In Jaws, the sound of impending doom was dramatically presented by two notes: BAH-DUM. In Contagion, the new hit from director Steven Soderburgh, it's the sound of an ordinary cough.

A disaster movie without aliens, zombies or extreme weather, Contagion fellows scientists, doctors and regular people attempting to deal with a deadly new virus that's sweeping the globe. So rather than indulge my latent OCD and take to wearing opera gloves and a wedding veil at all times — a little fancy, even for me — I recruited Melissa Nolan, the research coordinator in the Center for Infectious Diseases at The University of Texas School of Public Health, to see the movie with me.

Nolan studies the long-term effects of the West Nile virus and has worked on rabies and swine flu (H1N1) cases in Houston. And while she says the risk of seeing completely new viruses emerge and spread is real — West Nile and SARS are examples — she says a Contagion situation is extremely unlikely.

(If you want to avoid spoilers, stop reading here.)

"I wouldn't say that this wasn't realistic, but the probability of a disease that has an incubation rate of two days and that high of a mortality rate is unlikely. I'm not saying it can't happen, but it's unlikely. I mean, it took West Nile years to transmit," Nolan says.

In other words, it would be like hitting the virus lottery, except instead of getting rich, a percentage of the global population is wiped out. Also most viruses don't spread via touch, they move either through bodily fluids or an intermediary like a mosquito — so yes, it's okay to eat the beernuts.

"It's different because West Nile is a vector-borne disease, it's transmitted through mosquitos — there's no human to human transmission — but it's similar in that West Nile was novel, we'd never seen it in the U.S., and one summer there was an outbreak of about 69 or so cases and within the next three years it had completely gone across the whole country. It's been in all 48 contiguous states. You can look at the CDC maps and see it go boom-boom-boom across the country."

Nolan grew up in Atlanta and pegs the beginning of her fascination with infectious disease by being raised in close proxomity to the Centers for Disease Control. She's also considered working for the Epidemic Intelligence Service, which was Kate Winslet's job in the movie.

"It's like being a forensic scientist," Nolan says.

EIS scientists fly in to where outbreaks occur and have to hit the ground running, figuring out what the source is, how the disease spreads, how to handle the sick and how to stop it, all with limited information, resources and in a short amount of time. It also carries a high amount of risk, as witnessed by a less-than-happy ending for Winslet.

"They have to drive around with two suitcases in their cars at all times — one packed for warm weather and another for cold weather" says Nolan. "You can get a call at any time that says 'Hey, you're on the five o'clock flight to who-knows-where.' It's very intense."

And while we can only speculate on the breakdown of civil society that Contagion chronicles — storefronts abandoned, crime rampant, riots over food and vaccines — Nolan says that government plans to deal with a pandemic are already in place.

"Right after 9/11, the U.S. developed the biological terrorism unit and they talked about if people could use biological agents like smallpox as weapons. It's pretty much exactly what happened in this movie, if someone had a disease and they spread it out. Or when we saw anthrax in the mail. Anthrax is a bad agent to use, but it's a perfect example of how you can introduce something and it'll spread.

"That's why Homeland Security was in the movie. So over five years ago most of the main health departments, including Houston, they got together said, 'What are we going to do if there's a pandemic or an outbreak?' They aren't waiting until something happens, they already know what they're going to do, there's an order, there's a system, they know where they're going to set up clinics, all that."

"So when H1N1 happened, the first death was in Houston and we already knew what we were going to do and we implemented the policy. And honestly, it worked. We did our job. So people can say the threat warnings were overdone, but there was a potential for that to happen and because we did our job it didn't happen like that. So I think it's better to alert people than to not and have them die. But there's a thin line."

So what advice does an infectious disease researcher offer the average person who is freaked out about germs?

Don't panic, and wash your hands. (And no, anti-bacterial hand sanitizer doesn't count, as it's significantly less effective without washing one's hands for 30 seconds first.)

Basically, if someone offers a sip of their drink or to blow on your casino chips for luck, it's probably OK. You know, unless it's Gwyneth Paltrow, in which case it's already too late.