| Organism | First Choice (Duration, d) | Alternative | Comments |
|---|---|---|---|
| R. rickettsii (RMSF) and R. conorii (MSF) | Doxycyline (5-7) [1, 2, 4, 5] | Chloramphenicol | May be given until 3 days after defervescence |
| C. burnetii (Q fever) |
Acute infection Doxycycline (10-14) [7, 8] Chronic infection Doxycyline and hydroxychloroquine (18 months) [8] |
Trimethoprim/sulfamethoxazole | Clinical cure in chronic infection represents a drop in IgG or IgA phase I antibody titers to 1:200 or less [82] |
| F.tularensis (tularemia) | Streptomycin (7-10) [19, 22, 23] | Doxycycline, ciprofloxacin | |
| B. anthracis (anthrax) | Ciprofloxacin (60) [27] | Doxycycline Doxycycline plus clindamycin, penicillin or rifampin |
Doxycycline alone for cutaneous anthrax; in combination for inhalational, gastrointestinal or soft tissue infection |