In the scope of the OIE Reference Laboratory for equine influenza and equine herpesvirus infections (equine rhinopneumonitis, EHV), we are an active part of the Expert Surveillance Panel (ESP) for equine influenza. The panel follows disease outbreaks, vaccination successes, as well as the genetic and antigenic properties of new virus isolates in many countries around the globe.
Based on the collected information, the ESP suggests specific virus strains for use as antigen sources for use by vaccine manufacturers. At the last conference in Paris in early 2013, the ESP recommended the inclusion of the so-called Florida Clade 1 and Florida Clade 2 strains in the respective vaccines.
In order to determine the prevalence of EIV infections in Germany, sample kits containing virus transport medium, sterile swabs, and instructions, were sent to veterinarians all across Germany. Samples from horses that show respiratory distress are immediately sent to our laboratory and are then tested for EIV and EHV using virus isolation and quantitative PCR. In 2010-2012, we were able to identify EIV in many parts of Germany. The sequencing of the HA1 segment enabled us to show that the viruses circulating from 2010-2012 were mainly of the Florida Clade 2 strain, but recently a Clade 1 virus was also identified in disease outbreaks.
We also undertake virological and serological investigations of EIV in other countries, among them Kyrgyzstan, in order to study the EIV situation in the local equine population. Prof. Dr. Osterrieder visited Kyrgyzstan to help set up an observation project for respiratory diseases in the local equine population. Blood and nasal swab samples were taken from 76 non-vaccinated horses. Through virus cultivation of the nose samples, EIV could not be identified. Serums were tested for antibodies to EIV subtypes (H7N7 Prague and H3N8 Wildeshausen/08). H7N7 could not be identified in the population (HI Titer: 1:8 for the H3N8-isolate Wildeshausen/08. This result is a clear indication for the presence of EIV in the local equine population.
Dogs and cats are vulnerable to several Influenza subtypes. We are part of a serological observation with the aim of confirming the presence of influenza-specific antibodies in both species. To date, 750 dog and 400 cat samples were examined for antibodies using ELISA. Seroprevalences of influenza-specific antibodies were observed (3.4% in dogs and 2.2% in cats). The main HA type found in dogs and cats was H1, suggesting that owners may have transmitted the virus to their pets.