Chronic Q fever in patients with valvular heart disease

Marit de Lange

Chronic Q fever | 30-11-2016

Province North-Brabant

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Province North-Brabant

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The Netherlands 2007-2010

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4,000 notified acute Q fever patients

50,000 acute infections:symptomatic + asymptomatic

Chronic Q fever:323 patients

Chronic Q fever

Vascular infection > endocarditis

Vascular infection < endocarditis

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Aim of the study

How many experienced Q fever infections and chronic Q fever in patients with valvular heart disease

Evaluate whether the policy of not routinely screening should be adapted

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MethodsCross sectional study, started 15 February 2016

Small regional hospital

Eligible: 18 years or older, valvular heart disease, attended cardiologist

One blood sample

Underlying disease

One year, until 2,000 patients

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Laboratory methods

Immunofluorescence assay:

IgG phase II antibodies: indication passed acute infection● Titre of ≥ 1:64

IgG phase I antibodies: indication chronic infection● IgG phase I titre of ≥ 1:1024● IgG phase I titre 1:512 further examination by hospital

consultant

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Results

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792 invited people

727/792 (92%) participants

110/727 (15%) experienced infection

617/727 (85%) no passed infection

 107/110 (97%) no

chronic Q fever infection

3/110 (3%) chronic Q fever infection

DiscussionThis study:Valvular heart disease: 15% acute, 3% chronic

Other screening studies in the Netherlands, same area:● General population: 34% acute, 1% chronic● Other risk groups for chronic Q fever:

– Aneurysm or vascular prosthesis: 17% acute, 31% chronic

– Cardiac valve surgery: 20% acute, 8% chronic

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Discussion

Strong points:● High participation rate● High incidence area

Limitations:● Long after outbreaks● Incomplete inclusion due to high workload● Survivor bias

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Conclusion

Low % chronic Q fever found in this study

Social and political discussion about screening

Results used for cost-effectiveness study:● Is screening needed?● If yes, in which patient group, where and when?

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AcknowledgementsCo-authors:● Wim van der Hoek (National Institute for Public Health and the

Environment)● Peter Schneeberger (Jeroen Bosch and Bernhoven Hospital)● Arko Scheepmaker (Bernhoven hospital)● Monique Leclercq (Bernhoven hospital)

Funding:Study funded by the Q-Support foundation.

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