L45 Congenital and perinatal viral infections (IMP) Flashcards
(35 cards)
Definition of
a) Intrauterine infection
b) Perinatal infection
c) Neonatal infection
What is congenital infection?
a) Intrauterine infection - in utero, before birth
b) Perinatal infection - birth - 1 week
c) Neonatal infection - up to 4 weeks
Congenital infection = in utero +/- perinatal
List 6 causative organisms that causes intrauterine infection.
- Rubella
- Cytomegalovirus (CMV)
- Varicella Zoster virus (VZV)
- Parvovirus B19
- Toxoplasma
- Zika virus
Name 6 viruses that cause perinatal infection.
- HSV (Herpes simplex virus) [acute]
- HIV (Human immunodeficiency virus)
- HBV, HCV
- Enterovirus [acute]
- HTLV Human T cell lymphotrophic virus
- HPV (Human papillomavirus)
Severity of a congenital infection depends on?
- Primary or reactivation
- Timing - gestation
> affects overall risk , whether requires abortion
For congenital infection of rubella, permanent clinical presentation differs in 3 different phases in utero:
a) First 12 weeks
b) Weeks 13-16
c) Weeks 16 or above
For transient clinical manifestations:
- low birth weight
- thrombocytopenia
- hepatosplenomegaly
- bone lesion
- meningoencephalitis (rare)
a) First 12 weeks
- 90% with congenital rubella syndrome
1. permanent defects in ear (MC, deafness)
2. eye (e.g. cataract, glaucoma, retinopathy)
3. CNS (mental retardation)
4. Cardi (patent ductus arteriosus, pulmonary artery stenosis, VSD..)
5. DM
6. Thyroid disorder
b) Weeks 13-16
- deafness (20%)
c) Weeks 16 or above
- minimal, but deafness and retinopathy possible
For postnatal rubella infection A. Transmitted by aerosol B. Rash goes from limbs > trunk > face C. May cause arthritis of small joints esp in female D. Fever, malaise, lymphadenomathy E. 2-3 week incubation period
B is wrong:
face > trunk > limbs
Which of the following is correct for rubella?
A. Clinical diagnosis is accurate
B. Virological investigations is not needed in pregnant women with vaccination history/ previous antibody test results
C. Acute infection causes IgM to be increased by 4-folds in antibody titre
D. Viral isolation using urine or respiratory sample is fast
E. PCR cannot be performed on amniotic fluid
Only C is correct
A: inaccurate
B: always indicated in pregnant women!
D: slow!
E: PCR can be performed on urine, NPA/ ammonitic fluid (urine of baby)
Serology of rubella:
Increase in IgM by 4x = acute infection
Increase in IgG after __________ = immunity
Screening for ___________ for all antenatal women is required regardless of vaccination Hx
2 weeks;
rubella IgG
- Epidemiology: IgG+ in 90% of adults now
Which of the following are notifiable diseases? A.Rubella B Varicella Zoster Virus C. CMV D. Parvovirus B19
A and B
Cytomegalovirus is a member of family ______________?
90% of adults now is IgG+.
Primary infection is usually asymptomatic and common in childhood, followed by persistence.
Frequently shed in _______ and ________of children.
Secondary infection in immunocompromised, causing?
Herpesviridae;
urine and saliva;
CMV pneumonitis, hepatitis
For primary infection of CMV during pregnancy, it is symptomatic/asymptomatic in mother, and the fatal infection rate is _____%.
Fetal damages can result from maternal infections at ____ stage(s) of gestation.
5-10% symptomatic at birth, with severe congenital cytomegalic disease
another 10% develop deafness, psychomotor retardation
asymptomatic;
40; (around 1/3 transmitted to baby)
all;
What is clinical symptoms for cytomegalic inclusion disease (5-10%)? (4)
- Growth retardation
- Petechial haemorrhage
- Jaundice, hepatosplenomegaly
- Encephalitis, chorioretinitis
For secondary CMV infection, mother is symptomatic/asymptomatic. risk to fetus is ________, why?
asymptomatic;
low;
antibody in mother will clear the virus quickly
CMV: how do we diagnose:
- Maternal infection
- Congenital infection in fetus
- Congenital infection in newborn
- Maternal infection
- active search is not recommended as most HK adults are IgG+ - Congenital infection in fetus
- virus isolation/ detection of virus by PCR in amniotic fluid - Congenital infection in newborn
- virus isolation/ PCR in urine/saliva within 3 weeks of birth (if after 3 weeks: virus may be actually acquired post-natal)
- NOT IgM
- NOT 4 fold antibody titre
Primary infection and reactivation of Varicella Zoster virus is?
Primary infection: Chickenpox
- vesicular rash
- pustular and crusting
- life threatening in neonates, immunodeficiency
- pneumonia may occur
- encephalitis
Reactivation: Zoster (/shingles)
- pain before rash
- vesicular lesions in dermatome
- pain may persist after healing
- dissemination in immunodeficiency
Vesicular lesions of VZV distribution?
From trunk, head to extremities
Chicken pox in pregnant mothers:
A. Cause secondary bacterial infection, hemorrhage, encephalitis
B. Cause Reye’s syndrome, Guillain-Barre syndrome
C. Cause pneumonitis
D. Higher risk in smokers
E. Higher risk in 1st trimester
C esp in D,E
Should be 3rd trimester! 40% mortality!
VZV in pregnant mothers, effect on fetus:
A. Zoster has no harm to fetes at any stage of gestation
B. Severe maternal chickenpox infection may cause abortion
C. Chickenpox in 1st 20 weeks may cause congenital varicella syndrome (1-2%)
D. Chickenpox in 2nd and 3rd trimester causes zoster in infancy with no embryopathy
E. Perinatal chickenpox does not affect fetus
E is wrong!
- Cause severe neonatal varicella! (FATAL)
- maternal chickenpox 5 days before - 2 days after delivery
- inadequate time to produce adequate Ab and pass to the baby
C: low birth weight, cutaneous scarring, limb hypoplasia, microcephaly, cortical atrophy, ocular abnormalities, mental retardation
- perform seroscan to monitor disease progression, abortion is not recommended
VZV has characteristic clinical presentation thus lab diagnosis is seldom necessary. T/F?
T!
but if needed: best method is direct detection for viral antigen in skin scrape sample by IF
Varicella zoster immunoglobulin is expensive with limited supply. When is post-exposure prophylaxis given?
- High-risk neonates
- Susceptible pregnant women (IgG-, exposed to people infected)
- check VZV IgG status before treatment
Chickenpox vaccine
- What type of vaccine?
- Is it given to pregnant ladies?
- how many doses?
- Live-attenuated vaccine
- Contraindicated in pregnant ladies!
- 2 doses for adults, safe, 100% response
Parvovirus B19
A. by aerosol route
B. 50% adults IgG+ve worldwide, 30% in HK
C. 50% asymptomatic in immunocompetent host
D. Rash (Fifth disease) and arthritis in mother
E. Hydrops fetalis in fetus
F. IgG for serology
All except F!
IgM for serology
E: anemia and stillbirth too
Zika virus belongs to family ______________,
transmitted by the vector _____________, and also?
Flaviviridae
- Aedes species of mosquitoes
Sexual, intrauterine, possible blood transfusion and breastmilk
Clinical features for Zika virus?
A. Most commonly asymptomatic
B. Dengue like: fever, rash, myalgia, joint pain, conjunctivitis
C. associated with Gullain Barre sydrome
D. Microcephaly
E. High proportion of abnormality if infection is during 3rd trimester
E should be 1st trimester!
A: 80%
D: also eye, dural rube defects and CNS dysfunction
