HepFree

Know hepatitis

Hepatitis is the state of inflammation of cells in liver, an important organ. It is commonly caused by viral infection. There are five main hepatitis viruses, namely hepatitis A, B, C, D and E viruses. In addition, hepatitis can be caused by alcohol, drugs, chemicals or genetic diseases.

Clinical features of acute viral hepatitis

Acute hepatitis can be asymptomatic. If symptoms develop, typical clinical presentation may include:

• Non-specific symptoms, such as mild fever, fatigue, muscle pain, headache, nausea and diarrhea
• Loss of appetite
• Distaste for cigarette (in smokers)
• Yellowing of skin and the whites of the eyes (jaundice)
• Dark urine, almost like tea
• Clay or light colored stools

Progression of chronic viral hepatitis

Chronic hepatitis can be caused by infection with hepatitis B, C, D or E viruses. If left untreated, chronic hepatitis could lead to serious liver diseases, including cirrhosis and liver cancer. Typical prognosis of untreated chronic hepatitis would be as follows:

HEPATITIS A

Transmission

• Hepatitis A spreads commonly in all parts of the world
• Hepatitis A virus is primarily transmitted by faecal-oral route when an uninfected person consumes contaminated food or water
• Hepatitis A virus can also be transmitted through close physical or sexual contact with an infectious person

Prevention

• Hepatitis A vaccine is safe and effective to prevent the infection
• Risk of infection with hepatitis A virus can be reduced by observing personal, food and environmental hygiene

Management

• There is no specific treatment for hepatitis A
• Infected adults usually have symptoms compatible with acute viral hepatitis, while most children have asymptomatic infection
• The disease is self-limiting, and most symptoms usually resolve within a couple of months
• Hepatitis A infection is rarely fatal, but life-threatening debilitating symptoms and fulminant hepatitis may occur occasionally, leading to acute liver failure
• Hepatitis A virus infection does not cause chronic liver disease
• Most people recover fully from hepatitis A with lifelong immunity

HEPATITIS B

Transmission

• Hepatitis B is highly prevalent in Hong Kong and other Asian countries
• Hepatitis B virus can be found in blood and body fluids of an infected person
• The main routes of transmission include mother-to-child transmission, blood contact and sexual contact

Prevention

• Hepatitis B vaccination is the most effective way to prevent infection
• A complete course of hepatitis B vaccination normally takes 3 injections. The injections are given 1 month and 6 months, respectively, after the first shot
• Risk of hepatitis B virus infection can also be reduced by avoiding sharing razors, toothbrushes or needles with other people, handling wound properly, disinfecting objects contaminated with blood and practising safer sex

Management

• There is no specific treatment for acute hepatitis B
• Acute infection can be asymptomatic, though rare cases of fulminant hepatitis may also occur
• Over 90% of adults can recover completely from hepatitis B virus infection and do not become chronically infected, but infected children are more likely to become chronic carriers
• Chronic hepatitis B infection can be treated, but not cured, with medicines, which suppresses the replication of hepatitis B virus for slowing the progression of cirrhosis, reducing incidence of liver cancer and improving long-term survival
• Most people who start hepatitis B treatment must continue it for life

HEPATITIS C

Transmission

• Hepatitis C virus is mainly transmitted through blood contact, such as sharing injection equipment, reusing inadequately sterilised medical equipment and transfusion of unscreened blood products
• Other possible but less common routes of transmission include mother-to-child transmission and sexual transmission

Prevention

• There is no vaccine available against hepatitis C
• In health care settings, prevention of hepatitis C virus transmission depends largely on the protection of blood safety and upholding infection control standards
• Individuals should not share needles, syringes and other personal care items that can potentially be contaminated with blood

Management

• Hepatitis C does not always require treatment as the immune response in some people may clear the infection
• When treatment is necessary, therapy with direct acting antivirals can cure most persons with hepatitis C virus infection
• Chronic hepatitis C virus infection can result in serious long-term health problems, such as liver fibrosis, cirrhosis and liver cancer
• Hepatitis C virus infection does not confer protective immunity and reinfection can happen in individuals with ongoing risk behaviour

HEPATITIS D

Transmission

• Hepatitis D virus is transmitted through contact with blood or other body fluids of an infected person
• Hepatitis D infection is more prevalent in some Mediterranean countries, Africa and Asia, but rare in Hong Kong
• Vertical transmission from mother to child is possible but rare
• Hepatitis D virus exists like a parasite of hepatitis B virus. Infection can only occur in the presence of hepatitis B virus

Prevention

• Getting vaccinated against hepatitis B can prevent hepatitis D virus infection, but hepatitis B immunization does not provide protection against hepatitis D virus for carriers of hepatitis B virus
• Avoiding sharing of syringes, razors, toothbrushes and other objects that may be contaminated with blood and practising safe sex might reduce possible exposure to hepatitis D virus

Management

• Persistent hepatitis D virus replication is the most important predictor of mortality and the need for antiviral therapy
• There is currently no effective antiviral therapy for curing hepatitis D. The optimal duration of therapy is not well defined, but most patients relapse after discontinuation of therapy
• Liver transplantation may be required for cases of fulminant hepatitis and end-stage liver disease

HEPATITIS E

Transmission

• Hepatitis E is found worldwide
• Hepatitis E virus is mainly transmitted by faecal-oral route, principally via consumption of contaminated water
• Foodborne transmission by eating raw or undercooked meat or meat products derived from infected animals may occur
• Other identified, but uncommon, transmission routes include transfusion of infected blood products and mother-to-child transmission

Prevention

• Effective vaccine for hepatitis E virus infection is not available in Hong Kong
• Risk of infection with hepatitis E virus can be reduced by maintaining good personal hygiene, avoiding consumption of water or ice of unknown purity and adhering to food safety

Management

• There is no specific treatment for hepatitis E
• Symptomatic infection commonly occurs in young adults, while the disease is mostly asymptomatic or causes mild illness without jaundice in children
• The disease is usually self-limiting, and people with hepatitis E will recover completely in 4-6 weeks
• The overall case-fatality rate of hepatitis E virus infection is about 1-2%, but clinical disease can be severe in pregnant women in their third trimester, with a case-fatality rate of 20%.
• Cases of chronic hepatitis E infection have been reported in immunosuppressed people, who may require antiviral drugs for viral clearance