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(Weil's disease)
What is leptospirosis?
Leptospirosis is a disease of people and animals caused by bacteria of the genus Leptospira. There are  a wide range of symptoms in humans, and some people may not get sick at all.  An average of 1-2 cases per year are reported in New York City residents.


Cases of Leptospirosis Reported in New York City2003-2007













*Two cases diagnosed in 2005 were travel related.

Who gets leptospirosis?
Leptospirosis may be an occupational or recreational disease affecting those who work with animals (particularly rodents). Examples of people who might be at risk include farmers, veterinarians, international travelers, sewer workers, or persons involved in water activities such as swimming or whitewater rafting. However, anyone can get infected if they are exposed.
How is leptospirosis spread?
Leptospirosis is spread primarily through contact with water or soil contaminated by the urine of infected animals. The bacteria enter the body through the eyes or nose, or through wounds and cuts in the skin. In recent years, sporadic outbreaks have occurred among people exposed while swimming in lakes and rivers. In such cases, bodies of water are presumably contaminated by an infected wild animal, though a source for the bacteria is not often identified. Leptospirosis is generally not transmitted from person to person. Dogs can also become infected, but rarely transmit the infection to people.

For information about leptospirosis in dogs, read Leptospirosis Factsheet for Dog Owners (PDF)
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What are the symptoms of leptospirosis?
Leptospirosis is often a mild flu-like illness with headache, fever, vomiting and muscle aches. More severe symptoms and signs occur rarely, and include jaundice (yellow skin and eyes), a rash, abdominal pain, diarrhea and anemia (decreased red blood cells).  If treatment is not provided, complications including kidney and liver damage, meningitis (inflammation of the membrane around the brain and spinal cord) and respiratory difficulty can result.
How soon after exposure do symptoms appear?
The incubation period is usually 10 days, with a range of 2 days to 4 weeks.
How is leptospirosis diagnosed?
Leptospirosis can be diagnosed using a specific antibody test available through commercial or public health laboratories or through observation of leptospirosis bacteria in urine.
Does past infection with leptospirosis make a person immune?
There are several strains of the organism. Infection with one usually provides only short-term immunity to that organism but not to the other strains.
What is the treatment for leptospirosis?
Leptospirosis can be treated with antibiotics, including doxycycline or penicillin. Hospitalization and intravenous antibiotics may be necessary for patients with severe illness.
How can leptospirosis be prevented?
Disease prevention consists of good sanitation. Rodent control will reduce the risk of environmental contamination by infected rodents. Protective clothing or footwear should be worn by those exposed to contaminated water or soil because of their job or recreational activities.