Monday, July 28 marks World Hepatitis Day, a global public health campaign led by the WHO to raise awareness about the five hepatitis viruses (A, B, C, D, and E). Through this campaign, the WHO urges people worldwide to “think again” about hepatitis, an often neglected but potentially deadly group of viruses that kills almost 1.4 million people every year.
The five hepatitis viruses cause acute and chronic liver disease. Hepatitis A and E (HAV, HEV) are usually acute, causing symptoms such as jaundice, abdominal pain, vomiting, loss of appetite, fever, and an enlarged liver. Though HAV and HEV are not usually fatal, infection can lead to acute liver failure, which may be deadly. Of the approximately 20 million people who are infected with HEV each year, 3 million develop inflamed livers and 56,600 die. An additional 1.4 million people are infected with HAV every year. These two viruses spread through contaminated food and water and are especially prevalent in rural areas of developing countries, where sanitation may be inadequate.
Hepatitis B and C (HBV, HCV) cause both acute and chronic illness. Acute infection is usually asymptomatic or causes symptoms similar to those of acute HAV and HEV infection. The likelihood that acute HBV infection will lead to chronic illness depends highly on the age of infection: while 80-90% of infected infants will develop chronic infections, under 5% of adults will become chronically infected. HCV, on the other hand, causes chronic infection in 55-85% of infected people. Approximately 240 million people are chronically infected with hepatitis B and 150 million with hepatitis C, yet 70-80% of those infected with hepatitis C do not show symptoms and are likely unaware of their infection. Chronic infection can lead to fibrosis (scarring), cirrhosis, and liver cancer. Together, HBV and HCV are the leading cause of liver cirrhosis and cancer. HBV and HCV are spread by blood, semen, and other bodily fluids. Hepatitis D (HDV) is also spread by bodily fluids, but can only occur in people already infected with HBV.
The WHO released their first set of guidelines for the screening, care, and treatment of HCV-infected individuals this April. In addition, new guidelines for prevention and management of HBV are being developed. On World Hepatitis Day, today, the WHO released a “fact file” on hepatitis E with ten facts about its symptoms, transmission, and modes of prevention.
Vaccines for hepatitis A and B can help protect against infection of these two viruses and hepatitis D. A vaccine for hepatitis E has been developed in China but is not yet available worldwide. Improving sanitation is also an effective measure to prevent hepatitis A and E. No vaccine for hepatitis C is available yet, but research is ongoing. Fortunately, there are some effective drugs used to treat hepatitis C: Sovaldi, produced by Gilead Sciences, has been called a “breakthrough therapy” that can cure patients at up to a 90% rate. However, treatment with Sovaldi is costly—a twelve-week daily dose can cost $84,000—and Gilead has been accused of inflating prices to make a profit.
Certain populations are more at risk for hepatitis infection than others. These groups include but are not limited to people who have lived in or visited endemic areas (see these links for maps of HAV and HBV endemic areas), those who have ever injected drugs, received medical or dental treatment in unsterile conditions, baby boomers (born between 1945 and 1965), people with infected sexual partners, and those with HIV. According to the CDC, about 25% of HIV-infected people are also infected with HCV. To evaluate your own risk, take the CDC’s hepatitis risk assessment.
Sources:
http://www.who.int/campaigns/hepatitis-day/2014/en/
http://www.who.int/hiv/pub/hepatitis/hepatitis-c-guidelines/en/
http://www.who.int/features/factfiles/hepatitis-e/en/
http://www.voanews.com/content/australia-hepatitis-drug-costs/1965904.html
http://gamapserver.who.int/mapLibrary/Files/Maps/Global_HepA_ITHRiskMap.png
http://wwwnc.cdc.gov/travel/content/yellowbook/2014/map_3-04.pdf
