ARUP's Laboratory Test Directory

Rickettsia typhi (Typhus Fever) Antibodies, IgG & IgM by IFA : 0050384

Mnemonic: TYPHU G/M

Methodology: Indirect Fluorescent Antibody
Performed: Tue, Fri
Reported: 1-5 days
Specimen Required: Collect:  One 4 mL serum separator tube.

Transport:  1 mL serum at 2-8°C. (Min: 0.5 mL)  Submit specimen in an ARUP Standard Transport Tube.

Pediatric Collection/Transport:  0.15 mL serum at 2-8°C.

Remarks:  Separate serum from cells ASAP. Acute and convalescent specimens must be labeled as such; parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens. Please mark specimen plainly as "acute" or "convalescent."

Unacceptable Conditions:  Severely lipemic, hemolyzed, or contaminated specimens.

Stability:  After separation from cells: Ambient: 2 days; 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.
³ 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.
³1:64  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.
CPT Code(s): 86757 Typhus fever IgG; 86757 Typhus fever IgM
 
 

 

 

 
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