July 28 is World Hepatitis Day. Take a moment to learn what the key differences are between the most common strains of hepatitis.

Hepatitis is a general term for inflammation of the liver. Some chronic forms may cause lasting damage to the liver and can lead to serious long-term health effects, and in some cases, death. In fact, The World Health Organization (WHO) estimatesthat deaths resulting from hepatitis have increased 22 percent since 2000.

Michelle P. Zappas, DNP, FNP, clinical associate professor and family nurse practitioner in the Department of Nursing at the USC Suzanne Dworak-Peck School of Social Work, answers frequently asked questions about the differences between the main forms of viral hepatitis—A, B and C—and how to reduce your risk of infection.

What is hepatitis?

“When we think of hepatitis, we tend to think of viral strains, which includes hepatitis A, B, C, D and E,” Zappas said. “However, there are a number of both viral and nonviral forms of hepatitis, which may be caused by anything from alcohol or medication to autoimmune disease and metabolic defects.” Chronic hepatitis is defined by liver inflammation that lasts longer than six months.

How is hepatitis contracted?

Hepatitis A is most commonly transmitted via the fecal-oral route. “You can contract hepatitis A by either ingesting contaminated water or food, or by person-to-person contact—especially if the other person has been handling contaminated foods and has not washed their hands effectively,” said Zappas, who cites raw or undercooked seafood from contaminated water sources and raw produce as common contaminants. Additionally, she said, “hepatitis A may in rare cases be transmitted sexually, in relation to fecal-oral contact.”

Hepatitis B can be transmitted perinatally (from parent to child) or via sexual contact. It can be contracted through contact with a number of bodily fluids including blood, semen, vaginal secretions, breast milk and more. Hepatitis C is also commonly transmitted via IV drug use, sexual or household contact. “It can be contracted by having unprotected sex with an infected partner, through sharing needles, syringes or razor blades, or perinatally—from an infected pregnant woman to her child,” Zappas said.

What is the most common strain of hepatitis, and who is most at risk of contracting it?

Hepatitis C is the most common strain, with 71 million peopleworldwide suffering from chronic cases. According to Zappas, some 75 percentof people with hepatitis C in the U.S. are baby boomers, born between 1945 and 1965. Additionally, patients with HIV are at higher risk of contracting hepatitis C, the infection occurring in nearly 25 percent of patients who are HIV-positive, and up to 90 percent of HIV-positive injection drug users.

“Hepatitis B may be more prevalent among certain demographics, such as in Asian/Pacific Islander populations,” Zappas said. “Those who engage in regular physical or sexual contact with an infected patient are at higher risk of contracting the infection themselves, since both hepatitis B and C are transmitted via blood and bodily fluids.”

What are some of the symptoms of hepatitis?

“It depends on the type of hepatitis, but symptoms common to all viral strains include nausea and vomiting,” Zappas said. For hepatitis A, fever, jaundice, malaise, abdominal pain and discolored waste may also present as symptoms.

“Arthralgia and joint aches may occur in hepatitis B patients,” Zappas said, “but unfortunately, many hepatitis B and C patients are asymptomatic, meaning they don’t exhibit any symptoms.” Due to a high volume of hepatitis cases, the Center for Disease Control (CDC) recommends screening all baby boomers for hepatitis C.

Which type of hepatitis is considered the most dangerous?

Hepatitis A is considered the least threatening, because it is often transient—it’s rare that any patient experiences lasting effects or dies from this infection.

On the other hand, both hepatitis B and C can be chronic conditions and may generate long-term health effects, such as liver failure, cirrhosis (scarring of the liver) and even hepatocellular carcinoma (liver cancer).

Is there a cure for hepatitis?

According to Zappas, there is no technical “cure” for viral hepatitis, and antibodies will always test positive in a patient who has experienced hepatitis A, B or C. The management of chronic hepatitis B is complex and based on a myriad of factors. Some patients manage their condition with long-term antiviral medications.

However, vaccinations for hepatitis A and B have proven highly effective. Hepatitis A and B vaccinations are recommended and routinely done in infancy,” Zappas affirmed. Most people respond to these vaccinations, but post-vaccination testing may be indicated in high-risk patients.

The outlook is even brighter when it comes to hepatitis C: “Over the last 10 years, the hepatitis C treatment regimens have evolved,” Zappas said. “Now, there’s nearly a 90% ‘cure’ rate with certain antiviral medications, which can eradicate the replication of the hepatitis C RNA and therefore abate the damage of the virus on the liver. It is important to note that patients are not immune to hepatitis C after treatment, and can be reinfected and/or contract another strain.”

To measure the effects, providers look for a sustained virologic response (SVR) indicating that the virus remains inactive, which is evaluated between 12 and 24 weeks after beginning the medication.

“Today, there is a strong healthcare focus on prevention,” Zappas said. “The most important step you can take is to become educated on the risks of household contact, sharing needles and other behaviors that can make you more prone to infection — and, of course, to get vaccinated for hepatitis A and B!”