1 Field Epidemiology Training Program, Epidemiology Bureau, Department of Health, San Lazaro Compound, Sta Cruz, Manila, Philippines . ; Department of Health, San Lazaro Compound, Sta Cruz, Manila, Philippines .
2 Department of Health, San Lazaro Compound, Sta Cruz, Manila, Philippines .
3 Emerging Disease Surveillance and Response Unit, Division of Health Security and Emergencies, World Health Organization Regional Office for the Western Pacific, Manila, Philippines .