Demonstrating freedom from equine influenza in New South Wales, Australia, following the 2007 outbreak.

The research studied the probability of horses in New South Wales, Australia being free of equine influenza following the 2007 outbreak and concluded that the virus was successfully eradicated.

Testing and Estimates

• The authors of the research paper analyzed results from polymerase chain reaction (PCR) tests carried out on horses from the regions of New South Wales that had been infected during an outbreak of equine influenza (EI) in 2007. This testing was conducted from January 1 to April 30, 2008.
• Using the data from this random survey, they estimated the probability of detecting EI if it was present at various prevalence levels, ranging from 0.01% to 0.5%. These estimates provided them with the sensitivity of the testing method in detecting EI.

Combining Estimates with Probability of Freedom

• The sensitivity estimates were used in conjunction with an initial probability of freedom from EI to create a simulation model.
• From this model, they could estimate the posterior probability of horses in New South Wales being free from EI, given the negative results obtained from the random survey.

Conclusions

• Based on the high volume of PCR tests carried out and their resulting data, the researchers concluded with a high level of confidence that equine influenza had been successfully eradicated from New South Wales.
• This study can serve as an effective model for confirming the eradication of infectious diseases in animal populations.