Leptospirosis & Weil's Disease

What is it?

Leptospirosis is an infection, caused by the Leptospira bacterium.  It is uncommon in the UK, but prevalent in warmer, more tropical climates.  The bacterium is passed from infected animals, commonly cattle and rats, but also foxes, rodents and other wild animals, via their urine, which contaminates water.  There are many different types of Leptospira bacteria, the most common in the UK being Leptospira Hardjo (found in cattle) and Leptospira Icterhaemorragiae (found in rats).

"Weil's Disease" is a more severe form of Leptospirosis and is extremely rare in the UK.

How is it caught?

The Leptospira bacteria can be passed from animals to humans when contaminated/untreated water (e.g. rivers, canals, lakes) enters the body through abrasions in the skin, or via the mucous membrane/lining of the nose or mouth and the membrane at the front of the eye.  Stagnant and slow moving water seems to pose a greater threat than free flowing water, although both can potentially cause an infection.  The bacterium does not survive for very long in either salt water or in dry conditions.  Person to person spread is exceptionally rare (if possible at all).  Infection rates are low.  The most at risk of infection are farmers, sewer workers, people working in abattoirs, miners and water sport enthusiasts.

Symptoms of illness

Illness generally occurs between 7 and 12 days after infection (usually about 10 days).  It is generally short-lived and not serious (in an otherwise healthy individual).  Leptospirosis can be very mild and therefore almost missed, but in more severe cases the illness is very much like flu.  Symptoms include: fever, chills, malaise, muscle aching, joint aching, headache, sore throat, loss of appetite, pain and redness of the eyes, diarrhoea, vomiting and sometimes a skin rash. Symptoms normally last 2 to 3 weeks.

Very few cases develop severe Leptospirosis, with jaundice and kidney failure (i.e. Weil's Disease) and of these rare cases approximately 10-15% will die. Death is virtually unknown in cases that do not develop jaundice.


A diagnosis of Leptospirosis is usually made based on the symptoms in conjunction with the history of exposure.  Diagnosis can be confirmed via a blood test, where antibodies to the Leptospira bacterium would be detected (in rare cases the bacteria can be grown from the blood and other body fluids).

Leptospirosis is a notifiable illness in the UK, meaning that the doctor making the diagnosis must notify the local authority responsible for public health following this diagnosis.


Leptospirosis can be treated with antibiotics, although many cases recover without any specific treatment. If antibiotics are required, they need to be given as soon as possible, ideally within a few days following the onset of symptoms. Treatment is therefore often started before blood test results are received.


Unfortunately, no human vaccine against the disease exists (although there is a vaccine licensed for use in animals). Prevention is therefore dependent on avoiding contact with the bacterium, i.e. avoid contact with untreated/contaminated water. This can best be done by the use of suitable protective clothing. If Leptospirosis has been identified as a potential health risk on a risk assessment, suitable personal protective clothing must be worn, i.e. waterproof coveralls, thick waterproof gloves (and goggles if there is a risk/likelihood of splashes to the eyes). It is important that all cuts and abrasions on the skin are covered with a waterproof dressing/plaster. Footwear should be waterproof and robust enough to prevent the lower let and feet from getting cut or injured.

Occupational & other considerations

Anyone working with or in untreated water should advise their GP of this activity. This will allow the doctor to consider other reasons why someone might have flu-like symptoms, i.e. in the light of this activity/any recent exposure.

Anyone working with untreated water should shower as soon as they can after collecting their samples/completing their fieldwork, i.e. wash away any potentially contaminated water from their skin. Hands should be washed with soap and water after handling untreated water, this being particularly important before eating, drinking or smoking.

As with any other injury at work, all cuts, grazes, risky splashes etc, should be documented (i.e. an accident report must be completed) and advice should be sought from the GP (or an Emergency Department) as appropriate.

The carrying of a Weil's Disease "Card" is not a legal requirement of an employee and employees do not therefore have to carry one.  However, having a card with some basic information about potential contact is wise and helpful in the case of any accidental contact or emergency.  Suitable wording might be:

To the doctor: The card holder's work may expose him/her to the danger of Leptospirosis (L.icterohaemorrhagiae or L.hardjo). Early diagnosis and treatment are vital in Weil's disease, as jaundice is often absent in the early stages. The illness L.hardjo may also be greatly shortened by appropriate antibiotic treatment. (Your Public Health Laboratory Service or Hospital Consultant Microbiologist should be able to offer you advice on treatment and serological testing).