H7N9 avian flu
The influenza A (H7N9) virus is one subgroup among the larger group of H7 viruses that normally circulate among birds. A number of human infections of the H7N9 virus have been reported in eastern China, mostly in the Yangtze River Delta region since late March 2013. Some of the patients have died of severe pneumonia brought on by the virus.
17 people in isolation amid scare over Hong Kong's first H7N9 bird flu case
200 are under observation after having contact with helper confirmed to be infected with H7N9 virus, but all tests so far have proved negative
Seventeen people are in isolation after coming into contact with an Indonesian domestic helper who is the first person in Hong Kong to be infected with the deadly H7N9 strain of bird flu.
They are among more than 200 people who have been placed under observation as a precaution, the Centre for Health Protection said yesterday.
Those in isolation either lived in the same Tuen Mun flat as the patient or were in the same cubicle as her when she was treated in Tuen Mun Hospital.
The Indonesian consulate confirmed the patient was 36-year-old Tri Mawarti.
The centre's controller, Dr Leung Ting-hung, said: "There is so far no evidence to show the virus has spread to another person. According to the assessments of the World Health Organisation and Centre for Health Protection, the risk of locals contracting H7N9 has not increased or changed."
Tri was transferred to the intensive care unit at Queen Mary Hospital in Pok Fu Lam on Saturday, where she is in critical condition. Indonesia's vice-consul for public affairs Sam Aryadi said she would be offered as much help as possible.
Of the 17 classified as high-risk, 11 had tested negative in preliminary examinations but would undergo more tests, Leung said.
They are 10 members of the family the helper lived with and an Indonesian friend, aged 33, who accompanied her on November 17 to Shenzhen, where they killed and cooked a chicken.
All 17 were isolated at Princess Margaret Hospital in Kwai Chung. Five of them, who had shown no symptoms, would be transferred to the Lady MacLehose Holiday Village in Sai Kung, a site the government had reserved for quarantine purposes, Secretary for Food and Health Dr Ko Wing-man said.
Six of the 17 who had yet to be tested were patients at Tuen Mun Hospital while Tri was there for four days. Others under observation include staff from the clinics of Dr Simon Wong Siu-shan on Castle Peak Road - which Tri visited on November 25 - and Dr Wong Chun-yan in Tuen Mun, which she visited the next day. The rest are staff and patients of the two public hospitals and a member of ambulance staff who handled Tri's transfer.
On Wednesday morning, two private clinics visited by the Indonesian domestic helper infected with the deadly H7N9 strain of bird flu remained open.
A clinic nurse of Dr Simon Wong Siu-shan, who was among the 200 people placed under observation for having contact with the infected helper, said the doctor was seeing patients and declined an interview.
A male patient who was seen by Dr Wong at the Castle Peak Road clinic said he was not worried that the doctor may have been exposed to H7N9.
"It is not likely that there is any big risk," he said.
A staff member working at a cake shop next to the clinic said the fact that the helper's live-in family had not been infected proved that there was nothing to worry about.
Medical experts said that as Tri's infection was only confirmed after a third H7N9 test, this suggested a preliminary viral test might not be accurate enough. The University of Hong Kong's chair of virology, Professor Malik Peiris, said the virus might not be detectable when the strength was low.
"The avian influenza virus is found deep in the lungs. The patient's first two samples were taken from the upper respiratory tract because she was not so sick at the time. The third time it was taken from her lungs."
His university colleague, Ho Pak-leung, said evidence in four clusters of patients on the mainland suggested the virus could have developed a limited ability to pass from person to person.
The H7N9 virus has killed 45 of the 138 people infected on the mainland since the first human case was reported in February. One person has also been infected in Taiwan.
Additional reporting by Phila Siu