EVIDENCE OF EXPOSURE TO BRUCELLA SUIS BIOVAR 4 IN NORTHERN ALASKA MOOSE

Abstract

Historically, some moose (Alces alces) of northern Alaska have been tested for serologic evidence of exposure to viral and bacterial diseases. Recently, in response to poor recruitment and declining numbers of moose along the Colville River and associated drainages on the North Slope of Alaska (near Umiat), 42 cows and 5 bulls were serologically tested for Brucella spp. Surprisingly, 8 (19%) cows had antibody titers >400 to Brucella spp. No bulls tested positive. This antibody prevalence is higher than in published reports. Western blot analysis indicated antibody is specific to Brucella suis biovar. Three of 94 nulls (3%) and 1 of 69 cows (2%) sampled during 1992-97 in the Noatak River drainage had titers >100 (4 of 163 or 2%). The 12 positive moose detected since 1992 had relatively high titers. No significant antibody titers to Brucella spp. were detected in moose from the Seward Peninsula (34 cows), Selawik River (46 cows, 46 bulls) or the Arctic National Wildlife Refuge (38 cows, 14 bulls). Blood samples taken in 1996 from the Colville River moose were not optimal for recovery of viable bacteria and culture for Brucella organisms was unsuccessful.