Measles, Mumps & Rubella Flashcards
1
Q
Transmission of measles
A
Aerosol, respiratory route, extremely contagious
2
Q
Epidemiology of measles
A
- ubiquitous infection of early childhood
- without vaccination, infection acquired by age 5
3
Q
Incubation period of measles
A
10-14 days
4
Q
Symptoms of measles (4)
A
- Viremia, virus replication in respiratory epithelium & skin
- Fever, conjunctivitis, rhinorrhea, cough
- Koplik’s spots around parotid duct orifices herald onset (salt & pepper)
4, Few days later, typical maculopapular rash from face spreads to body
5
Q
Complications of measles (4)
A
- Mucosal infections - conjunctivitis, otitis media
- Respiratory - bronchopneumonia, giant cell pneumonia
- GIT - diarrhea (measles/sec bact inf)
- Neurological
- post infectious demyelinating encephalitis
- subacute sclerosing panencephalitis - develops long period after apparent recovery, myoclonic seizures, intellectual deterioration, cytoplasmic inclusions in neuronal cells, rapidly fatal
6
Q
Diagnosis of measles (2)
A
- Tissue culture
- virus isolated from pharynx, conjunctiva, urine
- infected monkey kidney cells - multinucleated giant cells - Serology
- IgM assay for recent infection
- IgG for retrospective diagnosis
7
Q
Treatment of measles
A
- Live attenuated vaccine (MMR) at age 1
- effective & long lasting immunity
- mild pyrexia, serious complications are rare
- contraindications: severely malnourished & immunocompromised children, pregnant women
- passive immunisation with immune gammaglobulin for contacts with immunodeficiency
- new MMRV vaccine includes VZV antigen
8
Q
Incubation period of mumps
A
2-3 weeks
9
Q
Symptoms of mumps
A
- fever, malaise, tender cervical lymphadenopathy (+/-)
- salivary gland enlargement, pain aggravated by eating esp parotid gland
- most infections between age 5-15
10
Q
Complications of mumps (3)
A
- Aseptic meningitis - relatively common but mild
- Orchitis - pain & swelling, usually unilateral
- more frequent in adults, pancreatitis 10%
11
Q
Diagnosis of mumps (4)
A
- Specimens - saliva, throat washings, urine, CSF
- Tissue culture
- CPE - rounding of cells, multinucleated syncytial formation, eosinophilic inclusions
- Serology - IgM, IgG
12
Q
Treatment of mumps
A
Live attenuated vaccine at age 1, recommended for unimmunized pre-adolescents who have not had mumps parotitis
13
Q
Symptoms of rubella
A
- often subclinical esp in children
- constitutional symptoms - mild but variable
- prodrome of malaise, headache, fever, conjunctivitis, coryza, cough, lymphadenopathy
- occasionally discrete rose spots on palate (Forschheimer’s spots)
- typically rubella rash - small maculopapular lesion from face to trunk to extremities (~3d)
- tender lymphadenopathy, freq suboccipital, post auricular & cervical nodes
14
Q
Complications of rubella (4)
A
- Arthralgia & arthritis - affects 1 or more joints when rash subsides
- Encephalitis - uncommon, more in adults, occassionally fatal
- Purpura - thrombocytopaenia & haemorrhage (+/-)
- Congenital rubella sydrome
- teratogenic to fetus (esp intrauterine inf in 1st trimester) - virus crosses placenta to invade & damage fetal organ - esp severe during earlier periods of organogenesis - stillbirth, spontaneous abortions
- permanent defects - ocular lesions (cataract, retinopathy, microphthalmia), ear (sensorineural deafness), CNS (microcephaly, mental retardation, spasticity), heart malformations, interstitial pneumonitis, DM, hepatosplenomegaly, thrombocytopaenia, bone
15
Q
Epidemiology of rubella
A
- worldwide distribution, recurrent spring endemics
- moderately infectious & transmitted via resp route
- viral replication in respiratory epithelium & lymph nodes followed by viremia
