Leptospirosis symptoms after wading in flood water: what to watch and when to get help

Leptospirosis is an infection caused by Leptospira bacteria. Many Filipinos call it lepto, or the sickness from rat urine (ihi ng daga). The bacteria live in the kidneys of infected animals and come out in their urine.

The Philippines has cases every year, mostly in the rainy and typhoon months from June to October, when floods mix animal urine with water and mud. After Typhoon Ondoy in 2009, 15 hospitals in Metro Manila recorded more than 2,000 suspected cases and 178 deaths in about two months.

Most infected people have no symptoms or a mild, flu-like illness. Some get very sick: severe leptospirosis can damage the kidneys and lungs, and it can kill. Early care saves lives.

You can get leptospirosis when water, mud or soil that has urine from an infected animal touches:

• a cut, scratch or wound on your skin
• your eyes, nose or mouth
• skin that has been soaked in water for a long time, such as feet that stayed wet in a flood

You can also get it by swallowing flood or river water.

Rats are the most common source, but dogs, pigs, cattle and carabao can also carry the bacteria. The bacteria can live for weeks to months in wet soil and still water.

You are at higher risk if you:

• wade or swim in flood water, especially in cities with many rats, or stay in it for days
• clean up mud and garbage after a flood
• work in rice fields, sugar cane farms or with farm animals
• clear garbage, clean drains or work in sewers
• work as a rescuer or relief worker during floods

Leptospirosis very rarely spreads from person to person. You can care for a sick family member at home: treat their urine as infectious, and wash your hands with soap after touching it or anything soiled with it.

Leptospirosis symptoms usually start 5 to 14 days after contact with dirty water. They can start as early as 2 days or as late as about 30 days later. So you need to watch for symptoms for up to a month after a flood.

The most common early symptoms are:

• sudden fever and chills
• muscle pain, often worst in the calves (the back of the lower legs) and the lower back
• red eyes without pus or discharge
• headache
• nausea, vomiting, diarrhea or belly pain
• a dry cough or a rash

Severe leptospirosis, sometimes called Weil's disease, can cause:

• yellow eyes or skin (jaundice)
• peeing much less than usual, or not at all, because the kidneys are failing
• coughing up blood or trouble breathing, from bleeding in the lungs
• bleeding, a stiff neck, or confusion

Older people and people with long-term illnesses are more likely to get very sick.

Leptospirosis can look like flu or dengue, which also rises in the rainy season. You cannot tell them apart at home, so always tell the health worker that you waded in flood water.

1. Wash with soap and clean water as soon as you can, including any cuts.
2. Cover wounds with a clean, waterproof plaster.
3. See a health worker as soon as you can, within 24 to 72 hours. Go to your barangay health station, rural health unit (RHU), health center or a doctor. They will ask how long you were in the water, whether you swallowed any, and about wounds.
4. Watch for symptoms for up to 30 days, even if you took preventive medicine.

Preventive medicine (prophylaxis). The Philippine guideline uses an antibiotic, doxycycline, to lower the chance of getting sick. How long you need it depends on your risk:

• Low risk: you waded once and had no wounds.
• Moderate risk: you waded once with a wound or cut, or you swallowed flood water.
• High risk: you waded many times or for many days, you live in a flooded area, you worked as a rescuer, or you swam in flood water.

Doxycycline is a prescription medicine, taken only after a doctor has checked you and set the right amount. The Philippine guideline advises against it in pregnancy and for children younger than 8, so tell the health worker if you are pregnant or the person exposed is a young child; the doctor will choose what is safe. Also say if you are breastfeeding, take other medicines, or have liver or kidney disease.

It does not protect you completely. If you get a fever after taking it, see a doctor quickly.

Not sure about your risk? Describe what happened to our symptoms assistant, or ask a nurse.

Doctors look at your symptoms and ask about contact with flood water, mud or animals. If leptospirosis seems likely, they start treatment right away: Philippine guidelines say treatment should not wait for test results.

Tests that may be done:

• Lepto rapid tests (IgM antibody tests) can be negative in the first days of illness, so a second test may be needed.
• MAT (microscopic agglutination test) is a more exact antibody test done in fewer laboratories.
• PCR finds the bacteria themselves, mostly in the first week.
• Complete blood count (CBC), urinalysis and kidney and liver tests show how your body is coping. They may be repeated to watch the kidneys.

Because leptospirosis and dengue can look alike, your doctor may also test for dengue.

Leptospirosis is treated with antibiotics, which work best when started early. Most people recover well with prompt care.

Mild leptospirosis. If your eyes are not yellow, you pee normally, you breathe easily and you can take medicine by mouth, the doctor may treat you at home with antibiotic tablets. Finish the course, even if you feel better, and go back at once if a red flag appears.

Moderate to severe leptospirosis needs a hospital. The Philippine guideline counts yellow eyes, peeing very little, belly pain, vomiting or diarrhea, a stiff neck, trouble breathing, coughing up blood, bleeding, confusion or unstable blood pressure and pulse as reasons for hospital care. You may get:

• antibiotics through a drip (IV)
• fluids and close checks of your urine and blood pressure
• dialysis if the kidneys stop working; they often recover with treatment
• oxygen or a breathing machine if the lungs are affected

At home:

• Rest and drink enough fluids.
• For fever and pain, paracetamol taken as the label says can help. Do not take ibuprofen or other NSAID pain relievers unless a doctor says so: a fever after a flood could also be dengue, and these medicines can upset the stomach when taken with doxycycline.
• Do not buy antibiotics on your own or take a neighbor's leftover tablets. You may get the wrong medicine or amount.

Recovery can take weeks or even months. Some people stay tired, feel low, or have eye problems for a while, so go to your follow-up visits.

Under the Universal Health Care law, every Filipino citizen is automatically a PhilHealth member, and hospitals must not ask you for a printed Member Data Record.

• Check-ups and mild leptospirosis. Care without a hospital stay is covered through PhilHealth YAKAP (primary care), GAMOT (outpatient medicines) and the Outpatient Emergency Care Benefit. PhilHealth says early detection and treatment of leptospirosis are covered under YAKAP and GAMOT. See our PhilHealth YAKAP guide.
• Hospital care. Since July 15, 2026, PhilHealth pays the hospital's bill up to a package rate of ₱63,000 for moderate to severe leptospirosis. Higher package rates, from ₱170,000 up to ₱411,000, apply when you need dialysis; the highest is for dialysis together with breathing support (rates as of November 2026).
• No extra bill in a ward bed. If you are admitted to a basic or ward bed, accredited public and private hospitals must not charge you extra for the essential care covered by the package. Hospitals should not send you out to buy medicines or IV fluids.
• Private rooms. If you choose a private room, your own doctor or other upgrades, the hospital may charge you up to 20% of the package rate on top.

If you still cannot pay, ask about the Malasakit Center in government hospitals (see our Malasakit Center guide). See what PhilHealth covers, or find a hospital with our care finder.

Families hear many things about lepto. Here is what the guidelines say.

• "Only rats spread it." Rats are the main source, but dogs, pigs, cattle and carabao can also carry it.
• "No wound, no lepto." The bacteria can also enter through the eyes, nose, mouth and soaked skin.
• "I took the medicine, so I am safe." Preventive antibiotics lower the risk but do not remove it. Keep watching for fever for about a month.
• "I will wait until I feel sick." Preventive medicine is started within 24 to 72 hours after contact, and early treatment protects the kidneys and lungs.
• "It is just trangkaso." Fever, body pain and red eyes after a flood can be leptospirosis. Get checked.

The best protection is to stay out of flood water whenever you can.

If you must go into flood water or mud:

• Wear rubber boots and, if you can, gloves. Cover cuts with a waterproof plaster first.
• Do not let children swim or play in flood water.
• Keep flood water away from your eyes and mouth.
• Wash with soap and clean water as soon as you get out.

Around the house:

• Keep rats away. Cover food, use garbage bins with lids, and clear clutter where rats hide.
• Drink only safe water. Boil water from wells, rivers or springs if you are not sure it is clean.
• When cleaning after a flood, wear boots and gloves; do not touch dead animals with bare hands.
• Ask a veterinarian about the leptospirosis vaccine for your dog. There is no vaccine for people in general use.

Preventive medicine before exposure is not routine. A doctor may suggest it for adults going into flooded areas for a short time, such as soldiers or rescuers. The Philippine guideline has no preventive medicine that is safe for this in pregnancy or breastfeeding. Do not start it on your own.