Serological detection of infection dynamics of respiratory viruses in cattle herds and virus isolation from clinical cases


Thesis Type: Doctorate

Institution Of The Thesis: Bursa Uludağ University, Veteriner Fakültesi, Klinik Öncesi Bilimler, Turkey

Approval Date: 2013

Thesis Language: Turkish

Student: Pelin Tuncer

Supervisor: Kadir Yeşilbağ

Abstract:

The aim of this PhD thesis is to reveal infection dynamics of bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus type 3 (PI-3), bovine herpesvirus 1 (BHV-1), bovine viral diarrhoea virus (BVDV), bovine adenovirus type 3 (BAV-3) and bovine coronavirus (BCoV) which are important viral pathogens of respiratory disease complex of ruminants. By this way regression period of maternally antibodies and optimum vaccination time can be recommended. Farms are grouped according to their animal population. For serological studies, blood samples are collected from calves (n=112) which are born in the same month and blood samples were gathered from these animals during their 1st, 2nd, 3rd, 4th, 6th, 8th, 10th and 12th months old. Also blood samples were taken from calves' mother during first sampling. For virological studies nose and eye swab samples were taken from clinically ill calves which are found from studied and unstudied farms. For detecting antibody titers serum neutralization test (SN50) was applied to blood sera. Besides detecting antigen commercial ELISA kit (BRSV, PI-3, BVDV and BHV-1 antigen detection kit), virus isolation and for non cytopathic BVDV strain immunoperoxidase test was used. At the end infection with BRSV, PI-3, BVDV, BAV-3 and BCoV at early ages of calves and role of seronegative calves in circulation of infections was determined. For BRSV, PI-3, BVDV, BAV-3 in the 3rd month and for BCoV in the 4th month maternally antibodies are started to decrease. During this period no maternal antibody was detected for BHV-1. In conclusion it was observed that maternally antibodies started to decrease from the 2nd month, first exposure of viruses to calves were encountered between 4th and 8th months and circulation of naturally infections were detected. On this basis, first vaccination should be done between 2nd and 4th month and it was judged that implementation of after 1 month booster shot can be useful.