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Virologists raise alarm over surge in measles cases worldwide.

What is Measles?

• Measles is a highly contagious viral disease caused by the Measles morbillivirus (from the paramyxovirus family).
• It primarily affects children, but any non-immune person (unvaccinated or without immunity) is at risk.
• The virus spreads via airborne transmission—through coughing, sneezing, and respiratory droplets. It can remain in the air or on surfaces for up to 2 hours.
• Infectivity: ~90% of unvaccinated individuals exposed will contract the virus.

Global Surge in Cases (2023–2025)

• The World Health Organization (WHO) and US CDC reported a 30-fold global surge in measles cases from 10,000 in 2022 to 10.3 million in 2023.
• Outbreaks have been recorded in Africa, Europe, Southeast Asia, and the Americas.
  • Africa: Nearly half of global outbreaks.
  • Europe: 41 of 53 countries reported cases.
  • United States: Worst outbreak since 1992 with 1,300+ cases across 40 states, including Texas, Ohio, and California.
  • Americas (2025): 11-fold increase in cases due to international travel.

Symptoms and Progression

• Incubation: Symptoms appear 7–14 days after exposure.
• Early signs: High fever, cough, runny nose, conjunctivitis (red, watery eyes), and white spots in the mouth (Koplik spots).
• Rash: Starts on the face and neck, spreads to the entire body, lasting 5–6 days.
• Contagious: 4 days before and after rash onset.

Complications

• Common: Pneumonia, diarrhoea, encephalitis (brain inflammation), deafness.
• Severe:
  • 1–3 per 1,000 unvaccinated children may die.
  • Can cause blindness, subacute sclerosing panencephalitis (SSPE) (a fatal brain disorder).
  • In pregnancy: Can lead to stillbirth or premature delivery.

Vaccination and Prevention

• No specific antiviral treatment exists; only preventive vaccination is effective.
• MMR Vaccine (Measles, Mumps, Rubella):
  • Two doses recommended:
    • 1st dose: 12–15 months
    • 2nd dose: 4–6 years
  • During outbreaks or travel: Can be given from 6 months of age.
• Herd Immunity Threshold: 95% vaccination coverage needed to prevent outbreaks.
  • Current US rate: 92.7%, with rising nonmedical exemptions at 3.3%, falling short of safety threshold.

Causes of Resurgence

• Vaccine hesitancy, misinformation, and declining immunisation rates.
• Conflict zones, weak health systems, and interrupted vaccination drives in developing regions.
• Post-COVID travel rebound accelerating transcontinental spread.

Call to Action by Scientists and WHO

• Global Virus Network (GVN) and virologists urge:
  • Urgent vaccination of unvaccinated children and vulnerable adults.
  • Strengthening public health infrastructure.
  • Enhancing outbreak surveillance and public awareness.
  • Focused outreach in rural and underserved communities.