Q fever across the Dutch border in Limburg province, Belgium

Data from three different data sources were compiled to estimate the presence of Coxiella burnetii in the Belgian Limburg province for both humans and livestock. First, serological data of all samples sent to the Belgian reference centre (2003–2010) for human Q fever were analysed, showing evidence for an acute Q fever infection in 1–5% of the cases. Second, a multi-centre prospective survey was conducted in Limburg in 2010 to detect undiagnosed human cases; evidence for a recent infection with Coxiella burnetii was found in three out of 100 patients from which clinicians suspected a Mycoplasma pneumoniae infection. Third, we analyzed data from the Belgian livestock screening program (2009–2010) which consisted of investigating all reported abortions, sampling tank milk, and serological screening of cattle. The results suggest an endemicity in the Limburgian livestock which seems to be especially high in cattle.

Detection of phase I IgG antibodies to Coxiella burnetii with EIA as a screening test for blood donations

The presence of a high phase I IgG antibody titre may indicate chronic infection and a risk for the transmission of Coxiella burnetii through blood transfusion. The outbreak of Q fever in the Netherlands allowed for the comparison of an enzyme immunoassay (EIA) with the reference immunofluorescence assay (IFA) in a large group of individuals one year after acute Q fever. EIA is 100 % sensitive in detecting high (≥1:1,024) phase I IgG antibody titres. The cost of screening with EIA and confirming all EIA-positive results with IFA is much lower than screening all donations with IFA. This should be taken into account in cost-effectiveness analyses of screening programmes.