Leptospirosis
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Leptospirosis or Weil's disease is a rare bacterial infection that can be fatal. It was classified in 1917.
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The infection is often transmitted to humans by allowing fresh water that has been contaminated by rat urine to come in contact with unhealed breaks in the skin or with the mucous membranes.
Leptospirosis is a bacterial disease that affects humans and animals. It is caused by spirochaetes of the genus Leptospira. Approximately 250 strains have been found, divided into serogroups, serovars and strains, depending on serological differences. Not all strains are pathogenic, and most pathogenic strains are host specific. Some hosts can be carriers (i.e. without having disease), such as rats.
In humans it causes a wide range of symptoms, and some infected persons may have no symptoms at all. Because of the wide range of symptoms the infection is often wrongly diagnosed. This leads to a lower registered number of cases than there really are. Symptoms of leptospirosis include high fever, severe headache, chills, muscle aches, and vomiting, and may include jaundice, red eyes, abdominal pain, diarrhea, or a rash. Complications include renal failure, meningitis, liver failure, and respiratory distress (This severe form of the disease is known as Weil's disease). In rare cases death occurs. Diagnosis is confirmed with serological tests like enzyme-linked immunosorbent assay (ELISA) and PCR.
On infection the microorganism can be found in blood for the first 7 to 10 days, invoking a serological reaction and then moving to the kidneys. After 7 to 10 days the microorganism can be found in fresh urine. Diagnostics are performed by testing a serum or blood sample serologically with a panel of different strains. It is possible to culture of the microorganism from blood or serum, fresh urine and possibly fresh kidney biopsy. Serological testing is laborious and expensive, thus often not an option in developing countries.
Outbreaks of leptospirosis are usually caused by exposure to water contaminated with the urine of infected animals (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. The disease is not known to be spread from person to person.
There are no human vaccines. Animal vaccines are only for a few strains, and are only effective for a few months.
Leptospirosis is treated with antibiotics, such as doxycycline or penicillin. Doxycycline can also be used as a prophylaxis.