Contributors Si-Cheng Dai and Sangyup Lee
Today is July 28th, 2020, and it’s a very special day. From its humble beginnings in Cuttack, Odisha, to its now worldwide renown as one of the World Health Organization’s (WHO’s) global public health campaigns, World Hepatitis Day has always been about one thing: spreading awareness about hepatitis — its prevention, its diagnosis, and its treatment.
An inflammation of the liver, hepatitis can be life-threatening; in 2015 alone, the disease was a result of 1.34 million deaths worldwide. And unlike tuberculosis and HIV, mortality rates are rising, with a 22% increase from 2000. But these frightening truths are exactly why World Hepatitis Day exists. Every year, millions of people are working to spread awareness about hepatitis, whether through donations, rallies, or vaccine drives. Heck, in 2012, the World Hepatitis Alliance set a Guinness World Record by having the most participants perform the proverbial “see no evil, hear no evil, do no evil” within 24 hours. Anyone can contribute to the movement.
We here at BMSA want to do our part as well; hopefully here, by giving a brief overview of hepatitis A, B, C, D, and E, you readers at home can be more informed and spread the word.
Hepatitis A: the abrupt
Hepatitis A, the first of our diseases, shares many characteristics with that of hepatitis E, our last item on the list. The virus is spread through the fecal-oral route. Because it inhabits shared water and food supplies, hepatitis A epidemics can arise seemingly out of nowhere. A 1988 incident of contaminated food in Shanghai led to 300 000 infected in a short period of time. Fortunately, hepatitis A is rarely fatal; symptoms typically include fever, loss of appetite, and diarrhea. Jaundice occurs in 70% of adults with the infection.
There is also a vaccine available; additional prevention involves an adequate disposal system and clean water supply, alongside good personal hygiene practices. Treatment is typically not necessary as individuals often recover by themselves. It is important to note, though, that just like hepatitis E, acetaminophen and vomiting inhibiting drugs should not be administered. Acetaminophen especially places too much pressure on the liver.
Hepatitis B: the biggest
Hepatitis B is the leading cause of death among all patients with hepatitis; according to WHO, 887 000 deaths result worldwide from the chronic complications of hepatitis B, liver cirrhosis and liver cancer. The disease is caused by the hepatitis B virus, and is most commonly acquired through sexual intercourse, a form of horizontal transmission (spread through body fluids). Vertical transmission (e.g. from mother to child) is also possible. In many cases, those infected by the virus are asymptomatic. For others, hepatitis B can be acute, where jaundice, fatigue, and vomiting can occur for six to eight weeks; or chronic, where liver damage is imminent. Interestingly, the risk of chronic infection is correlated with age. Ninety percent of newborn infants who acquire the disease are chronically infected, whereas only about 5% of infected adults are.
One cannot distinguish between different hepatitis diseases in a clinic, but blood tests in the laboratory can distinguish between viruses. Ironically, though affecting the most people, hepatitis B is the most preventable of the hepatitis line of diseases: vaccines provide 98 to 100% protection. Adopting safe sex practices and screening during pregnancy are also safeguards for the transmission of hepatitis B. Since there is no cure for hepatitis B, prevention is the best measure to take. However, drugs that suppress viral replication can be taken to slow the progression of the disease. Maintaining a well-balanced diet and replacing fluids are also important at keeping symptoms of the disease at bay.
Hepatitis C: the convoluted
Hepatitis C is the leading cause of liver cancer. Being quite prevalent among hepatitis diseases, its chronic variant affects 71 million people globally. The hepatitis C virus that causes the disease is blood-borne; thus, transmission occurs primarily through exposure to infected blood, with improper sterilization and the sharing of injection needles being high-risk situations. Vertical transmission is extremely rare. Something to be wary of is the fact that one can acquire hepatitis C more than once; the virus’ strands change so quickly that your body’s adaptive immunity is compromised. The symptomatology is also perplexing; 80% of patients are asymptomatic. Furthermore, the virus seemingly disappears among approximately 25% of those infected after a certain period of time. When it does show itself, the disease can be acute, causing fever, fatigue, and nausea; or chronic, leading to liver cirrhosis and cancer.
There is no vaccine for hepatitis C as a result of the virus’ shifting nature, but a relatively novel treatment is available. Implemented in 2010, direct-acting antivirals can cure more than 95% of patients; unfortunately, they are expensive and reserved for those with severe liver disease. If you’re curious about your risk for hepatitis C, feel free to utilize the Canadian Liver Foundation’s hepatitis C risk assessment quiz to help determine whether getting tested is right for you:
Hepatitis D: the dependent
Hepatitis D is the definition of a freeloader. The virus requires the help of its cousin, the hepatitis B virus, for its own replication. As a result, since successful hepatitis B vaccination programs were implemented in the 1980s, the rate of hepatitis D infections has decreased dramatically. The hepatitis D virus is primarily transmitted horizontally, though vertical transmission is also possible. Similar to its cousins, hepatitis D can be acute or chronic. In dubious fashion, hepatitis D infection in tandem with a pre-existing hepatitis B infection can exacerbate chronic symptoms — in 70 to 90% of people in this situation, the additional virus accelerates the effects of cirrhosis 10 years through a mechanism that is currently unclear.
Prevention of the disease lies once again with its benefactor; prevention of hepatitis B infection through vaccination is key in preventing the contraction of hepatitis D. Safe practices with regard to sex and needle use are also recommended. In terms of treatment, drugs are typically successful. Autoimmune drugs like interferons are common candidates, and novel drugs, such as hepatitis B virus entry inhibitors, are also viable options. For those with end-stage liver disease, liver transplants are often necessary.
Hepatitis E: the effluent
The hepatitis E virus has four different genotypes; genotype I and II are found only in humans, while III and IV are found primarily in other mammals (though they can occasionally infect humans as well). The hepatitis E virus is a worldwide phenomenon, but is most common in parts of East and South Asia. Transmission is fecal-oral, with the virus entering the body through the intestine. The conduit by which this occurs depends on the environment — in resource-poor areas, poor sanitation and subsequent fecal contamination of drinking water is the main culprit (genotype I is prevalent); in more developed areas, uncooked meat is the primary source of transmission (genotype III is prevalent). Hepatitis E has acute and chronic forms. As the virus is usually rid from the body after three to four weeks through defecation, chronic infection is extremely rare, though it has been seen in immunosuppressed people.
Prevention involves having access to proper sewage and disposal systems, and the avoidance of water from unknown sources. Treatment for acute hepatitis E is typically not necessary. Hospitalization is generally not required unless one is symptomatic and pregnant, or is immunocompromised. For chronic infections, antiviral drugs and interferons are used.