Introduction

Hepatitis A virus (HAV) a positive-sense RNA virus, is a unique member of the Picornaviridae family. HAV is highly contagious and is primarily transmitted by the fecal-oral route, either through person to person contact or consumption of contaminated food or water. Although hepatitis A is not ordinarily a sexually transmitted disease, the infection rate can increase following oral-analcontact.

The presence of anti-HAV IgM in blood samples suggests an acute or recent HAV infection. In most infected individuals, anti-HAV IgM rapidly increases in titer over a period of 4-6 weeks post-infection, and then declines to non-detectable levels within 3 to 6 months. Anti-HAV IgG can be detected at the onset of symptoms, and levels remain elevated throughout the life of an individual. Protective immunity from an infection with HAV is indicated by an anti-HAV IgG level ≥20-33 mIU/mL, however these levels do not necessarily ensure protection from a future HAV infection. A patient without protective levels of anti-HAV IgG (< 20-33 mIU/mL) is considered at risk of acquiring an HAV infection.