Leptospirosis

Question 1

2 phases of leptospirosis

Answer 1

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)

Question 2

Inhibitor of complement system

Answer 2

Binding factor H

Question 3

Leptospiral virulence factor

Answer 3

Loa22

Question 4

Most common presentation of mild leptospirosis

Answer 4

Asymptomatic

**Mild if stable VS and no signs of organ damage

Question 5

Classic presentation of severe leptospirosis

Answer 5

Weil’s syndrome: triad of hemorrhage, jaundice, and AKI

Question 6

Unique presentation of leptospiral nephropathy

Answer 6

Urinary losses of magnesium

Question 7

A sequela of leptospirosis

Answer 7

Autoimmune-associated uveitis

Question 8

Definitive diagnosis of leptospirosis

Answer 8

Isolation of the organism, culture with dark-field microscopy
1st week: blood, CSF, dialysate
2nd week: urine

Question 9

Can confirm diagnosis of leptospirosis during the first 5 days

Answer 9

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

Question 10

First line treatment for mild leptospirosis

Answer 10

Doxycycline

Alternative: amoxicillin, azithromycin

Question 11

First line treatment for moderate/severe leptospirosis

Answer 11

Penicillin G

Alternative: ceftriaxone, cefotaxime, IV ampicillin, IV azithromycin

Question 12

Chemoprophylaxis for leptospirosis

Answer 12

1. Pre-exposure: not recommended unless travel to endemic area –> doxycycline once weekly 1-2 days before until with exposure
   * *for pregnant: none recommended
2. Post-exposure, low risk: single exposure, no wound –> doxycycline x 1 dose
3. Post-exposure, moderate risk: single exposure, with wound, with accidental ingestion –> doxycycline x 3-5 days
4. Post-exposure, high risk: continuous exposure, +/- wound, deliberate ingestion, swimming –> doxycycline once weekly until end of exposure

Question 13

Duration of treatment for leptospirosis

Answer 13

7 days

Question 14

LeptoMAT cross-reacts with what organisms

Answer 14

Syphilis, viral hepatitis, Lyme disease, HIV, legionella, autoimmune

Question 15

Lab findings in severe leptospirosis

Answer 15

1. WBC > 12000, platelet < 100,000
2. Crea > 3, eGFR < 20, BUN > 23
3. AST/ALT x4, total bilirubin > 190
4. PT < 85, can be remedied with vitamin K
5. pH < 7.2, HCO3 < 10, sO2 < 90, pO2 < 60, PF ratio < 250
6. K > 4
7. CXR finding of extensive alveolar infiltrates
8. ECG finding of heart block, myocarditis, repolarization abnormality

Question 16

Most common presentation of AKI

Answer 16

Nonoliguric with mild hypokalemia

Question 17

Definition of oliguria

Answer 17

1. UO < 0.5ml/kg/hr
2. UO < 400ml/day
3. No UO for 12 hrs

Question 18

Management of oliguria

Answer 18

1. Check MAP –> if < 65, give inotropes
2. Check volume status –> if hypovolemic, give fast drip pnss 20ml/kg for 15 min, reassess and repeat if still hypovolemic
3. If euvolemic but still oliguric –> give bolus of Furosemide 40mg or bumetamide 1mg
4. If still oliguric post bolus diuretic –> double dose of diuretic every hour until reached max dose of 160mg furosemide or 4mg bumetamide
5. If still oliguric post max dose diuretic –> initiate RRT

Question 19

Indications for RRT in leptospirosis

Answer 19

Preferred hemodialysis + hemoperfusion

1. Uremic encephalopathy - absolute indication
2. Crea > 3
3. K > 5
4. pH < 7.2
5. ARDS, pulmonary hemorrhage
6. Fluid overload
7. Oliguria despite max diuretics

Question 20

Most common pulmonary complications of leptospirosis

Answer 20

ARDS and alveolar hemorrhage

Question 21

Steroids in leptospirotic ARDS

Answer 21

Must give methylprednisolone 1g IV within 1st 12 hours for 3 days then oral prednisolone 1mkd x 7 days