🐀 Leptospirosis is transmitted via the urine of infected animals (especially rats, mice, cows, pigs, and dogs). 💡 Start antibiotics based on clinical suspicion - do not wait for cultures.

🔎 About

Zoonotic infection caused by Leptospira interrogans.
Incubation period: typically 1–2 weeks.
Globally widespread; more common in tropical and subtropical regions.

🧫 Pathology

Leptospires live in the renal tubules of asymptomatic carriers.
Excreted in urine → survive for weeks in shaded, warm, humid environments.
Entry via mucous membranes or broken skin.

⚠️ Risk Factors

Occupational: abattoir, farm, and sewage workers.
Recreational: swimming, kayaking, water sports in contaminated rivers/lakes.
Pets and bites = rare sources.
Human-to-human transmission = extremely rare.

🧬 Aetiology

Leptospira = Gram-negative, coiled, motile bacteria with hooked ends.
Major reservoir host: rat (Rattus norvegicus).

🩺 Clinical Presentation

Fever, headache, myalgia (especially calf tenderness).
Conjunctival suffusion = classical sign.
Renal: oliguria, proteinuria, haematuria.
Hepatic: jaundice + hepatosplenomegaly (without frank liver failure).
Pulmonary: ARDS, pulmonary haemorrhage (severe cases, esp. Asia).
Bleeding: bruising, epistaxis, GI bleeding, effusions.
Neurological: aseptic meningitis, encephalitis.
Cardiac: myocarditis, arrhythmias.

📌 Classical Presentations

Mild flu-like illness.
Weil’s Syndrome: Jaundice + renal failure + haemorrhage + myocarditis.
Meningoencephalitis.
Pulmonary haemorrhage with respiratory failure.

🔍 Differentials

Dengue, Typhoid fever, Malaria, Scrub typhus, Hantavirus.

🧪 Investigations

FBC: Thrombocytopenia, neutrophilia.
U&E: AKI with raised creatinine, proteinuria, haematuria.
LFTs: ↑ AST/ALT, ↑ bilirubin, prolonged PT.
CSF: Aseptic (↑ protein, normal glucose).
Culture: Blood positive early (≤10 days); urine positive after day 7.
Serology: IgM detectable after 1 week.
PCR: Detects leptospiral DNA in blood/urine (most useful day 8+).

🛡️ Prevention

Good hygiene: wash hands after animal contact, cover wounds.
Protective clothing for at-risk occupations.
Avoid contaminated water; shower after exposure.
Vaccinate dogs 🐶 (no human vaccine available).
Boil untreated water before use.

⚠️ Complications

Oliguric AKI → dialysis may be required.
Severe pulmonary haemorrhage → high mortality, often ICU care.
Aseptic meningitis, ARDS, Guillain-Barré syndrome, DIC, shock.

💊 Management

Supportive care = cornerstone (hydration, renal replacement, transfusions if needed).
Severe disease:
- IV Benzylpenicillin 1.5 MU q6h × 7 days OR Ceftriaxone 1 g daily × 7 days.
Mild disease: Doxycycline 100 mg PO BD × 7 days.
Jarisch–Herxheimer reaction may occur with penicillin therapy.
Mortality >10% in severe forms.

🛡️ Prophylaxis (High-Risk Exposure)

Doxycycline 200 mg weekly can reduce risk in high-risk groups.

💡 Key Exam Pearl: Weil’s disease = jaundice + renal failure + haemorrhage. Always ask about occupational/recreational water exposure in febrile patients with jaundice + AKI.

The content on this website is provided for educational and informational purposes only to support exam preparation (e.g., MLA, MRCP, USMLE) and learning. This is NOT medical advice, diagnosis, treatment, or professional guidance. It does not replace consultation with a qualified healthcare professional, official guidelines (e.g., NICE, GMC, BNF), or supervised clinical practice. Always verify information with current, authoritative sources. Makindo and its contributors accept no liability for any reliance on this content, including errors, omissions, or any resulting harm, loss, or consequences. By using this site, you agree to these terms.

Leptospirosis (Weil's Disease) (Notifiable)