What is Measles?

Measles is a viral respiratory illness that remains one of the leading causes of childhood death globally. It is highly infectious and spreads rapidly through respiratory droplets. A single infected person can transmit the virus to 90% of nearby unvaccinated individuals.

Transmission & Virus Biology

The measles virus is part of the Morbillivirus genus and is spread through coughing, sneezing, or direct contact with nasal secretions. The virus remains active in the air or on surfaces for up to two hours.

• Incubation: 7–14 days
• Infectious period: 4 days before to 4 days after rash onset
• Mode of transmission: Airborne droplets & contact

Symptoms & Disease Progression

• Measles progresses in clear stages and presents with a recognizable combination of symptoms. It may also result in post-infectious immune suppression.

• Stage 1 (Prodrome): High fever, cough, runny nose, conjunctivitis
• Stage 2 (Koplik spots): Tiny white lesions inside cheeks
• Stage 3 (Exanthem): Rash starts at hairline and spreads downwards

Who is Most at Risk?

• Children under 5
• Unvaccinated individuals of any age
• Pregnant women
• People with weakened immune systems (HIV, cancer)
• Malnourished children (especially Vitamin A deficiency)

Complications of Measles

Measles can result in several life-threatening complications:

• Pneumonia – leading cause of death in children with measles
• Encephalitis – brain swelling that can cause seizures or disability
• Blindness – especially in Vitamin A deficient children
• SSPE – a fatal degenerative brain disease appearing years later
• Severe diarrhea – leads to dehydration and malnutrition

Diagnosis & Laboratory Testing

Diagnosis involves clinical evaluation followed by confirmation with laboratory tests:

• IgM ELISA: Detects recent infection in blood
• RT-PCR: Detects measles RNA in respiratory specimens or urine
• Genotyping: Helps trace origin of outbreak
• Saliva samples: Common for field surveys

Treatment & Vitamin A Supplementation

No specific antiviral exists for measles. Supportive care is the mainstay of treatment. WHO recommends high-dose Vitamin A for all measles cases.

• Fever and hydration management
• Antibiotics for complications (pneumonia, ear infection)
• Vitamin A: given 24 hours apart, reduces mortality by 50%
• Hospitalization: needed for respiratory failure, malnutrition

Prevention & Vaccination

Prevention depends on immunization and public health infrastructure. The MMR vaccine (Measles, Mumps, Rubella) is highly effective and safe.

• First dose: 12–15 months
• Second dose: 4–6 years
• Catch-up campaigns during outbreaks
• MMRV version includes varicella for young children

Global Impact and Outbreak Data

Global resurgence of measles has been fueled by misinformation, reduced vaccination, and healthcare disruptions from COVID-19.

• 107,500 measles deaths globally in 2023
• Over 22 million infants missed their first dose of vaccine
• 884 cases in the US (as of April 2025)
• Outbreaks linked to travel, undervaccinated communities