ARUP's Laboratory Test Directory

Rickettsia typhi (Typhus Fever) Antibody, IgG by IFA : 0050381

Mnemonic: TYPHU G

Methodology: Semi-Quantitative Indirect Fluorescent Antibody
Performed: Tue, Fri
Reported: 1-5 days
Specimen Required: 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: 0.05 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.

Stability (collection to initiation of testing): After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Reference Interval:
< 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.
Interpretive Data: This test is 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.
CPT Code(s): 86757
Cross References: Murine Typhus Antibodies, IgG (Rickettsia typhi (Typhus Fever) Antibody, IgG by IFA) , Typhus Fever Antibody (Rickettsia typhi (Typhus Fever) Antibody, IgG by IFA)