Severe outbreak of bovine coronavirus infection in dairy cattle during the warmer season.
A severe outbreak of enteric and respiratory disease associated with bovine coronavirus (BCoV) infection is described. The outbreak occurred in a dairy herd of southern Italy in the first decade of September 2006, when summer temperatures were still recorded, affecting calves, heifers and adult cows, with a marked decrease in milk production. By virus isolation and RT-PCR targeting the S gene, BCoV was identified as the etiological agent of the outbreak, whereas bacteriological, parasitological and toxicological investigations failed to detect other causes of disease. BCoV strains with 99-100% nucleotide identity in the S gene were isolated from nasal, ocular and rectal swabs, thus proving the absence of separate clusters of virus on the basis of tissue tropism. Sequence analysis of the haemagglutination-esterase and spike proteins of the strain detected in one rectal sample (339/06) showed a high genetic relatedness with recent BCoV isolates (98-99% amino acid identity), with several unique amino acid substitutions in the S protein. The BCoV outbreak described in this paper presents interesting aspects: (i) the occurrence of a severe form of disease in the warmer season; (ii) the simultaneous presence of respiratory and enteric disease; (iii) the involvement of young as well as adult cattle.
Decaro
Nicola
N
Department of Animal Health and Well-being, Faculty of Veterinary Medicine, Strada per Casamassima Km 3, 70010 Valenzano, Bari, Italy. n.decaro@veterinaria.uniba.it
Mari
Viviana
V
Desario
Costantina
C
Campolo
Marco
M
Elia
Gabriella
G
Martella
Vito
V
Greco
Grazia
G
Cirone
Francesco
F
Colaianni
Maria Loredana
ML
Cordioli
Paolo
P
Buonavoglia
Canio
C
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D002460:Cell Line; D018352:Coronavirus Infections / Q000097:blood / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D017938:Coronavirus, Bovine / Q000235:genetics / Q000302:isolation & purification*; D003588:Cytopathogenic Effect, Viral; D003612:Dairying; D004196:Disease Outbreaks / Q000662:veterinary*; D005260:Female; D010802:Phylogeny; D012367:RNA, Viral / Q000302:isolation & purification; D012621:Seasons; D013696:Temperature
D000914:Antibodies, Viral; D012367:RNA, Viral