Cytomegalovirus
aka CMV
Baltimore I (dsDNA) beta herpesvirus
Perinatal > Congenital
Risk factor: frequent prolonged contact with young children ie daycare workers (12% serocovert p.a., parents of children in daycare BUT not healthcare workers 2% seroconversion (same as background)
Prevention: pregnant women should assume all <3yo have CMV in saliva and urine and wash hands after diaper (nappy) changes and handling anything that has touched their mouth or nose (including toys), or perineum (inc nappies, clothes, baths)
Epidemiology: most common congenital infection (0.7%), most are asymptomatic
Symptoms:
viral illness
atypical lymphocytosis (monospot neg, toxo also does the same)
Screening not yet routine at start of pregnancy
> Signs on morphology scan > screen
> Exposure to known case of CMV > screen
Maternal diagnosis
Serology: IgG, IgM, IgG avidity
PCR: blood, urine, saliva
recent primary infection (ie IgM+ with IgG- or IgG pos with low/intermediate avidity, or PCR pos) has 30% transmission rate
Transmission prevention:
Nonsignificant reduction in in-utero transmission, and increased prematurity with CMV hyperimmune globulin mean no role currently.
Foetal diagnosis:
US +/- MRI (40% sens, poor spec)
CMV PCR via amniocentesis >6w from maternal infection (and >21w gestation) is gold standard (90%sens, 100% spec)
CMV PCR doesnt predict degree of damage, however risk is higher in 1st half of pregnancy
Treatment of affected foetus:
- can offer termination with caveat that positive PCR is not predictive of foetal damage
- benefits outweigh risks for CMV immunoglobulin in CMV pos foetus > give
Newborn diagnosis:
- Serology
- PCR: blood, urine, saliva
Sequelae i.e symptomatic
- Pneumonia
- Microcephaly (50%), seizures (10%), chorioretinitis (15%), DevDel (50%),
- Purpura, hepatomegaly
- FBE (plt), LFT (hepatitis)
- hearing: (50%) (continue screening q6m til 2y, then q1y until 6y)
- ophthalmology
- HUSS/MRI: hydrocephalus, intracranial calcification, cerebral atrophy, migrational abnormalities (lissencephaly, polymicrogyria) white matter abnormalities
Symptomatic primary congenital CMV has 50% morbidity (10% mortality)
Asymptomatic primary or non-primary (reinfection/reactivation) has 10% morbidity
Treatment:
Ganciclovir IV for 6w (started before 4wo) for those with CNS sequelae (reduces hearing and developmental morbidity)
Alternative: Valganciclovir 16 mg/kg/dose PO BD (duration 6m better than 6w)
Follow-up
- 6 monthly with ?gen paed or ID
- hearing as above
- ?ophthal
CMV pos neonates shed for 1y > HH/avoid pregnant women
PEP: IgG
Baltimore I (dsDNA) beta herpesvirus
Perinatal > Congenital
Risk factor: frequent prolonged contact with young children ie daycare workers (12% serocovert p.a., parents of children in daycare BUT not healthcare workers 2% seroconversion (same as background)
Prevention: pregnant women should assume all <3yo have CMV in saliva and urine and wash hands after diaper (nappy) changes and handling anything that has touched their mouth or nose (including toys), or perineum (inc nappies, clothes, baths)
Epidemiology: most common congenital infection (0.7%), most are asymptomatic
Symptoms:
viral illness
atypical lymphocytosis (monospot neg, toxo also does the same)
Screening not yet routine at start of pregnancy
> Signs on morphology scan > screen
> Exposure to known case of CMV > screen
Maternal diagnosis
Serology: IgG, IgM, IgG avidity
PCR: blood, urine, saliva
recent primary infection (ie IgM+ with IgG- or IgG pos with low/intermediate avidity, or PCR pos) has 30% transmission rate
Transmission prevention:
Nonsignificant reduction in in-utero transmission, and increased prematurity with CMV hyperimmune globulin mean no role currently.
Foetal diagnosis:
US +/- MRI (40% sens, poor spec)
CMV PCR via amniocentesis >6w from maternal infection (and >21w gestation) is gold standard (90%sens, 100% spec)
CMV PCR doesnt predict degree of damage, however risk is higher in 1st half of pregnancy
Treatment of affected foetus:
- can offer termination with caveat that positive PCR is not predictive of foetal damage
- benefits outweigh risks for CMV immunoglobulin in CMV pos foetus > give
Newborn diagnosis:
- Serology
- PCR: blood, urine, saliva
Sequelae i.e symptomatic
- Pneumonia
- Microcephaly (50%), seizures (10%), chorioretinitis (15%), DevDel (50%),
- Purpura, hepatomegaly
- FBE (plt), LFT (hepatitis)
- hearing: (50%) (continue screening q6m til 2y, then q1y until 6y)
- ophthalmology
- HUSS/MRI: hydrocephalus, intracranial calcification, cerebral atrophy, migrational abnormalities (lissencephaly, polymicrogyria) white matter abnormalities
Symptomatic primary congenital CMV has 50% morbidity (10% mortality)
Asymptomatic primary or non-primary (reinfection/reactivation) has 10% morbidity
Treatment:
Ganciclovir IV for 6w (started before 4wo) for those with CNS sequelae (reduces hearing and developmental morbidity)
Alternative: Valganciclovir 16 mg/kg/dose PO BD (duration 6m better than 6w)
Follow-up
- 6 monthly with ?gen paed or ID
- hearing as above
- ?ophthal
CMV pos neonates shed for 1y > HH/avoid pregnant women
PEP: IgG