Diagnosis of equine influenza virus infections in quarantine stations in Australia, 2007

Antibody responses after vaccination against equine influenza in the Republic of Korea in 2013

In this study, antibody responses after equine influenza vaccination were investigated among 1,098 horses in Korea using the hemagglutination inhibition (HI) assay. The equine influenza viruses, A/equine/South Africa/4/03 (H3N8) and A/equine/Wildeshausen/1/08 (H3N8), were used as antigens in the HI assay. The mean seropositive rates were 91.7% (geometric mean antibody levels (GMT), 56.8) and 93.6% (GMT, 105.2) for A/equine/South Africa/4/03 and A/equine/Wildeshausen/1/08, respectively. Yearlings and two-year-olds in training exhibited lower positive rates (68.1% (GMT, 14) and 61.7% (GMT, 11.9), respectively, with different antigens) than average. Horses two years old or younger may require more attention in vaccination against equine influenza according to the vaccination regime, because they could be a target of the equine influenza virus.

A Systematic Review of Recent Advances in Equine Influenza Vaccination

Equine influenza (EI) is a major respiratory disease of horses, which is still causing substantial outbreaks worldwide despite several decades of surveillance and prevention. Alongside quarantine procedures, vaccination is widely used to prevent or limit spread of the disease. The panel of EI vaccines commercially available is probably one of the most varied, including whole inactivated virus vaccines, Immuno-Stimulating Complex adjuvanted vaccines (ISCOM and ISCOM-Matrix), a live attenuated equine influenza virus (EIV) vaccine and a recombinant poxvirus-vectored vaccine. Several other strategies of vaccination are also evaluated. This systematic review reports the advances of EI vaccines during the last few years as well as some of the mechanisms behind the inefficient or sub-optimal response of horses to vaccination.

Applying Bayesian network modelling to understand the links between on-farm biosecurity practice during the 2007 equine influenza outbreak and horse managers' perceptions of a subsequent outbreak

Australia experienced its first ever outbreak of equine influenza in August 2007. Horses on 9359 premises were infected over a period of 5 months before the disease was successfully eradicated through the combination of horse movement controls, on-farm biosecurity and vaccination. In a previous premises-level case-control study of the 2007 equine influenza outbreak in Australia, the protective effect of several variables representing on-farm biosecurity practices were identified. Separately, factors associated with horse managers' perceptions of the effectiveness of biosecurity measures have been identified. In this analysis we applied additive Bayesian network modelling to describe the complex web of associations linking variables representing on-farm human behaviours during the 2007 equine influenza outbreak (compliance or lack thereof with advised personal biosecurity measures) and horse managers' perceptions of the effectiveness of such measures in the event of a subsequent outbreak. Heuristic structure discovery enabled identification of a robust statistical model for 31 variables representing biosecurity practices and perceptions of the owners and managers of 148 premises. The Bayesian graphical network model we present statistically describes the associations linking horse managers' on-farm biosecurity practices during an at-risk period in the 2007 outbreak and their perceptions of whether such measures will be effective in a future outbreak. Practice of barrier infection control measures were associated with a heightened perception of preparedness, whereas horse managers that considered their on-farm biosecurity to be more stringent during the outbreak period than normal practices had a heightened perception of the effectiveness of other measures such as controlling access to the premises. Past performance in an outbreak setting may indeed be a reliable predictor of future perceptions, and should be considered when targeting infection control guidance to horse owners and managers.