Leptospirosis (Weil's disease): symptoms, treatment and prevention

The NHS says most people who get leptospirosis have no symptoms, or mild flu-like symptoms, but some people get seriously ill. The UKHSA describes a wide range, from few or no symptoms to a severe illness affecting several organs that is sometimes fatal.

Early symptoms listed by the NHS are a high temperature, headache, body aches and pain, tummy ache, feeling or being sick, diarrhoea, redness in the white part of the eyes and yellowing of the skin or whites of the eyes (jaundice, which may be harder to see on black or brown skin).

The UKHSA says infection may come in two phases, with an initial feverish illness that appears to improve before a sudden deterioration. It lists liver failure and jaundice, kidney failure, meningitis and bleeding in the lungs as features of severe infection, and says severe leptospirosis with liver failure and jaundice is sometimes known as Weil's disease.

Leptospirosis is a bacterial infection that can affect both humans and animals. The UKHSA describes it as a zoonotic infection, meaning it passes from animals to people, caused by spiral-shaped Leptospira bacteria. The bacteria live in the kidneys of host animals, which are often not ill themselves.

It occurs worldwide but is more common in tropical regions, where the bacteria can survive longer in warm, humid conditions. TravelHealthPro says it occurs frequently throughout tropical areas of the world but is not common in the UK. The UKHSA reports an average of 57 laboratory-confirmed cases and 89 probable cases a year in England from 2020 to 2023, with more cases in summer and autumn.

The NHS says you can get leptospirosis if soil or fresh water containing infected pee gets in your mouth, eyes or a cut, usually during activities such as kayaking, outdoor swimming or fishing, or if you touch an infected animal's blood or flesh, usually through working with animals or animal parts.

The UKHSA says the bacteria can enter through the skin or mucous membranes (eyes, nose, mouth), especially if the skin is broken or waterlogged, and that outbreaks are often linked with heavy rainfall and flooding. It says transmission through animal bites and from person to person is rare, and the NHS agrees that it is very rare to get it from pets or other people.

The NHS says you have a higher chance of getting leptospirosis if you do outdoor activities such as water sports, especially while abroad in tropical areas, or if you work with animals or animal parts.

The UKHSA lists agricultural workers, military personnel, veterinary staff, pest control, construction and canal workers as higher-risk occupations, and says water-based recreation such as wild swimming and water sports is also associated with infection. It says reported infections in England are most common in adult men, likely because of occupational and recreational exposure, but anyone exposed can be infected. TravelHealthPro adds that travellers visiting areas with flooding may be at risk.

The NHS says leptospirosis can often be treated by your GP, who will usually give you antibiotic tablets. Most people recover in a few days or weeks, and it is important to finish the course even if you start to feel better. Paracetamol or ibuprofen can relieve aches, pains or a high temperature.

If you have severe symptoms you may need treatment in hospital. The UKHSA says treatment is with antibiotics and supportive therapy. The UKHSA also notes that testing is available through its Rare and Imported Pathogens Laboratory, using PCR and antibody tests.

Tell the GP or NHS 111 if you have been in contact with water, soil or animals that might be infected, and mention your job or activities.

• See a GP if you might have been exposed to infected pee, water or soil and have a high temperature or feel hot, cold or shivery, a headache, sickness, diarrhoea, body aches and pains, red eyes or loss of appetite.

• Ask for an urgent GP appointment or call NHS 111 if you have yellow skin or whites of the eyes, a rash, are unable to pee, have swollen ankles, feet or hands, chest pain or shortness of breath.

The NHS and UKHSA give broadly the same advice. There is no vaccine for people, although dogs and cattle can be vaccinated, and vaccination of dogs is part of the UK core vaccination programme.

On the NHS, leptospirosis is usually suspected by a GP or NHS 111 from your symptoms and exposure history, with blood tests sent to a reference laboratory, and is often treated in the community with antibiotics. People who are seriously ill are treated in hospital.

Private doctors and travel clinics can also assess fever after travel or water exposure and arrange tests. Whichever route you choose, say clearly where and when you may have been exposed, because that guides which tests are used and how quickly treatment starts.