by
Katrina Welch
You might have heard of the viral infection hepatitis before, but did you know that there are at least five different types of this disease? Though each one has a different cause, each type results in the inflammation of the liver. With vaccination, the spread of some of these types of hepatitis can be prevented.
Hepatitis B and hepatitis C are the two most prevalent types, and a study by the World Health Organisation (WHO) revealed that worldwide there are approximately 325 million people who live with one or both of these types of hepatitis. It has also been estimated that there are 1.4 million deaths annually as every 30 seconds someone dies from an illness which is hepatitis related.
A study published by the WHO also showed that by the year 2030, if diagnostic tests, medicines, vaccinations and education campaigns are made available to low- income and middle-income countries, approximately 4.5 million premature deaths due to hepatitis can be prevented.
As a result, each year World Hepatitis Day is observed on July 28 to raise awareness of the disease and educate people on the negative impact which hepatitis has globally on health and the economy, with the aim of effecting change by reducing its spread.
This year it will be observed under the theme, “Hepatitis Can’t Wait”. To this end, let’s take a closer look at the various types of hepatitis.
Hepatitis A (HAV)
Hepatitis A (HAV)
Hepatitis A is a viral disease of the liver that is usually transmitted via the consumption of food and water which has been contaminated by the faeces of an HAV infected person. This disease is most common in countries where people lack access to safe clean drinking water and good sanitisation practices.
HAV can also be spread directly through person-to-person contact and oral-anal sexual activities. The illness ,which results from this type of hepatitis can be mild to severe, but most people usually recover from HAV after a few weeks or months, and develop immunity to the disease. At present, there is a Hepatitis A vaccine available which is safe and effective in the prevention of the disease.
Hepatitis B (HBV)
A more widespread and potentially fatal form of this viral disease is hepatitis B. That’s because HBV causes chronic infection and increases the risk of developing other life threatening diseases such as cirrhosis, liver failure and carcinoma (liver cancer). A study by the WHO showed that 257 million people were infected with chronic hepatitis and in that same year 887 000 died as a result of cirrhosis and carcinoma caused by HAV.
There are still a high number of people who recover from HBV, but of this number some people become asymptomatic. This means that even after their bodies no longer exhibit symptoms of the disease, they are still carriers and spread the disease to others.
Transmission can occur with the exchange of bodily fluids during sexual intercourse with an infected partner and an infected mother can pass HBV on to her offspring during childbirth.
Contact with HBV infected blood, and sharing needles or syringes with an HBV infected person is also another common method by which this disease is spread. As with HAV, there are safe and effective vaccines available for HBV.
Hepatitis C (HCV)
It has been estimated by the WHO that there are 71 million people globally who are infected by chronic hepatitis C. HCV is a blood-borne virus which means that it is spread when persons come into contact with small quantities of HCV infected blood. This can occur through blood transfusions, childbirth, the sharing of needles for drug use, the administration of unsanitary injections, improper disposal of blood collection medical instruments, and bleeding during sexual intercourse.
The resulting liver disease can be either acute or chronic hepatitis. As the disease can be treated with antiviral medicines, some people recover from mild HCV in a few weeks. However, there are others who experience the HCV ailment lifelong, and go on to develop cirrhosis or liver cancer. It was estimated by the WHO that approximately 399 000 deaths occurred due to cirrhosis and carcinoma which developed from HCV in 2016.
Hepatitis D (HDV)
Hepatitis D occurs in people who have already been infected with hepatitis B and affects almost five per cent of the people globally who are diagnosed with HBV. Even though there has been a steady decline of HDV cases globally since the 1980s, Western Africa and Middle Africa are two of the main regions which still have a high prevalence of HDV. Unfortunately, the rates of successful treatment for people with HDV are low and to date the only prevention against HDV infection is the hepatitis B vaccine.
Hepatitis E (HEV)
This fifth type of viral hepatitis is most prevalent in South Asia and East Asia, even though cases of HEV can be found worldwide. Transmission is usually faecal-oral when water that has been contaminated by the faeces of an infected person is consumed. The WHO approximates that annually there are 20 million HEV infections across the globe and reports that in 2015 there were 44 000 deaths due to this disease. Even though a vaccine has been developed to protect against HEV, according to the WHO it is currently licensed for use in China and is not yet available anywhere else.
