Open Water Swimming and Weil's disease
Updated: Mar 30
One of the well known risks associated with open water swimming can be Weil’s disease. As with all risks there are precautionary measures that can be taken to minimise them, and in the event the unfortunate occurs, it is essential you are able to identify the symptoms early to ensure prompt treatment. The following information has been sourced from the NHS website and will help you in your quest of happy, healthy open water swimming.
Weil’s disease (also known as leptospirosis) is a bacterial infection spread by animal urine, especially that of rats. It tends to be found in urban rivers and canals, but you can also catch Weil’s disease in still water such as lakes, either by swallowing contaminated water or, more likely, by getting it into your bloodstream through a cut or graze.
What to do: Cover any cuts with a waterproof plaster before swimming and avoid swallowing the water. Never swim in an urban canal. If you develop symptoms of Weil’s disease within a few weeks of being in water, see your doctor. The condition can be treated with antibiotics.
Leptospirosis is a type of bacterial infection spread by animals. It is caused by a strain of bacteria called leptospira.
In 90% of cases, leptospirosis only causes mild flu-like symptoms, such as 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 that most leptospirosis infections are hard to diagnose. Diagnosis is easier if the infection causes more serious problems.
A detailed history of places you have been and any animals you have been in contact with can help with a diagnosis.
Why does leptospirosis happen?
Leptospirosis is spread to humans by animals. You can catch leptospirosis 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 sources of freshwater, such as rivers and lakes. This might be because of your occupation or through taking part in recreational activities such as water sports and fishing. Transmission between humans is incredibly rare.
Can leptospirosis be prevented?
The risk of contracting leptospirosis in the UK is so low that 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 are travelling to an area where leptospirosis is more common.
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 require admission to hospital so the functions of their body can be supported while the underlying infection is treated with injections of antibiotics.