CHICAGO (AP) - First-year students living in dormitories are at much greater risk of contracting meningitis than other university students, raising anew the question of whether incoming students should be vaccinated, researchers report.

Dr. Michael Bruce, a medical epidemiologist with the U.S. National Center for Infectious Diseases and lead author of the study in Wednesday's Journal of the American Medical Association, stopped short of recommending that colleges require vaccinations for freshmen.

But he said there could be a "major impact" on meningitis in college students by vaccinating a relatively small number of young adults.

Meningococcal meningitis is a bacterial infection of membranes around the brain and spinal cord that can be spread by kissing or sharing utensils. Symptoms include fever, neck stiffness and headache.

The disease kills in roughly 10 percent of cases and does serious harm, including brain damage, in another 10 percent. A viral form of meningitis exists but is generally less serious.

Previous studies have shown that university students living on campus have a higher risk of developing the disease than those living off campus. Undergraduates overall had a lower risk of developing the disease than non-students of the same age for reasons that are unclear.

For the latest study, researchers at the U.S. Centers for Disease Control and Prevention identified 96 U.S. college students ages 18 to 23 who were diagnosed with meningococcal infection from Sept. 1, 1998, to Aug. 31, 1999. Of the 79 patients for whom information was available, 68 percent had infections that might have been prevented through vaccination, Bruce said.

The overall incidence for undergraduates was 0.7 per 100,000 students, compared to 5.1 per 100,000 for freshmen in dormitories, the study found. Freshman in dormitories had a three times greater risk than all other college students of contracting the disease.

Possible explanations could be the crowded conditions. Upperclassmen also may have developed protective immunity to the disease, researchers said.

The current vaccine lasts three to five years. More effective, longer-lasting vaccines are expected within two years.

Colleges increasingly are warning of the bacterial disease on pre-admission health forms and holding vaccination clinics. In 1999, Michigan State University spent dlrs 1 million giving more than 16,000 students and faculty members free vaccinations after a student contracted the disease.

About 1.6 million U.S. college students have been vaccinated against the disease since 1997 at the recommendation of the American College Health Association, said Dr. James Turner, chairman of the group's Vaccine Preventable Disease Task Force.

The "dlrs 75 to dlrs 85 cost for the vaccine, which lasts four years, is about the same as for a good pair of tennis shoes," he said.

In another study in Wednesday's journal, researchers found the incidence of meningococcal infection in Maryland increased substantially among 15- through 24-year-olds in the 1990s and that almost one-fourth of cases in that age group were fatal. The infection rate dropped in 1998 and 1999.

In an accompanying editorial, Dr. Jay Wenger of the World Health Organization said: "Taken together, these studies demonstrate that meningococcal disease in this age group is severe, and a targeted approach of immunizing college freshmen who live in dormitories may be the most efficient way to make an impact on meningococcal disease."

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