Hepatitis may be produced by many infectious and noninfectious agents. Typically, viral hepatitis refers to several clinically similar diseases that differ in cause and epidemiology. These include hepatitis A, B, C, D (delta), E, and G. Chronic lifelong infection has only been documented with hepatitis B (HBV) and hepatitis C (HCV) virus.
The differential diagnosis of newborn liver disease includes idiopathic neonatal hepatitis (giant cell), biliary atresia, metabolic disorders, antitrypsin deficiency, cystic fibrosis, iron storage disease, and other infectious agents that cause hepatocellular injury (eg, cytomegalovirus [CMV], herpes simplex, rubella, varicella, toxoplasmosis, Listeria monocytogenes, syphilis, and tuberculosis, as well as bacterial sepsis, which can cause nonspecific hepatic dysfunction). Table 95–1 outlines various hepatitis panel tests useful in the management of this disease. Isolation precautions for all infectious diseases, including maternal and neonatal precautions, breast-feeding, and visiting issues, can be found in Appendix F.
Table 95–1.HEPATITIS TESTING ||Download (.pdf) Table 95–1.HEPATITIS TESTING
|Specific Test ||Description |
|HAV ||Etiologic agent of “infectious” hepatitis |
|Anti-HAV ||Detectable at onset of symptoms; lifetime persistence |
|Anti-HAV-IgM ||Indicates recent infection with HAV; positive up to 4–6 months postinfection |
|Anti-HAV-IgG ||Signifies previous HAV infection; confers immunity |
|HBV ||Etiologic agent of “serum” hepatitis |
|HBsAg ||Detectable in serum; earliest indicator of acute infection or indicative of chronic infection if present >6 months |
|Anti-HBs ||Indicates past infection with and immunity to HBV, passive antibody from HBIG, or immune response from HBV vaccine |
|HBeAg ||Correlates with HBV replication; high-titer HBV in serum signifies high infectivity; persistence for 6–8 weeks suggests a chronic carrier state |
|Anti-HBe ||Presence in carrier of HBsAg suggests a lower titer of HBV and lower risk of transmitting HBV |
|HBcAg ||No commercial test available; found only in liver tissue |
|Anti-HBc ||Identify people with acute, resolved, or chronic HBV infection (not present after immunization); high titer indicates active HBV infection; low titer presents in chronic infection |
|Anti-HBc-IgM ||Recent infection with HBV positive for 4–6 months after infection; detectable in “window” period after surface antigen disappears |
|Anti-HBc-IgG ||Appears later and may persist for years if viral replication continues |
|HCV ||Etiologic agent of hepatitis C |
|Anti-HCV ||Serologic determinant of hepatitis C infection |
Hepatitis A (infectious hepatitis) is caused by a nonenveloped 27-nM RNA virus that is a member of the Picornaviridae family (HAV). It is transmitted by the fecal-oral route. ...