The department said all four patients developed symptoms, such as fever, headaches and muscle pain, after visiting and taking part in water activities.

“One case was admitted to hospital for further treatment, while the other three received outpatient treatment,” it said, adding that samples had been taken for confirmatory testing.

The department said a risk assessment at the site found environmental conditions conducive to the spread of leptospirosis.

“As a control and preventive measure, the recreational area has been closed by the relevant agencies from May 10 to 17 to allow for cleaning and maintenance works to be carried out,” it said.

Leptospirosis, also known as rat urine disease, is caused by Leptospira bacteria and can spread through water, soil or food contaminated by infected animals.

The department said the disease is common in tropical countries such as Malaysia, with symptoms including fever, chills, muscle aches, headaches, nausea, vomiting and diarrhoea.

The public has been advised to avoid water recreation areas during the rainy season, maintain personal hygiene, avoid untreated river water, and stay out of the water if they have open wounds.