How virulent is rubella?

Rubella has a wide spectrum of clinical manifestations, ranging from mild or asymptomatic infections to severe disease. In most cases, rubella is a mild, self-limited viral illness with a relatively low risk of complications. The incubation period for rubella is typically 14 to 21 days. The characteristic rash usually appears 2 to 3 days after the onset of fever and lasts 3 to 5 days. Other common symptoms include sore throat, headache, mild fever, and swollen lymph nodes.

Congenital rubella syndrome (CRS) is the most serious complication associated with rubella. CRS occurs when a pregnant woman contracts rubella during the first trimester of gestation, particularly during the first 8 to 10 weeks of pregnancy. The virus can cross the placenta and infect the developing fetus, leading to a variety of congenital anomalies. The most common manifestations of CRS include heart defects, cataracts, hearing loss, developmental delay, and intellectual disabilities.

The severity of rubella can also be influenced by factors such as the individual's immune status and the strain of the virus. In immunocompromised individuals, the risk of severe disease and complications can be significantly higher.

Overall, rubella can range from a mild, self-limited illness in healthy individuals to a potentially devastating infection with severe outcomes, especially in pregnant women and those with weakened immune systems.