Surveillance of equine influenza viruses through the RESPE network in France from November 2005 to October 2010.

The research looks into the effectiveness of the French Réseau d’Epidémio-Surveillance en Pathologie Equine (RESPE) network in supporting equine influenza virus (EIV) surveillance in France between November 2005 and October 2010. The conclusions suggest that such a surveillance network may reduce economic losses from EIV outbreaks if implemented in other countries.

Objectives and Methodology

The study primarily aimed to analyse the efficiency of the RESPE network in France for the surveillance of equine influenza virus (EIV). A retrospective cross-sectional examination was performed on 1426 nasopharyngeal swabs received at the Frank Duncombe Laboratory from November 2005 to October 2010. The researchers used real-time reverse transcription polymerase chain reaction to conduct EIV detection and undertook phylogenetic analysis on a portion of the haemagglutinin gene from 47 samples that tested positive.

• The haemagglutinin gene is crucially related to the virus’s infectivity and the host’s immune response.
• Phylogenetic analysis provides an understanding of the evolutionary relationships between different strains of viruses.

Key Findings

The study reported that of the 920 samples submitted by RESPE-associated veterinarians, 121 (13.1%) from 42 premises tested positive for EIV. In contrast, only 5.1% of the 607 samples received from non-RESPE associated veterinarians turned out to be positive.

• The most extensive outbreak was registered between February and May 2009, affecting 70 horses across 23 premises, of which 15 were managed by RESPE-associated veterinarians.
• All detected strains belonged to the American lineage, specifically the Florida sublineage, belonging to Clade 1 and Clade 2. Clade 1 was identified only during the so-called “Grosbois episode”.

Conclusions

The RESPE network demonstrated its value in enhancing EIV detection in France, enabling accurate characterisation of the virus strains, supplying useful information related to the disease’s epidemiology, and identifying instances of vaccine breakdown.

• The study suggests that establishing a similar surveillance network in other countries could potentially help in reducing the economic losses associated with outbreaks of EIV.