Bovine Coronavirus detected in diarrheic calves in beef and dairy herds from Argentina from 1994 to 2010

PARREÑO, VIVIANA; RODRIGUEZ, DANIELA; BILBAO, GLADYS; LOUGE URIARTE, ENRIQUE; GALARZA, ROXANA; SAIF, LINDA J; FERNANDO FERNANDEZ

Madison

Congreso; 31 American society for virology meeting; 2012

Bovine Coronavirus detected in diarrheic calves in beef and dairy herds from Argentina from 1994 to 2010 Viviana Parreno1, Daniela Rodriguez1, Alejandra Badaracco1, Iracema Nuñez2, Enrique Louge Uriarte3, Roxana Galarza4, Gladys Bilbao5, Paulo Brandao2, Linda Saif6, Fernando Fernandez1. 1Instituto de Virologia. INTA, Buenos Aires, Argentina, 2Universidad de Sao Paulo, Sao Paulo, Brazil, 3EEA INTA Balcarce, Buenos Aires , Argentina, 4EEA INTA Rafaela, Santa Fe, Argentina, 5Facultad de Ciencias Veterinarias UNCPBA, Tandil, Buenos Aires, Argentina, 6FAHRP, The Ohio State University, USA Bovine coronavirus (BCoV) is an important viral pathogen associated with neonatal calf diarrhea, especially in the northern hemisphere. Few epidemiological studies are available from South America. Our aim was to investigate the incidence of BCoV in diarrhea outbreaks in beef and dairy herds from ten provinces of Argentina during a 16-year-period (1994-2010). A total of 4,332 fecal samples from diarrheic calves, corresponding to 1049 outbreaks were screened for BCoV by ELISA. BCoV was detected in 2.12% (92/4332) of the samples corresponding to 5.91% (62/1049) of the diarrhea outbreaks analyzed. The incidence of BCoV was significantly higher in dairy than in beef herds: 13.05% (29/223) vs. 4.22% (14/332), Chi-square, p=0.0013, while 3.87% (19/491) of the positive outbreaks were from farms of non-specified husbandry. BCoV was detected in the provinces of Buenos Aires, Santa Fe, Cordoba and La Pampa within the Pampean Region. Preliminary phylogenetic analysis of the spike protein S1 encoding region of representative samples indicated that most of the BCoV strains circulating in Argentinean cattle formed a cluster well-supported at the nucleotide and amino-acid level, closely related to BCoV from Italy; another strain was related to Brazilian strains and a third one was related to the reference strain DB2. All of them were distinct from the Mebus historic reference BCoV strain included in the vaccines available in Argentina. This work represents the first large survey describing BCoV circulation in Argentinean cattle. The results suggest that updated BCoV strains may be needed for the vaccines used to prevent calf diarrhea in Argentina, considering the epidemiology of the infection in the region. However since only a single serotype of BCoV has been described, further studies are needed to confirm in vitro cross neutralization among the strains and in vivo cross-protection in calves.