Abstract

Q fever, caused by Coxiella burnetii, is a zoonosis with a worldwide distribution that affects both humans and animals. In 2007, 2008, and 2009 large community outbreaks of Q fever were observed in the Netherlands. In 2008, several studies were started to investigate potential sources of C. burnetii infection and possible transmission routes. Temporal studies focussed on C. burnetii DNA content on farms, and their direct surroundings. Coxiella burnetii was found in veterinary and environmental samples obtained from a single farm, with an abortion wave among its goats in April 2007, during two successive years of Q fever outbreaks in 2007 and 2008. Within the Q fever outbreak of 2009, investigations at one location in Zuid-Limburg over a 16 week-interval demonstrated that the C. burnetii DNA content in both veterinary and environmental samples declined over time after the initial wave of abortions among goats. Although a decline of the C. burnetii DNA content was observed, environmental and veterinary samples were still found to be positive up to several months after the abortion wave at the farm. Human outbreak linked source investigations focussed on veterinary and environmental matrices on farms, which in previous studies were found to contain the highest C. burnetii DNA content. These matrices included vaginal swabs from animals and surface area swabs from horizontal surfaces, to investigate the potential link between the putative Q fever-affected goat farms and (clusters of) human Q fever cases in the near vicinity of these farms. Screening results for vaginal swabs obtained from goats and/or sheep are consistent with results for surface area swabs taken on the same farm.