WA health officials have warned travellers recently returned from Bali to be on the watch for symptoms of the potentially deadly bacterial infection legionnaires' disease.
The Health Department said two Western Australians and one Victorian who recently returned from Bali had been diagnosed with severe pneumonia because of infection caused by legionella pneumophilia.
Communicable Disease Control Director Paul Armstrong said all three people were most likely to have been infected in the central Kuta area of Bali.
Legionella pneumophilia is a type of bacteria commonly transmitted by the inhalation of water droplets from contaminated warm water environments such as air conditioning cooling towers in large buildings, evaporative air conditioners, spa pools, misting sprays and fountains.
"The early symptoms of legionnaires' disease are typically similar to severe flu-like illness, and may include fever, chills, muscle soreness, headaches, tiredness, reduced appetite and diarrhoea, along with dry cough and breathlessness," Dr Armstrong said
"Legionnaires' disease is treated with specific antibiotics, and while most people recover, some people may develop severe pneumonia requiring hospitalisation."
He said anyone who developed flu-like illness after returning from Bali should seek medical advice.