Leptospirosis: Symptoms, Causes, and Treatment

Medically Reviewed by Poonam Sachdev on November 03, 2021
6 min read

Leptospirosis is a rare bacterial infection we get from animals. It’s spread through their urine, especially from dogs, rodents, and farm animals. They may not have any symptoms, but they can be carriers.

In most cases, leptospirosis is unpleasant but not life-threatening, like a case of the flu. It rarely lasts more than a week. But about 10% of the time, when you have a severe form of leptospirosis, you’ll get better, but then get sick again. This is called Weil’s disease, and it can cause much more serious issues, like chest pain and swollen arms and legs. It often means a trip to the hospital.

A bacteria called Leptospira interrogans causes leptospirosis. Many animals carry the organism, and it lives in their kidneys. It gets into soil and water from their urine.

If you’re around soil or water where an infected animal has peed, the germ can invade your body through breaks in your skin, like scratches, open wounds, or dry areas. It can also enter through your nose, mouth, or genitals. It’s hard to get it from another person, though it can be passed through sex or breastfeeding.

You have a higher chance of getting the disease if you spend a lot of time around animals or outdoors. You’re more likely to be exposed to it if you have one of these jobs:

  • Farmer
  • Veterinarian
  • Underground worker (you work in a sewer or a mine)
  • Slaughterhouse worker
  • Military personnel

Also, if you raft, swim, or camp near affected lakes and rivers, you could get the disease.

You'll find leptospirosis more often in warm climates. And although the bacteria lives all over the world, it’s especially common in Australia, Africa, Southeast Asia, Central and South America, and the Caribbean.

There are two phases of leptospirosis:

  • Leptospiremic phase. During this phase, you'll suddenly have symptoms that feel a lot like the flu. They'll start a couple of days to a couple of weeks after you're first exposed to the leptospira bacteria. Symptoms can last for up to 10 days.

  • Immune phase. Once you reach this phase, the leptospira bacteria is now in your organs, especially your kidneys. The bacteria will show up in urine tests, and your body will build up protection (antibodies) against the bacteria. It's possible that you could get sick during this phase with another illness called Weil's syndrome, which causes internal bleeding, kidney damage, and jaundice (yellowing of the skin and eyes).

You usually start showing signs of leptospirosis within 2 weeks, though in some cases, symptoms may not show up for a month or not at all.

When the disease does hit, it hits fast. You’ll get a fever. It may spike to 104 F. Other typical symptoms include:

Many of these symptoms are similar to symptoms of other diseases, including the flu and meningitis, so it’s important to get tested.


To check for leptospirosis, your doctor does a simple blood test and examines your blood for antibodies. These are proteins your body produces to fight the bacteria. If you've had the disease in your system before, the blood test may give a false positive (or show antibodies from the previous infection). So your doctor will likely do a second test about a week later to make sure the results are correct. You may also have a urine test to look for signs of the bacteria.

Your doctor could order a DNA test. It’s more precise, but it's more expensive and takes longer, and in many areas of the world, it’s not available yet. Doctors can also spot the bacteria if it grows in a blood, spinal fluid, or urine culture.

Severe symptoms of leptospirosis may need a chest X-ray, CT scan, or other imaging. These tests will help show damage to your organs caused by the bacteria.

Doctors can treat leptospirosis with antibiotics, including penicillin and doxycycline. Your doctor may also suggest ibuprofen for fever and muscle pain.

The disease should run its course in about a week.

But you may have to go to the hospital if your infection is more serious. Symptoms may include kidney failure, meningitis, and lung problems. You may need a shot of antibiotics, and in very serious cases, the infection could damage your organs.

You could also need treatment for other health problems. For example, the disease can spread through your body (systemic inflammatory syndrome) and cause internal bleeding and inflame your pancreas or gallbladder. You or those around you might notice changes in your speech or behavior after the spread of this infection.

It also could inflame your heart muscle (myocarditis), leading to symptoms of heart failure, including blockages and an irregular heartbeat (dysrhythmia). Your doctor will consider your other symptoms, overall health, health history, age, and other things before deciding how to treat these health problems.

Avoid unsafe water. If you’re in a developing country, don’t drink the water unless you’re sure it’s clean. But because leptospirosis can enter through other body openings, it’s also a good idea to avoid swimming, waterskiing, sailing, or fishing in freshwater areas. Saltwater is generally safe.

Keep away from infected animals, especially wild rats. Rats and other rodents are the main carriers of the bacteria. Be careful if you have to handle wild rats or come in contact with their habitats.

In the developed world, farm animals are usually vaccinated, so there’s much less risk. If an animal is ill, avoid bites and body fluids. The disease can’t be passed through the air like a cold or the flu.

Be aware of your surroundings, especially when you travel. In countries with poor sanitation, leptospirosis is more common and may be hard to avoid. So, know the symptoms and get help if you become ill.

Use disinfectant. Bleach, Lysol, acid solutions, and iodine are deadly to the bacteria. Keep them on hand to clean up.

All animals can get leptospirosis. Though it used to be rare in pets, it has shown up more often in the past few years, especially in dogs. (Leptospirosis is rare in cats.) Leptospirosis in dogs happens the same way it does in people: through contact with the urine of infected animals, which can get into water or soil and survive for weeks or months.

Your pet might not show any symptoms. Many of the symptoms of leptospirosis are very similar to those of other diseases, such as:

  • Fever
  • Belly pain, vomiting, diarrhea
  • Weakness
  • Pain 
  • Stiffness

The only way to know for sure they have it is to ask your vet to do a test. And of course, if your pet is infected, they can pass it on to you. There is a leptospirosis vaccine available for dogs. Veterinarians recommend that any dog that goes outside at all – even just to go to the bathroom – be vaccinated against leptospirosis.