Almost half of the nation's 43,000 measles cases during 1989 and 1990 occurred in unvaccinated pre-school 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.
Before 1988, Maryland had been free of measles for a decade with the exception of a 1985 outbreak at the University of Maryland.
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.
The 1989 increase in measles cases throughout the nation 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 kindergarten or at entry to 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.
"This proposed requirement will enable all Maryland students to be fully covered with two doses of measles vaccine by 1998," said state health secretary Nelson J. Sabatini.
One of five measles cases in Maryland in the past two years were picked up in doctors' offices or in a hospital and more than a third of all adults who caught measles were health care workers -- doctors, nurses, X-ray technicians and emergency medical personnel, a state survey found.
The governor also wants to stop transmission of measles in health care settings by assuring that young adult health care workers are immune to measles. He has proposed regulations that would require new hospital employees to be immune.
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.
This is a departure from the mid-1980s when most measles cases occurred among school and college-age students who had not been vaccinated or had been vaccinated unsuccessfully, the committee 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.
Many of the inner-city preschoolers, often described as hard to reach, are in regular contact with public assistance programs that typically see enrolled families every month, and "opportunities exist through these programs to screen for immunization and, where practical, vaccinate children on site," the panel said.