Description of a Coxiella burnetii abortion outbreak in a dairy goat herd, and associated serology, PCR and genotyping results

Abstract

Using PCR on aborted foetal material, Coxiella burnetii infection was confirmed as the cause of abortions in a dairy goat herd with over 1000 adults. Ninety-five (22%) abortions and 355 normal births were recorded from 440 goats over 2 months. The herd was sampled three times in 6 months to look at the within-herd seroprevalence, with the 1st visit done 24 days after the last recorded abortion. The true seroprevalence in the herd was 79.2%, 66.5% and 45.7% on each of these visits, but introduction of a group of young goats prior to the 3d visit influenced these results. Using PCR, widespread environmental contamination was demonstrated in surface dust, bedding, muck heaps, milk, bird droppings and drinking water in the goat shed. MST and MLVA analysis showed the C. burnetii from this outbreak to be of a genotype previously observed in the UK and different from those recorded in the Netherlands outbreak of 2007-2011.