The patient, a long-time smoker, suffers from chronic obstructive pulmonary disease, which limits airflow to and from the lungs.

He had been on oxygen at home for the lung disease.

The hospital is providing Tamiflu and antibiotics for him, while his wife, who has no flu symptoms, is being tested for the virus.

Controller of the Centre for Health Protection Thomas Tsang Hoi-fai said the patient's condition had deteriorated yesterday morning.

'He has breathing difficulties and a high carbon dioxide level in his blood. The hospital will transfer him to the intensive care unit if needed,' Dr Tsang said.

Elderly patients and the chronically ill are vulnerable groups with a higher chance of complications if they contract flu. The centre's laboratory will conduct tests to determine whether there has been any genetic change in the virus found in the elderly patient. The results will be available in two weeks.

The World Health Organisation says 429 of the total 94,512 swine flu patients have died, with the death rate at about 0.4 per cent.

Hong Kong reported 41 new cases yesterday, taking the total to 1,055.

'We are now having a summer flu peak, and with more than 1,000 swine flu cases already reported here, we expected some severe cases and even deaths,' Dr Tsang said.

Seven flu patients in Hong Kong are staying in hospitals but none require intensive care.

Dr Tsang said the centre would work closely with the Social Welfare Department to minimise the risk of outbreaks at homes for the elderly. The centre's latest figures show that 54 per cent of all influenza A cases isolated in the week between June 29 and July 5 are of the new H1N1 virus.

Chinese University respiratory medicine expert David Hui Shu-cheong said the government should calm public fears if swine flu claimed its first life in Hong Kong.

'There are mortalities in each flu peak. There should not be undue alarm even if swine flu causes its first death,' Professor Hui said.

The government plans to provide 886,000 people aged over 65 with free vaccines against swine flu, seasonal flu and pneumococcal infections.

Tse Hung-hing, president of the Hong Kong Medical Association, said yesterday that the group would meet health officials again next week to discuss how private doctors could help implement the vaccination programme.

Age-old problem

Elderly patients and the chronically ill have a higher chance of complications from flu

The number of swine flu patients in Hong Kong over the age of 65 is: 4