Thomas Tu leads his own research group at Westmead Institute for Medical Research in Sydney. (ABC RN: Fiona Pepper)
Thomas Tu’s mission to understand hepatitis B is a deeply personal one.
The research scientist was just 14 when he discovered he had chronic hepatitis B — a viral infection that causes liver inflammation — during a routine blood test.
Now 33, Dr Tu has dedicated his career to researching the illness, which affects 257 million people worldwide.
“I converted my hepatitis diagnosis into fuel to drive towards my life’s passion — passion for my work,” Dr Tu said.
“It’s my hope that my work will lead to something — whether that be new diagnosis tools, treatments or knowledge — that will make life easier for those living with hepatitis B.”
In Australia, it’s estimated 221,000 people are living with chronic hepatitis B, about a third of whom remain undiagnosed. Only around 9 per cent are receiving treatment — significantly less than thought to be eligible.
Hepatitis B, or hep B, is the most common blood-borne virus in Australia, and a leading cause of liver cancer.
“I want to inform people [with hep B] that they’re not alone,” Dr Tu said.
“Knowing what it feels like to have a chronic hepatitis B infection makes me want to do more.”
Most people infected as babies
Since 2000, almost all children born in Australia have been immunised for hepatitis B.
However, the preventative vaccine has no impact on existing infection. There are still hundreds of thousands of people living with the disease in Australia, the vast majority of whom were born overseas.
“There’s more people infected with hepatitis B in Australia than there is with HIV and hep C combined,” said Peter Revill, senior medical scientist at the Doherty Institute.
“Hepatitis B has been the poor cousin of a few other infectious diseases over the years, and yet, globally, it kills more people than malaria.”
Hep B disproportionately impacts Aboriginal and Torres Strait Islander people, particularly those from rural and remote communities.
“We’re getting better at diagnosing … but we need to treat more people,” Professor Revill said.
It’s possible to contract hep B from unsafe sex or unsterile drug injecting equipment, but most adults who become infected with the virus clear it from their body, oftentimes unaware they ever had it.
“If a person with a normal, robust immune response is infected in adulthood … their body will surmount an immune response that will control the infection,” Professor Revill said.
Children who are infected, on the other hand, are much more likely to develop a chronic hepatitis B infection and experience long-lasting effects. In fact, the vast majority of people who develop chronic hepatitis B acquire the infection at birth or in childhood.
“If this virus is transmitted from mother to baby, and the baby is not vaccinated … the likelihood of developing chronic infection is about 90 per cent,” Professor Revill said.
“That’s thought to be due to the lack of immune development in the baby.”
A ‘silent disease’
One of the challenges of improving diagnosis and treatment rates of hep B is the invisibility of the illness in its early stage.
Chronic hepatitis B can be symptom-less for many years, meaning people may not realise they are infected until they develop liver problems.
“That’s the thing with hepatitis B — people often don’t even know they’ve got it,” Professor Revill said.
“It has really been a sort of silent disease.”
Untreated hep B can lead to liver scarring (or cirrhosis), liver cancer and death.
“Deaths from liver cancer have been increasing faster than deaths caused by any other cancer in Australia,” Professor Revill said.
“Hepatitis B probably contributes to 40 to 50 per cent of those liver cancers.”
Treatment for chronic hepatitis B involves regular check-ups and anti-viral medication that helps to control the amount of virus in the body.
“Current anti-viral therapy, even though it might control the virus, doesn’t eliminate the risk of liver cancer, and is lifelong,” Professor Revill said.
“It drops the risk of progressing to liver cancer by about 50 per cent, but this means there is still a significant likelihood that those affected will go on to develop cancer.”
It’s a prospect that Dr Tu is faced with every day.
“During my days, I get told that people with hepatitis B have a 25 per cent chance of dying of liver cancer or liver cirrhosis, and it sort of washes away,” he said.
“But at night, it really does wear away at me.
“I think it’s important to talk about … to give some sort of glimpse of what living with chronic hepatitis B actually means.”
Efforts to find a cure
In addition to expanding vaccine coverage, researchers are now working towards developing a cure to help prevent the 880,000 deaths that hep B causes around the world every year.
“The current [research] field is really focused on trying to clear the virus from chronically infected patients,” Dr Tu said, “to allow patients to stop treatment, and live a fuller life where they don’t have to worry so much.”
But it’s an enormous challenge, according to Professor Revill, given the complexity of the virus.
“Hepatitis B is a tricky little virus … it gets into the nucleus of our cells, and in there it can hide,” he said.
The virus makes a form of DNA called “cccDNA”, which is kind of like a master copy of the virus.
“It forms a reservoir … and no matter what virus you get rid of in the cytoplasm, that [reservoir] is always there, ticking away, and potentially the source of new virus,” Professor Revill said.
Dr Tu has developed a way of detecting this cccDNA — but more research is needed to work out how to directly target it.
Professor Revill said the 2016 introduction of highly effective curative drugs to treat hepatitis C in Australia had spurred a renewed push towards a cure for hep B.
“I don’t think one magic bullet is going to do it alone. It’s likely we’re going to need multiple approaches,” he said.
“The virus has been worked on for 35 years. There’s still a lot to do, but we’re getting closer.”
Dr Tu said another key barrier to overcome was the stigma associated with hepatitis infections.
“My parents were part of the first Asian migration wave after the White Australia policy had been repealed,” he said.
“So, they were very keen not to put their head up, become targets for being excluded.
“Because of that, keeping your head down and not mentioning that you have this infection is definitely a big part of my life and a lot of other people’s lives.
“I don’t know how to solve that. But I think it’s something we need to discuss — and overcome.”
The 2019 International Hepatitis B Virus Meeting is happening in Melbourne this week.