Rubella Flashcards
1
Q
What is the family?
A
Togavirus
2
Q
What is the genus?
A
Rubivirus
3
Q
Characteristics
Size, genome etc
A
Small RNA non-arthropod-borne virus
4
Q
How many serotypes?
A
1
5
Q
What “measles” is it known as?
A
German measles
6
Q
How long is the incubation period?
A
2-3 weeks
7
Q
What are the clinical presentations?
A
- Prodrome of maliase, headache, fever, conjunctivitis, coryza, cough
- Ocasionally discrete rose spots (Forschheimer’s spots) on palate herald onset of skin rash
- Typically rubella rash (small maculopapular lesions from face to trunk and extremities, lasting about 3 days)
- Tender lymphadenopathy (frequently suboccipital, postauricular and cervical nodes)
8
Q
What are the complications?
A
- Arthralgia, arthritis (affects one or more large and small joints when rash subsides)
- Fever
- Encephalitis (uncommon, adults>children, fatal)
- Purpura, thrombocytopaenia and haemorrhage
- Congenital rubella syndrome
9
Q
How does Congenital Rubella Syndrome affect foetus?
A
- Teratogenic to foetus particularly if intrauterine infection of mother during first trimester of pregnancy
- Virus crosses placenta to invade and damage practically any foetal organ
- Stillbirth, spontaneous abortion
- Permanent defects: ocular lesions (cataract, retinopathy, microphthalmia), ear (sensorineural deafness), CNS (microcephaly, mental retardation, spasticity)
- Cardiorespiratory (heart malformations, interstitial pneumonitis)
- Diabetes mellitus (insulin dependent)
- Hepatosplenomegaly
- Thrombocytopenia
- Metaphyseal osteitis
10
Q
Describe how the pathogenesis
A
Viral replication in respiratory epithelium and lymph nodes followed by viraemia
11
Q
How to diagnose?
A
- Cell culture (virus isolation is time-consuming)
- RT-PCR
- Serology (one month after rash to detect significant rise in antibody titre, part of TORCHES IgG panel)
12
Q
How to manage and prevent?
A
- Quarantine infected individual
- Specific immunoglobulin may be protective if given early after exposure
- Screen all surrounding family members, exposed contacts and hospital personnel
- Screen all pregnant mothers antenatlly for rubella antibodies
- Live attenuated rubella vaccine (current strain developed in human cells)
- Vaccination programme targeted for both sexes (vaccinate women of childbearing age)
13
Q
What are the adverse effects of vaccine?
A
Fever, rash, lymphadenopathy, arthralgia, arthritis, rarely polyneuropathy