Viral hepatitis, an inflammation of the liver caused by specific viruses, comes in types A through E, each with distinct transmission, symptoms, and potential for acute or chronic illness.

Understanding Viral Hepatitis

Hepatitis refers to inflammation of the liver [8]. When caused by specific viruses, it is known as viral hepatitis. There are five main types of hepatitis viruses, classified alphabetically as A, B, C, D, and E [2, 3]. These viruses are a significant global health concern, with certain regions being disproportionately affected [3]. While all forms can cause acute symptomatic infection, hepatitis B and C are particularly notable for their ability to lead to chronic infection, which can result in serious health issues such as cirrhosis, end-stage liver disease, and liver cancer [3].

Hepatitis A: Acute and Preventable

Hepatitis A virus (HAV) is typically transmitted through the fecal-oral route, often via person-to-person contact, poor sanitation, or contaminated food and water [6]. It can also be recognized as a sexually transmitted infection, especially among men who have sex with men [7]. HAV infection is often asymptomatic in children, but adults commonly experience symptoms like jaundice, abdominal pain, and elevated bilirubin levels [6]. General flu-like symptoms are also common across various hepatitis types [8].

Hepatitis A is generally considered a self-resolving illness that does not cause chronic hepatitis [1, 2]. Most adults recover completely from acute hepatitis A [1]. However, despite its often self-limiting nature, HAV infection can lead to severe conditions such as acute liver failure (ALF) or acute-on-chronic liver failure (ACLF), which can be fatal [7]. In 2016, HAV was responsible for 7,134 deaths worldwide [2]. Fortunately, a highly effective and safe vaccine is available for hepatitis A, providing long-lasting immunity [1, 3, 6]. Improved sanitation and public awareness also play crucial roles in preventing outbreaks [3].

Hepatitis B: Acute, Chronic, and Vaccinable

Hepatitis B virus (HBV) can be transmitted through direct inoculation and also frequently through nonparenteral routes [5]. It is considered a sexually transmitted disease [8]. Like other forms, acute hepatitis B can present with flu-like symptoms [8].

The outcome of HBV infection depends significantly on when it is acquired. While 95% of adults recover from acute hepatitis B, infection acquired during childhood typically becomes chronic [1]. Chronic hepatitis B can lead to severe complications, including cirrhosis, end-stage liver disease, and liver cancer [3]. In 2019, HBV was estimated to have caused 820,000 deaths globally [2]. Effective and safe vaccines are available for hepatitis B, offering long-lasting immunity and serving as a primary defense against the virus [1, 3]. For those with chronic HBV, safe and tolerable medications are available to suppress viral activity, prevent liver damage, and slow disease progression [3].

Hepatitis C: A Treatable Chronic Infection

Hepatitis C virus (HCV) was historically known to occur after blood transfusions and could account for more cases of post-transfusion hepatitis than hepatitis A and B combined [5]. Like hepatitis B, HCV infection can lead to chronic liver disease, progressing to cirrhosis, end-stage liver disease, and liver cancer [3]. In 2019, HCV was estimated to have caused 290,000 deaths worldwide [2]. A remarkable advancement in medical science is the availability of highly effective curative regimens for hepatitis C, offering a path to recovery for many patients [3].

Hepatitis D and E: Other Important Types

Hepatitis D virus (HDV) is unique because it is a satellite virus that relies on HBV to produce its infectious particles and spread [2]. Co-infection with HDV and HBV is considered the most severe form of chronic viral hepatitis [2].

Hepatitis E virus (HEV) is another orally transmitted virus, particularly common in low- and middle-income regions [2]. Like HAV, HEV is transmitted via the fecal-oral route [7]. HEV infection can also cause severe conditions such as acute liver failure (ALF) and acute-on-chronic liver failure (ACLF), especially in vulnerable populations like pregnant women in certain regions [7]. Improved sanitation and awareness are key strategies to curb outbreaks of hepatitis E [3].

Symptoms, Complications, and Prevention

All forms of viral hepatitis can initially present with general flu-like symptoms [8]. However, specific symptoms like jaundice, abdominal pain, and hyperbilirubinemia are common in adults with hepatitis A [6]. Acute liver failure (ALF) is an uncommon but devastating complication of acute viral hepatitis [1]. Signs such as continued vomiting, prolonged prothrombin time, and clouded consciousness are indications for urgent medical attention and transfer to a liver transplant unit [1]. Both HAV and HEV infections can lead to these severe conditions [7].

Diagnosis of viral hepatitis typically involves evaluating a patient's risk factor history and conducting serological tests [1]. For instance, immunoglobulin M (IgM) antibodies against HAV are used to diagnose hepatitis A [6]. Beyond vaccination for hepatitis A and B, which provides long-lasting immunity [3], improved sanitation and public awareness are vital in preventing outbreaks of hepatitis A and E [3]. While significant progress has been made in prevention and treatment, ongoing efforts are needed to achieve global eradication of viral hepatitis [3].

Sources

This article summarises published research for a general audience. It is not medical advice — talk to a qualified clinician about your own situation. Need help finding one? Browse doctors.

Understanding Viral Hepatitis: Types, Symptoms, and Recovery