Measles in Adult
Although measles was declared eliminated in the United States in 2000, outbreaks resulting from imported cases continue to occur. Most cases are associated with importation of measles by unvaccinated international travelers resulting in local outbreaks in communities, and by clusters of unvaccinated individuals. In the last decade, most cases of measles in the United States occurred in 2014: 644 cases from 27 states were reported to the Centers for Disease Control and Prevention (CDC), largely from underimmunized communities in 9 counties in Ohio. From January through May 2019, however, an even higher number of confirmed cases has been documented: over 900 cases from 26 states (Arizona, California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Missouri, New Mexico, Nevada, New Hampshire, New Jersey, New York, Oklahoma, Oregon, Pennsylvania, Texas, Tennessee, and Washington). Refer to the CDC for the latest information on measles cases and outbreaks in the United States.
Measles is transmitted via respiratory droplets and is highly infectious. The incubation period after the measles virus enters the upper respiratory tract and nasal passages is about 10 days (range 7-21 days), with the rash typically appearing about 14 days after a person is exposed. Infected individuals are considered contagious from 4 days before to 4 days after the rash appears.
A prodrome characterized by coryza (nasal congestion), cough, fever (up to 105°F [40.5°C]), and conjunctivitis occurs for about 3-4 days followed by the onset of the rash (sometimes immunocompromised individuals do not develop the rash). The coryza, a "barking" cough, and conjunctivitis will increase in severity until the rash reaches its peak. The CDC reports that approximately 1 of 10 children with measles will also have an ear infection, and up to 1 of 20 will develop a pneumonia. Encephalitis is a complication in about 1 of 1000 cases.
Subacute sclerosing panencephalitis (SSPE) is a late complication, occurring on average 10-11 years after acute infection. This catastrophic sequela is characterized by changes in personality, seizures, coma, and eventuates in death.
Related topic: Atypical measles
B05.9 – Measles without complication
14189004 – Measles
- Before the eruption, it is easy to confuse rubeola with common upper respiratory infections.
- Morbilliform or exanthematous drug eruption
- Other viral exanthems, including rubella, roseola, enterovirus, Epstein-Barr virus, parvovirus B19, human herpesvirus 6 (HHV-6), and dengue fever
- Rocky Mountain spotted fever
- Kawasaki disease
- Leukocytoclastic vasculitis
- Graft-versus-host disease