Ordering Recommendation

Confirm infectious agent as C. burnetii (Q-fever) in symptomatic patients. Recommend testing of acute and convalescent sera.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Serum separator tube (SST).

Specimen Preparation

Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP standard transport tube. (Min: 0.4 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens. Mark specimens plainly as "acute" and "convalescent."

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Contaminated, hemolyzed, or severely lipemic specimens.

Remarks
Stability

After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Methodology

Qualitative Indirect Fluorescent Antibody (IFA)

Performed

Mon, Wed, Fri

Reported

1-6 days

Reference Interval

Test Number Component Reference Interval
C. burnetii (Q-Fever) Ab, Phase I IgG Negative
C. burnetii (Q-Fever) Ab, Phase II IgG Negative

Interpretive Data

Acute Q fever is best demonstrated by a four-fold rise in phase II IgG titers when comparing two serum samples collected 3-6 weeks apart, and testing is performed in the same laboratory at the same time. Phase I IgG titers can increase during seroconversion. However, in the case of acute infection, the phase I IgG titer should remain lower than the phase II titer. In the absence of an acute sample, a single convalescent serum sample with a phase II IgG titer greater than 1:128 in a patient who has been ill greater than 1 week, indicates probable acute Q fever.

Chronic Q fever is best demonstrated by a phase I IgG titer greater than the phase II IgG titer. Phase I and phase II IgG titers may remain elevated for months.

Compliance Category

FDA

Note

If either C. Burnetii Abs IgG Phase I and/or Phase II result is indeterminate or positive, then titer(s) will be added. Additional charges apply.

Hotline History

N/A

CPT Codes

86638 x2; if reflexed add 86638 per titer

Components

Component Test Code* Component Chart Name LOINC
2012626 C. Burnetii Abs, IgG Phase I Screen 48720-7
2012628 C. Burnetii Abs, IgG Phase II Screen 48719-9
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • Coxiella burnetii
  • Coxiella Titer
  • Q Fever Phases I and II antibody
Coxiella burnetii (Q-Fever) Antibody IgG, Phase I and II with Reflex to Titer