Leptospirosis is an illness caused by the bacteria Leptospira. You can get leptospirosis after getting water or soil contaminated by animal pee (urine) in your nose, your mouth, your eyes or a break in your skin. Leptospirosis can cause flu-like symptoms that can worsen into Weil’s syndrome, a life-threatening illness, in a small number of people.
Leptospirosis is an illness caused by an infection with the bacteria Leptospira. You can get infected with Leptospira through abrasions or cuts in your skin, or through your eyes, nose or mouth.
Leptospirosis is a zoonotic disease, which means it’s transmitted between animals and humans. You can get infected through:
You can get leptospirosis no matter where you live, but it’s most common in tropical areas and warmer climates with lots of rainfall each year. You’re at an increased risk for leptospirosis if you live in or travel to these areas, including:
Outbreaks of leptospirosis have occurred in the U.S. after flooding in Hawaii, Florida and Puerto Rico. Recreational freshwater activities, especially ones that put you in contact with contaminated water for long periods of time, put you at increased risk. This includes activities that put your head underwater or cause you to swallow water (for instance, white water rafting, swimming and boating). Your risk is even greater after heavy rainfall or flooding.
It’s estimated that more than 1 million people worldwide get leptospirosis each year. Almost 60,000 of those die from it.
Leptospirosis consists of two phases: the leptospiremic (acute) phase and the immune (delayed) phase. You may have mild symptoms or no symptoms in the leptospiremic phase. Some people develop severe symptoms in the immune phase.
During the leptospirosis phase (also called the septicemic phase) you may experience a sudden onset of flu-like symptoms. This usually starts within two to 14 days after a Leptospira infection. It lasts between three and 10 days.
In this phase, bacteria are in your bloodstream and moving to your organs. Blood tests will show signs of infection.
In the immune phase, Leptospira bacteria has moved from your blood to your organs. The bacteria is most concentrated in your kidneys, which make pee (urine). Urine tests will show signs of the bacteria and you’ll have antibodies to Leptospira in your blood.
A small number of people will get very sick with Weil’s syndrome in this phase. Weil’s syndrome causes internal bleeding, kidney damage and severe yellowing of your skin and eyes (jaundice).
Some people have flu-like symptoms of leptospirosis and some have no symptoms at all. In severe cases of leptospirosis, you have symptoms of internal bleeding and organ damage.
In acute leptospirosis, symptoms come on suddenly, including:
Severe leptospirosis (Weil’s syndrome) symptoms may start three to 10 days later, including:
The bacteria Leptospira causes leptospirosis. Bacteria get into your body through your mouth, nose or eyes or through breaks in your skin. They travel through your blood to your organs, collecting in your kidneys (the organ that “cleans” your blood).
Your kidneys get rid of unnecessary or toxic matter in your pee (urine). Bacteria from your kidneys leaves your body in your pee, which can spread leptospirosis to other people or animals.
Leptospirosis is usually spread to humans from animal pee containing the bacteria Leptospira. Almost any mammal (like rats, dogs, horses, pigs or cows) can get leptospirosis. They may have few or no symptoms of illness.
Animals with leptospirosis can contaminate water or dirt (soil), which spreads the bacteria to other animals or humans. You can get leptospirosis from:
A lot of people can get leptospirosis at once (an outbreak) after heavy rains and flooding. The floodwaters wash into rivers, lakes and canals, bringing bacteria with them.
Leptospirosis is rarely contagious from one person to another.
Your healthcare provider diagnoses leptospirosis with a physical exam, blood tests and urine tests. Your provider will ask you about your symptoms, your travel history and whether you could’ve been in contact with anything contaminated. If you’re very sick, you may have a chest X-ray or CT scan.
Your healthcare provider will treat leptospirosis with antibiotics. If you have a mild case, they may have you keep an eye on your symptoms to see if you get better without treatment.
If you have severe leptospirosis, you’ll stay in the hospital. Your provider will give you antibiotics directly through an IV (a needle connected to a tube that brings medicine to your blood). Depending on which of your organs are affected, you may need additional medications or procedures.
For mild symptoms, your healthcare provider can recommend treatments to help you feel better. Over-the-counter medications like ibuprofen (Advil®, Motrin®), naproxen (Aleve®) or acetaminophen (Tylenol®) can help aches and pains and reduce your fever.
A vaccine for leptospirosis isn’t available in the U.S. The best way to prevent leptospirosis is by not swimming or wading in water that might have animal pee in it. This includes floodwaters. Other ways you can reduce your risk include:
Most cases of leptospirosis are mild and don’t need treatment. Your healthcare provider will still keep a close eye on your symptoms.
If your symptoms worsen or you have new symptoms, don’t hesitate to contact your provider. Go to the ER if you have any symptoms of Weil’s syndrome.
Mild cases of leptospirosis last a few days to a few weeks. If you have severe leptospirosis, you can be in the hospital for about two weeks. It can take several months to fully recover from severe leptospirosis.
Leptospirosis is rarely contagious from person to person, so you can go back to work or school as soon as you feel better.
Yes, you can survive leptospirosis. Most cases of leptospirosis have no symptoms or have very mild symptoms that go away on their own.
Only about 1% of people with leptospirosis get severely ill with Weil’s syndrome. Weil’s syndrome is often deadly if not treated or if you delay treatment. But if treated promptly, it’s very likely you’ll recover.
If you’ve been diagnosed with leptospirosis, keep an eye on your symptoms. Contact your healthcare provider if any of them worsen or if you have new symptoms.
Contact your healthcare provider if you’ve been in water or soil that could’ve been contaminated with bacteria and you have any symptoms of leptospirosis.
Go to the nearest ER if you have symptoms of severe leptospirosis, including:
A note from Cleveland Clinic
Leptospirosis is an uncommon disease that usually causes mild symptoms but can cause serious illness in a small number of people. It’s important to know if your job or hobbies put you at risk, but you don’t need to hang up your kayak or work boots just yet. Knowing your risks, taking precautions and recognizing symptoms can help keep you healthy and safe wherever life takes you.
Last reviewed by a Cleveland Clinic medical professional on 08/16/2022.
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