• 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

Treatment

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