Laboratory tests conducted by the WHO H5 Reference Laboratory in Cairo, Egypt and WHO Collaborating Center for Reference and Research on Influenza, in London, United Kingdom have confirmed the presence of avian influenza virus strain A(H5N1) in samples collected from one case in an affected family. The H5N1 positive case was a 25 year old male from the Peshawar area who developed febrile respiratory illness on 21 November, was hospitalized on 23 November, and died on 28 November. Additional laboratory analysis, including gene sequencing, is ongoing.

At the request of the Pakistan Government, a WHO team traveled to Pakistan to participate with national authorities in the ongoing investigations of several suspected cases of human H5N1 infections. The following conclusions have been made accordingly:

• The preliminary risk assessment found no evidence of sustained or community human to human transmission.
• All identified close contacts including the other members of the affected family and involved health care workers remain asymptomatic and have been removed from close medical observation.

The Ministry of Health in Pakistan has taken timely steps to investigate and contain this event including case isolation, contact tracing and monitoring, detailed epidemiological investigations, increasing the availability of personal protective equipment, dedicating hospital facilities for any new suspected cases, and other infection control measures. In addition, agricultural authorities, including the Ministry of Food, Agriculture and Livestock and FAO, have been active technical partners for the effective control of this limited outbreak.