Rtyphiigaseracnc
A blood test that detects IgA antibodies against Rickettsia typhi bacteria, used to diagnose murine typhus (endemic typhus).
{"Detects IgA antibodies to Rickettsia typhi bacteria","Used to diagnose murine typhus, a fleaborne infection","Performed on a blood sample drawn from a vein","Positive result indicates current or recent infection","Important for identifying the cause of fever and appropriate treatment"}
Key facts at a glance
- LOINC
- 22487-3
- Short code
- RTYPIgA
- Synonyms
- R typhi IgA Ser-aCnc
- Category
- cardiac
- Sample
- serum
- Container
- Serum separator tube (SST) or plain red top tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 64
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Enzyme-linked immunosorbent assay (ELISA)
- CPT
- 86757
- SNOMED
- 122442009
- Specimen volume
- 1.0 mL minimum, 2.0 mL preferred
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days
- Hemolysis max
- 50
- Lipemia max
- 300
- Icterus max
- 20
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The Rickettsia typhi IgA antibody test is a blood test that looks for IgA antibodies against Rickettsia typhi bacteria in your blood. Rickettsia typhi is a bacterium that causes murine typhus, also known as endemic typhus. IgA antibodies are proteins produced by your immune system to fight this specific infection.
Why is this test performed?
This test is performed to help diagnose murine typhus, especially when you have symptoms such as fever, headache, rash, and muscle pain. It is particularly useful when the cause of a fever is unknown. Murine typhus is typically transmitted through flea bites or contact with infected flea feces.
How is the test done?
A healthcare professional will draw a small blood sample from a vein in your arm using a needle. The blood sample is then sent to a laboratory where it is tested for the presence of IgA antibodies against Rickettsia typhi. The procedure is quick and usually takes only a few minutes.
What do the results mean?
A positive result means that IgA antibodies to Rickettsia typhi were detected in your blood, indicating that you have a current or recent infection with the bacteria that causes murine typhus. A negative result means that no antibodies were detected, which could mean you do not have the infection, or that it is too early in the infection for antibodies to be detected. Your healthcare provider will interpret the results in conjunction with your symptoms and other test findings.
Reference range
Negative: < 1:64 titer or < 4.0 units; Equivocal: 1:64 titer or 4.0-5.9 units; Positive: >= 1:128 titer or >= 6.0 unitsN/A
No special preparation required. Patient does not need to fast.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
What is murine typhus?
How is murine typhus treated?
Is the test painful?
Do I need to fast before this test?
How long does it take to get results?
Sources
- 1
- 2
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 10, 2026. · Read our editorial policy