Clinical and molecular evidences of circulation of sheep-associated MCF in cattle and buffaloes in Egypt

In this study, one cattle heifer and one buffalo heifer of 9-month-old out of 62 cattle and 14 buffaloes
reared in close association with a flock of 17 sheep and 3 goats in the Faculty of Veterinary Medicine,
Beni-suef University, Egypt showed fever, inappetence, and enlargement of the superficial lymph nodes,
nasal and ocular discharges and bilateral corneal opacity followed by nervous manifestations without
response to attempts of treatment for more than 10 days. The necropsy findings revealed congestion and
hemorrhages with enlargement of superficial lymph nodes especially prescapular and prefemoral lymph
nodes. Histopathologically, generalized necrotizing lymphocytic vasculitis was the most common lesion in
the blood vessels of liver, kidneys, spleen, heart, lymph nodes, intestine, uterus, fallopian tubes, pancreas,
brain and lungs. Based on the clinical manifestation, necropsy findings and histopathological examination,
Malignant Cattarrhal Fever was suspected. PCR using specific primers for Ovine herpesvirus 2 (ovHV2)
confirmed this suspicion and proved that these cases were suffering from sheep-associated Malignant
Catarrhal Fever. Sequence analysis of the 422 bP PCR product was carried out and alignmed with ovHV2
database available sequences derived from cattle and bison revealed 99% nucleotide identity and amino
acids similarities ranging from 97 to 100%. Concerning alignment with ovHV-2 sequences derived from
sheep, ovHv2_isolate_KarsSh1 (JN084009.1) and ovHv2_complete_genome (DQ198083.1); showed as
high as 99% nucleotide, and amino acids identity with the obtained sequence of the present study. In
conclusion, ovHV-2 is now proved to be circulating in our livestock, the matter that necessitates massive
surveying of bovines as well as contact sheep on serological basis in the future.