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Leptospirosis

Also known as: leptospirosis · Weil's disease · rat fever

A zoonotic spirochaetal infection (Leptospira) from water/soil contaminated with animal (rodent) urine — common after monsoon/flood exposure. It ranges from a mild fever to severe Weil's disease.

Source · Reviewed 2026-08-15 · v1.0— AI-assisted draft — verify against the cited guideline before clinical use.

⚕️ Education only — not medical advice. Verify against the latest official guideline and your local protocol; confirm every drug dose against the cited source before clinical use.

Who gets it

People exposed to contaminated water/mud — farmers, paddy-field and sewer workers, and flood-affected or recreational-water-exposed communities.

Red flags — escalate / refer

Weil's disease — jaundice with acute kidney injury and bleeding; pulmonary haemorrhage; shock; meningitis → severe leptospirosis: emergency/ICU.

Work-up / diagnosis

1Suspect clinically with fever, severe calf myalgia, conjunctival suffusion and an exposure history.
2Confirm serologically (MAT/IgM) or by PCR.
3Check renal and liver function, platelets, and a chest X-ray if there are respiratory symptoms.

Management — overview

Start antibiotics early on clinical suspicion — do not wait for confirmation.
Mild disease: oral doxycycline (or azithromycin/amoxicillin).
Severe disease: IV penicillin or ceftriaxone, with organ support (dialysis for AKI, ventilation for pulmonary haemorrhage).
Careful fluid and electrolyte management; monitor for deterioration.

In-depthFull dosing & advanced protocol

Drug dosing

Doxycycline

Mild leptospirosis

Adult dose: Oral course per guidance
Route: Oral

ICMRICMR Treatment Guidelines for Antimicrobial Use in Common Syndromes (2019) ↗

IV ceftriaxone or penicillin

Severe disease

Adult dose: IV, per guidance
Route: Intravenous

Caution: Begin empirically on suspicion; provide organ support for Weil's disease.

ICMRICMR Treatment Guidelines for Antimicrobial Use in Common Syndromes (2019) ↗

Severe disease & the monsoon-fever differential

Severe leptospirosis needs organ support (renal replacement, ventilation for pulmonary haemorrhage).
Doxycycline chemoprophylaxis may be used for high-risk exposure per public-health guidance.
Consider the monsoon acute-febrile differential together: dengue, malaria, typhoid and scrub typhus.

ICMRICMR Treatment Guidelines for Antimicrobial Use in Common Syndromes (2019) ↗

References

Guidelines change. If something here is out of date, tell us — we keep these current.

🚩 Report outdated / suggest update

More protocols

HypertensionPersistently raised arterial pressure (≥140/90 mmHg) — a leading, modifiable cause of stroke, heart attack, heart failure and kidney disease.DengueAn Aedes-borne viral febrile illness. Most cases self-limit, but plasma leakage can cause severe dengue — early recognition of warning signs and careful fluid therapy save lives.MalariaA mosquito-borne protozoal (Plasmodium) febrile illness. In India P. vivax and P. falciparum predominate; prompt diagnosis and species-specific treatment prevent severe disease.

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👤 Who gets it

🚩 Red flags — escalate / refer

🔎 Work-up / diagnosis

🧭 Management — overview

💊 Drug dosing

Doxycycline

IV ceftriaxone or penicillin

📈 Severe disease & the monsoon-fever differential

📚 References

More protocols

👤 Who gets it

🚩 Red flags — escalate / refer

🔎 Work-up / diagnosis

🧭 Management — overview

💊 Drug dosing

Doxycycline

IV ceftriaxone or penicillin

📈 Severe disease & the monsoon-fever differential

📚 References

More protocols

Who gets it

Red flags — escalate / refer

Work-up / diagnosis

Management — overview

Drug dosing

Severe disease & the monsoon-fever differential

References

Who gets it

Red flags — escalate / refer

Work-up / diagnosis

Management — overview

Drug dosing

Severe disease & the monsoon-fever differential

References