Congenital cytomegalovirus (Complete) Flashcards
Cytomegalovirus belongs to which viral family?
Herpesvirus family
Majority of people would have been infectied by CMV, often with no symptoms
What type of virus is CMV?
Enveloped
dsDNA genome
What is the mode of transmission of CMV?
Direct contact with bodily fluid (e.g. saliva, urine)
What is congenital cytomegalovirus?
Transmission of CMV to foetus in woman who have contracted CMV for the first time
Majority of people would have been infected by CMV at some point, often with no symptoms
What are the main clinical features of CMV in infected pregnant women?
Mostly assymptomatic however some may display:
Fever
Generalised malaise/fatigue
What percentage of women with CMV infection transmit the virus to foetus?
30-40%
What is the main clinical feature of CMV in neonates?
Mostly assymptomatic at birth (90%)
However, 10% will eventually go on to develop sensorineural hearing loss throughout childhood
The remaining 10% of symptomatic infants develop congenital cytomegalovirus disease
- Low birth weight
- Jaundice
- Microcephaly
- Seizures
- Pneumonia
- Petechial rash
Neonates with CMV are at risk of what long-term complications?
Neurological complications:
Sensorineural hearing loss
Visual impairment
Learning disabilities
What are the main clinical features of congenital CMV disease?
Low birth weight
Jaundice
Microcephaly
Seizures
Pneumonia
Petechial rash (Blueberry muffin)
Hepatosplenomegaly
Chorioretinitis
What rash is characteristic of congenital CMV disease?
‘Blueberry muffin’ petechial rash
What antenatal investigations should be considered if mother is suspected of having CMV infection?
Bedside:
Basic obs: Check temperature
Bloods:
Maternal serology
* IgM: Indicates recent infection
* Rising IgG titres: Confirms primary infection
Imaging/invasive:
Foetal USS: Check for foetal abnormalities
Amniocentesis: To confirm if CMV PCR present
Why is looking at IgM insufficient in determining primary infection?
Confirms a recent infection but can be elevated for up to a month post-infection
Rising IgG titres suggest ongoing infection versus stable IgG
What is the gold-standard investigation to confirm congenital CMV in antenatal period?
Amniocentesis with CMV PCR
What post-natal investigations should be considered in neonates with suspected congenital cytomegalovirus?
Bedside:
Urine sample: For CMV PCR
Saliva sample: For CMV PCR
Bloods:
CMV PCR and serological testing
How are neonates with congenital CMV managed?
Conservative:
Regular audiology and opthalmology follow-up: Check for complications
Medicine:
Antiviral for 6 months:
* IV ganciclovir
OR
* Oral valganciclovir
Name 2 examples of antivirals which can be considered in management of congenital CMV
Ganciclovir (IV)
Valganciclovir (oral)
What is the mechanism of action of ganciclovir?
Guanosine analogue which inactivates DNA polymerase (needed for DNA synthesis)
Neonates with confirmed CMV infection can be given antivirals for how long?
6 months
What differentials should be considred alongside CMV?
Toxoplasmosis
Rubella
HSV
How can congenital toxoplasmosis be differentiated from congenital CMV?
Toxplasmosis associated with triad of:
- Chorioretinitis
- Intracranial calcifications (versus paraventricular)
- Hydrocephalus (versus microcephaly)
Moresoe associated with chorioretinitis
