An outbreak of winter dysentery occurred in 8 mixed-species enclosures between January and February, 2009. Cases were identified from animals present in the population during the outbreak and included ruminants over 3 days of age with diarrhea for at least 48 hours. Duration of illness ranged from 2 to 14 days. Most cases resolved within 1 week. At least two animals died. Diagnostic tests showed a strong association with bovine coronavirus by EM and PCR in several animals.
Prevalence was estimated at 12.5% (81/649). Affected animals ranged from 2-months to 16-years and included 20 out of 46 species/subspecies. Affected animals were in the family Bovidae. Cervids and giraffe were unaffected. The highest species prevalence was observed among ankole, Ellipsen Waterbuck, Lake Victoria Defassa Waterbuck, Uganda Kob, Nile Lechwe, and Zambesi Lechwe. The outbreak spread spatially through the facility with prevalence varying significantly across the eight enclosures. Differences in enclosure prevalence may be due to species susceptibility, animal density, and/or environmental contamination.
Univariate contingency table analyses were used to estimate the relative risk of infection by sex and age groups. There was no significant difference in infection risk between males and females, but young animals (<5 years), were two times more likely to be infected than older animals. Twenty-eight percent of cases occurred among animals under 1 year of age.
Findings from this study are enabling us to identify high risk groups to better understand corona virus and diarrhea outbreaks in multiple species and guide future management efforts.