Hepatitis A

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Contents

Introduction

In Western countries much of risk now is not through oral-faecal route in childhood and with direct contact, but rather through contaminated food. The following is extracted from the Health Protection Agency website, from which detailed guidance and information hepatitis A can be obtained.

" Hepatitis A virus (HAV) infection causes a range of illness from mild through non specific nausea and vomiting through to hepatitis (liver inflammation, jaundice, or icterus) and rarely liver failure. Symptoms and severity of the illness are generally worse the older the person is when they become infected.

"Hepatitis A virus was a common childhood infection in the early 20th Century but now in the 21st century it is an unusual infection in the UK. It is normally spread by the faecal-oral route but can also be spread occasionally through blood. Infection is prevented by good hygiene, especially hand washing, safe drinking water and food. Vaccination, passive or active, can be used to prevent groups at high risk including people who have been in contact with someone else who has the infection, travellers to countries where the infection is common, and other groups such as injecting drug users.

"For further details, see the Guidelines for the control of hepatitis A virus infection. The Health Protection Agency Immunisation Division takes a lead for England in national surveillance of hepatitis A virus through statutory notifications (infectious jaundice since 1969, hepatitis A since 1987) and laboratory reports. The Immunisation Division provides advice and supplies human normal immunoglobulin for contacts of cases. This can be obtained by health professionals through the CDSC Duty Doctor service."

Aetiology

Hepatitis A virus.

Clinical

  • Fever
  • Malaise
  • Jaundice

Investigations

Blood tests

Imaging

Mainly to exclude other possibilities and is unlikely to be indicated in a non-index case

Treatment

Many cases are subclinical or minor, especially in children.

The likelihood of an adverse outcome increases with age (especially after the age of 50), and in the presence of other other liver disease (including cirrhosis of any cause, and pre-existing hepatitis B or C virus infection).

Medical

  • Usually supportive care

Surgical

Prevention

A vaccine is available, free of charge to NHS patients who are travelling to places where there is a risk of hepatitis A and for those in the following categories (see Green Book, chapter 17 for details):

  • Patients with chronic liver disease
  • Patients with haemophilia
  • Men who have sex with men
  • Injecting drug users
  • Occupational groups, including:
  • Laboratory workers who may be exposed to hepatitis A
  • Staff of some large residential institutions for those with learning difficulties
  • Sewage workers
  • People who work with primates (apes, not bishops!) that are susceptible to hepatitis A infection
  • In certain circumstances (usually only in response to a case or outbreak), to:
  • Food handlers and packagers (but usually only in response to a case or outbreak)
  • Staff in day care facilities

Healthcare workers are not at increased risk of hepatitis A, and routine vaccination is not indicated.

Vaccine efficiency falls off with age over 60[1].

Post-exposure prophylaxis

See Green Book, chapter 17 and HPA guidance.[2]

The following guidance is taken from the HPA guidance mentioned above (boxes not included at ganfyd):

Management of the index case

  • Advise on good hygiene practices
  • Exclude from work, school or nursery until 7 days post onset of jaundice
  • Identify possible source of infection

Management of household and sexual contacts (see Box 6)

  • Household or sexual contacts seen within 14 days of exposure to index case
  • Healthy contact aged 1-50 years
  • Offer hepatitis A vaccine
  • Healthy contact aged 2-12 months
  • Vaccinate carers to prevent tertiary infection OR offer hepatitis A vaccine to the infant (unlicensed) OR exclude from childcare
  • Healthy contact aged under 2 months
  • Offer vaccination to carers to prevent tertiary infection
  • Contact aged 50 years or over, or with chronic liver disease or chronic hepatitis B or C infection
  • Offer hepatitis A vaccine + HNIG
  • Household or sexual contacts seen more than 14 days post exposure
  • More than one contact within the household and contacts seen within 8 weeks of exposure
  • Offer hepatitis A vaccine to prevent tertiary infection
  • Contact has chronic liver disease or chronic hepatitis B or C infection and is seen within 28 days of exposure
  • Offer hepatitis A vaccine + HNIG to try to attenuate severity of disease
  • Contact is a food handler
  • Risk assessment of need for transfer to non-foodhandling duties (see Box 4)

Management of contacts beyond the household (specific settings)

  • Index case is a food handler
  • Risk assessment of need for post-exposure prophylaxis of contacts within work setting (see Box 5)
  • Index case is a child cared for in a pre-school childcare setting
  • Treat contacts working in, or being cared for in, the same room as household contacts.
  • If contacts treated more than 14 days post exposure and or more than one case identified in the setting, offer vaccine to household contacts of exposed contacts to prevent tertiary infection
  • Index case attends a primary school
  • If source of infection outside school not identified, assume infection acquired within school and offer hepatitis A vaccine to classroom contacts

(NB - the HPA guidance was updated in November 2009, and differs from the guidance previously produced by Crowcroft et al.[3])

Occupational health issues

Food handlers are a particular risk of spreading hepatitis A.

Notification

All forms of viral hepatitis are notifiable diseases. Because of the need to organise vaccination of contacts within a week of exposure to a possibly infectious case, it is particularly important to notify suspected cases of hepatitis A urgently, usually by telephone. This is even more important if a case or contact is a food handler.

External links

References