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 mL | Serum | SST (Gold) | Refrigerated | Separate 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 |
|---|---|
| Ambient | After separation from cells: 48 hours |
| Refrigerated | After separation from cells: 2 weeks |
| Frozen | After 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.