The objective of this project was to develop and implement an active surveillance program for the early and rapid detection of equine influenza viruses in Ontario. For this purpose, from October 2003 to October 2005, nasopharyngeal swabs and acute and convalescent serum samples were collected from 115 client-owned horses in 23 outbreaks of respiratory disease in Ontario. Sera were paired and tested for antibody to equine influenza 1 (AE1-H7N7), equine influenza 2 (AE2-H3N8), equine herpesvirus 1 and 4 (EHV1 and EHV4), and equine rhinitis A and B (ERAV and ERBV). Overall, the cause-specific morbidity rate of equine influenza virus in the respiratory outbreaks was 56.5% as determined by the single radial hemolysis (SRH) test. The AE2-H3N8 was isolated from 15 horses in 5 outbreaks. A 4-fold increase in antibody levels or the presence of a high titer against ERAV or ERBV was observed in 10 out of 13 outbreaks in which AE2-H3N8 was diagnosed as the primary cause of disease. In conclusion, AE2-H3N8 was found to be an important contributor to equine respiratory viral disease. Equine rhinitis A and B (ERAV and ERBV) represented an important component in the equine respiratory disease of performing horses.

A highly sensitive enzyme-linked immunoelectrotransfer blot (EITB) assay, capable of detecting aphthovirus-specific antibodies to replicating virus in sera from cattle with persistent infection, was developed. The assay uses a set of purified recombinant DNA-derived nonstructural viral antigens as serologic probes in lieu of the traditionally used virus infection-associated antigen(s) partially purified from baby hamster kidney-infected cells. Sera from cattle with experimentally induced aphthovirus infection were analyzed sequentially by EITB at various postinoculation days, and the results were compared with those obtained by currently used techniques. It was established that, in aU cases, EITB results remained positive at late stages of infection. At these times, results of virus infection-associated antigen-antibody determinations were negative by use of the conventional immunodiffusion in agarose gel test, and virus was recovered only occasionally from esophageal-pharyngeal fluid. Specificity of the EITB test was indicated by negative results for sera from cattle in aphthovirus-free areas, including samples from cattle infected with a variety of bovine viruses. Moreover, the test eliminated a substantial number of false-positive results (on the basis of the immunodiffusion in agarose gel assay) caused by reactivity of sera from vaccinated cattle. Use of additional nonstructural viral antigens, other than RNA polymerase, is proposed to differentiate between seropositivity resulting from vaccination or infection. This procedure may be considered to have potential applications as a sensitive, safe, rapid, and economic field test for specific diagnosis of persistent aphthovirus infection in affected animals.

Objective: Molecular based study was conducted to determine the associated serotypes in the reemergence of Foot and Mouth Disease (FMD) outbreak in Assiut governorate, Egypt during 2014 and 2015. Materials and methods: One hundred and twenty cattle with clinical signs suggesting their infection by FMDV were examined clinically and twenty three of them were used for confirmation by laboratory diagnosis. Different clinical samples including vesicular fluid and tongue epitheliums were collected and after RNA extraction using commercial kit, RT-PCR was done using different primer sets. Results: Serotype O was detected in 8 samples, 2 of them were also positive for SAT2 serotype. The determination of specific serotype was failed in case of the rest 13 samples although they were positive when tested by the universal primer specific for FMDV. Conclusion: Serotypes O and SAT2 were the more prevalent serotypes in the current outbreak in Assiut governorate, Egypt. [J Adv Vet Anim Res 2017; 4(1.000): 32-38]