Epidemiology and clinical features of childhood chronic hepatitis B infection diagnosed in England

Burden of selected infectious diseases covered by UK childhood vaccinations: systematic literature review

Aim: An overview of recent epidemiology and disease burden, independent of patient age, of diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis and Hemophilus influenzae invasive disease in the UK. Materials & methods: A systematic review was undertaken. Outcomes included incidence, prevalence, risk factors and cost burden. Results: 39 publications were included. Hepatitis B prevalence is high among certain risk groups. A small pertussis risk remains in pregnancy and for infants, which led to the introduction of maternal vaccination. H. influenzae invasive disease cases are limited to rare serotypes. Polio, tetanus and diphtheria are well controlled. Conclusion: The evaluated diseases are currently well controlled, thanks to a comprehensive vaccination program, with a generally low clinical and cost burden.

Molecular characterization of hepatitis B virus (HBV) in African children living in Australia identifies genotypes and variants associated with poor clinical outcome

Migration from sub-Saharan Africa is contributing to the rising incidence of chronic hepatitis B (CHB) infection and its complications in Australia. African CHB is associated with unique genotypes, such as E and A1, which are associated with reduced vaccine efficacy and early-onset hepatocellular carcinoma, respectively, although the prevalence of these genotypes outside Africa is poorly described. Treatment-naïve children of African origin with CHB were recruited at the Royal Children's Hospital Melbourne. Population-based sequencing of the complete HBV genome, or the clinically relevant basal core promoter (BCP)/precore (PC) region, was performed, and the HBV genotype/subgenotype assigned by phylogenetic analysis. HBV was characterized in serum from 67 children, median age 12.5 years. HBV genotype E was most frequent (70 %), with genotype D [25 %; subgenotypes D6 (formerly D7)/D3/D2)] and subgenotype A1 (5 %) also being identified. Despite their young age, over 50 % of the children were HBeAg-negative and had seroconverted to anti-HBe, with this being associated with canonical BCP/PC mutations in the majority of cases. The profile of HBV in African children living in Australia was characterized by early HBeAg seroconversion and infection with HBV variants associated with poor clinical outcome, as well as genotypes previously associated with reduced vaccine efficacy or rapid progression to liver cancer. These findings have important ramifications for patient monitoring and treatment guidelines in the Australian paediatric setting.

Acute infectious hepatitis in hospitalised children: a British Paediatric Surveillance Unit study

BACKGROUND

Hepatitis remains a key public health priority globally. Most childhood cases are caused by viruses, especially hepatitis A virus (HAV) and hepatitis B virus (HBV). This study aimed to estimate the burden of acute infectious hepatitis in hospitalised children and to describe their clinical characteristics and outcomes.

METHODS

Paediatricians in the UK and Ireland reported cases in children aged 1 month to 14 years diagnosed between January 2014 and January 2015 (inclusive) through the British Paediatric Surveillance Unit (BPSU) and completed a detailed questionnaire. Additional HAV and HBV cases in England and Wales were identified through a national electronic database, LabBase2. All confirmed cases were followed up at 6 months with a second questionnaire.

RESULTS

The BPSU survey identified 69 children (annual incidence, 0.52/100 000), including 27 HAV (39%), three HBV (4%), 16 other viruses (23%) and 23 with no aetiology identified (33%). LabBase2 identified an additional 10 HAV and 2 HBV cases in England. Of the 37 hospitalised HAV cases, 70% had travelled abroad, but only 8% had been vaccinated. Similarly, three of the five children with acute HBV had not been immunised, despite being a household contact of a known infectious individual. All patients with HAV recovered uneventfully. In contrast, three children with acute HBV developed liver failure and two required liver transplantation.

CONCLUSIONS

Acute infectious hepatitis is a rare cause of hospital admission. Most children recovered without complications, but those with acute HBV had severe presentations. At least three of the five HBV cases could have been prevented through appopriate vaccination of household contacts.

Management of chronic hepatitis B infection

The spectrum of chronic hepatitis B infection in children ranges from asymptomatic carriage with minimal disease, to progression to cirrhosis and risk of hepatocellular carcinoma in adulthood. Identifying those who will benefit from treatment is a challenge. Interferon-based therapies have limited efficacy, while prolonged use of nucleos(t)ide analogues may promote resistance. New antiviral agents have improved barriers to resistance, but long-term outcome is not yet known. Untreated infection, however, may in some, lead to natural seroconversion and reduce risk of further disease. Hepatitis B e antigen-positive infection is the most common scenario in chronically infected children, with e antigen-negative hepatitis rarely encountered. This paper reviews the clinical guidelines published in 2013 by the National Institute for Health and Care Excellence (NICE) and the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN), and focuses on the guidance for treatment in e antigen-positive children. The most significant difference is the lower threshold for starting treatment recommended by NICE guidelines. The need for regular evaluation of each child, in the light of new evidence and new drugs as they emerge, must remain the focus of each clinician involved in the care of children with hepatitis B virus infection.