First stroke awareness and prevention, and now hepatitis. May is a hectic time on the healthcare community’s calendar!
Viral hepatitis is the leading cause of liver cancer and the number one reason for liver transplantation. Here in the US, there are about 80,000 new hepatitis infections each year. Some 4.4 million people presently live with chronic hepatitis B or C infection, conditions that put them at real risk of serious liver diseases, including liver failure, cirrhosis and liver cancer. Here’s the worrying part: most infected individuals do not know they are infected. Worldwide, one in every 12 people is infected with viral hepatitis, resulting in about one million hepatitis-related deaths each year.
Our National Institute of Allergy and Infectious Diseases (NIAID) currently supports and conducts research on each of the five known hepatitis viruses — A through E. NIAID scientists have been part of many major breakthroughs during the past sixty years, including discovering the hepatitis A and E viruses, developing one of the first diagnostic tests for hepatitis A and studies that led to the creation of the vaccine for hepatitis A, and laying the groundwork for development of a hepatitis E vaccine. And there is more to come, including the development of new vaccines and treatments to prevent both chronic and acute hepatitis infection.
Here’s how the various viruses work, letter by letter:
Hepatitis A is a contagious, acute inflammatory disease of the liver. It is estimated by the CDC that nearly 25,000 people contracted hepatitis A in the US in 2007 alone. The number of reported cases is much lower than this because some victims show no symptoms. While most people who contract this disease eventually recover completely, an estimated 100 patients die from infection each year in this country.
Hepatitis B-induced liver cirrhosis and liver cancer kill some 3,000 Americans and approximately 620,000 people worldwide every year. It is vaccine-preventable. The virus can spread from mother to child during childbirth, through sex with an infected partner, through contact with the blood of an infected person and/or by sharing razors, toothbrushes, needles or syringes with an infected person. Co-infection with hepatitis B and HIV is quite common.
NIAID is working at present with scientists, researchers and the pharmaceutical industry to screen hundreds of new compounds for potential antiviral activity against hepatitis B. The goal is to develop treatments that will work either on their own or in combination with current drugs to resolve or reduce chronic infections.
Hepatitis C is mainly spread through contact with the blood of an infected person, such as through the needle-sharing habits of injection drug users, unsafe injection procedures in healthcare facilities, mother-to-child transmission during childbirth, and, though not often, through sexual contact with an infected partner.
There is currently no vaccine to prevent hepatitis C. Drugs presently available cure only a proportion of infected individuals. There is much hope that new drugs currently in trials may greatly improve this treatment success rate.
Hepatitis D is a viral infection that can propagate only when the hepatitis B virus is also present. It damages the liver. There are about 15 million individuals worldwide presently infected with hepatitis D.
Hepatitis E is rare in this country, thankfully. It is however, prevalent in the Middle East, sub-Saharan Africa and south and central Asia. It is spread through contact with contaminated water or food. Studies have found that in some regions, when pregnant women are infected with the hepatitis E virus during their second or third trimester, their babies are at greater risk of birth defects or poor health. NIAID-funded researchers are testing mothers with micronutrient deficiencies to explore what can be done about this effect. There is also investigation into whether the hepatitis E virus can be reactivated after a bout of acute disease.
There have been successful trials of hepatitis E vaccines, but no such vaccine has yet to be licensed for use in the US.
For more info, check out NIAID’s hepatitis site.
Special thanks, NIAID .