Q fever in the Netherlands - 2007-2010: what we learned from the largest outbreak ever.

Q fever is a zoonosis caused by Coxiella burnetii with a presentation ranging from asymptomatic seroconversion to possibly fatal chronic Q fever. The Netherlands faced an exceptionally large outbreak of Q fever from 2007 to 2010: 4026 human cases were notified, which makes it the largest Q fever outbreak ever reported. This outbreak, because of its size, allowed collecting a wide range of information on the natural history of Q fever, as well as on its transmission and clinical presentation. It also posed unprecedented public healthcare problems, especially for the concomitant management of the epizootic by veterinarian authorities and public health authorities, but also for the management of transmission risk related to blood donation. The need for cost efficient measures emerged rapidly because of the great number of infected individuals or at risk of infection, with a need for guidance on follow-up of acute Q fever patients, screening of pregnant women, or implementation of diagnostic algorithms. The acute outbreak was controlled by drastic veterinarian measures but chronic Q fever will remain a problem for the coming years.