Article Figures & Data
Figures
- Fig. 1.
Diagnostic algorithm for acute Q fever in an outbreak setting introduced 1 May 2009 in the Jeroen Bosch Hospital, 's-Hertogenbosch, Netherlands. Abbreviations: ELISA MII-screen, enzyme-linked immunosorbent assay for immunoglobulin M antibodies to Coxiella burnetii phase II antigens; IFA, immunofluorescence assay; IgM-II antibodies, immunoglobulin M antibodies to C. burnetii phase II antigens; IgG-II antibodies, immunoglobulin G antibodies to C. burnetii phase II antigens; IgG-I antibodies, immunoglobulin G antibodies to C. burnetii phase I antigens.
Tables
- Table 1.
Outcomes of the diagnostic algorithm for acute Q fever in an outbreak setting and definitions
Outcome in the diagnostic algorithm Definition Acute Q fever Presence of IgM and IgG antibodies to phase II antigens with or without IgM and IgG antibodies to phase I antigens or PCR positivity Past resolved Q fever Presence of IgG antibodies to phase II antigens with or without IgG antibodies to phase I antigens in the absence of IgM antibodies No acute Q fever Absence of a serologic response in serum samples obtained >14 days after onset of disease Cross-reactivity Presence of false-positive IgM antibodies to phase II antigens detected by ELISA but not confirmed by additional tests in first or follow-up serum samples Inconclusive outcome Noncompliance with the request to refer a follow-up serum sample Inconsistency with the diagnostic algorithm Nonadherence to the flowchart of the diagnostic algorithm - Table 2.
Outcome of acute Q fever diagnostics according to a diagnostic algorithm in 825 patients referred from 15 to 31 May 2009
Status No. of samples with definitive outcome Relative outcome overall (%) In first serum sample In follow-up serum sample Overall Acute Q fever 190 55 245 29.7 Past resolved Q fever 2 1 3 0.4 No acute Q fever 116 129 245 29.7 Cross-reactivity 0 4 4 0.5 Inconclusive outcome 299 2 301 36.5 Inconsistency with the diagnostic algorithm Acute Q fever 7 4 11 No acute Q fever 5 4 9 Cross-reactivity 0 2 2 Inconclusive outcome 5 0 5 Total with inconsistent result 17 10 27 3.3
