Scrub typhus

  • Scrub typhus (ST): Orientia tsutsugamushi (different strains/serotypes), Leptotrombidum mite

When to think of scrub typhus and give empirical Doxycycline/Azithromycin

  • Prolonged fever that keeps coming back despite injections

  • Fever with breathing difficulty

  • Patient treated for pnumonia or COVID but doesn't get better

  • Fever with unusual neuro signs, especially focal

  • Patient treated for "typhoid fever" because of a positive Widal, but doesn't get better with beta-lactam/cephalosporins


  • Limited immunity, reinfections with different strains common... high initial IgG antibody levels associated with increased risk of severe disease (??ADE like with dengue)