Measles cases in the United States have hit an all-time low, the Centers for Disease Control and Prevention reported.
During 2004, just 37 cases of measles were reported to the CDC. This number—the lowest ever reported in 1 year in the United States—represents a 16% drop from the 44 cases reported in 2002, the CDC said (MMWR 2005;54:1229–31).
Nearly half (18) of the 37 cases were children aged 1–4 years, another 7 were aged 5–19 years, 5 were younger than 12 months of age, 5 were 20–34 years old, and 2 were aged 35 years or older.
Three states—Washington, California, and New York—accounted for 49% of the cases, whereas 11 states reported one to three cases each.
Of the 37 cases, 27 (73%) were imported, including 14 in U.S. residents who had acquired measles while traveling abroad, and 13 in foreign nationals who acquired the disease abroad and subsequently traveled to the United States. China was the most frequent country from which measles was imported, accounting for 13 of the cases.
All 14 of the U.S. residents with imported measles cases were vaccine eligible. Of those, nine were not vaccinated, three had unknown vaccination status, and two had received at least one dose of measles vaccine.
Of the 13 non-U.S. residents with imported measles, 10 had not been vaccinated and 3 had unknown vaccination status.
Ten of the cases were indigenous (infected in the United States), of which six were linked to imported cases and four had unknown sources of exposure.
It will be necessary to maintain greater than 90% vaccination coverage in the United States as long as measles is endemic in most countries worldwide, the CDC said.