The purpose of this study is to collect epidemiological and clinical data to assess the vaccine impact and occurrence of confirmed acute hepatitis A cases in sentinel hospitals after the introduction of Havrix™ into the Expanded Program of Immunization.

This is an observational, prospective, multi-centre, sentinel based study in 3 hospitals in Panama. Hospitals are selected based on population density or hepatitis A disease burden.

The Pan American Health Organization (PAHO) definition for a possible case of acute hepatitis A are used for subjects aged between >1 month and <15 years.

Data regarding clinical and epidemiologic information are collected and serum samples are collected to test hepatitis A markers and determine if infection with hepatitis A virus has recently occurred.

Surveillance will be for a period of approximately 2.5 years from the date of study initiation.

Inclusion Criteria:

• A male or female between >1 month and <15 years of age at the time of enrolment, being referred to any of the 3 participating sentinel hospitals.
• Subjects with clinical diagnosis of possible acute hepatitis A.
• Written informed consent obtained from the parent or guardian of the subject.
• Subjects for whom a blood sample is collected.

Exclusion Criteria:

• Subjects with confirmed diagnosis of non-viral hepatitis

Children aged >1 month and <15 years of age being seen for possible acute hepatitis A during the study time period at the selected sentinel hospitals of Panama