Measles

Measles, also known as rubeola, is a highly contagious respiratory virus that is spread through airborne droplets from the coughing and sneezing of an infected individual.³ Measles is caused by a single-stranded, enveloped RNA virus, with humans being the only natural hosts.¹

Throughout recorded history, measles has been an important communicable disease. The first published clinical description of measles was authored by Rhazes, the chief physician in Baghdad in 910.⁶ Measles is considered to have been widespread throughout Europe, East Asia, China, and India in the Middle Ages. By the 18^th century, measles was considered endemic in Europe.  Many severe outbreaks were recorded in the Americas, Caribbean, and Pacific Islands when the pathogen was brought from Europe.⁶

In areas where vaccination rates are low, the highly contagious virus can quickly spread through communities. In 2023, an estimated 10.3 million people contracted measles globally.⁵

Symptoms of measles generally appear 7 to 14 days after infection.² Measles progress through distinct stages, beginning with early symptoms followed by a characteristic rash.

Initial Symptoms (Prodromal Phase):

• High fever (can exceed 104°F)
• Runny nose
• Cough
• Red eyes
• Sore throat
• Small white or grey lesions inside the cheeks (Koplik spots)¹

Rash Phase:

• Rash typically develops 3-5 days after the prodromal phase³
• Starts as flat red spots at the hairline before spreading down to the neck, trunk, arms, legs, and feet
• Typically lasts 4-8 days beforefading
• As the rash resolves, fever typically subsides

Some individuals may experience complications, such as diarrhea, ear infections, pneumonia, or encephalitis.^1,3 

Measles is among the most contagious human diseases. It spreads from person-to-person, not through animals.⁴ The disease is spread when an infected person breathes, coughs, or sneezes. Individuals are infectious from 4 days before symptoms appear to 4 days after rash onset.³

According to the US Centers for Disease Control (CDC) one infectious person can infect 90% of unvaccinated, susceptible people around them.⁴ The virus is transmitted through droplets, and the virus can survive in the air and on surfaces for up to two hours.³

While anyone who is not protected through vaccination or immunity can contract measles, certain populations are at greater risk for severe illness and complications.

Higher-risk groups include:^1,3

• Children younger than five years of age
• Adults older than 20 years of age
• Pregnant individuals
• Individuals with weakened immune systems

Globally, measles continues to cause significant illness and mortality, particularly among unvaccinated children under five years of age.³ Vaccination programs have prevented millions of deaths worldwide, but maintaining high immunization coverage remains critical to preventing future outbreaks.³

The most effective way to control and prevent measles is through vaccination. The measles vaccine can be on its own or combined in the MMR vaccine (measles, mumps, rubella). Two doses of the vaccine are recommended; two doses are about 97% effective at preventing measles, and one dose is about 93% effective.² Vaccination programs have prevented millions of deaths globally and remain the most effective control strategy.³

There is no specific antiviral treatment for measles and supportive care focuses on symptom management.³  Additional steps to reduce infection risk include:

• Stay home and isolate when sick
• Effective hand hygiene – using soap and water or alcohol-based hand rubs if soap and water is not available
• Thorough cleaning and disinfection of frequently touched surfaces and objects with products effective against the measles virus
• Cough etiquette and social distancing
• Avoid exposure in shared airspaces as measles can linger in the air after an infected individual leaves^3,4

In a food facility, focus on:

• Effective employee health practices including exclusion of sick workers
• Proper cleaning and disinfection of frequently touched surfaces and guest areas
• Effective handwashing 

Control in a healthcare setting:

• Use of airborne precautions or approved respirators⁷
• Isolation of infected individuals during the infectious period⁷
  • Limit contact with confirmed measles patients to vaccinated individuals or those with documented immunity.
• Immediate reporting of suspected cases to public health authorities
• Post-exposure interventions, including vaccination for susceptible contacts

Maintaining vaccination coverage, practicing good hygiene, and following public health guidance are important measures for reducing measles transmission and protecting vulnerable populations.

1. US Centers for Disease Control and Prevention (CDC). Clinical overview of measles. (2026, August 5). [CDC.gov – Clinical Overview]
2. US Centers for Disease Control and Prevention (CDC). About measles. (2026, April 29). [CDC.gov – About]
3. World Health Organization (WHO). Measles. (2026, July 15). [WHO.int – Measles]
4. US Centers for Disease Control and Prevention (CDC). How measles spreads. (2026, April 29). [CDC.gov – Spread]
5. US Centers for Disease Control and Prevention (CDC). Global measles outbreaks. (2026, September 14). [CDC.gov – Global Outbreaks]
6. Berche, P. (2022). History of measles. La Presse Médicale, 51(3):104149. [History]
7. Government of Canada. Notice: Updated infection prevention and control recommendations for measles in healthcare settings. (2025, January 20). [Canada.ca – Healthcare]