PATHOGENS

• Hepatitis A virus (HAV): non-enveloped, icosahedral, positive-stranded RNA virus
• Spread via fecal-oral route; more prevalent in low- and middle-income countries (20-30% of people in U.S. are seropositive).
• Transmission through contaminated food and water (including fruits and packaged foods imported into the U.S.) and through some sexual practices (oral-anal and digital-anal sex); multiple sexual partners and MSM are risks.
• Pathogenesis from robust HAV-specific CD8+ T-cell, NK T-cell, and IFN response leading to hepatocyte destruction.