People can get leptospirosis when they have contact with soil or water containing urine from infected animals, or direct contact with urine from infected animals.

Leptospirosis is a bacterial disease spread by urine from infected animals, which can include many different types of animals such as rodents, dogs, livestock and wildlife. People can get leptospirosis when they have contact with soil or water containing urine from infected animals, or direct contact with urine from infected animals. Some activities that increase a person’s risk of getting sick include:

• Drinking from untreated water sources that are contaminated (including floodwater, streams, rivers, contaminated tap water)
• Bathing, wading, or swimming in contaminated water, especially when putting their head under water or when a person has an open wound or scratch.
• Eating food that’s been exposed to contaminated water or has been eaten or potentially urinated on by rodents.

Symptoms can develop between 2 and 30 days but usually between 5 and 14 days after someone is exposed to the bacteria. In most cases, the illness involves flu-like symptoms (fever, chills, muscle aches, and headaches). Other symptoms may include: conjunctivitis (red eyes), vomiting, diarrhea, stomach pain, jaundice (yellowing of the skin and eyes), and skin rash. Anyone with symptoms of leptospirosis should see a doctor as soon as possible. Early treatment with antibiotics may help prevent more severe illness and decrease the length of the illness

Infection

The bacteria that cause leptospirosis are spread through the urine of infected animals, which can get into water or soil and can survive there for weeks to months. Many different kinds of wild and domestic animals carry the bacterium.
These can include, but are not limited to:

• Cattle
• Pigs
• Horses
• Dogs
• Rodents
• Wild animals

When these animals are infected, they may have no symptoms of the disease.
Infected animals may continue to excrete the bacteria into the environment continuously or every once in a while for a few months up to several years.
Humans can become infected through:

• Contact with urine (or other body fluids, except saliva) from infected animals.
• Contact with water, soil, or food contaminated with the urine of infected animals.

The bacteria can enter the body through skin or mucous membranes (eyes, nose, or mouth), especially if the skin is broken from a cut or scratch. Drinking contaminated water can also cause infection. Outbreaks of leptospirosis are usually caused by exposure to contaminated water, such as floodwaters. Person to person transmission is rare.

Signs and Symptoms

In humans, Leptospirosis can cause a wide range of symptoms, including:

• High fever
• Headache
• Chills
• Muscle aches
• Vomiting
• Jaundice (yellow skin and eyes)
• Red eyes
• Abdominal pain
• Diarrhea
• Rash

Many of these symptoms can be mistaken for other diseases. In addition, some infected persons may have no symptoms at all.
The time between a person's exposure to a contaminated source and becoming sick is 2 days to 4 weeks. Illness usually begins abruptly with fever and other symptoms. Leptospirosis may occur in two phases:

• After the first phase (with fever, chills, headache, muscle aches, vomiting, or diarrhea) the patient may recover for a time but become ill again.
• If a second phase occurs, it is more severe; the person may have kidney or liver failure or meningitis. This phase is also called Weil's disease.

The illness lasts from a few days to 3 weeks or longer. Without treatment, recovery may take several months.

Risk of Exposure

Leptospirosis occurs worldwide, but is most common in temperate or tropical climates. It is an occupational hazard for many people who work outdoors or with animals, such as:

• Farmers
• Mine workers
• Sewer workers
• Slaughterhouse workers
• Veterinarians and animal caretakers
• Fish workers
• Dairy farmers
• Military personnel

The disease has also been associated with swimming, wading, kayaking, and rafting in contaminated lakes and rivers. As such, it is a recreational hazard for campers or those who participate in outdoor sports. The risk is likely greater for those who participate in these activities in tropical or temperate climates.
In addition, incidence of Leptospirosis infection among urban children appears to be increasing.

Treatment

Leptospirosis is treated with antibiotics, such as doxycycline or penicillin, which should be given early in the course of the disease.
Intravenous antibiotics may be required for persons with more severe symptoms. Persons with symptoms suggestive of leptospirosis should contact a health care provider.

Prevention

The risk of acquiring leptospirosis can be greatly reduced by not swimming or wading in water that might be contaminated with animal urine, or eliminating contact with potentially infected animals.
Protective clothing or footwear should be worn by those exposed to contaminated water or soil because of their job or recreational activities.

Health Care Workers

Technical Information

Clinical Features

Symptoms include fever, headache, chills, muscle aches, vomiting, jaundice, anemia, and sometimes a rash. The incubation period is usually 7 days, with a range of 2-29 days. If not treated, the patient could develop kidney damage, meningitis, liver failure, and respiratory distress. In rare cases, death occurs.

Etiologic Agent

Leptospires are long, thin, motile spirochetes. They may be free-living or associated with animal hosts and survive well in fresh water, soil, and mud in tropical areas. Organisms are antigenically complex, with over 200 known pathogenic serologic variants. Although certain geographic regions contain specific leptospiral serovars and species, the serologic characterization of an isolate is not an absolute predictor of its species designation.

Sequelae

Clinical course is highly variable. The serious icteric form (Weil’s disease) is not common, but hemorrhage, hepatomegaly, pulmonary hemorrhage, ARDS, and jaundice are among the severe features. Case fatality rate is 1 to 5%.

Surveillance

Leptospirosis has been reinstated as a nationally notifiable disease as of January 2013. Read the updated 2013 case definition. Until CDC can receive case data via the Nationally Notifiable Disease Surveillance System, please send case notifications on the case report form[PDF – 1 MB].

Incidence and Trends

• It is estimated that 100-200 Leptospirosis cases are identified annually in the United States. About 50% of cases occur in Hawaii.
• The largest recorded U.S. outbreak occurred in 1998, when 775 people were exposed to the disease. Of these, 110 became infected.
• Although incidence in the United States is relatively low, leptospirosis is considered to be the most widespread zoonotic disease in the world.
• Significant increases in incidence have been reported from Peru and Ecuador following heavy rainfall and flooding in the spring of 1998. Thailand has also reported a rapid increase in incidence between 1995 and 2000.