人群是敏感人群。气象因素在兰州市细菌性痢疾的发生和发展中发挥重要作用，细菌性痢疾发病受到多种气象因子共同作用的影响，但首要影响因素是高温。气温对细菌性痢疾发病不是直接作用，而是通过影响细菌性痢疾发病的各个环节（居民生活习惯、传播途径与易感人群自身体质），间接影响细菌性痢疾在人群中的分布。

Distributed lag effects on the relationship between daily mean temperature and the incidence of bacillary dysentery in Lanzhou city

Objective： To discuss the lag effects of daily average temperature on the daily cases of ba-cillary dysentery in Lanzhou city. Methods: The data of daily cases of bacillary dysentery were collected during 2008 and 2015 in the city, and the meteorological data at the same period was integrated. The distributed lag non linear model was used to analyze the relevance between daily average temperature and the daily cases of bacillary dysentery. Results: The exposure response relationship between the daily tempe-rature and the incidence of bacillary dysentery was “J” type, the lowest incidence temperature was 17 ℃, and the effect of high temperature on different gender and age groups was higher than that of the intermediate effect. The effect of high temperature and intermediate effect on the male and female groups showed an acute effect, the effect of the day was the highest, followed by fluctuations in temperature, and the greater the impact on women. In different age groups, high temperature effect and the intermediate effect of bacterial dysentery in 0-3 years old groups were the biggest; the effects of high and interme-diate temperature on people aged 0-3 and 19-64 year all showed acute effects, which were the maximum value at the day, then decreased volatility; and for people aged over 65 years, the day after the onset, decreases and then increases slowly. There were obviously increasing risks of bacillary dysentery both the high temperature (32 ℃) and the middle temperature (26 ℃) with respect to 17 ℃. The accumulative effects were highest at lag14 days, and the RR (95%CI) values of middle temperature was 2.30 (1.53-3.13), 2.45 (1.65-3.30), 2.41 (1.59-3.28), 2.54 (1.40-3.79), 1.82 (0.41-3.43), 1.98 (1.11-2.93) , and 1.73 (0.68-2.88) among the males, females, 0-3 years old, 4-11 years old, 12-18 years old, 19-64 years old and over 65 years old people, respectively; while the high temperature was 2.93 (1.38-4.69), 3.08 (1.48-4.90), 3.26 (1.60-5.16), 3.12 (1.06-5.56), 1.94 (0.73-5.39), 2.31 (0.54-4.36), and 2.06 (0.02-4.51), respectively. Conclusion: The high temperature may increase risks of bacillary dysentery, and the females and younger people were the sensitive population. Meteorological factors play an important role in the occurrence and development of bacillary dysentery in Lanzhou. The incidence of bacillary dysentery is affected by multiple meteorological factors, but the primary one is high temperature. The temperature has not a direct effect on the incidence of bacillary dysentery, but an indirect influence in different populations through the impacts of various aspects of the incidence of bacterial dysentery (residents living habits, communication channels and the habits of the susceptible population).