Abstract

Due to the emergence and resurgence of infectious diseases in wild marine mammal populations, the U.S. Navy is conducting a formal risk assessment to proactively direct the prevention of infectious disease transmission from indigenous marine mammals to U.S. Navy marine mammals. The United States Navy marine mammal population includes Atlantic bottlenose dolphins (Tursiops truncatus) and California sea lions (Zalophus californianus). Novel and virulent infectious diseases, including morbillivirus, have recently emerged from wild marine mammal populations that affect both T. truncatus and Z. californianus. The Navy is committed to continuing demonstrated excellence in care for these animals.

A risk assessment model for infectious diseases in marine mammals has been created using risk assessment guidelines from the United States Department of Agriculture, Animal and Plant Health Inspection Service (USDA/APHIS) and the Office International des Epizooties (OIE). The three primary steps involved in this model are 1) creating a list of marine mammal pathogens of concern, 2) conducting individual pathogen risk assessments (utilizing geographical, seroprevalence, morbidity, mortality, and epizootic data), and 3) estimating the consequences of establishment (e.g., sociopolitical and economic impacts).

Data for the risk assessment are collected from peer-reviewed literature and U.S. Navy records; data are entered into EpiInfo 2000 (Centers for Disease Control and Prevention, Atlanta, GA) and are analyzed by SAS (SAS, Inc.). All data related to the risk assessment are presented to a team of subject matter experts who assign qualitative risk levels (e.g., low, medium, high, or cannot determine) to each pathogen of concern. Based upon these risk levels, the pathogens of concern are ranked, leading to targeted strategies to prevent infectious disease transmission.

Risk assessment facilitates the identification of risk factors for infectious diseases in marine mammal populations. The risk assessment process used by the U.S. Navy targets data-driven decisions to prevent illness, death, and epizootics caused by infectious diseases in marine mammals. It is anticipated that the U.S. Navy risk assessment methodology will be useful for other entities to estimate the risk of infectious disease transmission to both captive and wild marine mammal populations.

Acknowledgements

The authors wish to thank the National Research Council and Unconventional Concepts, Inc. for their financial and logistic support of the project. This effort was funded in part by the LEoDERS MAGIC Medical-Surveillance and Global Informatics Consortium Program of the Armed Forces Medical Intelligence Center and the United States Air Force.