Crow Deaths as a Sentinel Surveillance System for West Nile Virus in the Northeastern United States, 1999

Millicent Eidson,Faye Sorhage,Nicholas Komar,Robert Mclean,Randall Nelson,Farzad Mostashari,Tom Talbot,The West Nile Virus Avian Mortality Surveillance Group

doi:10.3201/eid0704.017402

Abstract

Abstract In addition to human encephalitis and meningitis cases, the West Nile (WN) virus outbreak in the summer and fall of 1999 in New York State resulted in bird deaths in New York, New Jersey, and Connecticut. From August to December 1999, 295 dead birds were laboratory-confirmed with WN virus infection; 262 (89%) were American Crows (Corvus brachyrhynchos). The New York State Department of Health received reports of 17,339 dead birds, including 5,697 (33%) crows; in Connecticut 1,040 dead crows were reported. Bird deaths were critical in identifying WN virus as the cause of the human outbreak and defining its geographic and temporal limits. If established before a WN virus outbreak, a surveillance system based on bird deaths may provide a sensitive method of detecting WN virus.

Highlights

Avian Mortality Surveillance Group1 *New York State Department of Health, Albany, New York, USA; †Centers for Disease Control and Prevention, Fort Collins, Colorado, USA; ‡New Jersey Department of Health and Senior Services, Trenton, New Jersey, USA; §Connecticut Department of Public Health, Hartford, Connecticut, USA; ¶New York City Department of Health, New York City, New York, USA;
In addition to human encephalitis and meningitis cases, the West Nile (WN) virus outbreak in the summer and fall of 1999 in New York State resulted in bird deaths in New York, New Jersey, and Connecticut
Bird deaths had not been frequently documented in previous human WN virus outbreaks, infected carcasses of a variety of bird species were found in Israel in 1998 [1,2], and deaths were observed after experimental infection in crows and sparrows [3]

Summary

Introduction

After initial evaluation of dead birds by the New York State Department of Environmental Conservation’s Wildlife Pathology Unit and the Wildlife Conservation Society, a virus isolated from specimens by the National Wildlife Health Center and the U.S Department of Agriculture’s National Veterinary Services Laboratory was identified as WN virus by the Centers for Disease Control and Prevention (CDC) on September 23 [5]. We reviewed data from systems in New York State, New Jersey, and Connecticut to describe how surveillance of bird deaths was used in 1999 to guide public health action, as well as the advantages and disadvantages of using dead birds as sentinels for West Nile virus in a given geographic area

Methods

Results

Conclusion