Global Perspectives of Viral Liver Disease
, Hep B is the only DNA virus out of the hepatitis viruses.
Hep D is only found in association with HBV as Hep D uses the surface antigens of HBV in
order to enter the hepatocyte.
EBV, CMV and HSV can also cause an acute hepatitis and should be considered while treating
young adults.
o Hep A and E only causes acute hepatitis, the chronic form doesn’t exist
o HBV and HCV can cause either acute or chronic hepatitis, but HCV is less likely to cause
recovery from it.
o The * highlights a qualification to indicate that infection can be chronic in immuno-
compromised individuals such as solid organ transplant patients and in older patients – for
HEV.
Hepatitis A and E:
HAV (only host is man) and HEV (can host pig too) are non-enveloped viruses and hence relatively
stable in environment for weeks or months. This feature of viruses permits their oral–faecal
transmission (otherwise termed enterically transmitted). HAV and HEV replicate at low levels in the
intestinal epithelia from where a primary viraemia allows the viruses to reach the liver via the
portal vein. Viruses replicate in hepatocytes and virions are shed via biliary system back into
intestinal tract and hence faeces which can then recontaminate. The host is infective before the
onset of symptoms. HAV excretion may continue for up to 3 weeks after onset of symptoms.
Viruses that are most fragile are the ones with an envelope as it contains phospholipids etc.
to virus can become susceptible to things like detergents etc.
Transmission:
o HAV: The most common source of HAV infection is direct person to person exposure. In
addition, for HAV, fresh fruit and veg and undercooked shellfish can sometimes be a source
of infection. Waterborne outbreaks of HAV are infrequent and usually associated with
sewage contaminated water. So HAV is more foodborne – contaminated food and poor
hygiene practices.
o HEV: The highest levels of HEV infection are seen in countries of low socioeconomic status
and poor sanitation. HEV outbreaks occur most commonly in rainy season when drinking
water becomes contaminated with faecal waste. In countries of high socioeconomic status,
the majority of HEV cases involve consumption of undercooked meat (pork, chicken and
rabbit) or from exposure to infected animals (especially swine) termed zoonotic
transmission. HEV infection can also occur from vertical transmission. In LEDC the water
borne virus is of genotype 1 and the meat/food borne virus in MEDC is via genotype 3.
Clinical features of acute hepatitis (can be asymptomatic):
Symptoms:
o Fever, malaise
o Nausea, vomiting
o Jaundice, dark urine
o Diarrhoea
o Right upper quadrant pain – inflamed liver expands and stretches its innervated capsule
Signs:
, Hep B is the only DNA virus out of the hepatitis viruses.
Hep D is only found in association with HBV as Hep D uses the surface antigens of HBV in
order to enter the hepatocyte.
EBV, CMV and HSV can also cause an acute hepatitis and should be considered while treating
young adults.
o Hep A and E only causes acute hepatitis, the chronic form doesn’t exist
o HBV and HCV can cause either acute or chronic hepatitis, but HCV is less likely to cause
recovery from it.
o The * highlights a qualification to indicate that infection can be chronic in immuno-
compromised individuals such as solid organ transplant patients and in older patients – for
HEV.
Hepatitis A and E:
HAV (only host is man) and HEV (can host pig too) are non-enveloped viruses and hence relatively
stable in environment for weeks or months. This feature of viruses permits their oral–faecal
transmission (otherwise termed enterically transmitted). HAV and HEV replicate at low levels in the
intestinal epithelia from where a primary viraemia allows the viruses to reach the liver via the
portal vein. Viruses replicate in hepatocytes and virions are shed via biliary system back into
intestinal tract and hence faeces which can then recontaminate. The host is infective before the
onset of symptoms. HAV excretion may continue for up to 3 weeks after onset of symptoms.
Viruses that are most fragile are the ones with an envelope as it contains phospholipids etc.
to virus can become susceptible to things like detergents etc.
Transmission:
o HAV: The most common source of HAV infection is direct person to person exposure. In
addition, for HAV, fresh fruit and veg and undercooked shellfish can sometimes be a source
of infection. Waterborne outbreaks of HAV are infrequent and usually associated with
sewage contaminated water. So HAV is more foodborne – contaminated food and poor
hygiene practices.
o HEV: The highest levels of HEV infection are seen in countries of low socioeconomic status
and poor sanitation. HEV outbreaks occur most commonly in rainy season when drinking
water becomes contaminated with faecal waste. In countries of high socioeconomic status,
the majority of HEV cases involve consumption of undercooked meat (pork, chicken and
rabbit) or from exposure to infected animals (especially swine) termed zoonotic
transmission. HEV infection can also occur from vertical transmission. In LEDC the water
borne virus is of genotype 1 and the meat/food borne virus in MEDC is via genotype 3.
Clinical features of acute hepatitis (can be asymptomatic):
Symptoms:
o Fever, malaise
o Nausea, vomiting
o Jaundice, dark urine
o Diarrhoea
o Right upper quadrant pain – inflamed liver expands and stretches its innervated capsule
Signs:
