Weil’s disease is a severe form of a bacterial infection known as leptospirosis. Leptospirosis is caused by bacteria from the genus Leptospira. The infection typically only causes mild flu-like symptoms, including headaches and chills. In severe cases, such as in Weil’s disease, it can lead to organ failure and bleeding.
Leptospirosis is spread to humans by contact with soil or water contaminated with the urine of certain wild animals, including cattle, pigs, dogs, and rats. The condition is rare, but people who regularly come in contact with animals, like farmers and veterinarians, are at a higher risk of infection. The disease is treated with a course of antibiotics. People with Weil’s disease may need to be admitted to a hospital for extra care while their underlying infection is treated with antibiotics.
Weil’s disease is caused by an infection with a bacterium from the genus Leptospira (Zavitsanou & Babatsikou, 2008). The bacteria are typically found in animals, including rodents, farm animals, and dogs. Humans become infected when water or soil contaminated with the bacteria come into contact with their eyes, mouth, nose, or open cuts on the skin. It is also possible to become infected through rodent bites and drinking contaminated water.
The mild form of the disease is known as leptospirosis. If the bacteria infect other organs of the body, such as the kidneys, heart, liver, lungs, or brain, it can lead to a more severe disease. This condition is called Weil’s disease.
Leptospirosis is primarily an occupational disease. This means that it usually only affects people whose occupation involves working with animals. Transmission of the disease in humans occurs by either direct or indirect contact with the urine, blood, or tissue of an infected animal.
Animals known to spread leptospirosis to humans include:
- reptiles and amphibians
- rats and other rodents, which are the most important sources for human infection (Zavitsanou & Babatsikou, 2008)
Therefore, people who are at a higher risk of contracting leptospirosis include:
- freshwater fishermen
- people who engage in water sports (swimming, canoeing, rafting, kayaking) or who bathe in fresh water lakes, rivers, or canals
- rodent control workers
- sewer workers
- butchers, and other people who work with dead animals
The disease is found worldwide, but it is more common in tropical regions than in temperate countries (Zavitsanou & Babatsikou, 2008). It occurs in both developed and developing countries.
Symptoms usually appear five to 14 days after infection, but may occur anywhere from two to 30 days after infection (NYSDOH, 2011).
According to the UK’s National Health Services (NHS), about 90 percent of leptospirosis infections cause only mild symptoms, including:
- muscle aches
- nausea and vomiting
- loss of appetite (NHS, 2012)
Severe infections, which are referred to as Weil’s disease, only occur in about 10 percent of cases. The symptoms typically occur one to three days after the mild symptoms pass, and depend on which organ(s) becomes infected:
Liver, Kidney, and Heart
If these organs are infected, symptoms may include:
- jaundice (yellowing of the skin and the white part of the eyes)
- loss of appetite and weight loss
- swollen ankles, feet, or hands
- painful swelling of the liver
- decreased urine
- shortness of breath
- rapid heartbeat
If the brain becomes infected, symptoms can include:
- high temperature
- confused mental state
- aggressive behavior
- inability to control movements or to speak
- aversion to lights
If the lungs are infected, symptoms might include:
- high fever
- shortness of breath
- coughing up blood
Leptospirosis is difficult to diagnose because the symptoms are very similar to other types of illnesses, such as the flu. Weil’s disease is easier to diagnose because the symptoms are more severe.
A personal history is helpful for a diagnosis. You should tell your doctor if you:
- have recently travelled
- have participated in water sports
- have come in contact with a freshwater source
- have an occupation that involves exposure to animals
Diagnosis is usually confirmed through blood and urine tests that detect the presence of the leptospira bacteria. In the case of Weil’s disease, a doctor may also perform scans, like a chest X-ray, to see which other organs are infected.
If left untreated, the infection can lead to kidney failure, liver failure, or heart failure. Death can occur in rare cases. Mortality is greatly reduced with prompt antibiotic treatment.
People with Weil’s Disease are often hospitalized. Once in the hospital, antibiotics given intravenously are used to treat the infection. The preferred antibiotics are penicillin or doxycycline (NHS, 2012).
Additional treatments depend on which organs are also infected. A ventilator may be used to assist with breathing. Dialysis may be required if your kidneys are not functioning properly.
A vaccine to prevent infection with Leptospira is available in some countries, including Cuba (González et al., 2004). There is no vaccine available in the United States. Vaccines are available for dogs, cattle, and some other animals (NHS, 2012).
People who work with animals can help prevent infection by wearing protective gear, like water-proof shoes, goggles, and gloves. Proper sanitation and rat-control measures are also helpful to prevent spread of the bacteria.