A 39-year-old Dongguan man is in critical condition after being diagnosed with the deadly H7N9 bird flu strain, Guangdong health authorities announced yesterday. Respiratory disease specialists from the provincial disease control centre and Guangzhou Medical University's First Affiliated Hospital had been sent to treat the Fenggang town resident, Xinhua reported. Health workers have examined 53 people indentified as having had close contact with the patient. So far, none has tested positive. They were given the antiviral drug Tamiflu. Early last month, a three-year-old Dongguan boy was confirmed to have contracted the virus. He was discharged from hospital after treatment. The new Dongguan case comes just days after health authorities closed two wet markets in Shenzhen's Longgang district where H7N9 had been found. Hong Kong has seen its first two confirmed cases of the bird flu strain since December 2. A spokesman for the Hong Kong Centre for Health Protection said Guangdong health authorities had informed it about the new Dongguan case. The spokesman said the centre was closely monitoring the situation and was following the advice of the World Health Organisation.