Public Health

Measles Virus

Measles is highly contagious infectious airborne disease caused by the Measles morbillivirus (MeV), a single-stranded enveloped RNA virus. Humans are the only known natural host of the Measles Virus, and there are no animal reservoirs are known to exist.

Other names for measles include morbilli, rubeola, red measles, and English measles. However, despite the names, both rubella, also known as German measles, and roseola are different diseases caused by unrelated viruses.

Complications from Measles Infection

Measles causes acute immuno-suppression which can lead to a variety of complications, including gastrointestinal infections, middle ear infections, and pneumonia. In rare instances measles can cause seizures, blindness, or brain inflammation (encephalitis).

Measles is a highly contagious acute respiratory infection that is spread through air when an infected person sneezes or coughs, as well as through  direct contact with mouth and nasal secretions of an infected person. Measles infections typically resolve after about three weeks.

Early Symptoms

Symptoms usually develop 10-12 days after exposure, beginning with fevers (often as high as 105°F) along with cough, runny nose, and eye redness. The fever generally lasts approximately a week after symptoms begin. The characteristic "Measles rash" typically starts to appear two to four days after the initial symptoms.

Koplik's Spots

A specific type of rash, called Koplik's spots, sometimes forms two to three days after symptoms. These small white spots commonly seen on the inside of the cheeks, opposite to the molars. They are described as looking like "grains of sand" on a red background. These spots appear early in infection, before the person reaches peak infectiousness, so if they are spotted quickly and the person is isolated, it can drastically limit the spread of disease. It is important to know that these Koplik's spots are also considered diagnostic for measles.

Rash Symptoms

The classic "measles rash" is a flat red area of the skin covered with tiny raised red bumps (maculopapular rash). It typically does not appear until three to five days after the initial symptoms. It usually starts on the back of the ears before spreading to the head and neck. It eventually spreads throughout the entire body and is often itchy. The rash can last up to eight days, beginning as a red rash and then changing to dark brown before disappearing.

There are no specific antiviral treatments for measles, but supportive care can improve outcomes. 

• Fever and pain reducing medicines (acetaminophen or ibuprofen)
• Bronchodilators (inhalers for cough if necessary)
• Oral hydration fluids (electrolyte drinks)
• Nutritional support (healthy foods)
• Vitamin A (decreases risk of blindness)

At-Risk Populations

Measles can be serious in all age groups. However, there are several groups that are more likely to suffer from measles complications:

• Children younger than 5 years of age
• Adults older than 20 years of age
• Pregnant women
• People with compromised immune systems, such as from cancer or HIV infection

Common Complications

• Ear infections occur in about one out of every 10 children with measles.
• Diarrhea is reported in less than one out of 10 people with measles.

Severe Complications

• Hospitalization - 1 in 5 unvaccinated people in the U.S. who get measles will be hospitalized
• Pneumonia - About 1 in every 20 children with measles will develop pneumonia, the most common cause of death from measles in young children
• Encephalitis - Around 1 child out of every 1,000 who get measles will develop encephalitis (swelling of the brain) that can lead to convulsions, deafness, and even death
• Death - Nearly 1 to 3 of every 1,000 children infected with measles will die from respiratory and/or neurological complications
• Pregnancy complications - Measles can cause unvaccinated pregnant women to give birth prematurely

Long Term Complications

Subacute sclerosing panencephalitis (SSPE) is a very rare, but fatal disease of the central nervous system that results from a measles virus infection acquired earlier in life.

• SSPE generally develops 7 to 10 years after a person has measles, even though the person seems to have fully recovered from the illness.
• Since measles was eliminated in 2000, SSPE is rarely reported in the United States.
• Among people who contracted measles during the resurgence in the United States in 1989 to 1991, 7 to 11 out of every 100,000 were estimated to be at risk for developing SSPE.
• The risk of developing SSPE may be higher for a person who gets measles before they are 2 years of age.