A Listeria outreak in apples has killed seven people and hospitalized 31, according the Centers for Disease Control and Prevention, which has trace the outbreak to Bidart Bros. apple-packing plant in California.

While apples are the second most popular fruit in America, according the Agricultural Marketing Resource Center, outbreaks linked to apples are rare, due to the natural hard surface of the fruit, which, prevents bacteria from entering the fruit, says Doug Powell, PhD, a former professor of food safety in the U.S. and Canada who publishes barfblog.com.

In a Yahoo! Health article, Amy Rushlow quotes Prof. Powell: “Fresh fruits and vegetables are probably the biggest source of foodborne illness today in North America, and that’s because they’re fresh — we don’t cook them — so anything that comes into contact has the potential to contaminate.” Powell especially sounds caution about the following five fruits and vegetables, which have been linked to a significant number of foodborne illness outbreaks over the past years:

1. Sprouts: A 2011 outbreak in Germany killed more than 50 people and sickened more than 4,000. In late 2014, more than 100 Americans became ill after eating sprouts tainted with E. coli. Sprouts are particularly prone to bacteria because they germinate in a high-temperature, high-moisture environment — the same environment where germs thrive. The CDC recommends that pregnant women, children, older adults, and people with weak immune systems avoid eating raw sprouts. Cooking sprouts destroys harmful bacteria.

2. Cantaloupe: Cantaloupes’ porous rinds allow bacteria to enter the fruit. In addition, the fields where cantaloupes are grown are often flooded, resulting in the fruits sitting in water that may have come downstream from a livestock operation.”

3. Leafy greens: Bacteria becomes trapped on the inner leaves as the head is forming, and leafy greens are difficult to wash effectively. Over the past several years in the U.S., bags of romaine lettuce, prepackaged salad mix, spinach, and spring mix have all been linked to E. coli outbreaks.

4. Tomatoes: There are several ways for germs to enter the fruit of the tomato, including via groundwater or through the water tomatoes are plunged into to give them a little shine.

5. Garnishes, such as green onions, cilantro, and parsley: Green onions and other herbs and vegetables used as garnishes are at high risk for outbreaks because we typically don’t cook them.

However, Powell advises that while there is no one measure that will keep you completely safe, a few small steps can add up such as rinsing fresh produce, and cooking then when you can.

Source: Yahoo! Health