Scrub typhus

non-malarial fever

• in Asia
  • dengue
  • leptospirosis
  • scrub typhus
  • typhoid
  • JEV
  • influenza
  • still 30-50% undifferentiated/undiagnosed

diagnosis/test

• reason of difficulty of lab test
  • obligate intracellular organism
  • very diverse stains (i.e., antigens) of Orientia
  • limited lab resources and experties

Indirect immunofluorescent assay (IFA)

• Orientia antigen - anti-Orientia antibody (primary) - anti- antibody-antigen complex (secondary) labelled by fluorescent
• serial dilution
• microscopic observation
• uses 3 or more primary antibodies (primary antibodies against antigens derived from 3 or more stains)
  • genotypes: Karp_A, Karp_B, Saitama, Gilliam, Kato, ....

ELISA

• Orientia antigen - anti-Orientia antibody (primary) - anti- antibody-antigen complex (secondary) labelled by fluorescent
• serial dilution
• machinery measurement of luminescence