Leptospirosis

What is leptospirosis?

Leptospirosis is a potentially serious illness that can affect many parts of the body.

What is the infectious agent that causes leptospirosis?

Leptospirosis is caused by Leptospira interrogans, a corkscrew-shaped bacterium (spirochete).

Where is leptospirosis found?

Leptospirosis-causing bacteria are common worldwide, especially in tropical countries with heavy rainfall. Infected rodents and other wild and domestic animals pass the bacteria in their urine. The bacteria can live for a long time in fresh water, damp soil, vegetation, and mud. Flooding after heavy rainfall helps spread the bacteria in the environment.

How is leptospirosis spread?

People get leptospirosis by contact with fresh water, damp soil, or vegetation contaminated by the urine of infected animals. People who canoe, raft, wade, or swim in contaminated lakes, rivers, and streams can get leptospirosis. Leptospirosis is also a problem for people who work in contaminated flood plains or wet agricultural settings.

Leptospirosis bacteria can enter the body through broken skin and mucous membranes. The bacteria can also enter the body when a person swallows contaminated food or water, including water swallowed during water sports. Once in the bloodstream, the bacteria can reach all parts of the body and cause signs and symptoms of illness.

What are the signs and symptoms of leptospirosis?

Most infected persons have a mild to moderate illness that is like many other tropical diseases. Symptoms include fever, headache, chills, nausea and vomiting, eye inflammation, and muscle aches. In more severe cases, the illness can result in liver damage and jaundice (yellowing of the skin and whites of the eyes), kidney failure, and internal bleeding. People who are seriously ill with leptospirosis often need to be hospitalized.

How soon after exposure do symptoms appear?

Symptoms usually begin about 10 days after infection.

How is leptospirosis diagnosed?

Leptospirosis is diagnosed by a special blood test that is available through state health departments.

Who is at risk for leptospirosis?

People who take part in freshwater recreational activities in areas where leptospirosis is common, especially during the rainy season or in times of flooding

Farmers, workers in rice fields, sewer workers, and others whose jobs involve contact with water or mud that is contaminated by animal urine, especially the urine of rodents

Veterinarians and others in contact with leptospirosis-affected animals

What complications can result from leptospirosis?

Severe or untreated leptospirosis can lead to organ system damage and, in rare cases, death.

What is the treatment for leptospirosis?

Leptospirosis is treatable with antibiotics. Treatment should be started as soon as possible. Severely ill persons might need intravenous antibiotic treatment and other supportive care.

How common is leptospirosis?

Mild leptospirosis is common in tropical countries where people have regular contact with fresh water and animals. The disease is under-diagnosed in the United States. The 50 to 150 cases reported each year are probably only a fraction of the total number of infections.

Is leptospirosis an emerging infectious disease?

Yes. Increased awareness of the disease has led to increased recognition. In 1995, after widespread flooding in Nicaragua, a leptospirosis epidemic killed at least 13 persons and made more than 2,000 others sick. In 1997, nine whitewater rafters from the United States were infected during a river trip in Costa Rica. Leptospirosis is also a problem in deteriorating inner cities that are infested with rats.

How can leptospirosis be prevented?

Minimize contact with fresh water, mud, and vegetation that might be contaminated with the urine of infected animals, especially rodents.

Wear protective clothing, such as waterproof boots or waders, when participating in recreational or work activities that might result in contact with contaminated water.

If your travel plans might put you at risk for leptospirosis, consider taking antibiotics before and during travel to help prevent infection from short-term, high-risk exposures.