Rickettsia Typhi IgG & IgM Abs




Test Mnemonic

TYPHUS

CPT Codes

  • 86757 - QTY (2)

Aliases

  • Typhus Fever IgG & IgM Abs

Includes

  • R. typhi Ab IgG
  • R. typhi Ab IgM

Performing Laboratory

ARUP


Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
1 mLSerumSST (Gold) RefrigeratedSeparate serum from cells ASAP or within 2 hours of collection and transfer into standard aliquot tube. Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens. Label specimens plainly as 'acute' or 'convalescent.'

Minimum Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
0.4 mL     

Stability

Environmental Condition Description
AmbientAfter separation from cells: 48 hours
RefrigeratedAfter separation from cells: 2 weeks
FrozenAfter separation from cells: 1 year (avoid repeated freeze/thaw cycles)

Days Performed

Sun - Sat

Turnaround Time

2 - 4 days

Methodology

Name Description
Indirect Immunofluorescence Assay (IFA)  

Reference Range

R. typhi Ab IgG
Sex Age From Age To Type Range Range Unit
       < 1:64 Negative 
       1:64 - 1:128 Equivocal - Questionable presence of R. typhi IgG antibody detected. Repeat tesing in 10-14 days may be helpful. 
       >= 1:256 Positive -Suggestive of current or past infection. 
R. typhi Ab IgM
Sex Age From Age To Type Range Range Unit
       <1:64 Negative 
       >= 1:64 Positive - Suggestive of recent infection 

Special Info

Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens. Contaminated, hemolyzed or severely lipemic specimens will be rejected. This test is New York DOH approved.

Clinical Info

Antibody reactivity to Rickettsia typhi antigen should be considered group-reactive for the Typhus Fever group, which includes 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. Acute - phase specimens are collected during the first week of illness, and convalescent - phase samples are generally obtained 2 - 4 weeks after resolution of illness. Ideally, these samples should be tested simultaneously at the same laboratory. If the sample submitted was collected during the acute phase of illness, submit a labeled convalescent sample within 25 days for paired testing.