Viral hepatitis is caused by viruses which specifically target the liver tissue. This infection of the liver causes inflammation of the liver and subsequent damage. The type of damage and severity depends on the type of virus.
Viral hepatitis can be broadly classified into two groups: acute which lasts for less than six months and chronic hepatitis which lasts for more than six months.
Acute hepatitis is most commonly caused by Hepatitis A,B,C and E although it can also be caused by other non-liver specific viruses.
Common causes of chronic hepatitis are Hepatitis B and Hepatitis C virus.
Hepatitis B: This is the commonest cause of chronic viral hepatitis in Singapore. It is transmitted by contact with infected blood. The common modes being transmission from mother to child during childbirth, having unprotected sex from partners infected with Hepatitis B, transfusion of infected blood products and the use of infected needles.
Hepatitis C: This virus is most commonly transmitted by infected needles and by transfusion of infected blood products. Sexual transmission is less common.
Acute hepatitis: In the acute phase common symptoms are the same as that of flu which is associated with loss of appetite, nausea, vomiting, teacolored urine, yellowness of skin may develop depending on the severity of hepatitis.
Chronic hepatitis: This may not cause any symptoms. However if chronic hepatitis persists it may lead to hardening of the liver or liver cirrhosis. Cirrhosis may progress to liver failure or liver cancer and cause jaundice, abdominal distension, swelling of legs, nausea, vomiting. Sometimes patients with chronic hepatitis may have flares of hepatitis activity causing jaundice, loss of appetite, nausea and vomiting.
Acute hepatitis is diagnosed after assessing symptoms and doing blood tests to detect the type of virus.
Chronic Hepatitis B and C is usually diagnosed by blood tests. However if the chronic hepatitis was undiagnosed for a long duration, it may lead to hardening of the liver which can be seen on ultrasound scan.
Treatment of viral hepatitis depends on type of virus and also the nature of presentation.
Acute hepatitis: The liver will recover spontaneously with supportive treatment. Liver failure may develop in rare cases. Treatment depends on the type of virus.
Chronic Hepatitis B: Not all the patients with hepatitis B will require treatment, regular monitoring will identify patients who will need treatment to prevent damage to liver. If there is significant inflammation in the liver the physician may decide to start treatment, in some cases liver biopsy may be needed.
Both oral medicines and injections are used to treat Hepatitis B. The oral medicines are lamivudine, telbivudine, adefovir,entecavir and tenofovir.
The injections are Interferon injections.
Chronic Hepatitis C: The duration of treatment and the type of medicine required depends on the genotype of virus. The common medicines used in the treatment are Interferon and Ribavirin.
Newer oral drugs will be available soon in Singapore. They have the advantage of needing only oral forms and avoiding Interferon injections.