title: Case-control study of microbiological etiology associated with calf diarrhea.
abstract: Calf diarrhea is a major economic burden for the US cattle industry. A variety of infectious agents are implicated in calf diarrhea and co-infection of multiple pathogens is not uncommon in diarrheic calves. A case-control study was conducted to assess infectious etiologies associated with calf diarrhea in Midwest cattle farms. A total of 199 and 245 fecal samples were obtained from diarrheic and healthy calves, respectively, from 165 cattle farms. Samples were tested by a panel of multiplex PCR assays for 11 enteric pathogens: bovine rotavirus group A (BRV-A), bovine coronavirus (BCoV), bovine viral diarrhea virus (BVDV), bovine enterovirus (BEV), bovine norovirus (BNoV), Nebovirus, bovine torovirus (BToV) Salmonella spp. (Salmonella), Escherichia coli (E. coli) K99(+), Clostridium perfringens with β toxin gene and Cryptosporidium parvum (C. parvum). The association between diarrhea and detection of each pathogen was analyzed using a multivariate logistic regression model. More than a half of the fecal samples from the diarrheic calves had multiple pathogens. Statistically, BRV-A, BCoV, BNoV, Nebovirus, Salmonella, E. coli K99(+), and C. parvum were significantly associated with calf diarrhea (p<0.05). Among them, C. parvum and BRV-A were considered to be the most common enteric pathogens for calf diarrhea with high detection frequency (33.7% and 27.1%) and strong odds ratio (173 and 79.9). Unexpectedly BNoV (OR=2.0) and Nebovirus (OR=16.7) were identified with high frequency in diarrheic calves, suggesting these viruses may have a significant contribution to calf diarrhea.
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine Iowa State University, Ames, IA 50011, USA.
authors.forename: Yong-Il
authors.initials: YI
authors.lastname: Cho
authors.forename: Jae-Ik
authors.initials: JI
authors.lastname: Han
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.forename: Vickie
authors.initials: V
authors.lastname: Cooper
authors.forename: Kent
authors.initials: K
authors.lastname: Schwartz
authors.forename: Terry
authors.initials: T
authors.lastname: Engelken
authors.forename: Kyoung-Jin
authors.initials: KJ
authors.lastname: Yoon
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D016022:Case-Control Studies; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000382:microbiology* / Q000821:virology; D060085:Coinfection / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary / Q000821:virology; D003967:Diarrhea / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary* / Q000821:virology; D005243:Feces / Q000382:microbiology / Q000821:virology; D014780:Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
keywords: Calf diarrhea; Case–control study; Enteric pathogens; Multiplex PCR detection