July 28th is World Hepatitis Day 2018 and the perfect opportunity to kick back off the SATKT blog. The goal of SATKT is to get people thinking (and talking!) about science and health topics and how they relate to their lives. I hope you find this post and the ones to come helpful. No medical advice is presented or should be inferred, and I encourage you to follow up with your healthcare professional to discuss your individual healthcare needs.
What do you already know about Hepatitis? Do you know how it can be prevented and how it is spread? Are you vaccinated? Do you know someone who is living with Hepatitis or had a Hepatitis infection in the past?
Like the graphic above shows, hepatitis is an infection caused by a virus that affects the liver. The liver is an organ in the upper part of the abdomen and sits underneath the diaphragm and on top of the stomach, right kidney, and intestines.
The liver plays a vital role in many bodily functions, including the production of bile, cholesterol, and some proteins. It regulates blood clotting, and stores and releases glucose when it is needed. Some people refer to the liver as the body’s filter because it works to clear the body of harmful substances like drugs, ammonia (a by-product of protein metabolism), and bilirubin. Importantly, the liver helps the body to resist infections by creating immune factors to remove harmful bacteria from the bloodstream.
Public health problem
Hepatitis is a major global health issue. According to a 2017 World Health Organization report, viral hepatitis infections (Hepatitis B & Hepatitis C) were behind 1.34 million deaths in 2015–more than the number of AIDS deaths and similar to those caused by tuberculosis (TB). But unlike AIDS and TB, the number of deaths caused by viral hepatitis is increasing, with 6-10 million new cases yearly. Although Hep. B is mostly found in the African and Western Pacific regions, it can be found around the world. Similarly, Hep. C is a global problem, but the European and Eastern Mediterranean regions have the highest reported prevalence of the infection. In the U.S., new cases of Hep. A and Hep. C are increasing, while the incidence of Hep. B has fallen. Overall, the number of Americans living with chronic Hep. B is estimated between 850,000-2.2 million and with chronic Hep. C, an estimated 3.5 million. Many people with viral hepatitis are asymptomatic (present no symptoms) or have symptoms that are minor (especially during early infection) and are undiagnosed.
When a person is infected with hepatitis that results in chronic infection, the liver is damaged by the body’s immune response, namely inflammation that results in scarring and death of liver cells. Symptoms that indicate liver damage include a build-up of bilirubin which causes jaundice (a yellowing of the whites of the eyes and skin), nausea and loss of appetite, and intense itching. The only cure for end-stage liver disease is a transplant.
image source: Medline
Types of Hepatitis
How a person becomes infected with hepatitis, the impact of that infection, and preventive measures and treatment options depend on which virus they come into contact with. There are 5 different types of hepatitis, each caused by different viruses: Hepatitis A (caused Hepatovirus A), Hepatitis B (caused by Hepatovirus B), Hepatitis C (caused by Hepatovirus C), Hepatitis D (Hepatovirus D), and Hepatitis E (caused by Hepatovirus E).
Hepatitis A does not cause chronic liver disease and most people who become infected with Hep. A recover and develop livelong immunity. However, it can still be a debilitating illness and a small number of people with Hep. A infections will develop a very serious, often fatal complication known as fulminant hepatitis.
Hepatitis A can infect a person when they eat or drink food/water that is contaminated or if they come into direct contact with someone who is infected with Hep. A. Good washing practices, general hygiene, and adequate sanitation are important ways to prevent Hep. A infection. In the U.S., a vaccine (2 doses) is given to children between their 1st and 2nd birthdays, or to previously unvaccinated in certain high-risk groups or who are traveling to an area where Hep. A is prevalent. The vaccine is an important tool in public health.
Hepatitis B & Hepatitis C
Hepatitis B and Hepatitis C both cause serious, chronic liver disease, though Hep. C can also be an acute (short-lived) illness. Hep. B and Hep. C are responsible for 96% of all hepatitis deaths. Hep. C is the #1 cause of liver cancer and reason for liver transplants. Like the image at the top notes, Hep. B and Hep. C can even lead to death. Infection with Hep. B occurs through contact with blood or other bodily fluids of someone who is already infected, such as through sexual behaviors. Hep. C is spread through contact with infected blood. This can happen with unsafe needle practices (such as through drug use) and unsafe medical practices (such as failure to adequately sterilize medical equipment or screen blood and blood products).
Because of the high public health risks and disease burden on individuals associated with Hepatitis B, the vaccine is crucial to preventing disease. The U.S. immunization schedule recommends 3 doses of the vaccine be given between birth and 18 mos. of age for most children.* There is currently no vaccine available for Hepatitis C, though new direct anti-viral medications like Harvoni, Zepatier, and Sovaldi can now cure the disease for many people.
Hepatitis D & E
In the U.S., Hepatitis D is somewhat uncommon and occurs only in people who are already infected with Hepatitis B. Infection can spread through contact with Hep. B-infected blood. There is no vaccine for Hep. D, but vaccinating for Hep. B can prevent Hep. D infection. Hepatitis E does not cause chronic liver disease and is rare in the U.S. It is often spread by contaminated water in areas with poor sanitation. There is no vaccine for Hep. E.
Science at the Kitchen Table
Now that you know some facts about Hepatitis, I hope that you will share the information with others. Sitting around the kitchen table for a meal is a great opportunity to talk about health problems and reduce the stigma associated with disease. Below are some links to reputable websites where you can find more information about Hepatitis if you’re interested:
*The U.S. vaccine schedule and recommendations can be found here: https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html
The April 2017 World Health Organization Global Hepatitis Report can be found here: http://www.who.int/hepatitis/publications/global-hepatitis-report2017/en/
Statistics about Hepatitis infection in the U.S. can be found at the Centers for Disease Control and Prevention’s website here: https://www.cdc.gov/hepatitis/statistics/index.htm