Leptospirosis is a type of bacterial infection spread by animals. It's caused by a strain of bacteria called leptospira.

In 90% of cases, leptospirosis only causes mild flu-like symptoms, such as a headache, chills and muscle pain.

However, in some cases the infection is more severe and can cause life-threatening problems, including organ failure and internal bleeding. In its most severe form, leptospirosis is also known as Weil's disease.

The common mild symptoms mean most leptospirosis infections are hard to diagnose. Diagnosis is easier if the infection causes more serious problems.

Read more about the symptoms of leptospirosis.

Why does leptospirosis happen?

Leptospirosis is spread to humans by animals.

You can catch it by touching soil or water contaminated with the urine of wild animals infected with the leptospira bacteria.

Animals known to be carriers of the leptospira bacteria include cattle, pigs, dogs and rodents, particularly rats.

Although the condition is uncommon in the UK, people who regularly deal with animals, such as farmers and vets, have a higher risk of developing leptospirosis.

You may also be at a higher risk if you frequently come into contact with rivers and lakes. This might be because of your occupation or through taking part in activities such as water sports and fishing.

It's incredibly rare for it to spread between humans.

Read more about the causes of leptospirosis.

When to see your GP

See your GP if you are experiencing symptoms of leptospirosis and you have recently:

• travelled to parts of the world where leptospirosis is widespread
• been exposed to a freshwater source, such as a river, lake, drain, canal, pond or flood water
• been exposed to animal urine or animal blood – for example, if you work in farming, an abattoir, or care for animals (veterinary care)

A diagnosis of leptospirosis can be confirmed by running a series of blood and urine tests to check for specific antibodies.

Who is affected?

Leptospirosis is rare in the UK, with less than 40 cases reported in England and Wales every year. Many cases originate overseas and the condition is rarely fatal.

Most of the people affected either worked with livestock, or contracted the condition from sewage or freshwater sources.

Leptospirosis is more common in tropical and subtropical areas of the world.

Can leptospirosis be prevented?

The risk of contracting leptospirosis in the UK is so low you don't need to take drastic measures to avoid the condition.

If you work with animals – dead or alive – or are in regular contact with freshwater sources, you can help protect yourself from leptospirosis by wearing appropriate protective clothing and by cleaning and dressing wounds.

This advice is particularly useful if you 're travelling to an area where leptospirosis is more common.

Read more about preventing leptospirosis.

How is leptospirosis treated?

Leptospirosis is treated with a course of antibiotics.

For mild forms of leptospirosis, antibiotic tablets that can be taken at home are usually used for about a week.

Most people with more severe leptospirosis will be admitted to hospital so their body's functions can be supported while the underlying infection is treated with injections of antibiotics.

Read more about treating leptospirosis.

Reporting leptospirosis

If you may have contracted leptospirosis at your place of work, notify your employer so they can report it. If you're self-employed, you should report it yourself.

You can read more about Reporting of Injuries, Diseases and Dangerous Occurrences Regulations on the Health and Safety Executive (HSE) website.