Last updated March 28, 2018 at 1:41 pm
Hep B still poorly diagnosed and not well treated.
Untreated, hepatitis B can lead to cirrhosis is a complication of liver disease which involves loss of liver cells and irreversible scarring. Credit: iStock
Nearly 300 million people have hepatitis B virus (HBV) but 90 per cent are undiagnosed and just 5 percent of eligible patients are getting treatment. And this is not just a problem for the developing world.
Research from the Polaris Observatory at the Center for Disease Analysis Foundation in the US suggests that two-thirds of those with HBV in the US and 80 per cent in the UK are unaware of their infection.
In Western Europe, the proportion of eligible patients receiving treatment ranged from 3 per cent in Belgium and 5 per cent in Ireland, Norway and Portugal to 95 per cent in Finland.
The researchers developed their figures by analysing data from 435 studies and 620 national experts then generating updated estimates by incorporating data on epidemiology, vaccination coverage, treatment, and diagnosis.
They say previous estimates of the HBV burden have not considered the impact of prevention strategies or changing prevalence over time and that theirs is also the first analysis to exclude studies done in blood donors, which typically report a low prevalence, and other non-representative populations.
Further, they warn that the WHO targets toward elimination of HBV are unlikely to be achieved by 2030 without a rapid scale-up in access to screening and treatment in most countries.
“We have all the tools necessary to eliminate HBV,” explains primary investigator Dr Homie Razavi. “Our estimates highlight an enormous opportunity for effective screening, diagnosis and treatment to substantially reduce the numbers of new infections in all countries by 2030.
“But we must accelerate efforts across the board. We hope this work will be the catalyst to support national strategies to eliminate the virus by 2030, which 194 countries have pledged to do.”
If left untreated, HBV can cause serious, long-term health problems; an estimated 600,000 people die every year from HBV-related liver disease alone. The virus is highly contagious and is mainly transmitted from infected mothers to their babies, or between children.
Although there is no cure, antiviral drugs and prophylaxis to minimise mother-to-child transmission make elimination of HBV feasible.
Despite this, the study suggests half of all babies born worldwide still do not receive life-saving vaccine at birth and less than 1 per cent of expectant mothers with HBV are receiving the appropriate treatment.
“Most mother-to-child transmission occurs within days of birth, so the birth dose is vital”, Dr Razavi said. “All children need to receive this life-saving vaccine at birth, not just half of them.”
The findings show that the virus is most common in east Asia and sub-Saharan Africa, where prevalence is as high as 12.1 per cent in the Central African Republic. In 2016, 21 countries accounted for more than 80 per cent of all infections, with China, India, Nigeria, Indonesia, and the Philippines accounting for over 57 per cent.
The authors note some limitations to their work, including that the quality of the available studies varied across countries, with a lack of high-quality data available from African nations.
They also note that the model does not explicitly take into account certain populations that might have a higher prevalence, including immigrants and sex workers, nor does it account for the substantial numbers of HIV-HBV or HBV and HDV co-infected individuals, in whom disease tends to progress more rapidly.
The paper published in the Lancet Gastroenterology & Hepatology.
