Measles

Measles is a highly contagious viral disease caused by the measles virus, a member of the genus Morbillivirus. It spreads mainly through respiratory droplets and can linger in the air for up to two hours, contributing to rapid transmission in communities with close contact or low vaccination coverage.

Initial symptoms typically begin about ten to fourteen days after exposure and resemble a nonspecific flu-like illness: high fever, cough, runny nose, red eyes, and fatigue. Koplik spots — small, white lesions on the inner lining of the cheeks — may appear inside a few days of fever. A widespread red-brown rash then emerges several days after the onset of fever and spreads from the face downward across the body.

Complications are common, especially in young children and adults who are not immune. Pneumonia, diarrhea, ear infections, and encephalitis are among the main risks; malnutrition and weakened immunity can worsen outcomes. A rare but fatal condition, subacute sclerosing panencephalitis, can occur years after infection.

Diagnosis is typically clinical, supported by laboratory tests such as serology for measles-specific IgM or RT-PCR from throat or nasal swabs. There is no specific antiviral treatment for measles; care is supportive. Vitamin A supplementation is recommended for children with measles in many settings, as it can reduce morbidity and mortality. Isolation of infectious individuals helps prevent further spread.

Prevention relies on vaccination. The measles-containing vaccine is usually given as the MMR vaccine in two doses, commonly at around 12-15 months and again at 4-6 years. The vaccine is highly effective and, together with herd immunity, can prevent outbreaks.