10. Clinical Features of HBV Infection Incubation period Average 8-12 weeks Range 6-26 weeks Acute illness (jaundice) 10% <5 yrs old 30%-50% > 5 yrs old Case fatality rate 0.5%-1% Chronic infection 30%-90% <5 yrs old 2%-6% > 5 yrs old Chronic hepatitis 66% Premature mortality from CLD 15%-25%

13. Reported Risk Factors for Acute Hepatitis B United States 2000-2003 Heterosexual 39% MSM 26% Injecting drug use 17% None identified 14% Other 4%* * Other - Household contact, occupational exposure, hemodialysis, institutionalization, transfusion Source: Adapted from Sentinel Counties and NNDSS, CDC

14. Hepatitis B Aguda: Perfil Serológico Incubación Síntomas HBeAg HBsAg Tiempo Concentración Relativa Fase Aguda 2-12 semanas 4-12 semanas Infección Aguda Reciente (2-6) semanas Anti-HBc IgM Anti-HBc total Anti-HBe Ventana Recuperación Años Anti-HBs

15. Acute HBV Infection with Recovery Weeks after Exposure Relative Concentration Symptoms HBeAg anti-HBe Total anti-HBc IgM anti-HBc anti-HBs HBsAg 0 4 8 12 16 20 24 28 32 36 52 100 Limit of Detection HBV DNA HBsAg

16. Progression to Chronic HBV Infection Weeks after Exposure Relative Concentration of Reactants IgM Anti-HBc Total Anti-HBc HBsAg Acute (6 months) HBeAg Chronic (Years) Anti-HBe 0 4 8 12 16 20 24 28 32 36 52 Years HBV DNA Limit of Detection

17. Interpretation of HBV Serologic Tests HBV DNA HBsAg Anti-HBc Anti-HBs Interpretation - - - - Susceptible + - - - Early acute, pre-SC + + - - Early acute infection + + + - Acute or chronic - - + + Recovered/immune + + + - Chronic infection

18. Interpretation of HBV Serologic Tests HBV DNA HBsAg Anti-HBc Anti-HBs Interpretation +/- - + - Resolving infection, past infection, &quot;low- level&quot; chronic infection - - - + Immune (>10 mIU/mL) - + - - Transient (<21 days) during vaccination