A 77-year-old man with chronic illnesses who was earlier confirmed with chikungunya fever died on Wednesday, health authorities said.

The man developed fever, joint pain and a rash after returning to Hong Kong from the mainland more than a week ago and sought medical attention at a private hospital.

His condition deteriorated and the patient was transferred to the intensive care unit of Ruttonjee Hospital.

The Centre for Health Protection said it’s extremely rare to see severe symptoms and deaths caused by the mosquito-borne disease, which has a mortality rate of less than one in a thousand.

“The occurrence of severe complications is mostly related to the patients' underlying health conditions. Elderly persons, young children, pregnant women and persons with chronic illnesses are at higher risk of developing complications after contracting chikungunya fever and may require a longer recovery period,” a spokesman said.

Hong Kong has recorded 42 chikungunya fever cases so far this year, all of which imported.