A three-year-old boy with encephalitis has died, the Centre for Health Protection says.

He had an underlying medical condition and developed fever and a rash over his hands and feet on May 22. He was admitted to United Christian Hospital in a deteriorating condition on May 24 and died today.

Lab tests show he had respiratory syncytial virus - a major cause of respiratory illness in young children that causes infection of the lungs and breathing passages. The tests ruled out influenza A, influenza B and enterovirus including EV71.

The boy had no recent travel history and the nursery he attended did not have an outbreak of similar symptoms. His family members did not have any symptoms, either.