Human infection

Can humans be infected?

Yes, but this occurs rarely. Human cases of avian influenza were described in Hong Kong in 1997 during the large outbreak of avian influenza affecting the live poultry markets, again in Hong Kong in 1999, in The Netherlands in 2003 and in British Columbia in 2004. These were different types of avian influenza and all human cases were probably infected through close contact with live infected poultry.

Information about the recent series of cases of human infection with avian influenza reported since late 2003 is available on the World Health Organization (WHO) website for up to date information.

How are humans infected?

Humans are usually infected through close contact with live infected birds*. Birds shed influenza virus in their faeces so contact with faeces (for example by visiting enclosures or markets where birds have been recently kept) is also a possible transmission route.

*Evidence to support limited human-to-human transmission has also been described - see relevant questions on the HPA website.

Last reviewed: 13 August 2008