Rubella is caused by an RNA virus. Infection results mostly in few or no symptoms. Viremia and viral shedding starts before a rash may be seen.
German physicians were probably the first to describe rubella in the early 19th century, hence the name "German measles". A British physician reported an outbreak in a boys’ school in India in 1841. He used the word rubella, "little red", a Latin diminutive from ruber (red).
Rubella is often indistinguishable from other viral exanthematous diseases, but palpable posterior auricular and suboccipital lymph nodes are almost pathognomonic.
Rubella infection during pregnancy may result in cataract, heart disease and deafness in an infant, forming the key triad defining ”congenital rubella syndrome”, CRS. Also mental retardation is common. After birth, rubella is a mild disease with rare complications only.
There is no treatment for rubella or CRS, but vaccination programs usually with MMR-vaccine maintaining high vaccine uptake over time can virtually eliminate rubella.