A 20-year-old woman from central Taiwan has been infected with the H6N1 avian influenza virus, a strain that has so far only been found in birds in Taiwan, the Centers for Disease Control (CDC) said yesterday.
The CDC said it was informed on May 20 by a hospital that an influenza type A virus with an unknown subtype had been isolated from a respiratory specimen taken from a patient with light pneumonia.
The specimen was sent to the center for genome sequencing, which found found it to be the H6N1 avian influenza virus, the CDC said, adding that the 36 people who had had close contact with the patient are now being closely monitored by the CDC. While four of them had experienced flu-like symptoms, all have since tested negative for the H6N1 strain.
The agency said that the woman, who was hospitalized on May 8 due to fever and shortness of breath, had not left the country prior to the infection and reported to have had no direct contact with birds.
The woman has recovered and was discharged from the hospital on May 11.
“We tested specimens from the poultry in the two poultry farms near the patient’s home, but found no H6N1 virus,” Council of Agriculture official Chao Parn-hwa (趙磐華) said.
“H6N1 was first found in Taiwan’s poultry in 1972. As it is not an OIE [World Organization for Animal Health]-reportable disease; no quarantine or culling measures are to be imposed,” Chao added.
Wu Ho-sheng (吳和生), director of the CDC’s Research and Diagnostic Center, said that the authority started a systematic influenza surveillance project in 1999, testing specimens collected from patients with notifiable communicable diseases, influenza-like illnesses and unexplained pneumonia.
“With 10,000 to 20,000 specimens each year, the center has to date tested more than 250,000 specimens and isolated 86,000 influenza virus strains. Other than the imported H7N9 strain tested earlier this year, no non-H1/H3 subtypes of influenza A viruses had been detected in humans in Taiwan until this H6N1 case,” Wu said.
CDC official Chuang Jen-hsiang (莊人祥) said H6N1 is a low-pathogenic avian influenza strain that is commonly found in poultry, and that no human infection has been reported.
“The genetic sequence of the H6N1 isolate taken from the patient shows that the virus is avian-origin and closely resembles the avian influenza A (H6N1) virus found in poultry,” Chuang said, adding that the CDC has already notified the WHO and countries that have close relations with Taiwan, including the US, China, Japan, South Korea and the EU.
Wang Ching-ho (王金和), professor of veterinary medicine at National Taiwan University, said all eight gene segments of the H6N1 virus isolate are avian.
The CDC is not concerned about a widespread poultry-to-human H6N1 infection, Wang said.
Chao said the bureau has ordered the poultry farm operators to tighten sanitation management.
The government’s decision to ban the slaughter of live poultry at traditional marketplaces from May 17 will help to protect people from being infected with avian flu viruses, he added.
Additional reporting by CNA