Leptospirosis after a flood
If you waded through floodwater, go to the nearest health centre or rural health unit within 24 to 48 hours, even if you feel fine and even if you had no wound. That is the DOH's advice. A doctor decides whether you need medicine to prevent it.
Written for the Philippines. Lumusong sa baha? Magpakonsulta sa health center sa loob ng 24 hanggang 48 oras, may sugat man o wala.
This page belongs with the flood guide: what to do before, during and after, because the risk starts the moment you step into the water. This is general information from the Department of Health and PhilHealth. It is not a diagnosis.
What leptospirosis is, and how you get it
Leptospirosis is a bacterial infection that can kill. You get it from floodwater or soil contaminated with the urine of infected animals, rats most of all, though DOH Cordillera points out that other infected four-legged animals spread it too.
The bacteria get in through cuts and wounds, but you do not need a wound. A DOH hospital in Bataan spells it out: they can enter through the eyes, the nose, the mouth or tiny breaks in the skin. Swallowing contaminated water or food is another way in.
Source: DOH Ilocos Center for Health Development, Press Release No. 067, DOH Ilocos warns residents anew against leptospirosis, 27 August 2026. Read 5 October 2026.
Source: Bataan General Hospital and Medical Center (DOH), Walang sugat pero lumusong sa baha?, 1 September 2026. Read 5 October 2026.
Leptospirosis symptoms
The early signs look like flu, which is why people wait. After floodwater, any of them is a reason to be seen.
Early symptoms
- Fever
- Headache
- Muscle pain, often in the calves
- Chills
- Red eyes
- Vomiting or nausea
- Abdominal pain
Severe symptoms: go to a hospital
- Yellowing of the skin or the eyes
- Dark urine
- Pale stools
- Passing very little urine
- A severe headache
The DOH says these come from the liver, kidneys and brain being involved. Left untreated, leptospirosis can cause kidney failure, brain damage, heavy internal bleeding and death.
Written for the Philippines. Sintomas: lagnat, pananakit ng ulo at katawan, pamumula o paninilaw ng mata, paninilaw ng balat.
Source: DOH Ilocos Center for Health Development, Press Release No. 067, DOH Ilocos warns residents anew against leptospirosis, 27 August 2026. Read 5 October 2026.
Source: DOH Cordillera, Intensified measures vs. leptospirosis lessened deaths amid rise in cases (2024). Read 5 October 2026.
Source: DOH, via ReliefWeb, The series of downpours may bring leptospirosis, 28 June 2018. Read 5 October 2026.
How long before symptoms show
DOH Cordillera puts it at about two weeks on average, and up to 30 days after the floodwater. So feeling well a few days later does not mean you are in the clear. Keep watching for fever for a month, and tell the doctor you were in floodwater, with the date.
An older DOH release gave seven to ten days, and its rule of thumb still holds: if you have had a fever for two days after a flood, go to the health centre.
Source: DOH Cordillera, Recent upward trend in W.I.L.D cases, 14 February 2025. Read 5 October 2026.
Source: DOH, via ReliefWeb, The series of downpours may bring leptospirosis, 28 June 2018. Read 5 October 2026.
Doxycycline: see a doctor first
There is medicine to lower the chance of infection after exposure, called prophylaxis, usually doxycycline. The DOH asks people not to take it on their own. It is a prescription medicine, and whether you need it depends on how and how long you were exposed, which is what the health centre assesses.
DOH Ilocos tells people to wash with soap and water and visit the rural health unit within 24 to 48 hours for it. Bataan's DOH hospital says it may be recommended for anyone who waded, with or without a wound, and that it is not recommended for pregnant women, breastfeeding mothers or children aged 8 and under. Take only the dose and schedule the doctor gives you.
PhilHealth adds that the medicine is not 100% effective, so you still watch for fever and flu-like symptoms afterwards.
Source: DOH Ilocos Center for Health Development, Press Release #61, health response amid severe monsoon flooding, 10 August 2026. Read 5 October 2026.
Source: Bataan General Hospital and Medical Center (DOH), 'Wag basta-bastang uminom ng doxycycline kontra leptospirosis, 1 September 2026. Read 5 October 2026.
How a doctor judges the exposure
PhilHealth's guidance for doctors, based on the 2010 leptospirosis clinical practice guidelines, sorts exposure into three levels. Knowing which one you are in helps you answer the doctor's questions. The decision on treatment stays with them.
- Low risk
- Waded once in floodwater or contaminated water, with no wound, cut or open sore on the skin.
- Moderate risk
- Waded once and had a wound, cut or open sore, or swallowed contaminated water by accident.
- High risk
- Exposed again and again, or for several days: people living in flooded areas, rescuers and relief workers. Swimming in floodwater, especially in cities with rats, and swallowing contaminated water also count as high risk.
Source: PhilHealth, Policy Recommendations on Diagnosis, Management and Prevention of Leptospirosis (based on the 2010 Leptospirosis CPG). Read 5 October 2026.
How to prevent leptospirosis
- Do not wade, swim or walk through floodwater unless you have to.
- If you have to, wear waterproof boots, and gloves if your hands go in the water.
- Keep cuts and wounds covered, and keep them out of the water.
- Afterwards, wash the parts of your body that were in the water with soap and clean water, straight away.
- Drink only clean water.
- Clean the house and the area around it once the water is gone, and get rid of rubbish properly so rats are not drawn in.
Floodwater also hides live wiring. Before you go back in, read what Meralco says about power and a flooded house.
Source: DOH Bicol Center for Health Development, Advisory: Leptospirosis. Read 5 October 2026.
Source: DOH Ilocos Center for Health Development, Press Release No. 067, DOH Ilocos warns residents anew against leptospirosis, 27 August 2026. Read 5 October 2026.
What PhilHealth covers
PhilHealth's 2026 circular sets a benefit package for moderate to severe leptospirosis that needs a hospital stay, open to all Filipinos, with no copayment in basic or ward accommodation. Mild cases that do not need admission, and the early detection and prevention services, fall under PhilHealth YAKAP and GAMOT.
Source: PhilHealth, Circular PC2026-0008, Benefits Package for Moderate to Severe Leptospirosis. Read 5 October 2026.
The rest of the flood guidance
The best protection is not being in the water. The flood guide covers leaving early, the warnings to watch, and what to do once the water drops.