Yale students use vaccines to protect against meningitis and condoms to protect against sexually transmitted diseases. Now they might think about carrying hand sanitizer to protect against pink eye.

Conjunctivitis, commonly known as pink eye, has infected hundreds of students at Princeton and Dartmouth, causing Dartmouth to send bottles of antiseptic hand gel to all of its students. Despite these outbreaks, Yale’s Chief of Student Medicine Jim Perlotto said there has been no rise in the number of cases of pink eye at Yale.

Dartmouth spokeswoman Laurel Stavis said her school has had approximately 500 or 600 cases of pink eye on campus so far. There have been 325 cases at Princeton, Princeton spokeswoman Marilyn Marks said, with more still being reported.

Dartmouth started to see a large number of students infected with pink eye in late January, Stavis said, and the Centers for Disease Control and Prevention sent a team to Dartmouth in February to determine the cause of the outbreak.

According to an article in the CDC’s Morbidity and Mortality Weekly Report, the cause of the conjunctivitis at Dartmouth was a bacterium called streptococcus pneumoniae.

As of Tuesday, Stavis said no link between the cases at Dartmouth and Princeton had been established.

Perlotto said symptoms of pink eye include redness and itchiness.Ê

“Sometimes people will wake up in the morning and their eye will actually feel shut from the crusting, the yellowish green crusting,” Perlotto said.

Perlotto said this type of outbreak of pink eye is very unusual.

“Pink eye usually is a random infection that just strikes people relatively randomly,” Perlotto said. “It doesn’t occur in a cluster outbreak of hundreds of people at a time.ÊWe see it [at Yale] throughout the year, but more commonly in winter. — We think that’s because people are inside more in the winter, around each other more in an enclosed space.”

Pink eye can be spread through hand contact, sharing utensils and towels, Perlotto said. It can be prevented through frequent hand-washing.

“What’s unusual about the outbreak at Dartmouth and Princeton is that it was shown to be caused by a bacteria,” Perlotto said. “Most commonly, conjunctivitis is caused by a virus.”

He said that bacterial conjunctivitis can be treated with antibiotic eye drops.

Though the outbreak is unusual, Stavis said pink eye is not a serious illness.

“I think the important thing to remember is that this is a really mild illness, and even without treatment it tends to resolve itself within a few days,” Stavis said.

Both Princeton and Dartmouth have been taking measures to inform students on how to prevent pink eye.

“All of the students received an e-mail before spring break alerting them to the outbreak, and the e-mail gave some information on what they could do to prevent conjunctivitis themselves,” Marks said. “And there is a Web site with further information.”

Perlotto said he has never seen an outbreak of conjunctivitis like the ones at Princeton and Dartmouth in his 15 years at Yale. The only comparable illness spread between colleges was the spread of herpes between members of different wrestling teams because of the close bodily contact.

“Maybe 15 years ago it would occasionally happen that an opposing player on a wrestling team would have herpes and could be spread to the mouth or face,” Perlotto said.Ê”It doesn’t happen in other sports at all. Otherwise I would say there’s no case of any type of illness spreading from other colleges.”