Cai Quan-Cai, Lu Jian, Xu Qin-Feng, Guo Qiang, Xu De-Zhong, Sun Qing-Wen, Yang Hua, Zhao Gen-Ming, Jiang Qing-Wu
Department of Epidemiology, School of Public Health, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China.
Public Health. 2007 Apr;121(4):258-65. doi: 10.1016/j.puhe.2006.09.023. Epub 2007 Feb 20.
To understand the association between the outbreak of severe acute respiratory syndrome (SARS) and meteorological factors and air pollution.
An ecological study was conducted.
Three hundred and fifty primary probable SARS cases diagnosed in mainland China between 1 January and 31 May 2003, and their 6727 close contacts during the period of their clinical symptoms before admission, were included in this study. Of the 6727 close contacts, 135 (2.0%) later developed clinical symptoms and were diagnosed as probable SARS cases. The daily meteorological data and daily air pollution data during the same SARS outbreak period in mainland China were used in the data analysis. Logistic regression analyses were conducted to explore the association between the secondary attack rate of SARS and meteorological factors and air pollution.
In univariate analyses, daily average temperature (DAT), daily average air pressure (DAAP), and daily average relative humidity (DARH) were inversely associated with secondary attack rate (P<0.001); a significant positive association was found for daily hours of sunshine (DHS) (P<0.001). In multivariate analyses, factors associated with secondary attack rate were DAAP (odds ratio (OR)=0.53, 95% confidence interval (CI): 0.42, 0.66), DARH (OR=0.73, 95% CI: 0.53, 1.00), and daily average wind velocity (DAWV; OR=0.81, 95% CI: 0.68, 0.96). Adjustment for the onset time of a primary case led to little change in the results. In addition, in Hebei Province, a major affected area in China, only DAWV (OR=0.38, 95% CI: 0.20, 0.72) was a significant predictor of secondary attack rate with adjustment for the onset time of primary case. In Inner Mongolia, another major affected area in China, DAWV (OR=0.50, 95% CI: 0.26, 0.94) and DHS (OR=0.27, 95% CI: 0.09, 0.81) were significant predictors of secondary attack rate with adjustment for the onset time of primary case.
Our results suggest that the SARS outbreak was significantly associated with DAWV, and that DAAP, DARH and DHS may also have influenced the SARS outbreak to some extent. However, because of ecological fallacy and uncontrolled confounding effects that may have biased the results, the association between the SARS outbreak and these meteorological factors and air pollution deserve further investigation.
了解严重急性呼吸综合征（SARS）暴发与气象因素及空气污染之间的关联。
进行了一项生态学研究。
本研究纳入了2003年1月1日至5月31日在中国内地确诊的350例原发性可能SARS病例，以及他们在入院前临床症状出现期间的6727名密切接触者。在这6727名密切接触者中，有135人（2.0%）后来出现临床症状并被诊断为可能的SARS病例。数据分析使用了中国内地同一SARS暴发期间的每日气象数据和每日空气污染数据。进行逻辑回归分析以探讨SARS二代发病率与气象因素及空气污染之间的关联。
在单变量分析中，日平均气温（DAT）、日平均气压（DAAP）和日平均相对湿度（DARH）与二代发病率呈负相关（P<0.001）；日照时长（DHS）与二代发病率呈显著正相关（P<0.001）。在多变量分析中，与二代发病率相关的因素有DAAP（比值比（OR）=0.53，95%置信区间（CI）：0.42，0.66）、DARH（OR=0.73，95%CI：0.53，1.00）和日平均风速（DAWV；OR=0.81，95%CI：0.68，0.96）。对原发病例发病时间进行调整后，结果变化不大。此外，在中国的主要疫区河北省，调整原发病例发病时间后，只有DAWV（OR=0.38，95%CI：0.20，0.72）是二代发病率的显著预测因素。在中国的另一个主要疫区内蒙古，调整原发病例发病时间后，DAWV（OR=0.50，95%CI：0.26，0.94）和DHS（OR=0.27，95%CI：0.09，0.81）是二代发病率的显著预测因素。
我们的结果表明，SARS暴发与DAWV显著相关，DAAP、DARH和DHS也可能在一定程度上影响了SARS暴发。然而，由于生态学谬误以及可能使结果产生偏差的未控制混杂效应，SARS暴发与这些气象因素及空气污染之间的关联值得进一步研究。
