North American Crane Working Group


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Olson, G.H. Whooping crane titers in response to eastern equine encephalitis immunization. In: Hartup, Barry K., ed., Proceedings of the Eleventh North American Crane Workshop, Sep 23-27, 2008, Wisconsin Dells, Wisconsin (Baraboo, WI: North American Crane Working Group, 2010), pp. 180-182.


Reproduced by permission of the North American Crane Working Group.


Eastern equine encephalitis (EEE) is a viral disease caused by a vector-borne alphavirus. Various bird species, primarily native passerines in eastern North America, act as reservoir hosts without suffering clinical disease. When outbreaks occur, the disease is maintained and amplified through a mosquito-wild bird-mosquito cycle. EEE does not cause morbidity or mortality in North American passerines, but does cause mortality in some non-native birds such as pheasants (Phasianus colchicus) and emus (Dromiceius novaehollandiae) (Tengelsen et al. 2001) plus horses (Main 1979) and humans. Between September and December 1984, EEE killed 7 of 39 captive whooping cranes (Grus americana) at the Patuxent Wildlife Research Center (PWRC), Laurel, Maryland (Dein et al. 1986). Following this epizootic, all captive whooping cranes at this facility received annual vaccinations with a human-licensed EEE vaccine (PE 6 WRAIR strain, The Salk Institute, Government Services Division, Stillwater, PA) supplied by the U.S. Army. This vaccination program proved efficacious, protecting whooping cranes when another outbreak of EEE was documented at the facility in 1989 (Olsen et al. 1997).