This section deals specifically with:

The epidemiology of HBV infection, with focus on the United Kingdom (UK) and European Union (EU).

The natural history of HBV infection.

HBV-related stigma and discrimination.

Disclosure from the perspective of patients living with HBV and the mandatory requirements for healthcare professionals.

Epidemiology

Global

HBV is one of the world’s most common infectious diseases. The World Health Organization (WHO) estimates that in 2015:1

257 million persons, or 3.5% of the general population, were living with chronic HBV.

2.7 million persons were coinfected with HBV and HIV.

Around 880,000 deaths could be attributed to complications associated with chronic HBV.

A further 2 billion people worldwide are estimated to have evidence of past or present infection with HBV.2

The major complications of chronic HBV are cirrhosis, liver failure and hepatocellular carcinoma (HCC). Data suggest that:

HBV is the leading cause of liver cancer worldwide, with 70–85% of liver cancers being HCC.3

Without appropriate monitoring or treatment, up to 1 in 4 people with chronic HBV will die from liver cancer or liver failure.4

The prevalence of chronic HBV varies significantly by country and is predominantly determined by the age at exposure. Approximately 90% of infected infants progress to chronic infection, compared with only 5% of immunocompetent adults.5

Figure 1 shows the geographic distribution of chronic HBV infection. The burden remains disproportionately high in low- and middle-income countries. In 2015, African and Western Pacific regions accounted for 68% of all infected persons.1

Figure 1. Prevalence of chronic HBV infection in the general population by WHO region, 20151

Most countries have now implemented universal infant vaccination, which has considerably reduced the incidence of new chronic HBV infections.1 However, the long delay between initial infection and the onset of complications, and the large number of existing chronic infections, means that the burden of disease attributable to HBV is likely to increase over the next several decades.6,7

Furthermore, population movements and migration are currently changing the prevalence and incidence in several low endemic countries in Europe owing to the higher HBV prevalence rates in migrants and refugees from outside Europe.8

Regional

Recently, the European Centre For Disease Control and Prevention (ECDC) performed a systematic literature review to estimate the prevalence of HBV among the adult general population in EU countries:9,10

General population estimates for HBV were available for 13 countries, ranging from 0·1% in Ireland to 4·4% in Romania.

The overall prevalence of chronic HBV in the EU is estimated to be around 0.9%, or approximately 4.7 million cases.

The UK has the largest estimated burden of chronic HBV in the EU with over one million cases, followed by Romania (877,682), Spain, France and Italy (each with 400,000 – 500,000 cases).

Figure 2: Chronic HBV prevalence in the adult general population in the EU, based on studies published between 2005 and 2015.9

The research also identified populations at highest risk for HBV or at risk for HBV in certain regions or under certain circumstances. Estimated prevalence ranges for high-risk groups are presented in Table 1.

Table 1. HBV prevalence estimates among selected high-risk populations in the EU10

 

MSM, men who have sex with men; PLHIV, people living with HIV; PWID, people who inject drugs.

HBV is a notifiable disease in the UK and it is mandatory for healthcare professionals to report any confirmed case.11 In 2017, 4,762 confirmed HBV cases were reported in the UK, of which 324 were acute.12

The highest incidence in the UK was reported in London (1.43 per 100,000).

The highest increase in incidence was reported from West Midlands region (from 0.50 to 0.82 per 100,000 in 2016 and 2017 respectively).

Natural history

Understanding the natural history of HBV is an essential component of assessment and management. Viral load, liver function results and hepatitis B e-antigen (HBeAg) status are all required to determine the disease phase and to arrange for appropriate treatment and/or monitoring.

Transmission

HBV is transmitted through blood or infected bodily fluids. The virus enters the bloodstream either through a break in the skin or through mucous membranes.4 Table 2 lists the avenues by which HBV may be transmitted.

Table 2. Modes of transmission of HBV5

Vertically

Mother to child during childbirth. Common in high prevalence countries (in the absence of infant vaccination).

Horizontally From an individual with HBV to unvaccinated household contacts (e.g. sharing toothbrushes, razors, other items that may lead to exchange of body fluids).
Sexually

Unprotected vaginal, anal or oral sex with a person who has HBV.

Percutaneously Sharing/re-use of injecting equipment; tattooing or body piercing including acupuncture, cupping and other practices involving blood or bodily fluids.
Medically

Medical procedures (e.g. dentistry, surgery, dialysis) pose a risk if appropriate infection control procedures are not adhered to.

Needlestick injury or splashing of infected blood or body fluids.

Despite the prevalence of chronic HBV in the community, public misconceptions about transmission are common. It is important for patients to understand that HBV infection is not transmitted by:

Sharing food and drink

Coughing

Sneezing

Kissing

Hugging or other forms of casual contact.

Natural history of HBV infection

HBV is an enveloped DNA virus that causes both acute and chronic infections. Persons infected with acute HBV are usually unaware of their infection, as it is usually asymptomatic or associated with mild non-specific symptoms.

There are four stages of acute HBV infection.5

Incubation phase

4 to 12 weeks but can be up to 6 months.

Symptomatic hepatitis

Develops after the incubation period and can last from 4–12 weeks. Symptoms may include fever, fatigue, nausea, dark urine, jaundice, myalgia and right upper quadrant abdominal pain. Symptoms are common in adults but not in infants and children.

Recovery period

This results in the normalisation of ALT levels.

Clearance phase

The HBsAg clears from the serum after a few months. It coincides with the development of anti-HBs.

HBsAg, hepatitis B surface antigen; ALT, alanine aminotransferase; anti-HBs, hepatitis B surface antibodies.

The progression from acute to chronic HBV infection is due to a failure of the immune response to remove the virus. Guidelines from the American Association for the Study of Liver Diseases (AASLD) define chronic HBV as a chronic necroinflammatory disease of the liver caused by the presence of hepatitis B surface antigen (HBsAg) for at least 6 months.13

The risk of developing chronic HBV infection after acute exposure is predominantly age-dependent, and can be summarised as follows:13

90% in newborns of HBeAg-positive mothers.

25%-30% in infants and children under 5.

Less than 5% in adults.

In addition, immunosuppressed persons are more likely to develop chronic HBV after acute infection.

Chronic HBV infection is a dynamic process that can be schematically divided into four phases of variable duration, which are not necessarily sequential (Figure 3). The terminology of the four phases has recently been updated based on the description of the two main characteristics of chronicity: infection vs. hepatitis.14

Figure 3. The phases of chronic HBV and relevance to treatment decisions14

 

Adapted from EASL Clinical Practice Guidelines 2017.

ALT, alanine aminotransferase; anti-HBe, antibodies to envelope antigen; HCC, hepatocellular carcinoma; HBeAg. Hepatitis B e-antigen; HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus; LFT, liver function tests; IU, international units.

Individuals with chronic HBV can transition through different clinical phases with variable levels of serum ALT activity, HBV DNA, and HBV antigens. The levels of serum ALT and HBV DNA as well as liver fibrosis are important predictors of long-term outcome that inform decisions for treatment initiation as well as treatment response.

No patient with chronic HBV should be considered a ‘healthy carrier’. Individuals with chronic HBV are always at risk of progressive liver damage and the development of cirrhosis and HCC.15

Social impact

The negative consequences of stigma and discrimination on the health and wellbeing of people living with HIV (PLHIV) and/or hepatitis C virus (HCV) infection are well documented.16-18 However, there are essential differences between chronic HBV, HIV and HCV, which influence the extent and nature of stigma and discrimination.

Current research indicates that chronic HBV-related stigma and discrimination:19

Is primarily related to a poor understanding of prevention and transmission.

May be greater among people from culturally diverse communities due to different attitudes and/or beliefs in their country of origin.

Is not linked to concepts of moral deficit that characterise HIV and HCV-related stigma and discrimination.

Varies between affected communities. Therefore, it is important not to assume that these issues are present in all communities affected by chronic HBV.

Many individuals with chronic HBV come from marginalised or stigmatised groups such as people who inject drugs (PWID), men who have sex with men (MSM), migrants or people with a history of incarceration. These broader issues of stigma and discrimination, and the resulting social isolation and anxiety, may negatively influence the engagement of some individuals and communities with HBV prevention and clinical management.20  

Primary care providers have a vital role in reducing the stigma and discrimination associated with chronic HBV. It is important that individual concerns be addressed through appropriate avenues:

Listening and demonstrating sensitivity to linguistic and cultural differences, which may affect an individual’s response to viral hepatitis.

Provision of verbal and written information relating to transmission or disease natural history may allay fears.

Referral to counselling or support services may be indicated for people with complex emotional, family and relationship or disclosure issues.

All individuals should be made aware of services such as counselling and support groups, telephone helplines and community organisations.

Disclosure

HBV is a notifiable disease in the UK. It is mandatory for healthcare professionals to report any confirmed case.11 Mandatory notification does not legally breech a person’s right to privacy, although individuals should be informed that notification will occur.

There are some situations that require mandatory disclosure of hepatitis status:21

Healthcare workers are required to disclose their status if they are carrying out exposure-prone procedures.

Some insurance companies require disclosure where the type of insurance being applied for is ‘relevant’ to the health condition (e.g. life, disability or income protection).

As HBV can be transmitted through sex, individuals have a legal obligation to protect sexual partners, through practicing safer sex and/or disclosing their status.

Primary care providers should refer individuals to seek independent legal advice if they have concerns about their disclosure obligations and the possible risks associated with failure to disclose in certain situations.

Hepatitis B

HBV

A comprehensive summary of currently available knowledge on HBV is provided here. 

Prevention and diagnosis

HBV

This section covers priority populations, testing, diagnosis and vaccination.

Treatment and management

HBV

Covering treatment decisions, who and when to treat as well as therapy recommendations and long-term monitoring. 

Expert insights

HBV

Expert insights and opinion on issues surrounding HBV and practical advice for healthcare professionals. 

References

  1. Global Hepatitis Report 2017. Geneva: World Health Organization; 2017.
  2. Schweitzer A, et al. Estimations of worldwide prevalence of chronic hepatitis B virus infection: a systematic review of data published between 1965 and 2013. Lancet 2015;386:1546–55.
  3. Jemal A. et al. Global cancer statistics. CA Cancer J Clin 2011;61:69-90.
  4. Lavanchy D. Hepatitis B virus epidemiology, disease burden, treatment, and current and emerging prevention and control measures. J Viral Hepat 2004;11:97–107.
  5. Matthews G, Robotin M. eds. B Positive – All you wanted to know about hepatitis B: a guide for primary care providers. ASHM, 2008.
  6. Razavi H, et al. Chronic hepatitis C virus (HCV) disease burden and cost in the United States. Hepatology 2013;57:2164–70.
  7. MacLachlan JH, Cowie BC. Liver cancer is the fastest increasing cause of cancer death in Australians. Med J Aust 2012;197:492–3.
  8. Coppola N, et al. Hepatitis B virus, hepatitis C virus and human immunodeficiency virus infection in undocumented migrants and refugees in southern Italy, January 2012 to June 2013. Euro Surveill 2015;20:30009.
  9. Hofstraat SHI, et al. Current prevalence of chronic hepatitis B and C virus infection in the general population, blood donors and pregnant women in the EU/EEA: a systematic review. Epidemiol Infect 2017;11:1-13.
  10. European Centre for Disease Prevention and Control. Hepatitis B and C epidemiology in selected population groups in the EU/EEA. Stockholm: ECDC; 2018.
  11. 2017 interim update of the 2015 BASHH National Guidelines for the Management of the Viral Hepatitides. Available at: https://www.bashh.org/guidelines (accessed November 2018).
  12. Public Health England. Acute hepatitis B (England): annual report for 2017. Health Protection Report Volume 12 Number 31 24 August 2018
  13. Terrault NA, et al. Update on prevention, diagnosis, and treatment of chronic hepatitis B: AASLD 2018 hepatitis guidance. Hepatology 2018;67:1560-99.
  14. European Association for the Study of the Liver. EASL Clinical Practice Guidelines: Management of chronic hepatitis B virus infection. J Hepatol 2017;67:370–98.
  15. Dev A, et al. Chronic hepatitis B. A clinical audit of GP management. Australian Family Physician 2011;40:533-8.
  16. ASHM in partnership with NCHSR, 2012. Stigma and discrimination around HIV and HCV in healthcare settings: Research report. Available at: https://www.ashm.org.au/resources/Stigma_and_Discrimination.pdf (accessed October 2018).
  17. Logie C, and Gadalla TM. Meta-analysis of health and demographic correlates of stigma towards people living with HIV. AIDS Care 2009;21:742-753.
  18. Young M, et al. Interpersonal discrimination and the health of illicit drug users. American Journal of Drug and Alcohol Abuse 2005;31;371–391.
  19. Ellard, J and Wallace, J. Stigma, discrimination and hepatitis B: A review of current research. ARCSHS Monograph Series 2013; No. 93, Melbourne: Australian Research Centre in Sex, Health and Society, La Trobe University. ISBN: 9781921915468.
  20. WHO guidelines on hepatitis B and C testing. Geneva: World Health Organization; 2017. Licence: CC BY-NC-SA 3.0 IGO.
  21. British Liver Trust. Living with liver disease. Available at: https://www.britishlivertrust.org.uk/publications/download-publications/ (accessed November 2018).

LID/IHQ/18-12//1048c(1) Date of preparation: August 2019