ANNAPOLIS -- State health officials are probing a possible link between an outbreak of measles among high school students in four counties and a wrestling tournament at Meade Senior High School in Anne Arundel County last month.
Edward M. Hirshorn, assistant chief of the state health department's immunization division, said yesterday that confirmed cases of measles have been detected in wrestlers and spectators from the tournament Feb. 22 and 23. The cases were found in schools in Anne Arundel, Calvert, Howard and Frederick counties.
"We've had reports of the onset of rashes between March 5 and March 11, and given the incubation time for measles, that would put the source date back to Feb. 22 or 23," he said.
However, the high school with the most suspected cases, Oakland Mills in Columbia, did not compete in the tournament. The school has had three confirmed cases of measles and may have five to seven more,said Patty Vierkant, a school board spokeswoman.
Mr. Hirshorn said someone from Oakland Mills may have attended the tournament, which would explain the larger number of cases at that school and scattered cases elsewhere. The disease could have other sources, he said.
Meanwhile, officials at the Howard County school barred about 55 students from classes over the last three days until they obtained proof they had been vaccinated against measles, Ms. Vierkant said.
Statewide, nine cases of measles have been confirmed and 20 suspected cases have been reported, Mr. Hirshorn said.
In Anne Arundel County, health officials ordered that all 1,250 students at Arundel Senior High School in Gambrills be immunized a second time after two juniors and a senior came down with the highly contagious disease. Students who don't have proof that they received two doses of the measles-mumps-rubella vaccine must sign up for a booster shot next Monday or Tuesday, said Evelyn Stein, the county health department's spokeswoman.
"Measles is highly contagious, so you have to do this kind of mass immunization whenever you have a lot of schoolchildren exposed," she said.
Other cases have been reported at MacArthur Middle School in Fort Meade and Annapolis and St. Mary's high schools in Annapolis, she said.
Anne Arundel has joined other Maryland jurisdictions in offering free booster shots to seventh-graders, but fewer than 20 percent of the 4,746 eligible students have signed up, Ms. Stein said.
Mr. Hirshorn said those figures reflect statewide statistics. "It's in the schools, it's free, but only 20 percent to 25 percent take advantage of it. If we made it mandatory, it would be more effective."
The sudden outbreak in measles cases has led school officials throughout central Maryland to re-examine student medical recordsand push the booster-shot program.
Last week, the principal at Harford Heights Elementary School, at Broadway and North Avenue in Baltimore, sent letters to the parents of several students warning them that their children would be excluded from school unless they could prove they had been vaccinated.
On Tuesday, Baltimore Mayor Kurt L. Schmoke and Elias A. Dorsey, the acting city health commissioner, kicked off a booster-shot campaign at Dunbar Middle School, urging parents make sure their sixth-grade children get booster shots in April.
Students are required to be immunized against measles for enrollment in Maryland public schools, but health researchers have found that the antibodies have faded in many secondary school children, said Dr. Susan Dwyer, chief of the state health department's Center for Clinical Epidemiology.
One theory is that many children 14 and older were not adequately immunized because they were vaccinated at age 1, when their immune systems were not properly stimulated, she said. Children now are vaccinated at 15 months.
JoAnna Daemmrich of The Arundel Sun, a suburban edition of The Baltimore Sun, contributed to this article.
Measles cases in Maryland
+!Jan. 1 - March 15, 1991: 9 cases
Jan. 1 - March 15, 1990: 21 cases
Total for 1990: 213 cases