You've likely had a herpes outbreak. Chances are it happened when you were very young. Maybe you were outside at recess when you first got that tingling itch. You thought it was just a bug bite, so you scratched it and went about your business, touched some other people. Before long, there were little red bumps all over your body driving you crazy with itchiness and you and your friends all had to stay home from school.

You knew it then as chicken pox, but you're old enough to handle the truth. You were actually infected with the herpesvirus varicella-zoster, and it still lives inside you, waiting for an opportunity to reemerge as shingles on the surface of your skin. This isn't to be confused with a herpes simplex virus which - as Dr. Robert Winfield, director of the University Health Service, explained to me with graphic photographs - is the sexually transmitted disease more readily associated with the name herpes, but they're both from the same family.

That's only one of the parasitic non-living yet non-dead entities that you're living with. Humans have snippets of ancient viruses our ancestors had to deal with scattered throughout our genomes, as well as DNA antibody codes for viruses we've encountered in this lifetime.

In fact, if you look at the human genome and compare the amount of human DNA with the amount of viral DNA, we are more virus than we are human.

They're all around us. But how close are viruses really? The Statement looked at the prevalence of viruses as recorded by the University Health Service, and found out how many people on campus actually have common viruses right now.The results are surprising.

HPV

The human papillomavirus is so astoundingly common that the Centers for Disease Control and Prevention estimates that more than 80 percent of adults will have been exposed to it by age 50.

"So many people are exposed to it and have been infected, yet many people never even know it," said Susan Ernst, Chief of UHS Gynecology Services.

A stealthy traveler, the HPV is transmitted sexually through skin-to-skin contact, so condom use, which is effective against viruses that are transferred by fluid, is far less effective at stopping HPV than it is at stopping babies.

In addition to causing genital warts, the virus has the ability to transform cells, sometimes resulting in cervical, penile and anal cancer.

Because you don't necessarily have to have sex with someone to get HPV and because it can't be reliably tested for in men, Dr. Ernst said it's almost impossible to figure out who the culprit is if you're looking for someone to blame.

In a study conducted in New Jersey a few years ago, a group of researchers tracked college women throughout their campus experience. Twenty percent of the women tested positive at first, and over the next three to four years, 40 percent of the initially HPV-free women became infected.

This study lends credence to the prediction that 60 percent of sexually active college-age women will contract HPV in their college careers.

Fortunately, though, the body's immune system can often rid itself of HPV much like it would do when exposed to a common cold virus.

In that same college study, 91 percent of the participants who initially tested positive for HPV at the start of the study tested negative again within two years.

"It's only those 9 percent of students who are persistently at risk for the more severe complications," Ernst said.

There are no cures or treatments, although in the past year a preventative vaccine called Gardasil has hit the market.

Herpesviruses

Epstein-Barr virus: Mononucleosis is the term used to describe the illness caused by the Epstein-Barr virus, another member of the herpesvirus family like chicken pox. It is marked by symptoms of excessive tiredness, fever and sore throat and is commonly referred to as mono or the kissing disease.

It was a big deal back in middle school when rumor had it that if you were out of school with mono it was because you had been kissing someone. So taboo. And although it all seems silly now that it appears to have gone away, once contracted, Epstein-Bar Virus remains entangled in genetic material forever.

Symptoms caused by the Epstein-Barr virus may not be as dramatic as a full-blown case of mono, but it has been linked to chronic fatigue syndrome. What's worse, even if you never actually got mono in grade school, it's still likely you contracted the Epstein-Barr virus. According to the Center for Disease control's statistics, it's present in 93 percent of adults, and it's hard to avoid because it's transmitted through saliva.