Why romaine and E. coli are hard to keep apart

Despite safety measures, the leafy greens are especially vulnerable to outbreaks

America tries to eat its vegetables, so the recent romaine lettuce E. coli outbreak has put everyone from Caesar salad fans to those who barely tolerate a splash of greens in a taco on high alert.

But how did these seemingly innocent little leaves turn deadly?

The Centers for Disease Control and Prevention has tallied 149 cases in 29 states stemming from the romaine lettuce grown in the Yuma, Ariz., region, including one death and 64 hospitalizations. Seventeen people suffered kidney failure.

We’ve sent men to the moon. So why can’t we keep romaine lettuce safe and clean? Here’s some reasons why lettuce is so vulnerable.

America loves lettuce

Thanks to the national wellness trend embraced by Millennials and Baby Boomers, the consumption of fresh vegetables is on the rise. Adding to that is the growing popularity of salad-centric restaurants, such as Tender Greens and Sweetgreen, and the increasing inclusion of salads at fast-food chains.

According to market research firm Mintel’s most recent data, 70% of vegetables sold in the U.S. in 2016 were fresh produce, up 13% from 2011, but growing at a 39% clip since then is fresh-cut salad. Fresh veggies are forecast to grow 9% by 2021 and fresh-cut salads, 33%.

The group most affected by the romaine lettuce E. coli outbreak is women. According to the CDC, 65% of the people sickened as a result of this episode are female.

Blame it on Mother Nature

Fields where produce is grown are subject to the whims of Mother Nature and her animals. Fruits and veggies grow in dirt and can be fertilized with manure. Animals may run wild through even fenced fields. Growing out in the open means lots of opportunities for bacteria to enter the picture.

“Stuff is grown in nature outside. It can’t be bacteria-free, virus-free, parasite-free,” University of Florida food-safety expert Keith Schneider said.

Lettuce is unprotected

Unlike some of its fruit and vegetable brethren, lettuce has nothing to keep it safe. The lack of rinds and peels gives bacteria countless entry points.

“The population is choosing to eat foods inherently more risky,” said Matthew Stasiewicz, an assistant professor of applied food safety at the University of Illinois at Urbana-Champaign.

Convenience can lead to illness

Processing the romaine lettuce — provides more chances for bacteria to sneak in.

A raw deal

Foods you eat raw miss out on a cooking phase that can kill bacteria and get rid of food poisoning-causing particles. For produce, washing is key.

CHRISTOPHER DYE/USA TODAY NETWORK, AND GETTY IMAGES