Prevalence and molecular typing of Coxiella burnetii in bulk tank milk in Belgian dairy goats, 2009-2013

Q fever, a worldwide zoonosis, is an arousing public health concern in many countries since the recent Dutch outbreak. An emerging C. burnetii clone, genotype CbNL01, was identified as responsible for the Dutch human Q fever cluster cases. Since 2009, Q fever surveillance in the goat industry was implemented by the Belgian authorities. The herd prevalence (December 2009-March 2013) ranged between 6.3 and 12.1%. Genotypic analysis highlighted the molecular diversity of the Belgian strains from goats and identified an emerging CbNL01-like genotype. This follow-up allowed the description of shedding profiles in positive farms which was either continuous (type I) and associated to the CbNL01-like genotype; or intermittent (type II) and linked to other genotypes. Despite the circulation of a CbNL01-like strain, the number of notified Belgian human cases was very low. The mandatory vaccination (in June 2011) on positive dairy goat farms in Belgium, contributed to a decrease in shedding.