L45 Congenital and perinatal viral infections (IMP) Flashcards
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
