Measles, rubella and congenital rubella

Overview & Definition

Picture a five-year-old brought to the emergency department with four days of fever, a streaming nose, a hacking cough and red, watery eyes, who this morning developed a blotchy red rash behind the ears that is now spreading down the body. The child has never been vaccinated. This is textbook measles, and the decision you make in the next five minutes — isolate, confirm, treat, notify — protects both the child and everyone who shared the waiting room. Recognising it early is what turns a preventable death into a survivable illness. [5] [1]

Measles, or rubeola, is an acute, highly contagious viral infection caused by the measles morbillivirus, a paramyxovirus spread largely by the airborne route. It is one of the most transmissible human pathogens known: a single case in a susceptible population can infect twelve to eighteen others, and the virus lingers in the air of a room for up to two hours after an infectious person has left it. Rubella, or German measles, is caused by the rubella rubivirus and is a far milder illness in children — but its teratogenic effect on the first-trimester fetus makes it one of the most consequential infections in pregnancy. Congenital rubella syndrome (CRS) is the constellation of permanent defects that follows maternal rubella in early pregnancy. [6] [1]

The clinician's work has three faces. The acute face is to recognise the child with measles, support them through the illness, give vitamin A, and prevent spread through isolation and notification. The obstetric face is to confirm or exclude rubella in early pregnancy and counsel honestly about CRS risk. And the population face is to run the immunisation programme — two MMR doses, antenatal screening, postpartum catch-up — because the child who never catches measles and the fetus who never meets rubella are the children the programme has protected. [8] [2]