Almost half of the nation's 43,000 measles cases during 1989 and 1990 occurred in unvaccinated preschool children, mostly minorities, says a "special communication" on the current measles epidemic in today's Journal of the American Medical Association.
And, the principal cause for the epidemic is failure to provide vaccine to vulnerable children at the recommended age, said the report by the National Vaccine Advisory Committee, headed by Dr. Donald A. Henderson of the Johns Hopkins School of Public Health.
Major reasons cited for low vaccine coverage exist in the health care system itself "which creates barriers to immunization and fails to take advantage of many opportunities to provide vaccines to children."
Gov. William Donald Schaefer has just announced a campaign for a "measles-free Maryland" that would address low vaccine coverage. Schaefer said the campaign, which runs Saturday to Sept. 27, urges health care workers to remove barriers to immunization by: increasing hours of availability, having walk-in immunization clinics, offering vaccines at cost and omitting a pre-vaccination physical examination.
The resurgence of measles over the past 2 1/2 years is cause for "serious concern," said members of the National Vaccine Advisory Committee and Schaefer.
In 1989, more than 18,000 measles cases and 41 deaths were reported nationally -- the largest number of reported cases since 1978 and the largest number of deaths in two decades. The next year, there were more than 25,000 cases and more than 60 deaths.
Between January 1989 and July 1991, a total of 493 cases were reported in Maryland by state health officials who described the figure as alarming. The cases occurred in preschool children who had not had their first dose of vaccine and in school-age children who had only one, they said.
Nearly a third of the state's measles cases were hospitalized -- with pneumonia, dehydration and ear infections -- but no deaths occurred.
To make Maryland measles-free, all children should get their first dose of measles vaccine at 15 months of age, Schaefer said. But, almost 20 percent of the state's children have not had their first measles shot by the time they are two years old. School-age children need a second dose of measles vaccine.
An increase in measles cases throughout the nation in 1989
prompted the American Academy of Pediatrics, the Immunization Practices Advisory Committee and later, the state health department, to recommend a second dose of measles vaccine at entry to either kindergarten or middle school.
Now, the state health department has proposed regulations requiring proof of two doses of measles vaccine for children entering kindergarten and for those entering sixth grade in the fall of 1992.
The measles epidemic has hit the nation's youngest and most vulnerable children hardest, the vaccine advisory panel said, noting that the recent increase has been greatest among children younger than 5.
"Minority children are disproportionately affected, with Hispanic and black preschool children, particularly in urban areas, facing seven to nine times the risk of contracting measles as white children," the report said.
Stressing that "essential changes can and should be made now," the JAMA report said many opportunities to provide needed vaccines are missed. For example, the failure to vaccinate children in emergency departments and acute care clinics was singled out because many inner-city children use such settings as a primary source of care.