Prevalence of Fulminant Hepatitis by Viral Etiology
The risk of fulminant hepatitis varies dramatically by viral type: hepatitis E in pregnant women carries the highest mortality at approximately 25%, followed by hepatitis A in patients with chronic liver disease (up to 40% mortality), while hepatitis B and D show lower but significant rates of fulminant progression.
Hepatitis A (HAV)
General Population
- Case fatality rates range from 0.01% to 2% in the overall population, with fulminant hepatitis occurring in only 0.14–0.35% of hospitalized cases 1, 2
- Spontaneous recovery occurs in 30–60% of fulminant HAV cases, with survivors regaining full liver function 1
High-Risk Populations
- Patients older than 50 years have substantially higher rates of fulminant disease 1
- Patients with chronic liver disease experience markedly elevated mortality: HAV superinfection in chronic hepatitis C patients resulted in fulminant hepatic failure in 7 of 17 patients (41%), with 6 deaths (35% mortality) in one prospective study 3
- Chronic hepatitis B patients with cirrhosis show high case fatality rates during HAV superinfection, though most without cirrhosis have uncomplicated courses 4, 3
- Alcoholic cirrhosis patients demonstrate elevated mortality with HAV superinfection 4
Hepatitis E (HEV)
Pregnant Women
- The mortality rate in pregnant women is approximately 25%, representing the highest fulminant hepatitis risk among all viral hepatitides 1
- Deaths result from fulminant hepatic failure and obstetric complications including eclampsia and hemorrhage, with associated high perinatal infant mortality 1
Patients with Chronic Liver Disease
- Mortality in patients with underlying chronic liver disease approaches 70% at 12 months in some studies from India 1
- Mortality rates vary widely (0–67%) across different studies of HEV superinfection in chronic liver disease patients 1
General Population
- HEV genotypes 1 and 2 typically cause brief, self-limiting hepatitis in young adults with low mortality in the absence of pregnancy or chronic liver disease 1
Hepatitis B (HBV)
Acute HBV Alone
- Acute HBV infection alone has relatively low rates of fulminant hepatitis compared to HAV in high-risk groups 1
HBV/HCV Coinfection
- Acute coinfection with HBV and HCV may increase the risk of severe hepatitis and fulminant hepatic failure 1
HBV/HDV Coinfection
- Coinfection with HBV and HDV results in more severe acute hepatitis with higher mortality than HBV alone, but rarely results in chronic infection 1, 5
HBV/HIV Coinfection
- HIV coinfection increases rates of liver-related mortality but does not specifically increase fulminant hepatitis rates 1
Hepatitis D (HDV)
Coinfection Pattern
- Simultaneous HBV/HDV coinfection causes more severe acute hepatitis with higher mortality rates than HBV alone 1, 5
- Chronic infection develops in only approximately 2–5% of coinfection cases 5
Superinfection Pattern
- HDV superinfection in HBV carriers manifests as severe "acute" hepatitis and results in chronic infection in >90% of cases 1, 5
- Higher proportions develop cirrhosis, hepatic decompensation, and hepatocellular carcinoma compared to HBV monoinfection 1
Key Clinical Considerations
Age-Related Risk
- Fulminant hepatitis A is more frequent in individuals older than 40 years, with age >50 years being a poor prognostic indicator 1, 6
Underlying Liver Disease as Universal Risk Factor
- Pre-existing chronic liver disease (hepatitis B, hepatitis C, or alcoholic cirrhosis) significantly increases mortality across all acute viral hepatitides 1, 4, 3
Geographic and Genotype Variations
- HEV genotypes 1 and 2 (Asia, Africa, Mexico) cause epidemic disease with high maternal mortality, while genotypes 3 and 4 (high-income countries) typically cause milder zoonotic infections 1