Rickettsia typhi (Typhus Fever) Antibodies, IgG & IgM by IFA
0050384
 
Ordering Recommendation
Mnemonic
TYPHU G/M
Methodology
Semi-Quantitative Indirect Fluorescent Antibody
Performed
Tue, Fri
Reported
1-5 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Serum separator tube.  
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 or 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)  
Reference Interval
Test Number Components Reference Interval
0050381Rickettsia typhi (Typhus Fever) Antibody, IgG by IFA < 1:64 Negative -​ No significant level of Rickettsia typhi IgG antibody detected.
1:64-​1:128 Equivocal -​ Questionable presence of Rickettsia typhi IgG antibody detected. Repeat testing in 10-​14 days may be helpful.
≥ 1:256 Positive -​ Presence of IgG antibody to Rickettsia typhi detected, suggestive of current or past infection.
0050383Rickettsia typhi (Typhus Fever) Antibody, IgM by IFA < 1:64 Negative -​ No significant level of Rickettsia typhi IgM antibody detected.
≥1:64 Positive -​ Presence of IgM antibody to Rickettsia typhi detected, suggestive of recent infection.
Interpretive Data
These tests are for antibodies to Rickettsia typhi. Any antibody reactivity to Rickettsia typhi antigen should, however, also be considered group-reactive for the Typhus Fever group (Rickettsia prowazekii). Seroconversion between acute and convalescent sera is considered strong evidence of recent infection. The best evidence for infection is a significant change (fourfold difference in titer) on two appropriately timed specimens, where both tests are done in the same laboratory at the same time.

While the presence of IgM antibodies suggests current or recent infection, low levels of IgM antibodies may occasionally persist for more than 12 months post-infection.
Note
CPT Code(s)
86757 x2
Components
Component Test Code*Component Chart Name
0050381Typhus Fever Antibody, IgG
0050383Typhus Fever Antibody, IgM
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, contact interface support at interface.support@aruplab.com.
Cross References
  • Murine Typhus Antibodies
  • R. typhi antibodies
  • Typhus Fever Group Antibody, IgG and IgM, Serum