College students living on campus are three times more likely to develop bacterial meningitis than people their age who do not attend college, according to a study in Wednesday's issue of the Journal of the American Medical Association.

Researchers at the Johns Hopkins University School of Hygiene and Public Health found an incidence of 3.24 annual cases per 100,000 on-campus students in the state of Maryland, compared to 0.96 cases for students living off-campus and about 0.8 to 1 case in the general population.

According to the study's principal investigator, Dr. Lee H. Harrison, "We found that the rate in college students [in general] and the general population was the same."

It is only students living on-campus who are at a higher risk, he said.

Although the study did not look into the causes of the higher risk, investigators blame the college lifestyle.

"I would expect that some of it is due to crowding," Harrison said.

He also attributes some of the increased exposure to smoking and drinking.

Meningitis is an infection of the covering of the brain, spinal fluid and the spinal cord. The meningococcal bacteria "is one of the few organisms that can take a young healthy adult and kill in a few hours," Harrison said.

"It is usually fatal without treatment," he added.

He said that symptoms include fever, chills, headache, rash, a stiff neck and a sense of confusion.

Fortunately, students can protect themselves.

"It is very reasonable for college students living on campus to receive a vaccine," Harrison said.

Harvard's health plan does not cover the vaccination unless there is reason to believe that a student has been exposed, said University Health Services (UHS) Director David S. Rosenthal '59. For example, if a student's roommate or friend has meningitis, the vaccination is covered. Otherwise, injections cost $77 at University Health Services (UHS).

But Harvard student apparently live a little cleaner than their college counterparts in Maryland.

"There has been no case of meningitis in the 10 years that I've been here," Rosenthal said.

The study looked at 228 cases of meningitis in Maryland over the past six years. Fourteen of those cases were among college students.