Analysis of Incubation Period and Spatial Clustering of a Common Source Outbreak

共同感染源群突發之潛伏期與群聚現象分析

秦淳(Chuen Chin) ； 沈秋香(Chiu-Shen Hslang)

《安泰醫護雜誌》 14卷4期 (2008/12) Pp. 213-222

https://doi.org/10.7078/TSMHMNJN.200812.0213

摘要

背景及目的：任何疾病都有其特有的潛伏期，尤其是傳染性疾病。確認疾病具有共同的同時暴露及空間的群聚現象，則有助於評估某一群突發。空間分布已是許多疾病流行病學資訊的中心課題。面臨一新興疾病，例如嚴重急性呼吸症候群，傳統的流行病學方法仍是有用的工具。
方法：吾人利用Sartwell's氏之對數常態模式，預估嚴重急性呼吸症候群在某一客機上造成之群突發的潛伏期。將病患個別的潛伏期取對數，作成常態機率分布圖，並以Kolmogorov-Smirnov法檢驗。再以變異數檢驗該病例分布是否呈波以松分布，評估是否有空間的群聚現象。
結果：根據Sartwell's氏之對數常態模式，預估的潛伏期為37.8小時，以常態機率分布圖及Kolmogorov-Smirnov法確認了潛伏期的常態對數模式，也證實該病在客機上的傳播來自共同感染源，這些病例的分布並不呈波以松分布的隨機模式，其具有空間的群聚現象。
討論：在無分子生物學的調查証據下，傳統的流行病學方法仍是適於用來研究群突發或是新興傳染病的。

關鍵字

共同感染源群突發 ； Sartwell氏常態對數模式 ； 波以松分布 ； 空間群聚性 ； 嚴重急性呼吸症候群

並列摘要

Background and purpose: The incubation period is a characteristic common to any disease, especially infectious diseases. To ascertain a simultaneous exposure and a spatial clustering are helpful in evaluating an outbreak. Spatial distribution has played a central role in the epidemiology of a number of diseases. Facing a novel disease, for example severe acute respiratory syndrome, traditional epidemiological approaches are applicable.
Methods: Sartwell's lognormal model was used to estimate the incubation period of the severe acute respiratory syndrome (SARS) outbreak on an airplane. A normal probability-probability plot of the logarithmic transformation of individual incubation periods was graphed and validated by the Kolmogorov-Smirnov test. A test of variance was applied to test the Poisson distribution, which was the description of objects distributed spatially at random.
Results: Based on Sartwell's model, the estimated median of the incubation period was 37.8 hours. The normal probability-probability plot and Kolmogorov-Smirnov test established the lognormal model of the incubation period. The transmission of SARS on the airplane was also shown to be due to a common source according to this model. The Poisson distribution was rejected, indicating there was spatial clustering.
Discussion: With the lack of a molecular work-up, traditional epidemiological approaches are appropriate in the investigation of an outbreak or an emerging disease.

並列關鍵字

common source outbreak ； Sartwell's lognormal model ； Poisson distribution ； spatial clustering ； severe acute respiratory syndrome