Perinatal infections Flashcards
CMV - prevention measures for infection in pregnancy
Routine hygiene practices for ALL pregnant women and those trying to conceive, regardless of their CMV serology status:
1. Avoid contact with saliva when kissing a child - e.g. kiss on forehead not on lips
2. Thoroughly wash hands with soap and water for 15-20 seconds after changing nappies, feeding a young child or wiping a young child’s nose or saliva
3. Clean toys, countertops and other surfaces that come into contact with children’s urine or saliva
4. Do not:
- Share food, drinks or utensils used by children under 3yo
- Share a toothbrush with a young child
- Put a child’s dummy in your mouth
Condoms
CMV - transmission
Transmission
- Horizontal - contact with urine, saliva; sexual transmission
- Vertical - transplacental, intrapartum (cervical secretions), BF
Highest risk severe neurological outcomes 1st trimester
CMV - high risk groups for infection
- Frequent, prolonged contact with young children, in particular children who are shedding CMV
- Day care workers – annual seroconversion rate 12.5%
- Parents with child in day care – annual seroconversion rate 2% for non-CMV shedding children, 24% for CMV shedding children
(Health care workers seroconvert at rate comparable to general population eg. annual seroconversion rate 2-3%)
CMV - interpret serology -
IgG and IgM negative
- Not CMV infection, and CMV susceptible; repeat test if clinically concerned
- If seroconversion or rise in IgG, recent primary infection
CMV - interpret serology -
IgG positive, IgM positive
- Perform CMV specific IgG avidity (test immediately, and also repeat testing on new sample)
-Low avidity = recent primary infection
-Intermediate avidity (cut off as defined by laboratory) = recent primary infection not excluded, manage as recent primary infection
-High avidity = past infection *
Avidity is also not a perfect test; some patients have high intermediate avidity w recent infection
*In-utero transmission less likely in non-primary infection but if infected full range of cCMV is possible
CMV - interpret serology -
IgG positive, IgM negative
= past infection *
*In-utero transmission less likely in non-primary infection but if infected full range of cCMV is possible
CMV - maternal diagnosis
Maternal diagnosis - serology
* IgG -ve IgM -ve = CMV susceptible, repeat test if concerned
* -IgG -ve IgM +ve - repeat test 2 weeks
* IgG +ve IgM +ve - immediate IgG avidity testing -> if low = recent primary infection
* IgG +ve IgM -ve = past infection, non-primary infection less likely but possible
Prevention of in-utero transmission with valaciclovir not routine
CMV - fetal diagnosis
Fetal diagnosis - US and amnio
* Imaging - US (+/- MRI), sensitivity <30-50%
BFG BIG FRIENDLY GIANT
Brain (microcephaly, cerebral VM, intracranial calcifications)
Fluid (ascites, pleural + pericardial effusions, hydrops, oligo or poly)
FGR
Gut (hyperechoic bowel, hepatomegaly, abdominal calcifications, pseudomeconium ileus)
* Amnio - CMV PCR, higher sensitivity if >21 weeks and >6 weeks after maternal infection
CMV - risks of fetal transmission
Risks of fetal transmission:
* Primary - 30% risk transmission -> 10% symptomatic (50% risk sequelae), 90% asymptomatic (10% risk sequelae)
* Non-primary - 1% risk transmission -> <1% symptomatic (<10% risk sequelae)
CMV - main outcomes of perinatal infection
Main outcomes
* Symptomatic cCMV - 1) early mortality in first 3 months 5-10% 2) neurological sequelae of microcephaly, seizures, chorioretinitis, developmental delay 3) sensorineural hearing loss
* Asymptomatic cCMV - sensorineural hearing loss (10%) chorioretinitis (2%)
CMV - neonatal management
Neonatal management
* Diagnosis - CMV PCR +ve urine or saliva or SNHL present
* Ophthalmology review + head US/MRI
* If classified as symptomatic cCMV infection -> treat with antivirals
* Audiological, ophthal and neurodevelopmental follow-up
Toxoplasmosis: incidence in pregnancy
2:1000 pregnancies
Toxoplasmosis: prevention measures
- Avoid raw / undercooked meat, unpasteurized milk
- Wash hands after gardening
- Wash raw vegetables
- Minimise contact with kittens / kitty litter
Toxoplasmosis: classic triad
Chorioretinitis
Hydrocephalus
Intracranial calcifications
CHIC
VZV: what counts as a significant exposure
- Living in same household as person with active chickenpox or herpes zoster
- Face-to-face contact with a case of chickenpox or zoster for at least 5 minutes or being in the same room for at least one hour
VZV: features of fetal varicella syndrome
- Skin scars 78%
- Eye abnormalities 60%
- Limb abnormalities 68%
- Prematurity, low birth weight 50%
- Cortical atrophy, intellectual disability 46%
- Poor sphincter control 32%
- Early death 29%
VZV: when are cases of chickenpox infectious?
From 2 days before rash until lesions crusted
Syphilis: transmission
Microbiology:
Bacteria = treponema pallidum (spirochaete organism)
Enters through mucous membranes of skin, reaching regional LN and disseminating
Incubation period: 9-90 days
Transmission:
Sexually transmitted, local contact with lesions or vertical transmission (transplacental)
Stages of syphilis
Primary - chancre (solitary painless ulcer)
Risk of fetal infection - HIGH
Secondary - develops after 1-6 months
25% of untreated patients
Risk of fetal infection - MODERATE
Systemic illness - “F-GIRL”
*Lymphadenopathy (generalised)
*Rash - symmetrical non-itchy maculopapular rash (90% of patients) involves palms, soles, mucous membranes (can be relapsing).
*Fever, malaise, anorexia
*“Itises” - hepatitis, iritis, meningitis, optic neuritis
* Genital lesions - condylomata lata
Latent - asymptomatic, early (<2 years) / late (>2 years)
Risk of fetal infection - LOW
Tertiary/neurosyphilis
- Cardiovascular
- Neurological
- Gummatous lesions
Risk of fetal infection - NEGLIGIBLE
