The threat of meningitis has long been a concern on college campuses, where the cramped living quarters, crowded classrooms and teeming party scene create an environment where it can spread more easily. (EDUARDO MUNOZ/REUTERS)

At Princeton University, where eight cases of bacterial meningitis have surfaced this year , officials have put up posters and e-mailed students warning them to guard against spreading the potentially fatal disease. Federal officials have taken the rare step of allowing the university to vaccinate thousands of students beginning next week using a drug not yet approved in the United States.

At the University of California at Santa Barbara, where a fourth bacterial meningitis case was confirmed this week, a freshman lacrosse player had both feet amputated. Campus leaders have suspended fraternity parties and other social events and ramped up cleaning in residence halls and recreation facilities.

The threat of meningitis has long been a concern on college campuses, where the cramped living quarters, crowded classrooms and teeming party scene create an environment where it can spread more easily. The disease has largely vanished from colleges and universities in recent years, as dozens of states required students to be vaccinated against it before arriving on campus.

But officials who monitor the disease are troubled by the recent outbreaks in California and New Jersey, in part because of the number of cases but also because each involves the uncommon “serogroup B” type of bacterial meningitis, for which the country has no approved vaccine.

“This is a very, very serious infection,” said James Turner, a professor of internal medicine at the University of Virginia who oversees the College Health Surveillance Network, which tracks student health trends. “It’s rare and it’s unpredictable.”

Still, Turner and other public health officials say there is not yet cause for panic. For starters, although the type of meningitis popping up on both campuses is the same, DNA testing has shown that they are not identical.

“It’s one strain at Princeton, and it’s a different strain at Santa Barbara,” said Tom Clark, chief of the meningitis branch at the Centers for Disease Control and Prevention, who is leading the response to the outbreaks.

In addition, Clark said, meningitis doesn’t spread through casual contact or merely breathing the air near an infected person, but rather through sustained contact or exchange of saliva, such as kissing. In addition, outbreaks seldom spread rapidly or widely.

“It’s pretty typical for outbreaks to have a few cases in a short period of time,” Clark said. “Most often, when you have a cluster, you won’t have more. And if you do have more [cases], you won’t have many more.”

That doesn’t mean public health officials or the universities involved haven’t taken seriously the recent outbreaks of meningitis, which can strike suddenly and result in brain damage, paralysis, hearing loss and amputation of limbs.

After Princeton saw its eighth documented case since March, the Food and Drug Administration and the CDC gave the university permission to import and administer a vaccine called Bexsero to thousands of students beginning Dec. 9. Princeton will pay for the costs of the vaccine, which will be given in two doses, the second of which will be made available in February.

The vaccine, which has been shown to protect against meningococcal disease caused by serogroup B bacteria, has been approved for use in Europe and Australia but has not been licensed by U.S. regulators.

In Santa Barbara, local health officials have worked feverishly to track down close contacts of the four affected students, said Susan Klein-Rothschild, a spokeswoman for the Santa Barbara County Health Department. As a result, more than 500 students who might have been exposed to the bacteria have received preventative antibiotics.

CDC officials have not recommended distributing the Bexsero vaccine in Santa Barbara, which has far more students than Princeton and has seen half as many cases.

“The goal is not to give a whole bunch of people vaccines when there aren’t going to be more cases anyway,” said Clark, who said his team is talking daily with officials in California. “It’s hard to know when to make that decision. Each outbreak is individual.”

Even if the current outbreak doesn’t spread, it has proven life-altering for at least one student. Santa Barbara freshman Aaron Loy, a member of the school’s lacrosse team, had his feet amputated recently after contracting the disease, according to news reports. Team members held a car wash fundraiser for him over the Thanksgiving weekend, and family members have posted regular updates online.

Loy’s struggles are all too familiar to Andy Marso, who contracted the serogroup B bacteria while he was a senior at the University of Kansas in 2004.

“I went to bed thinking I had the flu,” said Marso, a newspaper reporter in Kansas who wrote a book about his experiences. “By the next morning, I couldn’t get out of bed. I couldn’t walk. By that night, I was in critical condition.”

Marso spent three weeks in a coma, only to make a gruesome discovery when he awoke.

“My arms and legs were rotting while still attached to my body,” he said. “I lost the front half of both of my feet, and all my fingers except my right thumb. Even to save that much of my limbs was a painful process.”

Marso said that although his case might seem extreme, college students shouldn’t shrug off the threat of meningitis, which can attack a perfectly healthy person quickly and savagely.

“It’s not a joke,” he said. “I know what it’s like to be in college; you don’t think anything can happen to you. But it can kill you. . . . It came completely out of nowhere.”