It has been referred to as the silent killer, and for good reason. Hepatitis B claims more than a million lives every year. The Hepatitis B Foundation estimates that there are 400 million people chronically infected with the virus, a significant proportion of whom are in China. That’s roughly ten times the number estimated to live with HIV, and yet the attention thatHepatitis B receives is a fraction of what HIV/AIDS receives. Do a Google search on AIDS and you’ll get over 263 million hits. Do the same for Hepatitis B and it drops to 25 million hits.

 

So what exactly is Hepatitis B? In short, it’s the most common liver infection worldwide. The Hepatitis B virus (HBV) attacks liver cells, ultimately leading to liver failure, cirrhosis or liver cancer. It is transmitted via body fluids and blood, and estimated to be between 50 and 100 times more infectious than HIV. Unprotected sex, sharing needles, toothbrushes and razor blades, and even human bites can spread the disease. The most common means of transmission is from mother to newborn child. 

 

But here’s the interesting news: vaccines against Hepatitis B have been around for over 20 years, and there are a number of drugs already on the market that can help people suffering from chronic infection. So why is it still killing so many people each year?

 

Part of the answer lies with the “silent” nature of the disease. In most cases, adults infected with the HBV remain unharmed. “What we see is that the majority of patients are infected with the HBV for less than six months – most are able to clear the virus spontaneously. However, a small percentage go on to develop the chronic disease,” says Will Johnson, Senior Research Executive with Synovate Healthcare’s Global Hepatitis Monitor.

 

Chronic carriers are often unaware that they carry the HBV – they may even feel healthy. “Many infected individuals cannot remember being ill with hepatitis. The virus may remain dormant – these people are asymptomatic and referred to as ‘inhealthy’ carriers,” says Rhoda Schmuecking, Vice-President of Synovate’s Global Antiviral Therapy Monitors. The obvious problem is that chronic carriers may spread the virus without realising it.

 

Chronic carriers have a good chance of suffering liver damage, eventually resulting in liver cancer. “A significant portion of patients may have ongoing liver damage despite remaining asymptomatic,” Schmuecking says. Experts agree that up to 80% of liver cancer cases are due to Hepatitis B. Liver cancer itself is difficult to detect, as there may be no pain from the tumours that develop. And that means most diagnoses occur relatively late – often too late.

 

The reason that HBV persists is that vertical transmission – from mother to child – is the most common transmission, particularly in China. Infants have a 90% chance of becoming a lifetime chronic carrier of HBV due to their immature immune systems. By contrast, an adult has a 10% chance of becoming chronically infected. A child between the ages of one and five has between 30 and 60% chance of chronic infection, according to research by the Asian Liver Center at Stanford University.

 

Globally, Hepatitis B infection rates are substantially higher in the Asia Pacific region, Africa and Central Asia. But it is the Chinese who bear the biggest burden. Of the estimated two billion people worldwide who have contracted the disease, estimations of chronic infection range between 350 million and 400 million, and 75% of them reside in Asia Pacific. Of that, roughly 130 million chronically infected people reside in China. And of that, less than 1% is even aware that they have it, according to Dr George Lau, a trustee of the Cheng Si Yuan (China International) Hepatitis Research Foundation and a professor of hepatology at the University of Hong Kong.

 

The principal way of dealing with the HBV is a universal vaccination programme. China has had such a programme since 2002, and in 2005 began subsidising the costs of the vaccine. The GAVI Alliance – a collection of organisations including the World Health Organization and the Gates Foundation – and the Chinese Ministry of Health estimate that 70% of newborns now receive a vaccination dosage within the first 24 hours of birth.

 

Logistical and training problems hampered China’s vaccination efforts in the beginning. Doctors often reused needles, not realising that their actions would help the virus. For many of China’s rural poor, the original high cost of a vaccine dose, as well as the need for early immunisation, presented too many difficulties. There were even problems handling the vaccines as they needed to be kept cool and fresh for usage, according to Dr Lau.

 

There is also the issue of discrimination. Chinese people who are thought to have the disease may find themselves having difficulty getting or keeping a job and face social isolation due to fear.

 

Many of the problems are being overcome and Dr Lau feels that China’s vaccine programme and its Hepatitis B efforts are “improving and going in the right direction”. He notes that the price of the vaccination has gone down dramatically, putting it in the reach of China’s rural population. The World Health Organization reports that the price of a vaccine dose for HBV has gone from US$20 to as low as $0.25 in the past two decades.

 

“The major remaining hurdle is awareness and that requires education, on all fronts,” says Dr Lau. He also says that there are now five pharmaceutical options for dealing with chronic cases of Hepatitis B. “The tools are all there, so education is the key.”

 

Screening for HBV, knowing what to do if you have it, doctors understanding how to deal with it and mothers knowing the importance of early neonatal vaccination are all part of eradicating Hepatitis B. What’s surprising is that a vaccination exists for the Hepatitis B Virus, and yet the news about HIV, SARS and Avian Influenza tends to overshadow a curable disease that still claims millions of lives.

 

Treating chronic carriers of Hepatitis B is another difficulty. With the vast majority of carriers unaware of their condition, the first challenge is screening people for the disease. Then there is the need for a drug regime to prevent damage to the liver. For the people living in China’s more prosperous urban areas, this is much easier than for those living in the poorer rural areas. Adding to the complexity is the possibility that the guidelines for administering treatments for Hepatitis B may need reviewing.

 

Professor Lai Ching-lung of Hong Kong University’s Department of Medicine believes that the thresholds for treatment need to be lowered. He cites research showing that HBV carriers continue to suffer liver damage even after the viral load of HBV has been reduced to current guidelines for the termination of treatment. Although only one liver research agency in the US has lowered the thresholds for commencing and ending treatment, Professor Lai says that no agency in the EU or Asia Pacific has done so, though he expects they will eventually.

 

For the time being, Hepatitis B remains a problem primarily for Asians. But growing rates of migration and travel may change that. Without increasing awareness, Hepatitis B will continue to kill – silently.