Bhopal R S, Fallon R J
Division of Epidemiology and Public Health, Medical School, Newcastle upon Tyne, U.K.
J Infect. 1991 Mar;22(2):153-60. doi: 10.1016/0163-4453(91)91569-j.
A summer and autumn peak in incidence is a characteristic epidemiological feature of Legionnaires' disease, a fact which may help in diagnosis. Previous reports from Scotland have reported a winter peak. This study examined the seasonal variation in Legionnaires' disease in Scotland in each year and by category of diagnosis. A characteristic summer/autumn peak was seen for travel-related infection. For non-travel infection, there was an autumnal peak between 1978 and 1982 but an early winter peak between 1983 and 1986. Overall, the pattern could be described as a summer/autumn plateau reaching a peak in early winter. This pattern, seen in men and women, was clearest in the Greater Glasgow area. Nosocomial cases were clustered in the months of October, November and December. In non-travel cases the classical seasonal pattern was not observed and clinicians cannot rely upon this epidemiological feature for diagnosis. However, the relative infrequency of the disease between January and May was a consistent and potentially useful feature. Most reports on seasonal variation are based on aggregated data on travel and non-travel cases. The present observations question the hypotheses developed to explain the seasonal pattern and call for further studies.
发病率在夏秋季节达到高峰是军团病的一个典型流行病学特征,这一事实可能有助于诊断。此前苏格兰的报告称发病高峰出现在冬季。本研究调查了苏格兰每年军团病的季节性变化以及按诊断类别划分的情况。与旅行相关的感染呈现出典型的夏秋高峰。对于非旅行感染,1978年至1982年出现秋季高峰,而1983年至1986年则出现初冬高峰。总体而言,发病模式可描述为夏秋季节平稳,在初冬达到高峰。这种模式在男性和女性中均有出现,在大格拉斯哥地区最为明显。医院感染病例集中在10月、11月和12月。在非旅行病例中未观察到典型的季节性模式,临床医生不能依赖这一流行病学特征进行诊断。然而,1月至5月间该病相对罕见是一个持续且可能有用的特征。大多数关于季节性变化的报告基于旅行和非旅行病例的汇总数据。目前的观察结果对用以解释季节性模式的假说提出了质疑,需要进一步研究。