›Duration: continue until bacterial tick-borne illness excluded
›Minimum 5 to 7 days if ehrlichiosis or anaplasmosis confirmed
›If BRBV confirmed as sole pathogen, doxycycline can be discontinued
›No activity against BRBV itself
›Pure supportive care once viral etiology established
›Doxycycline does not alter BRBV course
›No FDA-approved antiviral therapy for BRBV
›Investigational agents with preclinical data only
›Evidence from animal models; no human clinical trial data
›Class IIb recommendation based on expert opinion and case basis
›Favipiravir
›Mechanism: RNA-dependent RNA polymerase inhibitor
›Prevented mortality in Ifnar1-/- mouse model
›Prophylactic or therapeutic up to 3 days post-infection in mice
›Human use: investigational; compassionate use discussion with CDC
›No established human dosing for BRBV
›Available under EUA or compassionate protocols in select scenarios
›Molnupiravir
›Mechanism: nucleoside analogue RNA mutagen
›In vitro and in vivo efficacy demonstrated in mouse models
›Therapeutic benefit when started 24 to 48 hours post-infection
›Improved thrombocytopenia and reduced liver/spleen pathology in mice
›Human use: requires compassionate use and infectious disease guidance
›FDA approval exists for COVID-19; not indicated for BRBV
›Coordinate with CDC for off-label consideration
›Ribavirin
›Mechanism: nucleoside analogue with broad antiviral activity
›Inhibited BRBV in cell culture (in vitro data only)
›No animal in vivo BRBV efficacy data published
›Human use: case-by-case basis with infectious disease and CDC input
›Hemolytic anemia side effect relevant in cytopenic patient
›Monitor CBC closely if used
›Platelet transfusion
›Threshold for prophylactic transfusion
›Platelet count < 10 x10^9/l with no active bleeding
›Platelet count < 20 x10^9/l with bleeding risk
›Threshold for therapeutic transfusion with active bleeding
›Maintain platelet > 50 x10^9/l for major bleeding
›Maintain > 100 x10^9/l for intracranial hemorrhage
›Avoid antiplatelet agents and anticoagulants in thrombocytopenia
›Aspirin, NSAIDs, and P2Y12 inhibitors withheld
›LMWH and heparin held unless life-threatening thrombosis
›Red blood cell transfusion
›Threshold: hemoglobin < 70 g/l in stable patient
›Higher threshold < 80 g/l if cardiac or respiratory compromise
›Symptom-guided transfusion in rapidly declining anemia
›DIC management
›Fresh frozen plasma for coagulopathy with active bleeding
›15 ml/kg IV
›Target INR < 1.5 for invasive procedures
›Cryoprecipitate if fibrinogen < 1.5 g/l
›1 pool (5 units) IV
›Recheck fibrinogen after transfusion
›Vasopressor support for septic shock physiology
›Norepinephrine first-line vasopressor
›Start 0.01 to 0.03 mcg/kg/minute IV infusion
›Titrate to MAP >= 65 mmHg
›Maximum dose typically 0.5 to 1.0 mcg/kg/minute before adding second agent
›Vasopressin as adjunct
›0.03 to 0.04 units/minute fixed dose
›Added when norepinephrine dose escalating
›Respiratory support escalation
›Supplemental oxygen titrated to SpO2 92 to 96%
›Nasal cannula or face mask first
›High-flow nasal cannula if escalating requirement
›Invasive mechanical ventilation for respiratory failure
›Lung-protective strategy for ARDS pattern
›Tidal volume 6 ml/kg ideal body weight
›Plateau pressure < 30 cmH2O