Anthrax Research Today is a free monthly online journal that collates and summarizes the latest research about Anthrax, including details on bacillus anthracis, contagiousness, exposure, effects.

A hypothesis test for the end of a common source outbreak.

Brookmeyer R, You X

Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA. rbrook@jhsph.edu

The objective of this article is to develop a hypothesis-testing procedure to determine whether a common source outbreak has ended. We consider the case when neither the calendar date of exposure to the pathogen nor the exact incubation period distribution is known. The hypothesis-testing procedure is based on the spacings between ordered calendar dates of disease onset of the cases. A simulation study was performed to evaluate the robustness of the methods to various models for the incubation period of infectious diseases. We investigated the impact of multiple testing on the overall outbreak-wise type I error probability. We derive expressions for the outbreak-wise type I error probability and show that multiple testing has minimal effect on inflating that error probability. The results are discussed in the context of the 2001 U.S. anthrax outbreak.

Published 17 March 2006 in Biometrics, 62(1): 61-5.
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