Measles 101: Symptoms, how it spreads, and why it’s back

Measles is a contagious viral infection caused by the measles virus. In fact, it’s one of the most contagious infectious diseases known [4, 5, 6]. 

The term measles likely comes from an older Dutch word masel, which means a spot or blemish. It could also stem from an old English word mesel, which meant leper or wretched person [7]. 

The disease has been a part of human history for centuries, but the introduction of the measles vaccine in the 1960s helped make it a highly preventable disease. However, vaccination rates are closely tied to whether the number of measles cases rise or fall [8].

Measles is highly contagious and is spread through the air. When a person infected with the measles coughs, sneezes, talks, or breathes, they can release the virus through airborne droplets. These droplets can be inhaled by people around them, leading to an infection [4, 9].

What many people may not know is that the measles virus actually stays in the air and on surfaces for up to two hours. So, people can get infected even if they were not in direct contact with the infected person [9].

Measles has shaped human health for centuries. Before a vaccine became available in 1963, it was a near-universal childhood illness worldwide, and as recently as 1980 it caused an estimated 2.6 million deaths each year, mostly among young children [8].

The impact of the measles vaccine

The introduction of the MMR vaccine changed everything. MMR stands for Measles-Mumps-Rubella, the three diseases that the vaccine protects against. The MMR vaccine helped prevent tens of thousands of measles-related deaths over the following decades [8, 10].

By the early 2020s, almost 82 countries had achieved or maintained measles elimination status. This meant that the measles virus was no longer circulating within these countries’ borders. However, in more recent years, the COVID-19 pandemic, vaccine hesitancy, and disinformation about the vaccine created a gap in vaccination coverage, leading to higher cases [10, 11].

In general, public health experts say that communities need about 95% vaccination coverage to prevent the measles virus from circulating [5, 8].

Notable measles outbreaks

For a comprehensive list of measles outbreaks, epidemiology maps, global vaccination rates, and more, visit gideononline.com.

A measles infection begins when a person inhales the measles virus particles. The virus takes hold in the cells that line the nose, throat, and lungs. It then targets the immune system directly. It binds to a receptor on the surface of certain immune cells and uses the cells to travel to the nearby lymph nodes and spread throughout the body. The virus continues to replicate and spreads through the lymphatic system and bloodstream, and eventually reaches the skin, where the characteristic measles rash appears [5, 6, 10]. 

The measles virus is also dangerous because it causes something called ‘immune amnesia.’ Usually, when our body fights an invading pathogen (virus, bacteria, and other toxins), our immune cells ‘remember’ them, and use this information to fight them again, when needed. The measles virus depletes immune cells, and can erase the body’s memory of the pathogens it’s fought before [12, 13]. 

So, even after a person recovers from the measles, their immune system may struggle against other viruses, bacteria, and pathogens, for months or even years. This type of long-term vulnerability is why a measles infection can be quite serious, and why prevention is necessary [12, 13, 14].

Once the virus enters a person, it takes about 7-18 days for symptoms to appear, according to WHO (The World Health Organization). This period is known as the incubation period of the virus [15].

Early symptoms

Early symptoms of measles include:

• Fever
• Cough
• Runny nose
• Red, watery eyes

These symptoms could last 2-4 days [4, 15]. 

Measles rash

A characteristic measles rash appears 2-4 days after the start of fever. Typically, the rash starts on the face before spreading to the neck, body, arms, and legs 4, 15].

Diagnosing measles starts with recognizing its classic symptoms: fever, a spreading rash, cough, runny nose, and red eyes [4].

Because these symptoms can look like other illnesses, lab tests are often needed to confirm the diagnosis [15].

Diagnostic tests for measles:

• Physical examination: One telltale early sign is the appearance of Koplik spots, tiny white spots inside the mouth, which can show up a day or two before the rash even begins [4, 5].
• RT-PCR test (Reverse Transcriptase-Polymerase Chain Reaction): This test detects measles RNA based on throat, nose, or urine samples [15].
• Testing for Measles-specific IgM antibodies: The presence of measles-specific antibodies in the blood can help confirm the diagnosis. However, it’s important to note that these antibodies are high 1-3 weeks after the measles rash appears, and are undetectable within 4-8 weeks [8, 15].
• Plaque neutralization (PRN) assay: This test is used very rarely because it needs specialized labs, a live virus, stronger safety protocols, and it takes time to complete. For this test, an infected person’s blood is mixed with live measles virus samples. Then there is an observation period to see if the antibodies in the blood can stop or neutralize the virus [8].

There is no antiviral treatment that can fight the measles virus directly. Treatment is usually supportive and focuses on keeping the infected individual comfortable while the immune system fights the virus [4].

Additionally, WHO recommends two daily doses of Vitamin A supplements for kids with measles. This is not a cure, but to reduce the risk of complications in children who are deficient in Vitamin A.

Severe cases of measles may be hospitalized [1, 4].

The best way to prevent measles is through the MMR vaccine.

Two doses of the measles vaccine have shown to offer 97% protection against measles. Even a single dose of the MMR vaccine provides ~93% protection [16].

Because measles is highly contagious, it’s important for entire communities to be vaccinated to prevent the spread of the disease. High vaccination rates in communities can also protect the vulnerable—newborn babies and those with weakened immune systems. This community protection is known as ‘herd immunity’ [8, 16].

Measles is a paradox: one of the most contagious and dangerous diseases known to medicine, yet also one of the most preventable. A more recent resurgence of this disease is due to gaps in vaccination rates in global communities. When MMR vaccination rates are high, the risk of measles can be mitigated. Preventing and eliminating measles, particularly during this period of global travel, requires the entire world to commit to educating and promoting measles vaccination in every community. It’s no easy feat but the rewards far outweigh the struggle.

Q. What are the first signs of measles?

Measles often starts off like a bad cold. Early symptoms include a cold, high fever, cough, a runny nose, and red, watery eyes. Sometimes, people develop white spots (Koplik spots) inside their mouth a few days before the characteristic red measles rash appears [4, 5]. 

Q. What does a measles rash look like?

The measles rash shows up as flat, red spots that start on the face near the hairline and spread downward to the neck, body, arms, and legs. The spots can join together as they spread, and they typically appear 3 to 5 days after the first symptoms. Please consult a healthcare provider if you notice any such symptoms [4, 15].

Q. How can you tell the difference between a measles rash and a regular rash?

One big difference between a measles rash and a regular rash is the pattern in which they appear. A measles rash often starts at the head and moves down the body, and it comes with high fever and cold-like symptoms first. Most everyday rashes may not follow that distinct head-to-toe pattern or they may not be accompanied by other symptoms of measles. If you notice a rash and are concerned about it, please consult a healthcare provider immediately [4].

Q. How long does measles last?

From the first symptoms to the rash fading, measles usually runs its course in about 2 to 3 weeks. The rash may typically lasts 5 to 6 days, and fades away [15].

Q. Can adults get measles?

Yes, adults can get measles. Anyone without immunity (through a prior infection or vaccination) is susceptible [4].

Q. Can you get measles twice?

Having a prior infection or getting the measles vaccine typically offers lifelong immunity to the disease. So, it is highly unlikely that someone can get the measles twice. However, there may be misdiagnoses that may lead people to believe they have had the measles twice [4, 16].

Q. How contagious is measles?

Measles is one of the most contagious viruses known to man. 9 in 10 unvaccinated people who come in contact with the virus are likely to get infected. It is even more contagious than the flu [4, 9].

Q. How long is someone contagious with measles?

A person with measles can spread the virus from about 4 days before and 4 days after the measles rash begins. This means, many people are contagious even before they know they are infected [4, 17].

Q. What should I do if I get exposed to measles?

Please call your local healthcare provider. If you are unvaccinated, getting the MMR vaccine within 72 hours of exposure to measles could potentially prevent or mitigate the severity of illness [16, 17].

Q. Can I get measles from being close to someone infected with measles?

Since the measles virus spreads through the air when an infected person coughs, sneezes, or even breathes, being in the same room with them is a risk [4, 9]. 

Q. How long does the measles virus stay in the air?

The measles virus can stay in the air for up to 2 hours. This means that you could catch measles by walking into a room after an infected person has already left it [9].

Q. How effective is the MMR vaccine?

The MMR vaccine has shown to be very effective at offering immunity against measles. Two doses are about 97% effective and even one dose is 93% effective [16].

Q. Is there a measles booster shot?

For most people vaccinated with the MMR, there is no need for a measles booster shot. However, adults who were vaccinated before 1968 with an older version of the vaccine may need to get the latest MMR vaccine. Please reach out to a healthcare provider to learn more [16].

Q. Can I still get the measles if I took the measles vaccine (MMR)?

In rare cases, people who are vaccinated with the MMR vaccine may get the measles when exposed to the virus. However, vaccinated people who get infected may experience a milder version of the illness [4, 16].

Q. What are the side effects of the MMR vaccine?

Side effects of the MMR vaccine are short and mild. They may include a sore arm, mild fever, or a temporary rash [16].

Q. Is measles dangerous?

While many recover fully, some people may face severe complications like pneumonia, encephalitis (swelling in the brain), sudden deafness, seizures, and even death. People who are especially vulnerable are young children, pregnant women, and those with a weakened immune system [4, 18].  

Q. Is measles more dangerous for babies?

Babies under 12 months cannot get the MMR vaccine, which leaves them unprotected against the measles virus. They may be at a higher risk of more serious complications like pneumonia and encephalitis [4, 17, 18].

Q. Is there a cure for measles?

There is no specific cure for the measles. Treatment for infected people is usually supportive care to ease symptoms during recovery. Prevention is through the MMR vaccine [4].

Q. Can vitamins prevent measles?

Vitamins cannot prevent measles and are not a substitute for the MMR vaccine. Sometimes, doctors may provide Vitamin A supplements for children who have the measles to help reduce the severity of the infection (particularly, if the child has a Vitamin A deficiency) [8].

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