Highly pathogenic Bovine Respiratory Syncytial virus variant in a dairy herd in Italy

Abstract

Bovine respiratory syncytial virus (BRSV) is an economically significant pathogen in cattle production worldwide. Usually, it is detected in outbreaks of respiratory disease, most often during the winter period. During the middle of October 2018, a serious outbreak of respiratory disease occurred in a cattle farm comprising about 300 heads located in Central Italy. The herd was affected by a severe flu‐like syndrome unresponsive to any antibiotic treatment. Within 3 weeks, 39 adult animals died, and 12 abortions occurred. Direct and indirect laboratory tests were performed to detect the main pathogens causing the respiratory disease of the affected cattle. The results of laboratory investigations provided evidence of an acute and severe BRSV syndrome characterized by unusual mortality. In order to investigate the molecular underpinnings of this syndrome, phylogenetic analysis of the BRSV strain detected from the outbreak was carried out. The sequence analysis showed that the strain was genetically divergent from BRSV strains previously identified in Italy, as it showed high sequence similarity of more than 97% with strains isolated during a major BRSV epizootic that occurred in Sweden, Norway and Denmark during 2010–2011. The infection of the herd in Italy with this BRSV strain was likely due to the introduction of animals imported into Italy from abroad.

Overview of Control Programs for Twenty-Four Infectious Cattle Diseases in Italy

“…The disease is not notifiable in Italy. There are no official data for the prevalence of BRSV, however we consider this disease to be endemic since different BRSV strains are circulating in Italy ( 42 , 43 ). Vaccination is widely used to control the disease, mostly in the beef sector.…”

Molecular Characterisation and Antibody Response to Bovine Respiratory Syncytial Virus in Vaccinated and Infected Cattle in Turkey

“…Both low and high detection rates of BRSV infection in cattle have been reported in other countries using real-time RT-PCR [ 57 , 62 ]. Concerning Europe, in Italy all nasal/oropharyngeal swabs, bronchoalveolar lavage samples, and lung samples were positive for BRSV-RNA [ 34 ]. In another study, 14.5% of 138 oropharyngeal swabs were positive in cattle transferred from France to Southern Italy [ 63 ].…”

“…Virus isolation as well as both serological and molecular techniques have been used for the detection and identification of BRSV [ 28 , 29 , 30 ]. BRSV has been isolated from many countries in Europe, America, Asia, and Africa including Turkey [ 31 , 32 , 33 , 34 , 35 ]. The majority of studies in Turkey have been aimed at determining the seroprevalence of BRSV among cattle herds, and there is limited knowledge available about sequence and phylogenetic analyses of BRSV [ 27 , 36 , 37 ].…”

Establishment of a real-time recombinase-aided isothermal amplification (RT-RAA) assay for the rapid detection of bovine respiratory syncytial virus

“…Presently, reports of BRSV isolation from cattle have been documented in Europe, the Americas, Africa, and Asia [2]. In 2007 the rst BRSV isolation in Heilongjiang province was reported in China [3].…”

“…In 2007 the rst BRSV isolation in Heilongjiang province was reported in China [3]. BRSV infection mainly appears in newly weaned calves and young cattle in intensive farming, and the morbidity rate in calves can be as high as 60%, with a mortality rate of about 20%, causing signi cant losses [2]. BRSV mainly replicates in the bronchiolar epithelial cells and the type II pneumocytes, causing bronchial interstitial pneumonia, necrosis of epithelial cells, exudative or proliferative pneumonitis, and the appearance of syncytial cells, which was associated with replicating BRSV [4].…”