A real risk, described honestly
Any article about rats eventually mentions Weil’s disease, often in alarming terms. The official picture is more measured. This article summarises what the UK Health Security Agency (UKHSA) says on GOV.UK and what the NHS website says, so that the risk is described at the level the sources support. Case figures quoted are for England. It is not medical advice; anyone who is unwell after possible exposure should speak to a GP or NHS 111.
What it is and how people catch it
Leptospirosis, also called Weil’s disease on the NHS website, is an infection you can get from animals, soil or water, and the NHS calls it rare in the UK. UKHSA describes it as a zoonotic infection caused by bacteria of the genus Leptospira, and says the bacteria live in the kidneys of host animals, which are often asymptomatic. Common animal reservoirs include rodents, cattle and pigs.
The infection is spread in the urine of infected animals, most commonly rats, mice, cows, pigs and dogs, according to the NHS. You can get it if soil or freshwater containing infected urine gets into your mouth, eyes or a cut, and the NHS says this usually happens during activities such as kayaking, outdoor swimming or fishing. It also says you can get it by touching the blood or flesh of an infected animal, usually through work with animals. UKHSA says humans can be infected through direct exposure to animal urine or urine-contaminated environments such as canals, rivers and lakes, with bacteria entering through the skin or mucous membranes, particularly if the skin is broken or waterlogged. It says transmission is most commonly through water contaminated with urine, and that transmission through bites or between people is rare. The NHS says it is very rare to get leptospirosis from pets, other people or bites.
What the England numbers show
UKHSA reports that in England from 2020 to 2023 there were on average 57 laboratory-confirmed cases and 89 probable cases each year, with more cases reported in summer and autumn. Many cases diagnosed in England report exposure to potentially contaminated water or direct contact with rodents as the probable source. Reported infections are most common in adult men, which UKHSA says is likely because of occupational and recreational exposures, although anyone directly exposed to infected urine or contaminated environments can be infected.
UKHSA lists high-risk occupations as agricultural workers, military personnel, veterinary staff, pest control, construction and canal workers, and says leptospirosis is also associated with water-based recreation such as wild swimming and water sports. In other words, the typical exposures involve water, soil and working with animals, not simply seeing a rat in the garden. That does not mean rats are irrelevant; rodents are named as a reservoir, and pest controllers are a listed at-risk group.
Symptoms and when to seek help
The NHS says most people who get leptospirosis have no symptoms or mild flu-like symptoms, but some become seriously ill. Symptoms may include a high temperature, headache, body aches, tummy ache, feeling or being sick, diarrhoea, redness in the whites of the eyes and jaundice. It advises seeing a GP if you might have been exposed to infected urine, water or soil and have symptoms such as a high temperature, headache, sickness, diarrhoea, aches or red eyes. It advises asking for an urgent GP appointment or contacting NHS 111 for jaundice, a rash, being unable to pass urine, swollen ankles, feet or hands, chest pain or shortness of breath.
UKHSA describes severe leptospirosis causing liver failure and jaundice as sometimes known as Weil’s disease, and lists kidney failure, meningitis and lung bleeding among the features of severe infection. It says treatment is with antibiotics and supportive therapy, and the NHS says the infection can often be treated by a GP with antibiotic tablets, with hospital treatment for severe symptoms.
Sensible precautions when rats are around
The NHS advice for avoiding infection is practical. Wash your hands with soap and water after handling animals or animal products, clean wounds as soon as possible, cover cuts and grazes with waterproof plasters, wear protective clothing if you are at risk through your job, and shower as soon as possible if you have been in potentially infected water. It says not to touch water or soil that may contain animal urine, not to touch dead animals with bare hands, and not to drink untreated water from rivers, canals or lakes. There is no vaccine for people, though dogs can be vaccinated, and UKHSA says vaccination is part of the core programme for dogs in the UK.
UKHSA also lists avoiding contact with rodents and putting prevention and control measures in place where necessary as part of prevention. For a homeowner, that is an argument for proofing, sensible hygiene and using a professional where rats are established, rather than handling carcasses or droppings casually.
The bottom line
Official sources describe leptospirosis as rare in the UK, with roughly 57 confirmed and 89 probable cases a year in England in 2020 to 2023, mostly linked to contaminated water or direct contact with rodents and animals. Rats are a recognised source, but most exposures involve water, soil and animal work. Take simple precautions around rodents, and get medical advice quickly if you become unwell after possible exposure.
Sources
- UK Health Security Agency, “Leptospirosis (GOV.UK guidance)”
- NHS, “Leptospirosis (Weil’s disease)”