Royal Government of Cambodia - Ministry of Health, Cambodia, Government of the United States of America - Centers for Disease Control and Prevention (CDC), World Health Organization (WHO) - Cambodia Branch, Institute Pasteur of Cambodia - Virology Unit, Government of the United States of America - Centers for Disease Control and Prevention (CDC), World Health Organization (WHO) - Cambodia Branch, World Health Organization (WHO) - Cambodia Branch, World Health Organization (WHO) - Cambodia Branch, Royal Government of Cambodia - Ministry of Health, Cambodia, Royal Government of Cambodia - Ministry of Health, Cambodia, Royal Government of Cambodia - Ministry of Health, Cambodia, Royal Government of Cambodia - Ministry of Health, Cambodia, World Health Organization (WHO) - Cambodia Branch, Institute Pasteur of Cambodia - Virology Unit, Government of the United States of America - Centers for Disease Control and Prevention (CDC) and Government of the United States of America - Global Seasonal Influenza Mortality Collaborator Network