Coxiella burnetii (Q-Fever) Antibody IgG, Phase I and II with Reflex to Titer
Ordering Recommendation

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

QF G 1/2
Semi-Quantitative Indirect Fluorescent Antibody
Mon, Wed, Fri
1-6 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
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: 0.1 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
Unacceptable Conditions
Contaminated, hemolyzed, or severely lipemic specimens. 
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles) 
Reference Interval
Test NumberComponentReference Interval
C. burnetii (Q-Fever) Ab, Phase I IgGNegative
C. burnetii (Q-Fever) Ab, Phase II IgGNegative

Interpretive Data
Single phase II IgG titers of 1:256 and greater are considered evidence of C. burnetii infection at some time prior to the date of the serum specimen. Phase I antibody titers of 1:16 and greater are consistent with chronic infection or convalescent phase of Q-fever.

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
CPT Code(s)
86638 x2; if reflexed add 86638 per titer
Component Test Code*Component Chart NameLOINC
2012626C. Burnetii Abs, IgG Phase I Screen48720-7
2012628C. Burnetii Abs, IgG Phase II Screen48719-9
* 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 view this test within the Laboratory Test Directory found at
  • Coxiella burnetii
  • Coxiella Titer
  • Q Fever Phases I and II antibody