Leptospirosis

What is leptospirosis?

Leptospirosis is an infection with a type of bacteria called spirochaetes, which are mobile and can burrow into the tissues. Leptospira bacteria are found in contaminated water and soil, and enter the body through minor abrasions or cuts in the skin, or through the membranes of the mouth, nose and eyes. They then enter the bloodstream and spread around the body.

Leptospirosis infection isn't that common in the UK - only a few dozen cases are reported each year. But it's much more common in tropical climates and developing nations, so travellers are at increased risk.

Leptospirosis affects farmers and anyone who has contact with sewage because the leptospirosis bacteria are carried by animals, such as foxes and rats. The animals excrete the bacteria in their urine, and this contaminates soil and water. Swimmers and people taking part in water sports in contaminated water are also at risk.

Causes and risk factors

Leptospirosis affects farmers and anyone who has contact with sewage because the bacteria that cause leptospirosis infection are carried by animals, such as foxes and rats. The animals excrete the bacteria in their urine, and this contaminates soil and water.

If you come into contact with contaminated soil, the bacteria enter your system through a minor skin cut or graze. Swimmers and people taking part in water sports in contaminated water are also at risk.

Symptoms

For most people infection with leptospirosis causes a 'flu-like' illness with:

• Fever
• Headache
• Muscle aches and pains
• Rashes
• Often swollen and inflamed eyes and eyelids

However, some people have no symptoms at all. These problems usually develop about 7-12 days after initial infection.

Typically, there are two phases to the illness. First, the initial symptoms develop - this is known as the bacteraemic phase, where the organisms spread to the tissues. These systems tend to settle down but then a second phase may begin, as fever, jaundice, abdominal pain, diarrhoea and a rash may return.

This more severe form of leptospirosis is known as Weil's disease and can be fatal. One in ten people who get leptospirosis infection develop Weil's disease and may suffer internal bleeding, liver damage and jaundice, and kidney damage.

Treatment and recovery

In about 90% of cases the illness is mild with few complications. But mortality in severe leptospirosis may be significant, especially among the elderly or immunocompromised.

Antibiotic treatment during the initial phase usually prevents further development of more serious illness such as meningitis or Weil’s disease, which may need intensive hospital treatment.

With treatment, most people recover fully within two to six weeks with no long-term effects, but every year a couple of people in the UK die from the infection.