Background: In 2007 Australia experienced its first outbreak of highly infectious equine influenza.
Government disease control measures were put in place to control, contain, and eradicate the
disease; these measures included movement restrictions and quarantining of properties. This study
was conducted to assess the psycho-social impacts of this disease, and this paper reports the
prevalence of, and factors influencing, psychological distress during this outbreak.
Methods: Data were collected using an online survey, with a link directed to the affected
population via a number of industry groups. Psychological distress, as determined by the Kessler
10 Psychological Distress Scale, was the main outcome measure.
Results: In total, 2760 people participated in this study. Extremely high levels of non-specific
psychological distress were reported by respondents in this study, with 34% reporting high
psychological distress (K10 > 22), compared to levels of around 12% in the Australian general
population. Analysis, using backward stepwise binary logistic regression analysis, revealed that
those living in high risk infection (red) zones (OR = 2.00; 95% CI: 1.57–2.55; p < 0.001) and disease
buffer (amber) zones (OR = 1.83; 95% CI: 1.36–2.46; p < 0.001) were at much greater risk of high
psychological distress than those living in uninfected (white zones). Although prevalence of high
psychological distress was greater in infected EI zones and States, elevated levels of psychological
distress were experienced in horse-owners nationally. Statistical analysis indicated that certain
groups were more vulnerable to high psychological distress; specifically younger people, and those
with lower levels of formal educational qualifications. Respondents whose principal source of
income was from horse-related industry were more than twice as likely to have high psychological
distress than those whose primary source of income was not linked to horse-related industry (OR
= 2.23; 95% CI: 1.82–2.73; p < 0.001).
Conclusion: Although, methodologically, this study had good internal validity, it has limited
generalisability because it was not possible to identify, bound, or sample the target population
accurately. However, this study is the first to collect psychological distress data from an affected
population during such a disease outbreak and has potential to inform those involved in assessing
the potential psychological impacts of human infectious diseases, such as pandemic influenza.