Hepatitis A Flashcards
Index case is HAV positive
What is the management?
Advise on good hygiene practices
Exclude from work, school or nursery until 7 days post onset of jaundice or in absence of
jaundice, from the onset of compatible symptoms (such as fatigue, nausea or fever)
Identify possible source of infection
Undertake risk assessment, particularly if case occurs in a non-household setting
Complete national standard questionnaire
Exposure to close contacts of an acute HAV case
What is the management of close contacts within 14 days of exposure
Healthy <12 months old
Healthy 1-59 years old
Healthy >60 years old
Chronic liver disease/ immunosuppression/ HIV
Healthy Food handler
Management of close contacts identified within 14 days of exposure to index case
Healthy close contacts aged <12 months: Offer immunisation to household contacts and persons who have been involved in nappy changing or assistance with toileting to prevent tertiary infection. If the infant contact
attends childcare, offer vaccine to the infant contact if ≥ 2 months (unlicensed) and reinforce hygiene in the childcare setting. If immunisation is not possible, reinforce hygiene in the childcare setting to prevent tertiary transmission. If there are concerns that high hygiene standards cannot be maintained in the childcare
setting: exclude the infant contact for 30 days. If exclusion is likely to have serious adverse consequences (e.g. loss of employment): immunise children and staff in the childcare setting
Healthy close contacts aged 1 - 59 years: Offer hepatitis A vaccine
Healthy close contacts aged 60 years or over: Offer hepatitis A vaccine + HNIG
Close contacts with chronic liver disease, chronic hepatitis B or C infection, and immunosuppression, including HIV positive individuals with CD4 count <200cells/mm3: Offer hepatitis A vaccine + HNIG
Close contact who is a food handler: Offer hepatitis A vaccine
Exposure to close contacts of an acute HAV case
What is the management of close contacts more than 14 days post exposure
More than 1 close contact within the household
Chronic liver disease/ immunosuppression/ HIV
Healthy food handler
Contact attends childcare setting
Management of close contacts identified more than 14 days post exposure
More than one close contact within the household and contacts seen within 8 weeks of
exposure: Offer hepatitis A vaccine to prevent tertiary infection
Close 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 attenuate severity of disease
Close contact is a food handler: Risk assessment of need for transfer to non-food-handling duties
Close contact attends childcare setting: reinforce hygiene in the childcare setting to prevent
tertiary transmission. If there are concerns that high hygiene standards cannot be maintained in the childcare setting: exclude the infant contact for 30 days. If exclusion is likely to have serious adverse consequences (e.g.
loss of employment): immunise children and staff in the childcare setting
Exposure to close contacts of an acute HAV case
How do you manage contacts where the index case actually attends a high risk setting - food handler/ school
food handler
child attending pre-school/ reception
child attending primary school
Management of contacts where the index case attends a high risk setting (beyond the household)
Index case is a food handler or staff in residential care setting : Risk assessment for post-exposure prophylaxis of contacts within work setting
Index case is a child cared for in a pre-school childcare or reception setting: Manage contacts working in, or being cared for in, the same room as close contacts. If contacts seen more than 14 days post exposure and / or more than one case identified in the setting, consider widening immunisation in the early years setting and
offering vaccine to close contacts of exposed contacts to prevent tertiary infection
Index case attends early years setting or primary school: If source of infection outside
early years setting/ school not identified, assume infection acquired within early years setting/school
,unless oral fluid testing of household contacts suggests otherwise, and risk assess for the need to
offer hepatitis A vaccine to classroom contacts, year or a wider population at risk in that setting
What is the case definition of HAV infeciton?
Possible
Probable
Confirmed
- Clinical case (Possible)
A person with an acute illness, discrete onset of symptoms AND jaundice or elevated serum aminotransferase levels - Probable case
A person that meets the clinical case definition and has an epidemiological link to a confirmed hepatitis A case
OR
A person that meets the clinical case definition (see above) AND is IgM positive
- Confirmed case
A person that meets the clinical case definition AND IgM/ IgG pos
OR
A person with hepatitis A RNA (HAV RNA) detected regardless of clinical features
OR
An asymptomatic person with no recent history of immunisation with anti-HAV IgM from oral fluid or serum
AND an epidemiological link to a confirmed hepatitis A case
What is the infectious period for HAV?
Presenting with jaundice
Presenting without jaundice
Asymptomatic positive test
The infectious period is taken from two weeks before onset of first symptoms and until one week after the onset of jaundice
Where jaundice is not reported a history of dark urine or pale stools should be enquired about. If there are no symptoms of jaundice, onset of other symptoms (such as fatigue, nausea, and fever) should be used.
For asymptomatic cases the infectious period should be estimated using the timing of contact with the source
if known (such as contact with an index case or consumption of contaminated food) and with consideration of the laboratory test results
HAV contact
What constitutes a contact?
Same household/ school/ care home regularly sharing food/ toilet facilities or nappy changing
Individuals injecting drugs and sharing injecting paraphernalia with the index case
A person who has had sexual contact with the index case during the infectious period
HAV contact
But previously immunised
When are they considered fully protected?
Fully protected:
2x vaccine course within last 10 years
1x vaccine within past year
While evidence suggests that a complete course of hepatitis A vaccination should give immunity beyond
25 years, a more precautionary approach is advisable for those close contacts who have had a definite exposure to hepatitis A
So if been 13 years since vaccine course, a booster is likely to be recommended
What HAV vaccines are available?
How effective are they?
HAV monovalent vaccine
HAV/HBV bivalent vaccine
> 95% effective at preventing infection
Who should be offered HAV vaccine?
Travel to high risk country
chronic liver disease
haemophilia
MSM
IVDU
occupational risk
What type of vaccine is HAV vaccine?
Inactivated
What is incubation period of HAV?
14-28 days
Scenario
Close contact is food handler
Identified >14 days after exposure
What action would you take?
If vaccinated in past 10 years, consider immune
If not immune, are they a high risk contact? e.g index case is a child <5 years old OR index case regularly
cooked for the contact OR index case had poor personal hygiene or diarrhoea OR contact had sex with index case).
If they are high risk contact, transfer them to different duties, and re-inforce hand hygiene.
Workplace exclusion only required if cannot guarantee hand hygiene
If they present <14 days they would be able to have HAV vaccine
What would be the definition of a HAV outbreak?
2 or more cases linked in time and place
What is role of HAV oral fluid testing in an outbreak?
Asymptomatic patients can be screened quickly with oral fluid testing.
Uses same kits as MMR tests
can use blood tests, but oral fluid can be quicker/ cheaper
