Spatial and temporal investigation of Echinococcus granulosus coproantigen prevalence in farm dogs in South Powys, Wales.

The prevalence of canine echinococcosis appears to have been increasing in mid/south Wales in recent years - raising the concern of a potential resurgence in transmission to humans. A campaign was therefore conducted in 2008 in order to provide dogs in South Powys with anthelmintics, estimate the coproantigen prevalence amongst these dogs, and evaluate potential risk factors for coproantigen positivity. The coproantigen prevalence identified in these dogs (n=577) was 10.6% (95% confidence interval 7.6-13.5%), with 20.6% (15.6-25.7%) of farms (n=247) containing at least one coproantigen-positive dog. Further spatial investigation identified considerable spatial heterogeneity amongst the farms, with an increased coproantigen prevalence in the regions of Brecknockshire and the Brecon Beacons National Park. Within these areas, there was strong evidence of an increase in coproantigen prevalence, compared to that found in a study conducted in 2002. Finally, a mixed effects logistic regression model identified increased roaming behaviour and decreased dog weight as being associated with increased odds of coproantigen positivity, whereas pet dogs on some farms had similar odds of infection to working dogs. Further surveillance efforts in South Powys are required and should also include the northern areas of Gwent and Glamorgan.