1. Infectious Disease Service, Hospital Militar de Santiago, Santiago, Chile.
2. Send correspondence to: Alberto Fica, albertoficacubillos@gmail.com
3. Department of Epidemiology, Ministerio de Salud, Santiago, Chile.
4. Viral Hepatitis and Emerging Diseases Section, Viral Diseases Subdepartment, Instituto de Salud Pública de Chile, Santiago, Chile.
5. Central Laboratory, Hospital Militar de Santiago, Santiago, Chile.
6. Comprehensive Family Immunization Unit, Pan American Health Organization, Washington, D.C., United States of America.
7. School of Medicine, Universidad Austral de Chile–Campus Isla Teja, Valdivia, Chile.