Prevalence of Chronic Q Fever in Patients with a History of Cardiac Valve Surgery in an Area Where Coxiella burnetii Is Epidemic

ABSTRACTChronic Q fever develops in 1 to 5% of patients infected withCoxiella 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 againstC. burnetii, and if titers were above a defined cutoff level,C. burnetiiPCR was performed. Chronic Q fever was considered proven ifC. burnetiiPCR was positive and probable if the phase I IgG titer was ≥1:1,024. Among 568 patients, the seroprevalence ofC. burnetiiantibodies (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.

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Delayed Diagnosis of Chronic Q Fever and Cardiac Valve Surgery

Emerging Infectious Diseases ◽

10.3201/eid1905.120353 ◽

2013 ◽

Vol 19 (5) ◽

pp. 768-773 ◽

Cited By ~ 8

Author(s):

Linda M. Kampschreur ◽

Elske Hoornenborg ◽

Nicole H. M. Renders ◽

Jan Jelrik Oosterheert ◽

Joost F. Haverman ◽

...

Keyword(s):

Q Fever ◽

Delayed Diagnosis ◽

Valve Surgery ◽

Cardiac Valve ◽

Cardiac Valve Surgery ◽

Chronic Q Fever

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Preoperative Statin Treatment Is Associated With Reduced Postoperative Mortality After Isolated Cardiac Valve Surgery in High-Risk Patients

Journal of Cardiothoracic and Vascular Anesthesia ◽

10.1053/j.jvca.2010.03.017 ◽

2010 ◽

Vol 24 (6) ◽

pp. 921-926 ◽

Cited By ~ 15

Author(s):

Nicolas Allou ◽

Pascal Augustin ◽

Guillaume Dufour ◽

Laura Tini ◽

Hassan Ibrahim ◽

...

Keyword(s):

High Risk ◽

Postoperative Mortality ◽

Statin Treatment ◽

Valve Surgery ◽

Cardiac Valve ◽

High Risk Patients ◽

Cardiac Valve Surgery ◽

Risk Patients

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Screening for Coxiella burnetii seroprevalence in chronic Q fever high-risk groups reveals the magnitude of the Dutch Q fever outbreak

Epidemiology and Infection ◽

10.1017/s0950268812001203 ◽

2012 ◽

Vol 141 (4) ◽

pp. 847-851 ◽

Cited By ~ 44

Author(s):

L. M. KAMPSCHREUR ◽

J. C. J. P. HAGENAARS ◽

C. C. H. WIELDERS ◽

P. ELSMAN ◽

P. J. LESTRADE ◽

...

Keyword(s):

High Risk ◽

The Netherlands ◽

Confidence Interval ◽

Coxiella Burnetii ◽

Catchment Area ◽

Q Fever ◽

Risk Groups ◽

Chronic Q Fever ◽

Epidemic Area ◽

Acute Q Fever

SUMMARYThe Netherlands experienced an unprecedented outbreak of Q fever between 2007 and 2010. The Jeroen Bosch Hospital (JBH) in 's-Hertogenbosch is located in the centre of the epidemic area. Based on Q fever screening programmes, seroprevalence of IgG phase II antibodies to Coxiella burnetii in the JBH catchment area was 10·7% [785 tested, 84 seropositive, 95% confidence interval (CI) 8·5–12·9]. Seroprevalence appeared not to be influenced by age, gender or area of residence. Extrapolating these data, an estimated 40 600 persons (95% CI 32 200–48 900) in the JBH catchment area have been infected by C. burnetii and are, therefore, potentially at risk for chronic Q fever. This figure by far exceeds the nationwide number of notified symptomatic acute Q fever patients and illustrates the magnitude of the Dutch Q fever outbreak. Clinicians in epidemic Q fever areas should be alert for chronic Q fever, even if no acute Q fever is reported.

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Microbiological Challenges in the Diagnosis of Chronic Q Fever

Clinical and Vaccine Immunology ◽

10.1128/cvi.05724-11 ◽

2012 ◽

Vol 19 (5) ◽

pp. 787-790 ◽

Cited By ~ 18

Author(s):

Linda M. Kampschreur ◽

Jan Jelrik Oosterheert ◽

Annemarie M. C. Koop ◽

Marjolijn C. A. Wegdam-Blans ◽

Corine E. Delsing ◽

...

Keyword(s):

Phase I ◽

Q Fever ◽

Strong Association ◽

False Negative ◽

High Morbidity ◽

Igg Antibody ◽

Predictive Values ◽

Content Type ◽

Chronic Q Fever ◽

High Phase

ABSTRACTDiagnosis of chronic Q fever is difficult. PCR and culture lack sensitivity; hence, diagnosis relies mainly on serologic tests using an immunofluorescence assay (IFA). Optimal phase I IgG cutoff titers are debated but are estimated to be between 1:800 and 1:1,600. In patients with proven, probable, or possible chronic Q fever, we studied phase I IgG antibody titers at the time of positive blood PCR, at diagnosis, and at peak levels during chronic Q fever. We evaluated 200 patients, of whom 93 (46.5%) had proven, 51 (25.5%) had probable, and 56 (28.0%) had possible chronic Q fever. Sixty-five percent of proven cases had positiveCoxiella burnetiiPCR results for blood, which was associated with high phase I IgG. Median phase I IgG titers at diagnosis and peak titers in patients with proven chronic Q fever were significantly higher than those for patients with probable and possible chronic Q fever. The positive predictive values for proven chronic Q fever, compared to possible chronic Q fever, at titers 1:1,024, 1:2,048, 1:4,096, and ≥1:8,192 were 62.2%, 66.7%, 76.5%, and ≥86.2%, respectively. However, sensitivity dropped to <60% when cutoff titers of ≥1:8,192 were used. Although our study demonstrated a strong association between high phase I IgG titers and proven chronic Q fever, increasing the current diagnostic phase I IgG cutoff to >1:1,024 is not recommended due to increased false-negative findings (sensitivity < 60%) and the high morbidity and mortality of untreated chronic Q fever. Our study emphasizes that serologic results are not diagnostic on their own but should always be interpreted in combination with clinical parameters.

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