Viral hepatitis is common and the best-known viruses causing hepatitis are types A, B and C. Little known, but important, is delta hepatitis or hepatitis D. While delta hepatitis affects about 15-20 million worldwide compared to the hundreds of millions the others affect, it results in the most severe form of viral hepatitis with a significantly increased risk of developing liver failure, cirrhosis and liver cancer. By the numbers, 10 to 20 percent of people with hepatitis C will develop cirrhosis within 20 years of exposure, 20 percent of people with chronic hepatitis B will develop cirrhosis within five years and a staggering 70-80 percent of patients with hepatitis D will develop cirrhosis within five to 10 years. People with hepatitis D have a 60 percent mortality rate within 10 years.
So why is hepatitis D relevant to us as this disease is far less common than the other viral hepatitis viruses? Interesting, of the 20 zip codes in the United States with the greatest prevalence of this infection, nine are located in our area with several of these on Long Island. None are more than an hour drive from Nassau County.
So how does someone acquire hepatitis D? The risks factors for hepatitis D are similar to those of hepatitis B. The most common risk factors are sexual contact, intravenous drug use, tattoos and body piercing.
Hepatitis D or delta hepatitis is unique as it only affects people with hepatitis B. Infection with delta hepatitis can occur at the same time as infection with hepatitis B, termed co-infection, or it may affect people previously infected with hepatitis B, termed super-infection.
Co-infection usually results in acute disease characterized by fatigue, abnormal liver tests and jaundice. Most people who simultaneously contract hepatitis B and D will recover within six months of exposure although a small percentage may develop acute liver failure or develop chronic disease.
Superinfection with hepatitis D is more worrisome. This occurs when a person already infected with hepatitis B acquires hepatitis D. Superinfection leads to chronic disease in more than 90 percent of cases. In those patients whose hepatitis D resolves after superinfection, the underlying hepatitis B persists. Superinfected patients are the ones most likely to develop cirrhosis, liver cancer and need a liver transplant. In fact, superinfected patients develop liver cancer at a rate that is three times that of hepatitis B alone.
There are currently no approved therapies for hepatitis D although injectable interferon therapy is used in some patient. Research is ongoing to develop new and effective therapies. Liver transplantation is the best treatment for end stage liver disease secondary to this virus with the risk of reinfection of the graft low but still possible. Because of the lack of effective treatments, current strategies are focused upon disease prevention. There is no vaccination specifically formulated to prevent hepatitis D. Luckily, vaccination against hepatitis B will also protect an individual from acquiring hepatitis D. Risk factor avoidance is also effective.
So, what is the take home message regarding hepatitis D? First, health care providers and patients should think about and test for this infection in the correct setting. And second, risk factor avoidance is good medicine as is universal hepatitis B vaccination, which will prevent against acquiring this worrisome and potentially deadly disease.