Leptospirosis is an infection caused by spiral-shaped bacteria called Leptospira. These bacteria live in the kidneys of many animals and come out in their urine. People usually get sick when urine from an infected animal mixes with water or soil and then gets into the body through small cuts on the skin, the eyes, the nose, or the mouth. The illness can be mild, like a flu, or very serious, with liver, kidney, lung, or brain problems. Because it often appears after heavy rains, floods, and in warm, wet places, it is more common in tropical countries and in people who work with animals or dirty water.
Leptospirosis is an infection caused by spiral-shaped bacteria called Leptospira. People usually get it when urine from infected animals (especially rats, dogs, cattle, and pigs) gets into cuts on the skin or onto the eyes, nose, or mouth. The bacteria also survive in fresh water and wet soil, so wading, swimming, or working in contaminated floodwater can cause infection. Person-to-person spread is very rare. Early antibiotics shorten illness and can prevent severe disease, so treatment should start as soon as a clinician suspects it. World Health OrganizationCDC+1
Leptospirosis matters because it can look like many other diseases—such as dengue, malaria, typhoid, or viral hepatitis. Quick recognition and testing help doctors treat it early and prevent complications. This guide explains the condition in very simple English, step by step, so it is easy to understand.
Pathophysiology
When Leptospira bacteria enter the body, they spread through the blood to many organs. They particularly like the liver, kidneys, lungs, and the linings around the brain and eyes. The illness often has two phases:
Early (septicemic) phase: The bacteria are in the blood. Fever, headache, and muscle pain are common. Eyes can look red without pus (called conjunctival suffusion).
Immune (second) phase: The immune system reacts to the bacteria. In some people this causes inflammation of the brain coverings (aseptic meningitis), the eyes (uveitis), the kidneys (nephritis), the liver (hepatitis), or the lungs (which may bleed).
A very severe form is called Weil’s disease, which includes jaundice (yellow skin/eyes), kidney failure, bleeding, and low blood pressure.
Who gets leptospirosis
Leptospirosis can affect anyone. It is more likely in warm, rainy areas, during or after floods, and in places with poor sanitation. It is also common in certain jobs (farmers, sewage workers, veterinarians, slaughterhouse workers) and in people who swim, wade, or play in rivers, ponds, or floodwater. Rodents (especially rats), dogs, cattle, pigs, and many wild animals can carry Leptospira without looking sick.
Types of leptospirosis
Mild leptospirosis: Flu-like illness with fever, headache, muscle aches, red eyes, and fatigue. Most people recover with proper care.
Biphasic leptospirosis: Two-wave illness—first with fever and aches, then a brief improvement, then a second phase with meningitis-like symptoms or organ irritation.
Icteric leptospirosis (Weil’s disease): Severe form with jaundice, kidney failure, bleeding, low blood pressure, and risk to life. Needs urgent hospital care.
Pulmonary hemorrhagic leptospirosis: Severe lung involvement with cough, shortness of breath, and sometimes coughing blood.
Ocular leptospirosis: Eye inflammation (uveitis) days to months after the first illness; causes light sensitivity, pain, and blurry vision.
Aseptic meningitis due to leptospirosis: Headache, neck stiffness, and sensitivity to light without typical bacteria in spinal fluid.
Subclinical or asymptomatic infection: Some people get infected but have no symptoms; blood tests later can show past infection.
Causes
Here “causes” are written as real-life ways the bacteria reach people.
Contact with floodwater contaminated by animal urine, especially after heavy rains.
Swimming or wading in rivers, ponds, lakes, or canals that are contaminated.
Walking barefoot on wet soil that contains the bacteria, especially with small skin cuts.
Rodent (rat) infestation in homes, markets, farms, or food storage areas.
Handling livestock (cattle, pigs, goats, sheep) that quietly carry the bacteria.
Working in rice paddies or wet fields where animal urine washes into standing water.
Cleaning animal shelters or kennels without gloves or boots.
Sewage and drain work, including clearing blocked drains, septic tanks, or latrines.
Slaughterhouse and meat processing work with exposure to animal fluids.
Fishing or aquaculture in contaminated ponds or shallow waters.
Adventure sports like white-water rafting, canyoning, or triathlons in natural water.
Poor sanitation and overcrowded housing, especially in urban slums with rats.
Sleeping or living in rodent-infested buildings where surfaces are contaminated.
Gardening with bare hands in damp soil where pets or rodents urinate.
Caring for sick animals without protective gear (gloves, goggles).
Drinking untreated surface water from streams or wells contaminated by runoff.
Disaster cleanup after cyclones, hurricanes, or monsoon floods.
Pet dogs not vaccinated (in places where canine leptospirosis vaccines are used) and allowed to roam and contact rodents.
Recreational camping with exposure to wet ground and contaminated mud.
Accidental splashes to the eyes, nose, or mouth during farm chores or cleaning.
Symptoms
Fever and chills: Sudden high temperature with shaking chills are common early signs.
Severe headache: Often frontal or behind the eyes; can be pounding.
Muscle aches (especially calves and lower back): Calf tenderness is classic and can be strong.
Red eyes without pus (conjunctival suffusion): The white of the eyes looks red but not sticky.
Nausea and vomiting: Loss of appetite and stomach upset are frequent.
Diarrhea or abdominal pain: The belly may cramp or feel sore.
Extreme tiredness and weakness: Energy feels very low, even after rest.
Cough or shortness of breath: Lung involvement can cause breathlessness.
Jaundice (yellow skin and eyes): Signals liver involvement; urine may look dark.
Passing little urine or foamy urine: Suggests kidney stress or failure.
Neck stiffness and light sensitivity: May point to meningitis-like irritation.
Confusion or irritability: Severe cases can affect the brain.
Bleeding (nosebleeds, gum bleeding, easy bruising): Because the blood’s clotting system is disturbed.
Rash or small red spots (petechiae): Some people develop skin signs.
Low blood pressure, dizziness, or fainting: In severe disease or dehydration.
Not every person has all these symptoms. Some have only a few. Any combination with fever after water or animal exposure should raise suspicion.
Diagnostic tests
Doctors choose tests based on symptoms, exposure, and severity. Early in the illness, some tests may be negative. Combining clinical clues with the right labs gives the most accurate diagnosis.
A) Physical examination
Vital signs check (temperature, pulse, blood pressure, breathing rate): Fever suggests infection; fast heart rate and low blood pressure suggest severe disease or dehydration; fast breathing may signal lung or acid-base problems.
Eye exam for conjunctival suffusion and jaundice: Red eyes without pus and yellowing of the whites point toward leptospirosis with liver involvement.
Muscle and calf tenderness assessment: Pressing the calf muscles often causes pain in leptospirosis and helps distinguish it from other fevers.
Lung, abdomen, and hydration check: Listening for crackles in the lungs, pressing the belly for tenderness or enlarged liver, and checking skin turgor and mouth dryness help stage severity.
B) Manual bedside tests
Capillary refill time (CRT): Pressing a fingernail and seeing how fast color returns screens for circulation problems and dehydration.
Orthostatic blood pressure and pulse: Measuring when lying and then standing can reveal volume loss; dizziness with big drops suggests dehydration or shock risk.
Meningeal signs (Kernig and Brudzinski maneuvers): Gentle leg and neck movements can show irritation of the brain coverings in the immune phase.
Costovertebral angle (CVA) tenderness and peripheral edema check: Tenderness over the kidney area and ankle swelling can point to kidney inflammation or failure.
C) Laboratory and pathological tests
Complete blood count (CBC): May show low platelets, low or high white cells, and anemia; low platelets increase bleeding risk.
Kidney function tests (serum creatinine and urea/BUN, electrolytes): Detect kidney injury and imbalances such as low potassium or low sodium.
Liver tests (AST, ALT), bilirubin, and alkaline phosphatase: Mixed liver enzyme patterns with high bilirubin are common in severe disease.
Urinalysis: Protein, blood, white cells, or granular casts in urine suggest kidney involvement.
Leptospira IgM ELISA (serology): Detects early antibodies; often positive from the end of the first week; useful screening test.
Microscopic agglutination test (MAT): Reference standard serology; shows rising antibody titers in paired samples; helps confirm diagnosis.
Leptospira PCR on blood, urine, or CSF: Detects bacterial DNA; best early in the disease; very helpful when serology is not yet positive.
Cerebrospinal fluid (CSF) analysis (if meningitis suspected): Usually shows increased white cells (mostly lymphocytes), normal glucose, and mild protein rise; helps rule out other causes.
D) Electrodiagnostic and monitoring tests
12-lead electrocardiogram (ECG): Checks for arrhythmias or signs of myocarditis; important in severe cases with chest symptoms, electrolyte imbalance, or shock.
Continuous cardiac rhythm monitoring or short-term Holter (if available): Detects intermittent arrhythmias during acute illness, especially with low potassium or low blood pressure.
E) Imaging tests
Chest X-ray: Looks for pneumonia-like changes or lung bleeding (patchy opacities or diffuse alveolar infiltrates) in patients with cough or low oxygen.
Ultrasound of abdomen and kidneys: Noninvasive way to look for enlarged liver, gallbladder wall edema, or kidney changes; also helps guide fluid management.
Non-Pharmacological Treatments
These are supportive measures that sit alongside antibiotics, not instead of them.
Oral rehydration therapy (ORS) – replaces water and salts lost from fever/vomiting; helps protect kidneys.
IV crystalloids (in hospital) – restores blood pressure and urine flow in dehydrated or severe cases; protects kidneys. MDPI
Electrolyte correction – fixes low potassium, sodium, or acid–base problems that worsen weakness/arrhythmias. PMC
Bed rest & energy conservation – lowers oxygen and fluid needs while the body fights infection.
Cool sponging/temperature control – comfort and lowers metabolic stress during fevers.
Nutritional support (small, frequent meals) – maintains calories during nausea; prevents muscle breakdown.
Anti-nausea non-drug tactics – ginger tea, clear fluids, and slow sips to reduce vomiting (medicines can be added if needed).
Light-protected room/sunglasses – relieves light sensitivity and headache.
Breathing exercises & incentive spirometry – help keep lungs open and clear in bedridden patients.
Oxygen therapy (nasal cannula or mask) – treats low oxygen from lung involvement; improves organ perfusion. MDPI
Non-invasive ventilation (selected patients) – supports breathing without a tube in early respiratory failure. MDPI
Strict intake–output charting – early warning for kidney or fluid problems.
Avoid kidney-toxic exposures – no alcohol, avoid unnecessary NSAIDs/contrast dyes; protects injured kidneys. PMC
Skin and pressure-sore care – turns, cushions, and hygiene for weak patients.
Infection control – gloves/masks when handling vomit/urine; protect caregivers.
Wound protection – cover any skin breaks to prevent re-entry of bacteria.
Safe water & hygiene during recovery – boil/treat water; prevents re-exposure. Washington State Department of Health
Psychological support – anxiety and insomnia are common; reassurance improves recovery.
Early referral to higher-level care if red flags appear – delays increase risk. CDC
Rehabilitation after severe disease – gentle strengthening and breathing rehab help return to work/activities.
Drug Treatments
Start antibiotics as soon as leptospirosis is suspected—don’t wait for lab confirmation. Duration is commonly 7 days unless noted. Always adjust dosing for kidney function and pregnancy; children require weight-based dosing. CDC
Doxycycline (tetracycline class) — 100 mg by mouth twice daily for 7 days for mild disease.
Purpose/Mechanism: Stops bacterial protein synthesis (bacteriostatic). Side effects: nausea, photosensitivity; avoid in pregnancy if safer options available. CDCAmoxicillin (aminopenicillin) — 500 mg PO three times daily for 7 days (mild disease alternative).
Purpose: Cell-wall kill (bactericidal). Side effects: rash, diarrhea. Good option in pregnancy. CDCMedscapeAmpicillin (aminopenicillin) — 500 mg PO four times daily for 7 days (mild disease alternative).
Mechanism: Cell-wall inhibition. Side effects: GI upset, rash. MedscapeAzithromycin (macrolide) — 500 mg PO once daily for 3 days (mild disease alternative, especially in pregnancy).
Mechanism: Blocks bacterial protein synthesis. Side effects: GI upset, rare QT prolongation. CDCMedscapePenicillin G (natural penicillin) — 1.5 million units IV every 6 hours for severe disease (Weil’s disease), usually 7 days.
Purpose: First-line for severe disease; bactericidal. Side effects: allergy, electrolyte load. CDCCeftriaxone (3rd-gen cephalosporin) — 1 g IV once daily for severe disease; as effective as penicillin G in trials.
Mechanism: Cell-wall kill. Side effects: diarrhea, rare biliary sludging. CDCOxford AcademicCefotaxime (3rd-gen cephalosporin) — 1 g IV every 6–8 hours in severe disease when ceftriaxone unavailable.
Side effects: diarrhea, rash. MedscapeErythromycin (macrolide) — 500 mg PO four times daily if other options unsuitable.
Notes: Less used today; check interactions. MedscapeAcetaminophen/Paracetamol (antipyretic—adjunct) — 500–650 mg PO every 6–8 hours as needed (max 3,000 mg/day without clinician oversight).
Purpose: Fever and pain relief; gentler on kidneys than NSAIDs. Side effects: liver risk at high doses. (Adjunct; not an antibiotic.)Ondansetron (antiemetic—adjunct) — 4–8 mg PO/IV every 8–12 hours as needed.
Purpose: Controls vomiting so fluids and antibiotics stay down. Side effects: constipation, rare QT issues.
For severe kidney or lung complications, patients may also need vasopressors, dialysis, or mechanical ventilation—these are supportive measures, not disease-specific drugs. MDPI
Dietary Molecular Supplements
No supplement treats leptospirosis. These options may support recovery (immunity, gut, antioxidant defenses) after antibiotics are started. Discuss with your clinician, especially if pregnant or on other medicines.
Oral Rehydration Salts (ORS) — per packet as directed; replaces sodium/potassium/glucose to pull water into the body; protects kidneys.
Probiotics (e.g., Lactobacillus rhamnosus GG 10¹⁰ CFU/day) — helps gut balance during/after antibiotics; may reduce antibiotic-associated diarrhea. PMC
Zinc (10–20 mg elemental/day) — supports mucosal immunity and gut barrier.
Vitamin D₃ (1,000–2,000 IU/day) — supports innate and adaptive immunity.
Vitamin C (500–1,000 mg/day) — antioxidant; supports white cells.
Selenium (100–200 mcg/day) — antioxidant enzyme cofactor.
N-Acetylcysteine (600 mg 1–2×/day) — replenishes glutathione; hepatic antioxidant support.
Omega-3 (EPA+DHA 1–2 g/day) — anti-inflammatory; may help recovery after severe illness.
Thiamine (Vitamin B1 50–100 mg/day) — supports energy metabolism, especially if low intake.
L-Glutamine (5–10 g/day) — fuel for gut cells; may aid recovery from catabolic illness.
(Evidence for these in leptospirosis specifically is limited; use as supportive nutrition only.) PMC
Regenerative / stem-cell drugs” — Important Safety Note
There are no approved immunity-booster, regenerative, or stem-cell drugs for leptospirosis. Using such products outside a clinical trial is not recommended and may be harmful. In very severe, hospital-managed cases (especially with lung hemorrhage or multiorgan failure), clinicians sometimes consider immunomodulatory adjuncts on a case-by-case basis:
High-dose corticosteroids (e.g., methylprednisolone pulses) — studied with mixed and limited evidence; not routine care. Potential benefit in severe pulmonary hemorrhage has been reported in small studies/case series, but systematic reviews say evidence is insufficient for routine use. Risks include infection and high blood sugar. PMCBioMed Central
Intravenous immunoglobulin (IVIG) — occasionally tried as rescue therapy in severe cases, often together with plasma exchange; evidence is limited to case reports/series. PMCBioMed Central
These decisions belong in the ICU with infectious-disease specialists and informed consent. The backbone of care remains early antibiotics plus organ support (fluids, ventilation, dialysis as needed). CDC+1
Procedures / “Surgeries” and why they’re done
Hemodialysis (renal replacement therapy) — used when severe kidney failure causes dangerous fluid, toxin, or acid build-up. Can be intermittent or continuous (CRRT) in ICU. Early use can be life-saving in Weil’s disease. PMC+1
Endotracheal intubation with mechanical ventilation — supports breathing during lung hemorrhage or ARDS; buys time while antibiotics work. MDPI
Extracorporeal membrane oxygenation (ECMO) — rare, last-resort oxygenation for uncontrollable respiratory failure; not routine and evidence is limited. Wiley Online Library
Therapeutic plasma exchange (plasmapheresis) — in selected, critically ill patients (e.g., extreme jaundice with kidney failure or severe pulmonary hemorrhage), some centers report benefit; evidence is evolving and not definitive. PMC+1
Central venous catheter placement — allows dialysis, vasopressor drugs, and plasma exchange in ICU care.
Practical Ways to Prevent Leptospirosis
Avoid wading/swimming in floodwater or muddy fresh water in endemic areas. CDC
Protect cuts with waterproof dressings; wash skin after freshwater exposure. World Health Organization
Wear boots and gloves for farm, sewer, or cleanup work. Washington State Department of Health
Control rodents at home/work (seal entry points, remove food/water, traps). CDC
Secure food and water from rodent contamination; store in sealed containers. CDC
Treat drinking water (boil/chemically disinfect) if sources might be contaminated. Washington State Department of Health
Vaccinate dogs/livestock where available to reduce animal shedding (animal vaccines exist; no widely used human vaccine). Wikipedia
Good sanitation & waste management in communities reduces risk after heavy rain. SpringerLink
Prompt wound care after outdoor/flood exposure (wash with soap and clean water). World Health Organization
Antibiotic prophylaxis for very high-risk short-term exposure (e.g., certain deployments/adventure events): some authorities suggest doxycycline 200 mg once weekly, but recent reviews show limited effectiveness and more nausea, so discuss risks/benefits with a clinician. Philippines HealthPMC+1
When to see a doctor urgently
High fever with severe calf/back pain.
Yellow eyes/skin, very dark or reduced urine.
Shortness of breath, coughing blood, severe headache, confusion, or stiff neck.
Any symptoms after floodwater or fresh-water exposure or after rodent contact. Do not wait for tests—early antibiotics save lives. CDC
What to eat ( do’s & don’ts during recovery)
Eat/Drink:
Plenty of clean water/ORS; 2) Warm broths and soups; 3) Soft carbs (rice, porridge, toast); 4) Lean proteins (egg, fish, chicken, dal); 5) Fruits rich in vitamin C (guava, orange); 6) Yogurt or probiotic drinks if tolerated; 7) Potassium-rich foods (banana, coconut water if potassium is low and doctor agrees); 8) Small, frequent meals to fight nausea; 9) Healthy fats (a little olive oil, nuts if no nausea); 10) Iron-rich foods later if anemic and your doctor agrees.
Avoid/Limit:
Alcohol (stresses liver); 2) Raw/undercooked foods from uncertain sources; 3) Street juices/ice of unknown hygiene; 4) Very salty/processed foods if swollen or hypertensive; 5) Large, greasy meals (worsen nausea); 6) Herbal mixtures of unknown safety; 7) Unboiled surface water; 8) Extra protein supplements without clinician advice in kidney injury; 9) Unnecessary NSAIDs for pain (kidney risk)—prefer paracetamol; 10) Energy drinks/caffeine excess (dehydrating). PMC
Frequently Asked Questions
Is leptospirosis curable?
Yes. Most people recover fully with early antibiotics and supportive care. Severe cases need hospital treatment. CDCHow soon should antibiotics start?
Immediately when suspected—do not wait for test results. Early treatment reduces complications. CDCWhich antibiotic is best?
For mild disease, doxycycline is commonly used. For severe disease, IV penicillin G or ceftriaxone are standard; cefotaxime is another option. Doctors choose based on the patient and local practice. CDC+1How long do I take antibiotics?
Often 7 days, adjusted by your clinician based on response and severity. MedscapeCan children or pregnant people take doxycycline?
Alternatives (e.g., penicillins, azithromycin) are often preferred; your clinician will choose the safest option. CDCWhat tests confirm it?
Early PCR can detect the bacteria. Later, IgM ELISA and MAT show antibodies (often need a repeat sample). CDCWhy do some people get jaundice and kidney failure?
In a minority, the infection triggers strong inflammation damaging the liver, kidneys, and sometimes lungs (Weil’s disease). PMCCan it affect the lungs?
Yes—some develop pulmonary hemorrhage, a severe complication requiring ICU and sometimes ventilation. PMCIs there a vaccine for humans?
Not widely. Some countries have limited human vaccines; animal vaccines (dogs/livestock) are more common and help reduce spread. WikipediaIs weekly doxycycline good for prevention?
It’s been used, but recent reviews show limited benefit and more nausea. It may be considered only in very high-risk short-term situations after discussing risks with a clinician. PMC+1How is kidney failure treated?
Fluids, careful monitoring, and dialysis when needed; kidneys often recover with timely care. PMCDo steroids help?
Evidence is inconclusive; not routine. Some ICUs try them in life-threatening lung bleeding, but this is specialist territory. BioMed CentralCan I catch it from another person?
Person-to-person spread is very rare. The main risk is animal urine and contaminated water/soil. World Health OrganizationHow long until I feel better?
Many improve within a week of treatment; severe cases may take weeks with rehab.What about long-term problems?
Most people recover fully. A few may have fatigue or kidney/liver issues for a while and need follow-up.
Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.
The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members
Last Updated: August 17, 2025.
