Measles is an acute viral respiratory illness. It is characterized by a prodrome of fever (as high as 105°F) and malaise, cough, coryza, and conjunctivitis -the three “C”s -, a pathognomonic enanthema (Koplik spots) followed by a maculopapular rashexternal icon. The rash usually appears about 14 days after a person is exposed. The rash spreads from the head to the trunk to the lower extremities. Patients are considered to be contagious from 4 days before to 4 days after the rash appears. Of note, sometimes immunocompromised patients do not develop the rash. The measles vaccine (MMR) also vaccinates against mumps and rubella and is a routine childhood immunization. Currently two doses are recommended in childhood.
Measles is Extremely contagious - preventative measures should be taken in case of contact. Seek proper medical care if you believe you have contracted measles.
Measles is caused by a single-stranded, enveloped RNA virus with 1 serotype. It is classified as a member of the genus Morbillivirus in the Paramyxoviridae family. Humans are the only natural hosts of measles virus.
In the decade before the live measles vaccine was licensed in 1963, an average of 549,000 measles cases and 495 measles deaths were reported annually in the United States. However, it is likely that, on average, 3 to 4 million people were infected with measles annually; most cases were not reported. Of the reported cases, approximately 48,000 people were hospitalized from measles and 1,000 people developed chronic disability from acute encephalitis caused by measles annually.
Some U.S. travelers have become sick with measles after traveling abroad. Before you leave on an international trip, check the CDC Travel Notices on measles.
Travel Notice: Watch (Level 1): Measles in Israel
Travel Notice: Watch (Level 1): Measles in Ukraine
Travel Notice: Watch (Level 1): Measles in Japan
Travel Notice: Watch (Level 1): Measles in Brazil
Travel Notice: Watch (Level 1): Measles in Philippines
In 2000, measles was declared eliminated from the United States. Elimination is defined as the absence of endemic measles virus transmission in a defined geographic area, such as a region or country, for 12 months or longer in the presence of a well-performing surveillance system. However measles cases and outbreaks still occur every year in the United States because measles is still commonly transmitted in many parts of the world, including countries in Europe, Asia, the Pacific, and Africa. Worldwide, 19 cases of measles per 1 million persons are reported each year; an estimated 89,780 die each year.
Since 2000, when measles was declared eliminated from the U.S., the annual number of cases has ranged from a low of 37 in 2004 to a high of 667 in 2014. The 2019 case count exceeded 2014 levels as of April 26, 2019, and continues to climb. The majority of cases have been among people who are not vaccinated against measles. Measles cases in the United States occur as a result of importations by people who were infected while in other countries and from transmission that may occur from those importations. Measles is more likely to spread and cause outbreaks in U.S. communities where groups of people are unvaccinated.
Outbreaks in countries to which Americans often travel can directly contribute to an increase in measles cases in the United States. In recent years, measles importations have come from frequently visited countries, including, but not limited to, England, France, Germany, India, and the Philippines, where large outbreaks were reported.
Common complications from measles include otitis media, bronchopneumonia, laryngotracheobronchitis, and diarrhea.
Even in previously healthy children, measles can cause serious illness requiring hospitalization.
One out of every 1,000 measles cases will develop acute encephalitis, which often results in permanent brain damage.
One or two out of every 1,000 children who become infected with measles will die from respiratory and neurologic complications.
Subacute sclerosing panencephalitis (SSPE) is a rare, but fatal degenerative disease of the central nervous system characterized by behavioral and intellectual deterioration and seizures that generally develop 7 to 10 years after measles infection.
People at High Risk for Complications
People at high risk for severe illness and complications from measles include:
Infants and children aged <5 years
Adults aged >20 years
People with compromised immune systems, such as from leukemia and HIV infection
Measles is one of the most contagious of all infectious diseases; up to 9 out of 10 susceptible persons with close contact to a measles patient will develop measles. The virus is transmitted by direct contact with infectious droplets or by airborne spread when an infected person breathes, coughs, or sneezes. Measles virus can remain infectious in the air for up to two hours after an infected person leaves an area.
“Measles | For Healthcare Professionals | CDC.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, www.cdc.gov/measles/hcp/index.html.