Chronic Q Fever Infections in Israeli Children: A 25-year Nationwide Study

Background: Q fever is a zoonosis caused by the bacterium Coxiella burnetii (C. burnetii) with a worldwide distribution. Our aim was to assess the epidemiology, clinical manifestations and treatment regimens of chronic Q fever infections in Israeli children during the past 25 years. Methods: Cases were collected from the national Q fever reference laboratory database. Demographic, epidemiologic and clinical data were reviewed using a structured questionnaire sent to the referring physician. Cases were defined according to the new Dutch Consensus Guidelines. Results: A total of 16 children originating from all regions of the country were found positive for chronic Q fever infections. The most common infection site was bone or joint (8/16, 50%), all in previously healthy children. Endovascular infections were found in 5 children (31%), all with an antecedent cardiac graft insertion. According to the new Consensus Guidelines, 9 children (56%) had a proven infection, 3 (19%) a probable infection and 4 (25%) a possible chronic Q fever infection. Almost all cases were treated with a long-Term antibiotic regimen, often necessitating a change in medication because of persistent or rising titers. Conclusions: Although pediatric chronic Q fever infections are rare, incidence has been rising. The most common infection site was bone or joint. A high index of suspicion is necessary, even in cases of previously healthy children without a possible exposure history. Use of the relatively new diagnostic tools in combination with serologic methods is helpful in diagnosing proven cases. There is no consensus as to the selection or duration of antibiotic treatment.