Module 1: The liver and hepatitis viruses - section 4

In this document:

Hepatitis and hepatitis viruses

Activity: Group work and discussion with lecture presentation
Section Time: Approximately 20 minutes

This section gives participants introduction to hepatitis and an overview of the viruses that can cause it.

Start with a small group exercise, show Slide 1.9 (Group work) and ask the following questions:

Ask each group to record answers on flipchart paper. Allow about 10 minutes before gaining feedback from each group and discuss the learning in the large group.

To facilitate the group exercise and discussion:

  • Summarise and compare understanding using the following Slides 1.10 (Hepatitis and viral spread) and 1.11 (Hepatitis, liver disease and damage)
  • Encourage participants to be concise as the natural history, of HCV in particular, will be covered in more comprehensive detail in subsequent sections

Supporting content:

Hepatitis refers to viral infections that cause inflammation of the liver. Hepatitis A, B and C are the most common types with hepatitis D and E being less common. This wide ranging family of viruses have different causes and symptoms but also some related characteristics.

Hepatitis A (HAV) is found in faeces and infection is spread contaminated food or drinking untreated water. It causes an acute illness causing a range of clinical problems from mild illness to no symptoms to more severe illness and, very rarely acute liver failure. Typical symptoms, which mainly can be treated, include nausea, vomiting, diarrhoea, fever, fatigue, rash, jaundice, liver pain, and dark brown urine. HAV goes away by itself, usually within two months and does not cause chronic problems. Vaccines are available to provide protection against HAV.

Hepatitis B (HBV) can be found in blood, semen, and vaginal fluid of infected persons. A person can get HBV from sharing injection or tattooing equipment, unprotected anal, vaginal or oral sex, and by sharing personal care implements such as toothbrushes and razors. HBV can be passed from mother to child during birth. The vast majority of people who are infected with HBV are able to fight off the virus, meaning their infection never becomes chronic and they may remain healthy without any symptoms while they clear the virus from their bodies. Some will not even know they have been infected although they’ll remain infectious to others until the virus has been cleared. Symptoms are similar to those from HAV and include flu-like symptoms, such as tiredness, general aches and pains, headaches and fever, loss of appetite and weight loss, nausea or vomiting, diarrhoea, stomach pains, and jaundice. For HBV, immunisation is the best way to prevent infection and it has been shown to be effective in 95% of cases.

Hepatitis C virus (HCV) a single-stranded RNA virus that is highly infectious and usually spread through blood to blood contact, when the blood from a person infected with HCV enters into the body of someone who isn’t infected. On entering the body, it targets the liver cells where it replicates and causes inflammation and damage. HCV is often described as an indolent virus. This means that it is usually slow to establish itself and it can take time to cause chronic infection. Genetically, the virus varies, mutates and evolves, helping it evade attack from an infected person’s immune system.

HBV and HCV co-infection accounts for a substantial proportion of liver diseases worldwide, representing one of the biggest threats to global health and killing approximately 1.5 million people a year. Because the two viruses share similar modes of transmission, co-infection with the two viruses is not uncommon. The exact number of people co-infected with HCV and HBV is unknown. In those with chronic HBV, estimates of the rates of HCV co-infection vary from 9% to 30%. The primary concern with HBV/HCV co-infection is that it can lead to more severe liver disease and an increased risk for progression to liver cancer. The prevalence of HCV and HBV will be explored further in later modules.

HBV can be treated with interferon and oral antiviral drugs although treatment of co-infected people is invariably complicated with significant concerns. No standard recommendations exist for treatment of HBV/HCV co-infection, but safe and effective vaccines can prevent HBV. It is generally recommended that people infected with HCV should receive both HAV and HBV vaccinations.

Hepatitis D (HDV) infection only occurs in people with HBV and increases risk of cirrhosis. HBV vaccination also protects against HDV. Hepatitis E (HEV) is similar to HAV but there is no vaccine for HEV. A person can only be infected once and this is not usually serious except in pregnancy. There is much less known about Hepatitis F (HFV). It is thought to be similar to HBV but this is unconfirmed by research and GB virus C (CBV-C), formerly known as Hepatitis G (HGBV-C), is similar in structure to HCV but its role and importance is unclear; although known to infect humans it is not known to cause disease.

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