Measles: More Than a Rash

Recently, measles outbreaks in the southwestern United States have attracted a lot of global attention. As of April 24, 2025, 884 measles cases and 3 deaths have been confirmed by the Centers for Disease Control and Prevention (CDC). You might think that measles is just a fever and a rash; no big deal. However, measles has more significance beyond these symptoms. In the days before vaccines, measles killed about 2.6 million people worldwide each year. In 2023, measles was estimated to kill 107,500 people worldwide, according to the CDC. 

Measles Overview

Measles is an extremely contagious disease caused by the measles virus that infects the respiratory tract before spreading to the rest of the body. It’s estimated that if one person has measles, 9 out of 10 people around them will become infected if they aren’t protected by the vaccine or have immunity from a prior measles infection. It can occur in all seasons, with high incidence in the winter and spring. The measles virus mainly passes through respiratory droplet transmission, such as if an infected person coughs or sneezes. Only humans infected with measles can spread the disease, and they are contagious for up to four days before and after they begin to have visible symptoms. 

Symptoms of Measles

Initial symptoms of measles include high fever, cough, runny nose, red eyes, etc. which can easily be mistaken for the common cold. Another early warning sign are Koplik spots, small, gray-white bumps can appear on the cheek lining inside your mouth. The tell-tale and most famous sign of measles is a red rash that begins about 3-5 days after symptoms begin. The rash usually first shows up behind the ears and hair, then spreads to the face and neck, and gradually to the rest of the body, down to the hands and feet. Some people may have complications from measles, including ear infection, pneumonia (lung infection), encephalitis (brain swelling), and even death.

How to Prevent Measles

Vaccines are the strongest protection against measles, especially the measles, mumps, and rubella (MMR) vaccine. All children should receive two doses of the MMR vaccine, first when they are around 12-15 months of age, and the second when they are around 4-6 years old. Measles was considered eliminated from the United States in 2000, mainly due to the widespread use of the highly safe and effective MMR vaccine.

The recent rise of measles outbreaks in the US may be attributed to an increase in vaccine hesitancy. It’s important for as many people as possible to get vaccinated to prevent the size, spread, and severity of measles outbreaks.

Who is More Likely to Get Infected?

All people who have not been vaccinated against measles or who have not contracted the measles virus are at risk of developing illness after infection. In particular, pregnant women, young infants not yet vaccinated, and people with weakened immune systems are at higher risk of serious complications. 

Measles, a seemingly distant “old enemy,” has never really left. It’s important that we understand the measles and do our part to prevent the spread of this disease.

References

1. 1. CDC. (2024, May 20). History of measles. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/measles/about/history.html
   2. CDC. (2025a, April 24). Measles cases and outbreaks. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/measles/data-research/index.html
   3. CDC. (2025b, April 25). Measles vaccination. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/measles/vaccines/index.html
   4. Mayo Clinic Staff. (2025, April 23). Measles. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/measles/symptoms-causes/syc-20374857
   5. Measles. (2024, November 14). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/measles
   6. Rosen, A. (2025, February 26). Measles outbreaks in the U.S. highlight the importance of vaccination. Johns Hopkins Bloomberg School of Public Health. https://publichealth.jhu.edu/2025/what-to-know-about-measles-and-vaccines