HBV diagnosis and treatment rates well below levels needed to achieve WHO 2030 elimination target

Michael Carter
Published:
27 March 2018

Ninety per cent of people with chronic hepatitis B virus (HBV) are undiagnosed, according to research published in The Lancet Gastroenterology & Hepatology. The study also showed that just 5% of eligible patients are receiving HBV therapy. These proportions are well below those needed to achieve the World Health Organization (WHO) target of eliminating HBV as a health threat by 2030.

“Successive governments in high-prevalence regions have accepted the doctrine of vaccination, but have overlooked the larger picture of screening, diagnosis, and treatment to prevent progression,” comment the authors of an editorial accompanying the study. “The incidence of new chronic HBV infections will increase in unvaccinated adults unless large increases in screening and linkage to care are implemented.”

In 2016, WHO set the target of eliminating chronic HBV as a public health threat by 2030. Although there is no cure for HBV, there is a highly effective vaccine and the infection can be controlled by treatment with antiviral drugs.

Elimination of HBV by 2030 will require:

  • 90% coverage of three-dose infant vaccination by 2020
  • Timely birth-dose vaccination in 50% of infants by 2020, reaching 90% by 2030
  • Chronic HBV prevalence in children of 1% by 2020 and 0.1% by 2030
  • Diagnosis of 90% of people infected with HBV
  • Antiviral treatment of 80% of diagnosed people eligible for therapy.

To enable monitoring of progress towards these targets, a team of investigators estimated national, regional and global prevalence of HBV, as well as rates of diagnosis, vaccination and treatment. Data were obtained from published studies, government reports and interviews with national experts.

On the basis of these data, the investigators calculated that 364 million individuals – 5% of the world population – had chronic HBV infection. But after taking into account epidemiology, demographic changes, vaccination coverage, treatment and diagnosis, the researchers revised their prevalence estimate down to 4% of the world population.

Prevalence was highest in East Asia and sub-Saharan Africa, reaching 12% in the Central African Republic, compared to less than 1% in the UK. Just 21 countries accounted for 80% of all cases of chronic HBV in 2016. Moreover, 57% of these infections were in five countries: China, India, Nigeria, Indonesia and the Philippines.

Global diagnosis rates were poor. Even though an accurate test has been available since the 1970s, only 10% of people with the infection had been diagnosed in 2016. Diagnosis was not just a problem for poor countries: two-thirds of those with chronic HBV in the US and 80% in the UK were unaware of their infection status.

Only a small fraction of eligible people – 5% – were receiving anti-HBV drugs. Treatment coverage was even poor in Western Europe: just 3% in Belgium, 5% in Ireland, Norway and Portugal and 25% in the UK.

Globally, less that 1% of expectant mothers with a high HBV viral load received antiviral prophylaxis to prevent mother-to-child transmission.

In 2016, an estimated 1.4% (1.8 million) five year olds had chronic HBV. Globally, 87% of infants received the three doses of the vaccine needed to prevent infection. Encouragingly, 94 of the 120 countries included in the study had already met the interim 2020 target of 1% prevalence among five year olds and 46 had achieved the 2030 target of 0.1% prevalence.

Despite these positive data, only 48% of babies were receiving their first vaccination dose within the crucial first 24 hours after birth, and just 10% of infants were receiving protective antibodies – hepatitis B immunoglobin (HBIG) – along with the full vaccination strategy. It was only in 2017 that the UK and Norway introduced routine HBV vaccination for newborns.

Most of the countries with a high burden of infant HBV have yet to fully scale up infant vaccination and to provide HBIG.

“We have all the tools necessary to eliminate hepatitis B in children. In spite of this, 1.8 million children aged 5 years were infected with HBV in 2016, with a very similar number of new infections occurring annually,” conclude the authors. “This analysis provides a marker on the road to elimination by quantifying the use of prophylaxis and treatment at the national, regional, and global levels. This work can support national strategies to eliminate HBV and decrease the number of new infections by 90% by 2030.”

Reference

The Polaris Observatory Collaborators. Global prevalence, treatment, and prevention of hepatitis B virus in 2016: a modelling study. The Lancet Gastroenterol Hepatol, online edition: http://dx.doi.org/10.1016/s2468-1253(18)30056-6 (2018).