Scrub Typhus IgG Test

The Scrub Typhus IgG Test detects IgG antibodies against Orientia tsutsugamushi, the bacteria responsible for scrub typhus. IgG antibodies indicate past exposure or late-stage infection and are useful for epidemiological studies or confirming a prior infection.

Why is the Test Done?

A doctor may order a Scrub Typhus IgG test if a patient has:

✅ A history of fever, rash, and body aches with previous exposure to endemic areas
✅ Suspected past scrub typhus infection
✅ Follow-up testing after an IgM-positive result
✅ Assessment of immune response or past infection in endemic regions

How is the Test Done?

1. Blood Sample Collection:

   • A sample is drawn from a vein.
   • Tested using ELISA (Enzyme-Linked Immunosorbent Assay) or Indirect Immunofluorescence Assay (IFA).

2. Detection of IgG Antibodies:

   • IgG antibodies develop later (2–3 weeks after infection) and persist for months or years.

Interpreting the Results

📌 Note:

• A positive IgG test alone does not confirm an active infection.
• If active infection is suspected, Scrub Typhus IgM and PCR tests should be done.
• IgG titers (paired samples 2-4 weeks apart) can help determine recent vs. past infection if there is a 4-fold rise in titer.

Next Steps After a Positive Result

🔬 Additional Tests May Be Ordered:

• Scrub Typhus IgM Test: To check for active infection.
• PCR Test: Confirms active bacterial presence in early cases.
• Complete Blood Count (CBC), Liver & Kidney Function Tests: To assess organ impact.

💊 Treatment Considerations:

• If IgG is positive but symptoms are absent, no treatment is required.
• If symptoms persist, antibiotics like Doxycycline or Azithromycin may be considered.