Rubella

Rubella, also known as German measles, is a mild viral infection caused by the rubella virus, characterized by fever, rash, and lymphadenopathy. In children, it is usually self-limiting but poses significant risk in pregnancy due to congenital rubella syndrome.

Definition

Epidemiology

Primarily affects children and young adults
Incidence has declined in countries with routine MMR vaccination
Peak incidence in school-aged children
Transmission is via respiratory droplets
Highly contagious in the week before and after rash onset

Etiology

Rubella virus, a single-stranded RNA virus of the Togaviridae family
Transmission via inhalation of respiratory droplets from infected individuals
Risk factor: unvaccinated children or community outbreaks
Vertical transmission during pregnancy can lead to congenital rubella syndrome

Pathophysiology

Virus enters via respiratory tract and replicates in nasopharyngeal mucosa and regional lymph nodes
Viremia spreads virus throughout the body
Immune response leads to rash, lymphadenopathy, and mild systemic symptoms
Congenital infection disrupts organogenesis, causing heart, eye, ear, and brain defects
Immune-mediated clearance usually resolves infection in 1–2 weeks
Persistent virus can cause complications in immunocompromised children