Neonates: Congenital Infections & SIDS Flashcards
What is rubella (German measles)?
A viral infection.
If rubella is contracted during pregnancy, what is there a risk of?
Congenital rubella syndrome
When is the risk of congenital rubella highest?
The risk is highest during the first 3 months of pregnancy.
Why is rubella now very rare (<5 cases a year in the UK)?
Due to MMR vaccine
How can women planning to become pregnant reduce their risk of rubella infection?
1) Ensure they have had MMR vaccine
2) If in doubt they can be tested for rubella immunity
3) If they do not have antibodies to rubella they can be vaccinated with 2 doses of the MMR 3 months apart
Can pregnant women receive the MMR vaccine?
No - it is a live vaccine.
Non-immune women should be offered the vaccine after giving birth.
What are the clinical features of rubella infection?
- maternal rubella infection is often asymptomatic
- prodrome e.g. low grade fever, malaise, headache
- diffuse maculopapular rash: initially on the face before spreading to the whole body, usually fades by the 3-5 day
- lymphadenopathy: suboccipital and postauricular
What is a maculopapular rash?
Macule –> A flat, reddened area of skin present in a rash.
Papule –> A raised area of skin in a rash.
The term maculopapular describes a rash with both flat and raised part.
What are the features of congenital rubella syndrome?
1) Congenital cataracts
2) Congenital heart disease (PDA and pulmonary stenosis)
3) Learning disability
4) Hearing loss
Pregnant women can be tested for rubella infection and immunity.
What 2 tests are performed?
IgM antibody –> acute infection
IgG antibody –> present following infection or vaccination
In cases where neither antibody was present, the woman is encouraged to seek rubella vaccination post-delivery.
Incubation period of rubella?
14-21 days
Management of a pregnant woman with a positive rubella screen?
Refer to foetal medicine specialist.
Maternal –> no treatment, self-limiting (inform her that she is infective)
What affects the risk of vertical transmission, and likelihood of developing congenital rubella syndrome?
The gestational age at the time of infection.
Lower gestational age at time of infection = higher risk of congenital rubella syndrome (and higher risk of defects).
Risk of Congenital Rubella Syndrome if infection at <12 weeks gestation?
90%, with high likelihood of multiple defects.
It is reasonable to consider a termination of the pregnancy.
Risk of Congenital Rubella Syndrome if infection at 12-16 weeks gestation?
20%m with single defects most common.
Can do prenatal diagnosis of foetal rubella infection.
Risk of Congenital Rubella Syndrome if infection at >20 weeks gestation?
No additional risk.
The clinical features of congenital rubella syndrone can be classified into ‘present at birth’ and ‘late onset’.
What are some ‘present at birth’?
1) Sensorineural deafness
2) Cardiac Defects:
- Pulmonary Stenosis
- Patent Ductus Arteriosus
- Ventricular Septal Defect
3) Ophthalmic Defects:
- Retinopathy
- Congenital cataracts
4) CNS Abnormalities:
- Learning disabilities
- Microencephaly
5) Haematological:
- Thrombocytopaenia
- Blueberry muffin appearance
What are some ‘late onset’ features of congenital rubella syndrome??
1) diabetes mellitus
2) thyroiditis
3) GH abnormalities
4) behavioural disorders
What is the varicella zoster virus (VZV) responsible for?
1) Chickenpox - a result of primary infection.
2) Shingles (herpes zoster) - a result of viral reactivation.
Is VZV dangerous to contract during pregnancy?
Yes - if contracted during pregnancy there is increased morbidity and mortality for both mother and fetus.
Clinical features of primary maternal VZV infection?
- pruritic maculopapular rash: characteristically becomes vesicular and crusts before healing
- can be associated with pneumonia, hepatitis, and encephalitis in mothers
What can severe cases of VZV infection in pregnant women lead to?
Varicella pneumonitis, hepatitis or encephalitis in mothers.
What can be done to determine the immunity status of a woman against VZV?
IgM and IgG antibodies to varicella zoster.
What are the management steps in a case where a pregnant woman has encountered a person infectious with VZV?
1) Ask if mother has had previous 1ary VZV infection:
If yes –> assume immunity (no further action).
If no –> go to 2)
2) VZV IgG testing required to confirm immunity status.
3) If not immune and <20 weeks gestation –> woman should receive varicella zoster immunoglobulin (VZIG) within 10 days of the contact, and before the onset of rash.
4) If not immune and >20 weeks gestation –> woman can receive either VZIG, or alternatively Aciclovir can be given from days 7 to 14 following exposure.
If a mother with suspected contact with infectious VZV person is found not to have immunity and is <20 weeks gestation, what is next step?
They should receive varicella zoster immunoglobulin (VZIG) within 10 days of the contact, and before the onset of rash.
If a mother with suspected contact with infectious VZV person is found not to have immunity and is >20 weeks gestation, what is next step?
The woman can receive either VZIG, or alternatively Aciclovir can be given from days 7 to 14 following exposure
If VZV infection is confirmed in pregnant woman, what is next step?
If >20 weeks gestation –> Aciclovir (800mg PO 5tds) in patients presenting within 24 hours of rash onset.
Consider aciclovir prescription in mothers <20 weeks.
What are the 2 potential foetal complications of maternal VZV infection?
1) Varicella of the newborn
2) Foetal varicella syndrome
What is the key risk factor for varicella of the newborn?
If maternal chickenpox occurs within the last 4 weeks of the pregnancy.
This confers a 50% risk of varicella infection of the newborn.
Possible routes of infection in varicella of the newborn?
1) transplacental
2) vaginal
3) direct contact after birth
Management of varicella of the newborn?
Varicella-zoster immunoglobulin (VZIG) +/- aciclovir.
What is foetal varicella syndrome caused by?
Subsequent reactivation of of the virus in utero as herpes zoster.
This reactivation ONLY occurs when the fetus is infected by maternal varicella before 20 weeks gestation.
Clinical features of foetal varicella syndrome?
1) Skin scarring in a dermatomal distribution
2) Eye defects:
- Microphthalmia
- Choriorenitis
- Cataracts
- Optic atrophy
3) Hypoplasia of the limbs
4) Neurological abnormalities:
- Microcephaly
- Cortical and spinal cord atrophy
- Seizures
- Horner’s syndrome
If a mother with suspected contact with infectious VZV person is found not to have immunity and is <20 weeks gestation, how soon should IV varicella immunoglobulins be given?
Within 10 days of exposure
What are 5 key maternal infections that can have foetal complications?
1) Rubella
2) Varicella zoster virus
3) Cytomegalovirus
4) Toxoplasmosis
5) Zika virus
What is the most common virus transmitted to the fetus during pregnancy?
Cytomegalovirus
What % of maternal CMV infections are then vertically transmitted to the fetus?
1/3
However, only 5% of fetal infections will cause CMV related damage to the fetus, with the risk highest in the first trimester.
In what trimsester is the risk of CMV related damage to the fetus highest?
1st trimester
Clinical features of maternal CMV infection?
Usually asymptomatic.
It can occasionally produce a mild flu-like illness.
In some patients, it can cause a mononucleosis syndrome (similar to Epstein-Barr); resulting in fever, splenomegaly and impaired liver function.
If maternal cytomegalovirus infection is suspected, what is next investigation?
Viral serology for CMV specific IgM and IgG
Management of maternal CMV infection in an immunocompetent woman?
No treatment.
How can foetal CMV be diagnosed prenatally?
Via amniocentesis and PCR of the resulting amniotic sample.
When must amniocentesis to diagnose foetal CMV infection be carried out?
After 21 weeks gestation, because functioning fetal kidneys are required for the virus to be excreted into the amniotic fluid.
Management of confirmed foetal CMV infection?
There is no effective therapy.
Termination of pregnancy can be offered.
If the woman wishes to continue the pregnancy, serial ultrasound scanning should be performed to assess for manifestations of congenital CMV.
Clinical features of congenital CMV?
1) Intrauterine growth restriction
2) Hepatosplenomegaly
3) Thrombocytopaenic purpura
4) Jaundice
5) Microencephaly
6) Chorioretinitis
There is 20-30% mortality in this symptomatic group. This is often due to disseminated intravascular coagulation (DIC), hepatic dysfunction and/or bacterial superinfection.
Babies born without symptoms of CMV infection have a 10-15% chance of developing sequelae of the infection within 2 years. This may include:
1) Sensorineural hearing loss
2) Psychomotor development delay
3) Visual impairment
How is the zika virus spread?
- By the Aedes mosquito
- It can also be spread by sex with someone infected with the virus.
Presentation of zika virus infection in adults?
Typically asymptomatic, or causes minimal symptoms or a mild flu like illness.
What can zika virus infection in pregnancy result in?
Congenital zika syndrome
What are the features of congenital zika syndrome?
1) microcephaly
2) foetal growth restriction
3) intracranial abnormalities e.g. ventriculomegaly and cerebellar atrophy
Management of pregnant women that may have contracted the Zika virus?
1) Test for the viral PCR and antibodies to the Zika virus
2) Positive result –> refer to fetal medicine to monitor the pregnancy (there is no treatment for virus)
What is toxoplasmosis?
Infection with the Toxoplasma gondii parasite via the GI tract, lung or broken skin.
Transmission of Toxoplasma gondii?
The usual animal reservoir is the cat, although other animals such as rats carry the disease.
It is primarily spread by contamination with faeces from a cat that is a host of the parasite.
Presentation of toxoplasmosis infection in immunocompetent?
Usually asymptomatic.
Symptomatic patients usually have a self-limiting infection, often having clinical features resembling infectious mononucleosis (fever, malaise, lymphadenopathy).
Other less common manifestations include meningoencephalitis and myocarditis.
Investigation of choice in suspected toxoplasmosis?
Serology
Impact of toxoplasmosis infection in HIV/immunosuppressed patients?
Cerebral toxoplasmosis accounts for around 50% of cerebral lesions in patients with HIV:
Constitutional symptoms, headache, confusion, drowsiness.
What can toxoplasmosis infection in pregnancy cause?
Congenital toxoplasmosis
When is the risk of congenital toxoplasmosis higher in pregnancy?
The risk is higher LATER in pregnancy
What triad of features is seen in congenital toxoplasmosis?
1) Intracranial calcification
2) Hydrocephalus
3) Chorioretinitis (a type of uveitis involving the posterior segment of the eye, which includes inflammation of the choroid and the retina of the eye)
What is the commonest cause of death in the first year of life?
Sudden infant death syndrome (‘cot death’)
When is sudden infant death syndrome (SIDS) most common?
At 3 months of age
What is SIDS?
Sudden infant death syndrome (SIDS) is a sudden unexplained death in an infant.
What are the major risk factors for SIDS?
1) Prematurity (4x)
2) Hyperthermia (e.g. over-wrapping) or head covering (e.g. blanket accidentally moves)
3) Bed sharing
4) Parental smoking
5) Putting the baby to sleep prone
Protective factors for SIDS?
1) Breastfeeding
2) Room sharing (but NOT bed sharing)
3) Use of dummies (pacifiers)
What are some measures that can reduce the risk of SIDS?
1) Put the baby on their back when not directly supervised
2) Keep their head uncovered
3) Place their feet at the foot of the bed to prevent them sliding down and under the blanket
4) Keep the cot clear of lots of toys and blankets
5) Maintain a comfortable room temperature (16 – 20 ºC)
6) Avoid smoking. Avoid handling the baby after smoking (smoke stays on clothes).
7) Avoid co-sleeping, particularly on a sofa or chair
8) If co-sleeping avoid alcohol, drugs, smoking, sleeping tablets or deep sleepers
What team supports parents with their next infant after a sudden infant death?
Care of Next Infant (CONI)
This provides extra support and home visits, resuscitation training and access to equipment such as movement monitors that alarm if the baby stops breathing for a prolonged period.
