W hen cases of avian influenza in humans occur,

information on the extent of influenza infection in animals as

well as in humans and on circulating influenza viruses is

urgently needed to aid the assessment of risks to public health

and to guide the best protective measures. Thorough

investigation of each case is also essential. Although the

W orld Health Organization and the members of its global

influenza network, together with other international agencies,

can assist with many of these activities, the successful

containment of public health risks also depends on the

epidemiological and laboratory capacity of affected countries

and the adequacy of surveillance systems already in place.

Internet: http://www.who.int/csr/don (with adaptations).