Hepatitis B Symptoms in Singapore: Hepatitis B may be asymptomatic, but it may also be symptomatic.
CLINICAL FEATURES
Incubation period. 40-160 days
Symptoms
Virtually all infants and children have asymptomatic acute infection
Asymptomatic infection is also found in 10-50% of adults in the acute phase and is especially likely in those with HIV coinfection
Chronic carriers are usually asymptomatic but may have fatigue or loss of appetite
The prodromal and icteric phases are very similar to hepatitis A, but may be more severe and prolonged
Signs
As for Hepatitis A in the acute phase
If chronic infection occurs there are often no physical signs. After many years of infection, depending on the severity and duration, there may be signs of chronic liver disease
Complications
Fulminant hepatitis occurs in <1% of symptomatic cases but carries a worse prognosis than that caused by hepatitis A
Chronic infection (>6 months) occurs in 5-10% of symptomatic cases but the rate is higher in immunocompromised patients with HIV infection, chronic renal failure or those receiving immunosuppressive drugs. Immunosuppressive treatment can also reactivate hepatitis B. Almost all (>90%) of infants born to infectious (HBeAg +ve) mothers will become chronic carriers unless immunised
There are 4 phases of chronic carriage:
Immune Tolerant (HBe Ag +ve, normal ALT levels, little or no necroinflammation on liver biopsy)
Immune Active, HBe Ag +ve phase (HBe Ag +ve, raised ALT, progressive necroinflammation and fibrosis)
Inactive hepatitis B carrier (HBsAg+ve, HBeAg -ve, low levels of HBV DNA and normal ALT)
HBeAg –ve chronic active hepatitis (Precore, Corepromotor mutations, HBeAg –ve, detectable HBV DNA, progressive inflammation and fibrosis). Types 2 and 4 may progress to cirrhosis and liver cancer, with type 4 generally progressing fastest
Concurrent hepatitis C infection can lead to fulminant hepatitis, more aggressive chronic hepatitis and increased risk of liver cancer. Concurrent HIV infection increases the risk of progression to cirrhosis and death. Hepatitis A coinfection can be severe acutely, but may lead to the reduction of longterm HBV replication
Concurrent Delta virus infection, or delta virus superinfection may lead to progressive fibrosis, cirrhosis and endstage liver disease
Mortality is <1% for acute cases. Between 10 – 50 % of chronic carriers will develop cirrhosis leading to premature death in approximately 50%. Ten percent or more of cirrhotic patients will progress to liver cancer
There is an increased rate of miscarriage/premature labour in acute infection. There is a risk of vertical transmission