By Blandina Steinhauslin, AILO Florence and Linda Harvan, FAUSA
Hepatitis refers to inflammation of the liver, which is the largest solid organ in the body and helps digest food, store energy, and remove poisons. Viruses cause most cases of hepatitis, but other infections, toxic substances (alcohol, recreational drugs and certain prescription medicines) and autoimmune diseases can also cause hepatitis. Viral hepatitis can either be acute (lasting less than 6 months) or chronic (lasting more than 6 months).
There are a few specific viruses that primarily attack the liver and are responsible for about half of all hepatitis cases. These include types A, B, C, D, E and possibly G, with A, B and C being the most common. These viruses constitute a major global health risk with around 240 million people being chronically infected with hepatitis B and around 150 million people chronically infected with hepatitis C. Hepatitis viruses multiply primarily in the liver cells. This can cause the liver to be unable to perform its functions and produce the symptoms associated with hepatitis.
Many people with acute hepatitis have no symptoms and aren’t aware they are infected. If symptoms do occur, they can appear any time from two weeks to six months after exposure. Symptoms include nausea, vomiting, abdominal pain, fatigue, loss of appetite, fever, dark-colored urine, pale bowel movements, jaundice and joint pain. Complications of acute viral hepatitis include fulminant hepatitis resulting in severe liver failure, which can be life-threatening. Another complication is chronic hepatitis, which can cause scarring of the liver (cirrhosis), loss of liver functions and in some cases, liver cancer.
Millions of people are living with viral hepatitis and millions more are at risk of becoming infected. Most people with chronic infections of hepatitis B or C are unaware that they continue to carry the virus. They are therefore at high risk of developing severe chronic liver disease and can unknowingly transmit the virus to other people. Approximately one million people die each year from causes related to viral hepatitis, most commonly cirrhosis and liver cancer.
Hepatitis A
- Hepatitis A is a viral liver disease that can cause mild to severe illness.
- The hepatitis A virus (HAV) is transmitted through ingestion of contaminated food and water or through direct contact with an infectious person.
- People most likely to contract hepatitis A include those who travel to developing countries, use illegal drugs, have unprotected sex with an infected person, live with someone with an active infection or provide childcare.
- Someone with hepatitis A is most infectious from around 2 weeks before symptoms appear until about a week after symptoms first develop.
- Almost everyone recovers fully from hepatitis A with a lifelong immunity. However, a very small proportion of people infected with hepatitis A could die from fulminant hepatitis (acute liver failure).
- People most at risk for complications include the elderly and those with pre-existing liver problems.
- The risk of hepatitis A infection is associated with a lack of safe water and poor sanitation and hygiene (such as dirty hands).
- Epidemics can be explosive and cause substantial economic loss.
- A safe and effective vaccine is available to prevent hepatitis A.
- Safe water supply, food safety, improved sanitation, hand washing and the hepatitis A vaccine are the most effective ways to combat the disease.
Hepatitis B
- Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease.
- The virus is transmitted through contact with the blood or other bodily fluids of an infected person.
- It can be spread from a mother to a newborn baby, especially in countries where the disease is prevalent.
- Symptoms tend to occur 2 or 3 months after exposure to the hepatitis B virus.
- An estimated 257 million people are living with hepatitis B virus infection (defined as hepatitis B surface antigen positive).
- In 2015, hepatitis B resulted in 887,000 deaths, mostly from complications including cirrhosis and hepatocellular carcinoma.
- Most adults infected with hepatitis B can fight the virus and recover in one to three months with lifetime immunity.
- Babies and young children are those most likely to develop a chronic infection.
- Treatment with current antiviral drugs suppresses viral reproduction in about 50 to 90 percent of patients with chronic hepatitis B; however, the medicines do not cure the infection and relapse is common.
- Hepatitis B is an important occupational hazard for health workers.
- It can, however, be prevented by currently available safe and effective vaccine.
Hepatitis C
- Hepatitis C is a liver disease caused by the hepatitis C virus: the virus can cause both acute and chronic hepatitis, ranging in severity from a mild illness lasting a few weeks to a serious, lifelong illness.
- The hepatitis C virus is a bloodborne virus, and the most common modes of infection are through exposure to small quantities of blood. This may happen through injection drug use, unsafe injection practices, unsafe health care, and the transfusion of unscreened blood and blood products.
- You are at a higher risk for hepatitis C if you have hemophilia and received clotting factor before 1987, or if you had a blood transfusion or organ transplant before July 1992.
- It is difficult for the human immune system to eliminate hepatitis C from the body, and infection with hepatitis C usually becomes chronic.
- Globally, an estimated 71 million people have chronic hepatitis C infection.
- A significant number of those who are chronically infected will develop cirrhosis or liver cancer.
- Hepatitis C is one of the most common causes of liver disease in the US, and the number one reason for liver transplants.
- Approximately 399,000 people die each year from hepatitis C, mostly from cirrhosis and hepatocellular carcinoma.
- Antiviral medicines can cure more than 95 percent of persons with hepatitis C infection, thereby reducing the risk of death from liver cancer and cirrhosis, but access to diagnosis and treatment is low.
- There is currently no vaccine for hepatitis C; however, research in this area is ongoing.
- For those with hepatitis C, receiving vaccination for hepatitis A and B can prevent those infections, which can further damage the liver.
Hepatitis D
- Hepatitis D virus (HDV), also called the delta agent, is a ribonucleic acid (RNA) virus that requires hepatitis B virus (HBV) for its replication. HDV infection occurs only simultaneously or as super-infection with HBV.
- The virus is transmitted through contact with the blood or other body fluids of an infected person.
- Vertical transmission from mother to child is rare.
- Approximately 15 million people across the world are chronically coinfected with HDV and HBV.
- People who have chronic hepatitis B and D develop complications more often and more quickly than people who have chronic hepatitis B alone.
- Hepatitis D is more common in Eastern and Southern Europe; the Mediterranean region and Middle East; parts of Asia, including Mongolia; Central Africa; and the Amazon River basin in South America.
- Currently there is no effective antiviral treatment for hepatitis D, although researchers are studying new treatments.
- Alpha interferons are currently used, and although the sustained response is low, the treatment is a factor associated with a lower likelihood of disease progression.
- Hepatitis D infection can be prevented by hepatitis B immunization.
Hepatitis E
- Hepatitis E is a liver disease caused by infection with a virus known as hepatitis E virus (HEV).
- Every year, there are an estimated 20 million HEV infections worldwide, leading to an estimated 3.3 million symptomatic cases of hepatitis E, and 56,600 hepatitis E-related deaths.
- Hepatitis E is usually self-limiting, but some cases may develop into fulminant hepatitis (acute liver failure).
- Chronic hepatitis E is rare and only occurs in people with weakened immune systems, like people taking medicines that weaken their immune systems after an organ transplant, or in people who have HIV or AIDS.
- Some types of the virus are transmitted via the fecal-oral route, principally via contaminated water. Other types are transmitted by eating undercooked pork or wild game, such as deer.
- Adolescents and young adults are most likely to be affected by the types of hepatitis E found in developing countries, while older men are more likely to be affected by the types of hepatitis E found in developed countries.
- Hepatitis E is a major public health problem in developing countries and is most dangerous for pregnant women, who can die or have miscarriages or stillbirths due to the disease.
- Hepatitis E is found worldwide, but the prevalence is highest in East and South Asia.
- A vaccine to prevent hepatitis E virus infection has been developed and is licensed in China, but is not yet available elsewhere.
Hepatitis G
- Hepatitis G virus (HGV, also termed GBV-C) was recently discovered and resembles HCV, but more closely, the flaviviruses.
- The virus and its effects are under investigation, and its role in causing disease in humans is unclear.
- It is believed to be responsible for many sexually transmitted and bloodborne cases of hepatitis.
- Hepatitis G often infects people already infected with Hepatitis C.
Other Causes
- Alcoholic hepatitis is most likely to occur in people who drink heavily over many years, but can also occur in people who only drink moderately. People who are diagnosed with hepatitis caused by alcohol and continue to drink have a high risk of serious liver damage and death.
- Autoimmune hepatitis, which generally occurs in young women, is a chronic disease in which the body’s immune system attacks the liver and causes inflammation and liver damage. Doctors treat autoimmune hepatitis with medicines that suppress the immune system, most often corticosteroids.
While each hepatitis virus produces similar symptoms, each has a different route of transmission and different populations that are commonly affected. Find out if you should get tested or vaccinated for viral hepatitis by using the Centers for Disease Control and Prevention’s quick online Hepatitis Risk Assessment tool.
In June 2016, the World Health Organization published the Global Health Sector Strategy on Viral Hepatitis, 2016‒2021. This first global health sector strategy on viral hepatitis contributes to the achievement of the 2030 Agenda for Sustainable Development and addresses the five major hepatitis viruses (hepatitis A, B, C, D, and E.) Emphasis is on hepatitis B and C because of the public health burden they represent. WHO considers viral hepatitis an international public health challenge comparable to other major communicable diseases, including HIV, tuberculosis, and malaria.
The strategy provides
- A vision of a world where viral hepatitis transmission is halted and everyone living with viral hepatitis has access to safe, affordable and effective care and treatment;
- A goal of eliminating viral hepatitis as a major public health threat by 2030;
- Targets that seek to reduce the incidence of chronic hepatitis infection from the current 6–10 million cases of chronic infection to 0.9 million infections by 2030, and to reduce the annual deaths from chronic hepatitis from 1.4 million to less than 0.5 million by 2030. Achieving these targets will require a radical change in the hepatitis response and will mean that hepatitis is elevated to a higher priority in public health responses.
Ending hepatitis epidemics is possible by investing in five core intervention areas:
- Vaccines: Effective vaccines are available for preventing viral hepatitis A, B, and E infections;
- Prevention of mother-to-child transmission of hepatitis B virus: Timely hepatitis B virus birth-dose vaccination is a key intervention for preventing the transmission of the virus from mother to infant at birth;
- Injection, blood and surgical safety: transmission of viral hepatitis B and C in health care settings can be stopped through the rigorous application of universal precautions for all invasive medical interventions, promotion of injection safety measures and securing the safe supply of blood products;
- Harm reduction for people who use drugs: Ensuring access to sterile injecting equipment and effective drug dependence treatment can prevent and control epidemics of hepatitis B and C among people who inject drugs;
- Treatment: New oral, well-tolerated medicines and treatment regimens for people with chronic hepatitis C virus infection can achieve cure rates of over 90 percent. Effective treatment is also available for patients with hepatitis B, although it usually needs to be lifelong.
The largest conference of global hepatitis specialists, the International Liver Congress 2019, took place in Vienna, Austria on April 10-14 and was organized by the European Association for the Study of the Liver (EASL). At the conference, WHO reported that more people are receiving life-saving services for viral hepatitis; however, a more ambitious global investment is needed to attain the elimination targets by 2030. There is encouraging news, with more countries reporting progress on increasing prevention, testing, treatment and care services, and 124 countries out of the 194 that signed the elimination strategy have developed or are developing national hepatitis plans. Challenges inlcude the lack of focus on harm reduction and prevention services for people who inject drugs and the fact that most people living with viral hepatitis lack access to hepatitis testing, treatment and care. Funding continues to be a major barrier since, only 58 percent of countries have provided funding for enlarging their hepatitis programs.