Several mathematical models of epidemic cholera have recently been proposed in response to outbreaks in Zimbabwe and Haiti. These models aim to estimate the dynamics of cholera transmission and the impact of possible interventions, with a goal of providing guidance to policy makers in deciding among alternative courses of action, including vaccination, provision of clean water, and antibiotics. Here, we discuss concerns about model misspecification, parameter uncertainty, and spatial heterogeneity intrinsic to models for cholera. We argue for caution in interpreting quantitative predictions, particularly predictions of the effectiveness of interventions. We specify sensitivity analyses that would be necessary to improve confidence in model-based quantitative prediction, and suggest types of monitoring in future epidemic settings that would improve analysis and prediction.
From the aDivision of Infectious Diseases, Brigham and Women's Hospital, Boston, MA; bDepartment of Epidemiology, Center for Communicable Disease Dynamics, Harvard School of Public Health, Boston, MA; cFogarty International Center, National Institutes of Health, Bethesda, MD; and dDepartment of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA.
Submitted 21 November 2011; accepted 6 February 2012.
Supported by Award Number U54GM088558 to M.L. from the National Institute of General Medical Sciences. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of General Medical Sciences or the National Institutes of Health. Y.H.G. received support from National Institutes of Allergy and Infectious Disease (T32 grant AI007061). J.C.M. received support from the RAPIDD program of the Science and Technology Directorate, Department of Homeland Security and the Fogarty International Center, National Institutes of Health. The authors reported no other financial interests related to this research.
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Correspondence: Marc Lipsitch, Departments of Epidemiology and Immunology & Infectious Diseases, Center for Communicable Disease Dynamics, Harvard School of Public Health, 677 Huntington Avenue, Kresge Building, Room 506, Boston, MA 02115. E-mail: firstname.lastname@example.org.