A 61-year-old man has become the first person in Hong Kong to die of H7N9 bird flu this season, after contracting the virus during a visit to the mainland. It came as three more adults died from seasonal H3N2 influenza yesterday - taking the total deaths from flu this year to 307. The flu death toll is now higher than that of the Sars outbreak in 2003, which claimed the lives of 299 people in Hong Kong. But with the flu death rate at 2 to 3 per cent - and most victims elderly or chronically ill - while that of Sars was 17 per cent, health experts have stressed that the two viruses cannot be compared. The H7N9 victim was the third person to be diagnosed with bird flu in the city this year. A 69-year-old woman remains in critical condition in hospital, while another patient has been discharged. All three had travelled to the mainland. Secretary for Food and Health Dr Ko Wing-man reminded the public to remain vigilant. "If any citizens feel unwell after visiting mainland China, they must report to medical staff on where they have been, and whether they have had any contact with live poultry," Ko said yesterday. The man, who had other underlying illnesses, was diagnosed with bird flu last Monday and had been at the Queen Mary Hospital in Pok Fu Lam. He died at about 6am yesterday. He had visited a wet market in Dongguan and bought two fresh chickens before he became ill. Five health care workers who were quarantined after they treated the patient without full protective gear have not shown any symptoms of the illness. Ko said there had been about a dozen bird flu cases in Hong Kong since the H7N9 epidemic emerged on the mainland in 2013. All the victims had travelled to the mainland or been in contact with live poultry. The seasonal flu death toll includes 306 adults and one child. So far, 415 adults and 17 children have required intensive care. These figures far exceed the toll for all of last year, when 149 people died from flu and 136 required intensive care, according to the Hospital Authority. University of Hong Kong microbiologist Yuen Kwok-yung has said this winter's outbreak is not the worst. Some 800 to 1,000 deaths were estimated to have been associated with the H3N2 flu virus in both 2004 and 2005. Ko earlier voiced concern over the possibility of the H7N9 bird flu and H3N2 seasonal flu mixing to create a more contagious virus. He said the number of flu cases had fallen, but warned the figures could be misleading. "The decline may be a result of fewer people visiting a doctor over Lunar New Year," Ko said. "But the schools go back [today] … so we should not lower our guard." Chairman of the Hong Kong Parents Association Henry Chan Sing-tat urged schools to follow flu guidelines. He said he believed many parents would not want classes suspended as a precaution against seasonal flu. Two more H7N9 cases were reported in Guangdong yesterday, taking this year's total to 593 on the mainland.