First human infection with Influenza A(H6N1) virus

In May 2013, a 20-year-old woman was admitted into a Taiwanese hospital with an influenza-like illness and shortness of breath. An unsubtyped influenza A virus was isolated and was transferred to the Taiwan Centres for Disease Control (CDC) for identification[1].

The unsubtyped Influenza A virus was identified as the H6N1 subtype. 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.

The source of infection was not established. Sequence analyses showed that this human isolate was highly homologous to chicken H6N1 viruses that were (and are) circulating 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.

This is the first report of human infection with a wild avian Influenza A(H6N1) virus. All known Influenza viruses continue to evolve and accumulate changes, increasing the potential risk of human-to-human transmission.

[1] Sung-Hsi Wei et al: Human infection with avian influenza A H6N1 virus: an epidemiological analysis in The Lancet Respiratory Medicine - 2013