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Leptospirosis in Puerto Rico after floods, rivers and streams
Leptospirosis in Puerto Rico is a bacterial infection you can catch from water, mud or soil contaminated with animal urine, especially after floods and hurricanes and in rivers and streams. It is endemic on the island. If you get a fever 2 to 30 days after wading or swimming in floodwater or a river, get seen in person that same day: early treatment matters.
Is it an emergency? Call 911.
Is this an emergency?
This is not an emergency service. Call 911 or go to the nearest emergency room if you have:
- Fever after contact with floodwater, a river or a stream: in-person evaluation the same day
- Yellow skin or eyes
- Peeing very little or not at all
- Shortness of breath, coughing up blood, or any bleeding
- Confusion, unusual drowsiness, or a bad headache with a stiff neck
- You felt better for a few days and the fever came back worse
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What is leptospirosis?
Leptospirosis is a disease caused by bacteria that pass from animals to people. According to the CDC, it spreads through the urine of infected animals, which can contaminate water or soil for weeks to months. Puerto Rico’s Department of Health explains that on the island it is carried mainly by rodents, dogs and pigs, and that you catch it through direct contact with their urine or with contaminated water, soil or food.
According to the CDC, the risk rises with contact with water or soil that contains animal urine, with drinking water or eating food contaminated by it, and with water recreation such as swimming or kayaking in rivers and creeks. The risk is highest after hurricanes and floods, and when you bathe in rivers, streams and swimming holes after heavy rain.
Leptospirosis in Puerto Rico
Leptospirosis is endemic in Puerto Rico, meaning cases are reported every year. According to a CDC report, about 10% to 15% of people who get sick develop severe, potentially fatal illness.
After Hurricane Fiona (September 2022) flooded much of the island, 156 cases were reported in 15 weeks: 3.6 times as many cases per week as before the storm. The share of patients who had contact with possibly contaminated water rose from 11% to 35%. That year the Department of Health required doctors to report each case within 24 hours. See also health after a hurricane.
Leptospirosis symptoms
According to the Department of Health, symptoms appear 2 to 30 days after exposure, most often between 5 and 14 days. Many can be mistaken for other illnesses, such as dengue or flu:
- Fever and chills
- Headache
- Muscle aches
- Red eyes
- Nausea, vomiting, diarrhea or belly pain
- Rash or cough
- Yellow skin or eyes (jaundice)
Why a fever after a flood needs an in-person visit
The CDC describes two possible phases: first fever and aches, then a short improvement, and in some people a severe second phase with kidney or liver failure or meningitis (inflammation of the membranes around the brain). Without treatment it can cause kidney damage, breathing problems and death.
Leptospirosis is treated with antibiotics, and the CDC says to give them as early as possible. Deciding that takes an exam and often same-day blood and urine tests. So if you have a fever after being in floodwater, a river or a stream, don’t wait for an appointment: go today to an urgent care center (CDT) or an emergency room and tell them where you were. Not sure where to go? Read ER vs urgent care in San Juan.
How we help by video
A video visit helps before symptoms appear, or after you have been treated in person. For example: you waded through floodwater and want to know what to watch for, a cut got wet and you want it checked, or you have been discharged and have questions about your recovery. We do not promise a “just in case” antibiotic: the doctor decides based on your situation.
You see Dr. Diana Nieves Castro, a Puerto Rico–licensed general practice physician with several years of emergency-department experience, in English or Spanish. We evaluate, diagnose and treat; if needed, we give you a lab order for a lab near you. If appropriate, the doctor prescribes and we send your prescription to your pharmacy. We do not prescribe controlled substances.
A doctor visit costs US$79, the same price for every age, with no membership; your card is charged when you request it, with a full refund if the visit can’t take place. Request a visit online 24/7 — we confirm your time by email or text. We send you a secure video link that works on your phone, tablet or computer. For patients under 21, a parent or legal guardian stays on camera with photo ID. You need to be physically in Puerto Rico. Book your visit.
How to prevent leptospirosis
According to the CDC and the Department of Health:
- Don’t wade in, bathe in or swallow floodwater, or river or stream water that may contain animal urine, especially after heavy rain.
- Cover cuts and scratches with waterproof bandages.
- Wear waterproof clothing and boots when you clean up debris, mud or standing water.
- Drink bottled, boiled or chemically treated water when tap water isn’t safe.
- Keep food, water and trash in closed containers and bins, and control rats.
When to go to the ER
With any of these signs, go to an emergency room or call 911. Don’t book a video visit. See when to go to the ER.
- Fever after contact with floodwater, a river or a stream: in-person evaluation the same day
- Yellow skin or eyes
- Peeing very little or not at all
- Shortness of breath, coughing up blood, or any bleeding
- Confusion, unusual drowsiness, or a bad headache with a stiff neck
- You felt better for a few days and the fever came back worse
How we care for you
We evaluate, diagnose and treat; if needed, we give you a lab order for a lab near you.
We see adults and children of all ages. Patients under 21: a parent with patria potestad (parental authority) or a legal guardian is on camera for the whole visit and shows photo ID.
Real-time video visit. We send you a secure video link. It works on your phone, tablet or computer.
If appropriate, the doctor prescribes and we send your prescription to your pharmacy. We do not prescribe controlled substances.
You must be physically in Puerto Rico during the visit (visitors, tourists and cruise passengers are welcome).
In an emergency, call 911.
Frequently asked questions
How long after exposure does leptospirosis start?
Can I get an antibiotic to prevent leptospirosis?
Is it safe to swim in a river in Puerto Rico after rain?
Can leptospirosis be mistaken for dengue?
About this page
Author: The Health Initiative
Medical care provided by Dr. Diana Nieves Castro, MD (PR license 24027)
Disclosure: Founding Executive Director of The Health Initiative
Published: 2026-10-02 · Updated: 2026-10-02
Sources (5)
- About leptospirosis (CDC) (opens in a new tab) (accessed 2026-10-02)
- Preventing leptospirosis (CDC) (opens in a new tab) (accessed 2026-10-02)
- Leptospirosis outbreak in aftermath of Hurricane Fiona — Puerto Rico, 2022 (CDC MMWR 73(35)) (opens in a new tab) (accessed 2026-10-02)
- Información sobre la leptospirosis (Puerto Rico Department of Health, in Spanish) (opens in a new tab) (accessed 2026-10-02)
- Puerto Rico: traveler information (CDC) (opens in a new tab) (accessed 2026-10-02)
