Disease outbreak news
Today, Taiwan’s CDC published an epidemiological analysis of that case in The Lancet Respiratory Medicine, which highlights the need to be prepared for known novel influenza threats (like H5N1, H7N9, H3N2v), but also for something emerging from out of left field (which is exactly what happened with the swine-origin H1N1 pandemic virus of 2009).
Concerned infectious area
Model of avian influenza virus
Influenza virus and its components under the microscope
Abstract ใน The Lancet Respiratory Medicine Journal
Human infection with avian influenza A H6N1 virus: an epidemiological analysis
Sung-Hsi Wei*, Ji-Rong Yang*, Ho-Sheng Wu*, Ming-Chuan Chang*, Jen-Shiou Lin, Chi-Yung Lin, Yu-Lun Liu, Yi-Chun Lo, Chin-Hui Yang, Jen-Hsiang Chuang, Min-Cheng Lin, Wen-Chen Chung, Chia-Hung Liao, Min-Shiuh Lee, Wan-Ting Huang, Pei-Jung Chen, Ming-Tsan Liu, Feng-Yee Chang
Background
Avian influenza A H6N1 virus is one of the most common viruses isolated from wild and domestic avian species, but human infection with this virus has not been previously reported. We report the clinical presentation, contact, and environmental investigations of a patient infected with this virus, and assess the origin and genetic characteristics of the isolated virus.
Methods
A 20-year-old woman with an influenza-like illness presented to a hospital with shortness of breath in May, 2013. An unsubtyped influenza A virus was isolated from her throat-swab specimen and was transferred to the Taiwan Centres for Disease Control (CDC) for identification. The medical records were reviewed to assess the clinical presentation. We did a contact and environmental investigation and collected clinical specimens from the case and symptomatic contacts to test for influenza virus. The genomic sequences of the isolated virus were determined and characterised.
Findings
The unsubtyped influenza A virus was identified as the H6N1 subtype, based on sequences of the genes encoding haemagglutinin and neuraminidase. The source of infection was not established. Sequence analyses showed that this human isolate was highly homologous to chicken H6N1 viruses in Taiwan and had been generated through interclade reassortment. Notably, the virus had a G228S substitution in the haemagglutinin protein that might increase its affinity for the human α2-6 linked sialic acid receptor.
Interpretation
This is the first report of human infection with a wild avian influenza A H6N1 virus. A unique clade of H6N1 viruses with a G228S substitution of haemagglutinin have circulated persistently in poultry in Taiwan. These viruses continue to evolve and accumulate changes, increasing the potential risk of human-to-human transmission. Our report highlights the continuous need for preparedness for a pandemic of unpredictable and complex avian influenza.
Funding
Taiwan Centres for Disease Control.
Migratory birds get in contact with domestic birds, and transmit infection to them
Reference สามารถอ่านเพิ่มเติมที่วารสารการแพทย์ The Lancet Respiratory Medicine
http://www.thelancet.com/journals/lanres/article/PIIS2213-2600(13)70221-2/abstract
