Detection of Bovine Coronavirus in Healthy and Diarrheic Dairy Calves.
BACKGROUND
BCoV is identified in both healthy and diarrheic calves, complicating its assessment as a primary pathogen.


OBJECTIVES
To investigate the detection rates of bovine coronavirus (BCoV) in feces of healthy and diarrheic calves and to describe the usefulness of a pancoronavirus reverse transcriptase (RT) PCR (PanCoV-RT-PCR) assay to identify BCoV in samples of diarrheic calves.


ANIMALS
Two hundred and eighty-six calves <21 days. Calves with liquid or semiliquid feces, temperature >39.5°C, and inappetence were considered as cases, and those that had pasty or firm feces and normal physical examination were designated as controls.


METHODS
Prospective case-control study. A specific BCoV-RT-PCR assay was used to detect BCoV in fecal samples. Association between BCoV and health status was evaluated by exact and random effect logistic regression. Fecal (n = 28) and nasal (n = 8) samples from diarrheic calves were tested for the presence of BCoV by both the PanCoV-RT-PCR and a specific BCoV-RT-PCR assays. A Kappa coefficient test was used to assess the level of agreement of both assays.


RESULTS
BCoV was detected in 55% (157/286) of calves; 46% (66/143), and 64% (91/143) of healthy and diarrheic calves, respectively. Diarrheic calves had higher odds of BCoV presence than healthy calves (OR: 2.16, 95% CI: 1.26 to 3.83, P = 0.004). A good agreement between PanCoV-RT-PCR and BCoV-RT-PCR to detect BCoV was identified (κ = 0.68, 95% CI: 0.392 to 0.967; P < 0.001).


CONCLUSIONS AND CLINICAL IMPORTANCE
BCoV was more likely to be detected in diarrheic than healthy calves. The PanCoV-RT-PCR assay can be a useful tool to detect CoV samples from diarrheic calves.
['Gomez|D E|DE|http://orcid.org/0000-0001-7495-4868', 'Arroyo|L G|LG|', 'Poljak|Z|Z|', 'Viel|L|L|', 'Weese|J S|JS|']
D000818:Animals D000831:Animals, Newborn D016022:Case-Control Studies D002417:Cattle D002418:Cattle Diseases D018352:Coronavirus Infections D017938:Coronavirus, Bovine D003967:Diarrhea D005243:Feces D009296:Nasal Cavity D009864:Ontario D011446:Prospective Studies D020133:Reverse Transcriptase Polymerase Chain Reaction
Pancoronavirus Emerging Epidemiology Infectious diseases Prevalence Re-emerging