​Viral hepatitis is associated with significant morbidity and mortality. There are several types with which the pediatrician should be familiar, and they include Hepatitis A-E & G. These hepatitis viruses can be differentiated into two groups: those transmitted parentally (HBV, HCV, HDV, HGV) and those transmitted enterically (HAV and HEV). Other viruses such as CMV, EBV and HHV6 can also cause mild, self resolving forms of hepatitis with no sequel, although one fulminant case of hepatitis associated with HHV 6 has been described. Enteroviruses, other than hepatitis A, also occasionally cause hepatitis as part of a general infection with involvement of other organs usually more dominant.
 
Viral hepatitis - laboratory diagnosis. 

Once the clinical diagnosis of acute hepatitis has been made, a cost-effective initial approach to determining the causal viral agent is to test the patient’s serum for the presence of three viral serum markers: HBsAg, Anti-HBc IgM and anti HAV IgM. A positive HAV IgM indicates acute infection, immune globulin for contacts, or vaccine for prevention.

If a diagnosis of hepatitis B has been confirmed, the degree of infectivity and prognosis can be monitored, using four serum markers: HBsAg, HbeAg, anti HBe and HBV DNA. The disappearance of HBeAg and detection of anti HBe is considered a favourable prognosis for disease outcome. 

The laboratory diagnosis of hepatitis C infection is also serum-based. A positive HCV test in conjunction with clinical symptoms and a negative hepatitis A and B serology provides support for an acute infection. However, proven HCV seroconversion during clinical disease remains necessary for the diagnosis of acute HCV infection, since a HCV IgM test is not yet available. A positive antibody test should be confirmed with RIBA or HCV RNA PCR. HCV viral load tests are helpful to prove the presence of HCV genome.
 
Hepatitis D also requires serological diagnosis and can occur as a coinfection or superinfection with hepatitis B. Hepatitis E is currently a significant problem in the Far East, in particular for pregnant women who may have a fatal outcome with HEV infection.