WASHINGTON — Measles, once a common rite of passage for U.S. children, has all but been wiped out in this country, federal health officials announced Thursday.
In 1998, there were only 100 cases reported to the Centers for Disease Control and Prevention, most of them believed to have originated outside the United States.
The achievement was attributed in large part to a concerted push in recent years to raise vaccination rates across the nation, as well as the addition of a second dose of the vaccine for young schoolchildren, affording even greater protection.
The recent low rates were even more remarkable in light of a dramatic and frightening resurgence of the disease that occurred from 1989 to 1991, when there were nearly 56,000 cases reported in the United States.
The resurgence, caused both by a pandemic in North and South America and low vaccination rates among preschoolers in this country, peaked in 1990, with nearly 28,000 cases. California experienced nearly 12,500 cases that year.
Dr. Mark Papania, acting chief of the CDC's measles elimination program, termed it "impressive" to go from 27,786 cases to 100 cases in the course of a decade. "It's been a tremendous decrease."
With Thursday's announcement, measles joins the ranks of smallpox, polio and diphtheria as childhood diseases wiped out by vaccines in the United States.
Before 1963, when the measles vaccine was introduced, virtually every child in America came down with this highly contagious viral infection, with more than 500,000 cases reported annually. At its known peak, in 1941, measles infected 894,134 Americans, according to federal officials.
The illness is characterized by fever, cough, watery eyes and its hallmark: a red, blotchy rash that usually appears by the third or fourth day.
Occasionally complications can arise, such as ear infections or encephalitis, a brain inflammation that can lead to deafness, mental retardation, even death.
Despite the record low rates in the United States, measles still remains a problem in other countries, and "the elimination of measles from the United States should motivate other countries to adopt the goal of global eradication of the disease early in the new millennium," the CDC said.
In 1997, 702,298 cases were reported to the World Health Organization, with most of them occurring outside the Western Hemisphere.
In 1990, during the measles resurgence in the Western Hemisphere, there were more than 250,000 cases in the region.
"One of the big differences between 1990 and now is that all of the countries in the Western Hemisphere have been working vigorously to eliminate measles, with the U.S. a partner in that effort," Papania said.
By 1996, the number of cases in the region had been reduced to just over 2,000.
The resurgence in the late 1980s and early '90s also resulted from low vaccination rates among toddlers in inner cities, Papania said. Many preschoolers developed measles because they failed to receive the first dose--recommended at 12 to 15 months of age--and were not vaccinated until it was required for entry in kindergarten, he said.
In the United States, health officials have been "working really hard, focusing on trying to deliver that first dose on time," Papania said.
Also, beginning in 1989, federal health officials recommended that schoolchildren have a second dose of the vaccine.
"Although one dose is 95% effective, in close populations like schools, it's such a highly contagious virus that one dose isn't sufficient to prevent all outbreaks," he said.
All but two states--Idaho and Nebraska--require the second dose. California implemented its second-dose policy in 1997, according to Papania.
The CDC said that, of the 100 cases reported last year, 26 were "internationally imported" and 74 were contracted here. However, 45 of those 74 cases were linked to importation, meaning that the original sources were outside this country.
Thirty-two cases occurred in an outbreak in Alaska, which began four weeks after a case was diagnosed in a visitor from Japan, the CDC said.
Additionally, testing showed that virus from cases in New York, Vermont, California, Massachusetts and Washington matched viruses from Germany, Cyprus, Japan, China and Croatia, respectively, the CDC said.
The 26 directly imported cases represented the lowest number since reporting of such cases began in 1983, CDC said.
Still, health officials stressed that the continuing threat of imported cases underscores the importance of maintaining the vaccine regimen in this country.
Of the 100 measles cases in 1998, California had nine, the CDC said.