More than half of all the measles cases reported among United States residents during 2001–2004 were preventable, according to the Centers for Disease Control and Prevention.
Although endemic measles has been eliminated from the United States, cases continue to be imported from other parts of the world, and infected travelers can transmit the disease to susceptible contacts, the CDC said (MMWR 2005;54:817–20).
Of the 251 measles cases reported to the CDC during 2001–2004, 71% occurred among U.S. residents and 29% among nonresidents. Of the 177 cases among U.S. residents, 100 (56%) were considered preventable, meaning that they occurred in persons for whom vaccination against measles is recommended by the Advisory Committee on Immunization Practices, but those individuals had not received 1 or more doses of measles-containing vaccine.
Among the 177 U.S. residents, 52% (92) were aged 0–19 years and 48% (85) were aged 20 years or older. Nearly one-third (31%) had traveled abroad, while the other 69% were infected in the United States. More than three-fourths (77%) of the total group had not been vaccinated. Of those 136, only 7 cases (5%) were considered not preventable, because the individuals were born before 1957 and vaccination is not recommended for that age group.
Current recommendations for travelers include vaccination for infants 6–11 months of age and two doses of measles-containing vaccine for travelers aged 12 months and above. Yet the 100 preventable cases in this report included a total of 43 travelers: 17 infants aged 6–15 months, 11 children and adolescents aged 16 months to 19 years, and 15 adults aged 20 and older.
One of these cases was an 11-year-old girl who developed a rash 3 days after returning to the United States from the United Kingdom. She had close contact with an 11-month-old infant, who subsequently had contact with up to 234 persons at a summer camp 2 days before he also developed a rash. Thanks to extensive investigation and control efforts, no further cases were subsequently identified.
Measles cases among persons born before 1957 are rare. However, individuals in this age group who travel internationally might wish to consider vaccination, the CDC advised. Information on vaccination recommendations for travelers is available at www.cdc.gov/travel