The Department of Health's Centre for Health Protection today announced that three new cases of chikungunya fever (CF) had been recorded, all of them imported cases, as of 5pm today.

The first case involves a 79-year-old woman with good past health, living in Southern District. The patient travelled to Foshan in Guangdong to visit relatives between July 1 and 31, and did not recall receiving any mosquito bites during her stay.

The woman experienced fever and joint pain from August 4. She went to Queen Mary Hospital's accident and emergency department yesterday and tested positive for CF virus. She was admitted for treatment in a mosquito-free environment and is now in stable condition.

The woman had no travel companions in Guangdong and has not had household contacts. The centre has reported the case to Guangdong's health authorities.

The second and third case involve a 55-year-old man with underlying illnesses and his 10-year-old son, who has good past health. They live in Kwai Tsing District.

Both patients travelled to Bangladesh on July 12 and arrived back in Hong Kong on August 3. The boy recalled experiencing mosquito bites during their stay, although his father did not.

The boy's father experienced fever and joint pain in Bangladesh from July 27. After returning to Hong Kong, he sought medical attention at Tsing Yi Cheung Hong General Out-patient Clinic on August 4 and was referred to Princess Margaret Hospital's accident and emergency department. He was admitted to Princess Margaret Hospital for treatment in a mosquito-free environment on the same day.

The boy developed similar symptoms in Bangladesh from August 1. He sought medical attention at and was admitted to the Hong Kong Adventist Hospital - Tsuen Wan on August 3. He was transferred to Princess Margaret Hospital yesterday for treatment in a mosquito-free environment.

Both patients tested positive for CF virus and are now in a stable condition.

The patients' two household contacts, who were also in Bangladesh, are currently asymptomatic and under medical surveillance. The centre has reported the cases to the health authority of Bangladesh.

Head of the centre's Communicable Disease Branch Dr Albert Au urged the public to adopt precautions in the rainy season against mosquito-borne diseases.

He added that if people return from areas affected by mosquito-borne diseases, they should apply insect repellent for 14 days upon arrival in Hong Kong and closely observe their personal health condition.