| Abstract [eng] |
Analysis of Bovine Infectious Rhinotracheitis (Bovine Herpesvirus 1) by Immunological Methods The aim of research work: to investigate and analyse antibodies against Infectious Bovine Rhinotracheitis in blood/serum samples using Enzyme-Linked Immunosorbent Assay (ELISA) kits from two different manufacturers. Research methods. Studies conducted in years 2017-2018 at National Food and Veterinary Risk Assessment Institute’s Department of Virological Research. During the study, 2115 cattle blood serum samples were tested for BHV-1 gB and 888 for BHV-1 gE by ELISA. Results and conclusions. Of all tested cattle: 13% of tested by gB and 9% tested with gE kits had antibodies against BHV-1. Female cattle are more likely to be infected with BHV-1 virus (12–14% by gB, 6–46% by gE). Connection between age and infection by BHV-1 has been shown: spread in younger cattle groups in 2017 was 42% in 0–1 month and 21% in 2–6 months age groups, more infected cattle were also detected and in older than 2 years cattle – in the 25-60 months old group 21% were gB-seropositive. Minimum spread noticed in 7–12 months (4–8%) and 13-24 months (3–4%) age groups. There are significant seasonal differences in BHV-1 spread among cattle. According to data of years 2017 and 2018 – in the autumn (13–14%) seropositive cattle were more frequent than in summer (5–8%). By cattle breeds, Lithuanian Greens (16–17%) have a higher incidence of IBR in Lithuania compared to Limousines (0–1%) and Black-and-White Beef (2%) cattle breeds. Comparing the areas, some regions have a higher gB seropositivity of BHV-1 in cattle. In 2017, 35 regions were tested for IBR gB and 12 regions were diagnosed with seropositive cattle. In 2018 the prevalence has increased – gB-seropositive cattle has been detected in 20 regions of 37 tested regions. It has been found that the used X and Y kits, both for the detection of gB and gE antibodies, exhibits differences in sensitivity, intensity of colour reaction. |
