2 phases of leptospirosis
Leptospiremic phase: proliferation phase where leptospires are in the blood
Immune phase: appearance of antibodies that coincides with disappearance of leptospires in the blood (but not from the organs)
Inhibitor of complement system
Binding factor H
Leptospiral virulence factor
Loa22
Most common presentation of mild leptospirosis
Asymptomatic
**Mild if stable VS and no signs of organ damage
Classic presentation of severe leptospirosis
Weil’s syndrome: triad of hemorrhage, jaundice, and AKI
Unique presentation of leptospiral nephropathy
Urinary losses of magnesium
A sequela of leptospirosis
Autoimmune-associated uveitis
Definitive diagnosis of leptospirosis
Isolation of the organism, culture with dark-field microscopy
1st week: blood, CSF, dialysate
2nd week: urine
Can confirm diagnosis of leptospirosis during the first 5 days
PCR
Diagnostic screening test: LAATS (Leptospira Antigen-Antibody Agglutination Test
Diagnostic confirmatory test: MAT (Microagglutination test) serology
*in the Philippines, single titer of 1:1600 in symptomatic patient is comfirmatory
First line treatment for mild leptospirosis
Doxycycline
Alternative: amoxicillin, azithromycin
First line treatment for moderate/severe leptospirosis
Penicillin G
Alternative: ceftriaxone, cefotaxime, IV ampicillin, IV azithromycin
Chemoprophylaxis for leptospirosis
- Pre-exposure: not recommended unless travel to endemic area –> doxycycline once weekly 1-2 days before until with exposure
* *for pregnant: none recommended - Post-exposure, low risk: single exposure, no wound –> doxycycline x 1 dose
- Post-exposure, moderate risk: single exposure, with wound, with accidental ingestion –> doxycycline x 3-5 days
- Post-exposure, high risk: continuous exposure, +/- wound, deliberate ingestion, swimming –> doxycycline once weekly until end of exposure
Duration of treatment for leptospirosis
7 days
LeptoMAT cross-reacts with what organisms
Syphilis, viral hepatitis, Lyme disease, HIV, legionella, autoimmune
Lab findings in severe leptospirosis
- WBC > 12000, platelet < 100,000
- Crea > 3, eGFR < 20, BUN > 23
- AST/ALT x4, total bilirubin > 190
- PT < 85, can be remedied with vitamin K
- pH < 7.2, HCO3 < 10, sO2 < 90, pO2 < 60, PF ratio < 250
- K > 4
- CXR finding of extensive alveolar infiltrates
- ECG finding of heart block, myocarditis, repolarization abnormality
Most common presentation of AKI
Nonoliguric with mild hypokalemia
Definition of oliguria
- UO < 0.5ml/kg/hr
- UO < 400ml/day
- No UO for 12 hrs
Management of oliguria
- Check MAP –> if < 65, give inotropes
- Check volume status –> if hypovolemic, give fast drip pnss 20ml/kg for 15 min, reassess and repeat if still hypovolemic
- If euvolemic but still oliguric –> give bolus of Furosemide 40mg or bumetamide 1mg
- If still oliguric post bolus diuretic –> double dose of diuretic every hour until reached max dose of 160mg furosemide or 4mg bumetamide
- If still oliguric post max dose diuretic –> initiate RRT
Indications for RRT in leptospirosis
Preferred hemodialysis + hemoperfusion
- Uremic encephalopathy - absolute indication
- Crea > 3
- K > 5
- pH < 7.2
- ARDS, pulmonary hemorrhage
- Fluid overload
- Oliguria despite max diuretics
Most common pulmonary complications of leptospirosis
ARDS and alveolar hemorrhage
Steroids in leptospirotic ARDS
Must give methylprednisolone 1g IV within 1st 12 hours for 3 days then oral prednisolone 1mkd x 7 days
