Rubella virus
From IDWiki
- Also known as German measles
- Causes fever, rash, ± arthritis
- Congenital syndrome: deafness, cataracts, and CHD
Background
Microbiology
- RNA virus in the Matonaviridae family, genus Rubivirus
- Previously in the Togaviridae family
Epidemiology
- Seasonal, in spring, if no vaccine
- Less contaggious than measles, spread by respiratory droplets
- Most contagious while the rash is erupting, but ranges from 10 days prior to 15 days after
- Infants with congenital rubella can shed it in body fluids for months
- Epidemics happened every 6 to 9 years, with larger epidemics every 30 years
- Worldwide, until it was eliminated in the Americas in 2009
- All cases are imported
Clinical Manifestations
- Incubation period 18 days (range 12 to 23 days)
- Benign after birth (postnatal rubella)
- In adults, prodrome of fever, malaise, and anorexia, followed by the rash
- Rash appears along with development of immunity
- Rash starts at the head and moves down
- Maculopapular
- May desquamate during healing
- May be absent
- Can have Forschheimer's spots (petechial lesions on the soft palate), but not pathognomonic
- Adenopathy can last weeks, primarily posterior auricular, posterior cervical, and suboccipital
- Can develop arthritis in a third, usually fingers, wrists, and knees
- Onset soon after the rash, can take up to a month to resolve
- Hemorrhage from thrombocytopenia and vascular damage, more commonly in children
- Encephalitis is rare
Congenital rubella syndrome
- Refer to Congenital rubella
Diagnosis
- Acute and convalescent ELISA serology, or single IgM titre
- Can do PCR for viral RNA on throat swabs, CSF, or amniotic fluid
Management
- First trimester infection is more likely to have congenital rubella, rare in third trimester
- Confirm vaccination status of the exposed individual, in which case they will be very low risk
Prevention
- Live attenuated vaccine is included in MMR at 12-15 months and 4-6 years
- Vaccine is 95% effective
- Should revaccinate most young women
