Distribution of bovine cysticercosis in Washington.
Data from slaughter plants (n = 3) and feedlots (n = 18) in eastern Washington were analyzed to characterize occurrence patterns of cysticercosis in Washington during 1984. Three concurrent peaks in cysticercosis rates (0.6/1,000 to 5/1,000 slaughtered cattle) were detected at 3 slaughter plants. Peaks were observed at 8 feedlots from December 1983 to March 1984, at 6 feedlots from April to July 1984, at 2 feedlots from August to October 1984, and at 3 feedlots from November 1984 to February 1985. Affected feedlots were not closely associated geographically and were feeding cattle from many, predominantly northwestern, origins. For 3 feedlots for which time in the feedlot was available for each slaughter shipment, an increase in cysticercosis rate with increasing time in the feedlot was noticed. Within these 3 feedlots, cases of cysticercosis were widely scattered spatially. The pattern of cysticercosis indicated human fecal contamination of a regionally available feed source. Of feedstuffs in use, potato waste, a byproduct of the processed potato industry, appeared to be the most likely source of Taenia saginata ova.
Hancock
D D
DD
Field Disease Investigation Unit, College of Veterinary Medicine, Washington State University, Pullman 99164.
Wikse
S E
SE
Lichtenwalner
A B
AB
Wescott
R B
RB
Gay
C C
CC
D000003:Abattoirs; D000821:Animal Feed; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology*; D003551:Cysticercosis / Q000453:epidemiology / Q000662:veterinary*; D014861:Washington