We consume more than eight billion per year. They’re a staple of most Americans’ diets – a lean, low-fat source of healthy protein.

But it might surprise you to know that chicken is also linked to everything from kidney disease, to urinary tract and staph infections, to Campylobacter, one of the deadliest foodborne illnesses that kills 100 people annually.

The culprit? Antibiotics, used in poultry production, says science journalist Maryn McKenna in her newest book, “Big Chicken: The Incredible Story of How Antibiotics Created Modern Agriculture and Changed the Way the World Eats.”

The widespread prescription of antibiotics to fight bacteria and infections in people has led to drug resistance and rendered many ineffective.

That’s exactly what’s also happened with mass-produced chickens. Antibiotics were first in the 1940s as a growth hormone to fatten them up for slaughter. Antibiotics were cheap, and readily available; chickens were small, easily controlled, and best of all, they responded to treatment that bolstered U.S. poultry production. (By 1950, there were 1.6 million poultry farms.)

“Big Chicken” makes the case that when people started getting sick, doctors and medical experts connected the dots and found that livestock were becoming resistant to the antibiotics. As a result, bacteria wasn’t being killed and were being passed along to the patient – accomplishing the exact opposite of what the antibiotics were designed for in the first place.

“There are a lot of unintended consequences in this story,” McKenna tells Newsmax Health. “The bacteria gets in the food animals and moves through the food chain, or gets in the environment, in soil and groundwater, and they carry their resistant DNA to other places and create bacteria far from where the resistance arose.

“I don’t think (people) could have imagined what was happening.”

McKenna notes that more than 80 percent of antibiotics sold are not for humans, but animals. According to the Centers for Disease Control and Prevention, at least two million people in the U.S. become infected with antibiotic-resistant bacteria each year – and 23,000 people die.

“Big Chicken” recounts the history of antibiotic use in the poultry industry, with interviews from those victimized from it, those who investigated the problem, and those who propagated the issue.

The book tells how for decades, health officials tried (mostly) in vain to trace related, yet random, incidences of foodborne illnesses (oftentimes salmonella) to one source, but lacked the resources and wherewithal to confirm it was from bacteria resistant chicken. The outcomes are often devastating to read.

“In one especially poignant example,” writes McKenna, “a young pregnant woman caught resistant salmonella from a calf that had been fed antibiotics. She passed the infection to her baby at birth, and then, while the baby lay in the hospital nursery, nurses unknowingly picked up the infection and transferred it to other newborns.”

The good news is that a movement away from antibiotic use is underway, she notes. Today, factory farm producers, fast food franchises, and others are making it a point to phase out antibiotics from their chickens. McDonald’s, Panera, and Chipotle are among the few to make an antibiotic-free promise, and poultry and meat producers Tyson, Perdue, and Pilgrim’s Pride have recently followed suit.

Don’t let that give you a false sense of security that all chicken everywhere is antibiotic free. McKenna suggests taking some precautions to avoid antibiotic-fed chickens:

When food shopping: You may see “organic” plastered on every chicken breast, wing and thigh in the poultry section, but that doesn’t always mean antibiotic free. Organic chickens, according to McKenna, don’t need to be antibiotic free until their second day of life. “That’s possible enough to produce resistant bacteria,” she says.

“If you want to be sure that the bird you buy is antibiotic free, the choice is not organic, but No Antibiotics Ever, or Raised Without Antibiotics.” You’ll sometimes see them printed as acronyms, like NAE, RWA, or ABF, for Antibiotic Free.

When cooking at home: Take reasonable precautionsbif you’re prepping some chicken in your kitchen. Cook chicken thoroughly to kill pathogens, but also take particular care in how you handle the chicken.

When unwrapping the bird, says McKenna, do it in the sink so blood and fluids from the meat don’t splash anywhere. Also use separate cutting boards, one just for the chicken, one for vegetables and other ingredients. Use fresh knives and always wash your hands after handling uncooked chicken. “That way,” she says, “you’re avoiding cross contamination.”

When eating out: You can already rest assured that eateries like Chipotle and Chick-fil-A serve chicken raised without antibiotics. But when in doubt, if it’s not listed on the menu, the simplest way to find out if that chicken on the menu is antibiotic free is to ask where the food comes from.

“A restaurant with a printed menu may not have antibiotic-free chicken, but it’ll say that it’s from a farm that doesn’t use antibiotics,” says McKenna. “If it says we get our chicken from a grass fed farm, it’s likely they’re antibiotic free. But your best bet is to ask the waiter.”

Getting acquainted with antibiotic-free livestock producers is also helpful. McKenna says look for chicken that comes from Springer Mountain, Joyce Farms, or Mary’s Chicken, to name a few.

McKenna says she hopes that “Big Chicken” will raise awareness to the antibiotic crisis – and the health risks it poses – to influence more funding for research and surveillance into the issue.

But ultimately, it’ll be consumers who’ll make the biggest difference in swaying the poultry industry away from antibiotics.

”I do really think people are going to make a difference here,” she says. “People are asking a lot of questions about this, and the way they spend their dollars, I only think that’s going to expand and increase. From my sense, from talking to so many people about this, is that people can make an intuitive connection.”

For more on “Big Chicken,” visit McKenna's Website.