Wikipedia Definition:
Leptospirosis (also known as Weil's disease, Weil's syndrome, canicola fever, canefield fever, nanukayami fever, 7-day fever and many more) is a bacterial zoonotic disease caused by spirochaetes of the genus Leptospira that affects humans and a wide range of animals, including mammals, birds, amphibians, and reptiles. It was first described by Adolf Weil in 1886 when he reported an "acute infectious disease with enlargement of spleen, jaundice and nephritis". Leptospira was first observed in 1907 from a post mortem renal tissue slice.
Though being recognized among the world's most common zoonoses, leptospirosis is a relatively rare bacterial infection in humans. The infection is commonly transmitted to humans by allowing water that has been contaminated by animal urine [or bat urine from roosting bats] to come in contact with unhealed breaks in the skin, eyes or with the mucous membranes. Outside of tropical areas, leptospirosis cases have a relatively distinct seasonality with most of them occurring August-September/February-March.
Information from CDC:
What is leptospirosis?
Leptospirosis is a bacterial disease that affects humans and animals. It is
caused by bacteria of the genus
Leptospira.
In humans it causes a wide range of symptoms, and some infected persons may have
no symptoms at all. Symptoms of leptospirosis include high fever, severe
headache, chills, muscle aches, and vomiting, and may include jaundice (yellow
skin and eyes), red eyes, abdominal pain, diarrhea, or a rash. If the disease is
not treated, the patient could develop kidney damage, meningitis (inflammation
of the membrane around the brain and spinal cord), liver failure, and
respiratory distress. In rare cases death occurs.
Many of these symptoms can be mistaken for other diseases. Leptospirosis is
confirmed by laboratory testing of a blood or urine sample.
How
do people get leptospirosis?
Outbreaks of leptospirosis are usually caused by exposure to water contaminated
with the urine of infected animals. Many different kinds of animals carry the
bacterium; they may become sick but sometimes have no symptoms. Leptospira
organisms have been found in cattle, pigs, horses, dogs, rodents, and wild
animals. Humans become infected through contact with water, food, or soil
containing urine from these infected animals. This may happen by swallowing
contaminated food or water or through skin contact, especially with mucosal
surfaces, such as the eyes or nose, or with broken skin. The disease is not
known to be spread from person to person.
How
long is it between the time of exposure and when people become sick?
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.
Where is leptospirosis found?
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, for example, farmers, sewer workers, veterinarians, fish workers, dairy
farmers, or military personnel. It is a recreational hazard for campers or those
who participate in outdoor sports in contaminated areas and has been associated
with swimming, wading, and whitewater rafting in contaminated lakes and rivers.
The incidence is also increasing among urban children.
How
is leptospirosis treated?
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.
Can
leptospirosis be prevented?
The risk of acquiring leptospirosis can be greatly reduced by not swimming or
wading in water that might be contaminated with animal urine. Protective
clothing or footwear should be worn by those exposed to contaminated water or
soil because of their job or recreational activities.