Estimated prevalence of chronic Q fever among Coxiella burnetii seropositive patients with an abdominal aortic/iliac aneurysm or aorto-iliac reconstruction after a large Dutch Q fever outbreak.

OBJECTIVES: The aim of this study was to estimate the seroprevalence of Q fever and prevalence of chronic Q fever in patients with abdominal aortic and/or iliac disease after the Q fever outbreak of 2007-2010 in the Netherlands. METHODS: In November 2009, an ongoing screening program for Q fever was initiated. Patients with abdominal aortic and/or iliac disease were screened for presence of IgM and IgG antibodies to phase I and II antigens of Coxiella burnetii using immunofluorescence assay and presence of C. burnetii DNA in sera and/or vascular wall tissue using polymerase chain reaction (PCR). RESULTS: A total of 770 patients with abdominal aortic and/or iliac disease were screened. Antibodies against C. burnetii were detected in 130 patients (16.9%), of which 40 (30.8%) patients showed a serological profile of chronic Q fever. Three patients presented with acute Q fever, one of which developed to chronic Q fever over time. The number of aneurysm-related acute complications in patients with chronic Q fever was significantly higher compared to patients negative for Q fever (p = 0.013); 9.0% (30/333) vs. 30.0% (6/20). Eight out of 46 patients with past resolved Q fever (8/46, 17.4%) presented with aneurysm-related acute complications (no significant difference). CONCLUSION: The prevalence of chronic Q fever in C. burnetii seropositive patients with abdominal aortic and/or iliac disease living in an epidemic area in the Netherlands is remarkably high (30.8%). Patients with an aneurysm and chronic Q fever present more often with an aneurysm-related acute complication compared to patients without evidence of Q fever infection.

Prevalence of chronic Q fever in patients with a history of cardiac valve surgery in an area where Coxiella burnetii is epidemic.

Chronic Q fever develops in 1 to 5% of patients infected with Coxiella burnetii. The risk for chronic Q fever endocarditis has been estimated to be ≈ 39% in case of preexisting valvulopathy and is potentially even higher for valvular prostheses. Since 2007, The Netherlands has faced the largest Q fever outbreak ever reported, allowing a more precise risk estimate of chronic Q fever in high-risk groups. Patients with a history of cardiac valve surgery were selected for microbiological screening through a cardiology outpatient clinic in the area where Q fever is epidemic. Blood samples were analyzed for phase I and II IgG against C. burnetii, and if titers were above a defined cutoff level, C. burnetii PCR was performed. Chronic Q fever was considered proven if C. burnetii PCR was positive and probable if the phase I IgG titer was ≥ 1:1,024. Among 568 patients, the seroprevalence of C. burnetii antibodies (IgG titer greater than or equal to 1:32) was 20.4% (n = 116). Proven or probable chronic Q fever was identified among 7.8% of seropositive patients (n = 9). Valve characteristics did not influence the risk for chronic Q fever. Patients with chronic Q fever were significantly older than patients with past Q fever. In conclusion, screening of high-risk groups is a proper instrument for early detection of chronic Q fever cases. The estimated prevalence of chronic Q fever is 7.8% among seropositive patients with a history of cardiac valve surgery, which is substantially higher than that in nonselected populations but lower than that previously reported. Older age seems to increase vulnerability to chronic Q fever in this population.

Identification of risk factors for chronic Q fever, the Netherlands.

Since 2007, the Netherlands has experienced a large Q fever outbreak. To identify and quantify risk factors for development of chronic Q fever after Coxiella burnetii infection, we performed a case-control study. Comorbidity, cardiovascular risk factors, medications, and demographic characteristics from 105 patients with proven (n = 44), probable (n = 28), or possible (n = 33) chronic Q fever were compared with 201 patients who had acute Q fever in 2009 but in whom chronic Q fever did not develop (controls). Independent risk factors for development of proven chronic Q fever were valvular surgery, vascular prosthesis, aneurysm, renal insufficiency, and older age.

[Chronic Q fever during pregnancy]. / Chronische Q-koorts tijdens de zwangerschap.

A 42-year-old woman visited the pulmonologist for follow-up after a pneumonia. In retrospect the pneumonia appeared to be a manifestation of an acute Q fever infection. A few weeks later the patient was found to be unexpectedly pregnant. At the normal serological follow-up six months after the primary infection chronic Q fever infection was diagnosed. Doxycycline and hydroxychloroquine are contraindicated in pregnancy and the patient was found to be allergic to co-trimoxazole. Therefore treatment with erythromycin was chosen on empirical grounds. The patient had many symptoms during pregnancy. After 38 weeks and 2 days amenorrhea labour was induced on maternal indication. Finally a healthy boy of 3850 grams was born by caesarean section. In view of the increased risk of chronic Q fever infection during pregnancy we advise intensified serological monitoring of patients with acute Q fever who subsequently become pregnant.

Chronic Q fever-related dual-pathogen endocarditis: case series of three patients.

Following Coxiella burnetii infection, there is a 1 to 5% risk of chronic Q fever. Endocarditis, mycotic aneurysm, and vascular prosthesis infection are common manifestations. We present three patients with endocarditis by C. burnetii concomitant with another bacterial pathogen. Chronic Q fever should therefore be considered in all endocarditis patients in regions where Q fever is endemic.

[Screening for chronic Q fever in symptomatic patients with an aortic aneurysm or prosthesis]. / Screening op chronische Q-koorts bij symptomatische patiënt met aneurysma of prothese van de aorta.

A 76-year-old man was referred to the Emergency Department because of collapse, epigastric pain and nausea. The patient had been diagnosed with an infrarenal aneurysm of the abdominal aorta nine years earlier. His symptoms were attributed to an aortic-duodenal fistula originating from the aneurysm. The patient died despite placement of an aortic prosthesis. A hospital screening programme for chronic Q fever in patients with aortic aneurysm revealed chronic Q fever. Until recently, vascular infection with Coxiella burnetii was an unknown disease in the Netherlands. In view of the nonspecific clinical presentation, severity and therapeutic consequences of the disease, we advise screening for chronic Q fever in all symptomatic patients with an aortic aneurysm or prosthesis - whether or not with aspecific symptoms - in regions where the disease is endemic.