Specific virus summaries 2 Flashcards
Hepadnaviruses
What percentage develop:
- acute HBV hepatitis
- chronic HBV infection
- HCC
- acute HBV hepatitis
- chronic HBV infection
5% if acquired in adulthood
30% of children aged 1-5 years
90% of neonates - HCC
10%
Herpesviruses
What is seroprevalence for
HSV1
HSV2
HSV1 65%
HSV2 16%
Herpesviruses
How does VZV spread to skin?
Mucus membranes - lungs/ eyes
Lymph nodes
Viraemia spread to organs - including skin, lungs, liver, brain
Herpesviruses
What percentage of people develop shingles?
99% of people have had chickenpox
30% risk of shingles following primary infection
Herpesviruses
Which viruses fall into each category?
Alphaherpesviruses
Betaherpesviruses
Gammherpesviruses
Alphaherpesviruses
HSV 1/2
VZV
Betaherpesviruses
CMV (HHV5)
HHV6
HHV7
Gammherpesviruses
EBV
HHV8
Herpesviruses
What disease is HHV8 associated with?
HHV8
- Kaposi Sarcoma
- Primary effusion lymphoma (B-cell)
- Multicentric Castleman disease
Herpesviruses
What diseases is EBV associated with?
Infectious mononucleosis
Lymphoma
Burkitt’s lymphoma - in combination with malaria
Nasopharyngeal carcinoma
Orthomyxoviruses
What are examples?
Influenza A/ B/ C
Paramyxoviruses - RSV/ Measles
Orthomyxoviruses
Why is influenza associated with secondary bacterial infection?
S. pneumoniae, Haemophilus, Staph aureus most common
Viral infection compromises epithelial barriers and suppresses immune response
Papillomaviruses
What disease do papillomaviruses cause?
Skin warts - including anogenital
Head/ neck tumours
Cervical neoplasia/ cancer
Papillomaviruses
What genotypes does vaccine protect against?
6/ 11/ 16/ 18
Paramyxoviruses
What are examples?
RSV
MEasles
Paramyxoviruses
What disease can measles cause?
Ear infections
Bronchopneumonia
Encephalitis
Paramyxoviruses
What types of encephalitis can measles cause?
Primary encephalitis - e.g virus in CNS. Occurs shortly after infection
SSPE - subacute sclerosing panecenphalitis - viral replication present, but no viable virus produced. As remains inside neurons, immune system cannot attack it. Occurs years after infection - median 7 years
ADEM - post-infectious demyelination. Occurs few weeks/ months after infection
Paramyxoviruses
How does Measles spread within body?
Initially via mucosal surfaces
Lymph node
Viraemia - spread to skin (rash), lungs, brain
Paramyxoviruses
Measles confirmed in child
What is the process for assessing who is at risk requiring Post-Exposure prophylaxis?
At risk -
pregnant
immunocompromised
infant - <9 months
Paramyxoviruses
Measles PEP
What should be given to a contact who is pregnant/ immunocompromised?
Check exposure history
Check immunity
If non-immune:
pregnant - give HNIG within 6 days of exposure
mild immunosuppression - give HNIG within 6 days of exposure
severe immunosuppression - can give HNIG without testing required
Paramyxoviruses
Measles PEP
What should be given to a contact who is:
- <6 months old
- 6-8 months old
- >9 months old
- <6 months old
assume susceptible regardless of maternal status. Given HNIG up to 6 days - 6-8 months old
- household exposure - give HNIG
- community exposure - MMR vaccine
- > 9 months old
- MMR vaccine
MMR vaccine normally given at 12 months, but can be given earliest at 9 months
Paramyxoviruses
Measles PEP
What should be given to an immunosuppressed patient who is inadvertently given a live Measles vaccine?
If minor immunosuppression, and previously shown to be immune, may not need any PEP
If severely immunosuppressed - need HNIG
Paramyxoviruses
Measles PEP
What should be given to an pregnant patient who is inadvertently given a live Measles vaccine?
No HNIG necessary - mother unlikely to have an infection, and unlikely to affect foetal outcome
PHE has undertaken surveillance of vaccination in pregnancy since 1981 and the data to date are reassuring with regards to maternal and infant outcomes, when MMR is given in pregnancy or shortly prior to pregnancy
Paramyxoviruses
Measles PEP - HNIG required
How soon does this need to be adminsitered
ASAP - ideally <72 hours after exposure
up to 6 days max
Paramyxoviruses
RSV
Who is at risk of severe RSV infection?
Age <6 months - most common cause bronchiolitis/ pneumonia
Age - elderly
immunosuppressed
Airway disease e.g COPD
Paramyxoviruses
RSV
What treatment is available?
Palivizumab for high risk infants
Ribavirin for infants
No treatment for adults. Vaccine in development
