Liz Szabo

USA TODAY

Writing about public health can make you a little crazy.

After 14 years as a medical reporter, I'm a self-confessed germaphobe. I buy hand sanitizer in bulk. I haven't touched a raw chicken in years. I no longer eat sprouts or cantaloupes, which have caused far too many food poisoning outbreaks.

But I'm not even a little worried about getting Ebola.

Because viruses aren't all the same. Because Ebola is not the flu. And Dallas is not West Africa.

Unlike the common cold or viruses that cause food poisoning, Ebola does not spread through casual contact.

Ebola spreads through direct contact with bodily fluids, primarily blood. It can only spread after someone develops symptoms, such as a fever. So if you're exposed to Ebola, the odds are that you are going to know it.

So what has allowed Ebola to ravage West Africa?

Extreme poverty, a broken public health system and the trauma of countries newly emerged from years of brutal warfare.

These conditions aren't present in the USA. They aren't even present in much of Nigeria, where the Ebola epidemic appears to be over. Nigeria, which is considerably more developed than many of its neighbors, was prepared for the possibility of Ebola and took quick action to limit its spread.

I would hope that the USA would respond at least as effectively. While we may see more cases, it's just not likely that we are going to be overwhelmed.

Still, many people remain convinced that the USA is on the verge of an apocalypse.

In some ways, it's easy to see why people are confused.

For nearly two decades, since avian influenza emerged in China in 1996, we've been bombarded with one terrifying disease outbreak after another. Some of these outbreaks were real — bird flu, swine flu, MERS, SARS and even anthrax. Other imagined threats — such as a bioterrorist attack using smallpox — haven't materialized.

But here's what all of the scary germs mentioned above have in common: They can spread through the air, Ebola doesn't. Public health leaders have almost 40 years of experience with Ebola, and they've never seen cases where someone got Ebola because an infected person coughed on them.

If Ebola spread that easily, there would be 7 million cases, not 7,100 cases, as the World Health Organization reports.

Is it possible that we will see more cases of Ebola, either in contacts of the Dallas patient or in additional travelers who fly here from abroad? Yes.

But the USA has safely treated five people with Ebola-like viruses without any mass outbreak. These deadly viruses were here, in the USA, unbeknownst to most of us, and we all survived just fine.

Some of the excessive fear about Ebola reminds me of the hysteria over AIDS in the 1980s. That fear led an Indiana town to bar a 13-year-old boy named Ryan White from attending school. Ryan was infected with the AIDS virus from a blood transfusion, and he posed no threat to anyone.

I would hate to see anyone face that sort of discrimination today.

Does that mean we shouldn't care about Ebola? Absolutely not.

The Ebola epidemic is heartbreaking. I've covered it for months, hoping that my stories will move people to help. Many reputable charities have been on the scene in West Africa since the first days of the outbreak in March. Americans who are concerned about Ebola should consider making a donation.

People might also want to consider protecting themselves from diseases that pose far greater risks in the USA.

Half of Americans skip the flu shot, even though influenza kills up to 49,000 Americans a year.

As Paul Offit, chief of infectious diseases at Children's Hospital of Philadelphia, told me, "I bet that if we put out an Ebola virus vaccine tomorrow, half of this country would take it, even though it hasn't killed anyone who hasn't traveled" to the affected countries. "Yet you can't get parents to give their children an HPV vaccine to prevent a virus that kills 4,000 U.S. citizens a year."

Szabo covers medicine for USA TODAY