Over the course of several inspections in February of a Whole Foods' kitchen in Massachusetts, Food and Drug Administration (FDA) staff found multiple violations, including the presence of listeria on a food prep surface. The bacteria is especially dangerous to pregnant women.

FDA reps sent a letter to Whole Foods last week describing the listeria contamination. After swabbing 100 surfaces throughout the facility, inspectors found a swab from the vegetable chopping machine tested positive for listeria. According to the FDA, this indicated that other surfaces were at risk of growing listeria, as well.

Whole Foods Market North Atlantic Kitchen prepares ready meals for 74 stores in Massachusetts, Maine, Connecticut, Rhode Island, New York and New Jersey, according to its Facebook page. Kitchen staff may have altered cleaning and food prep practices since the inspections.

But to be safe, if you are pregnant, avoid prepared meals, including salad bars, chefs' cases, sandwiches and wraps, in Whole Foods in the Northeast, especially those with chopped vegetables.

The letter also outlined several other concerning violations, including:

Ceiling condensation dripping on to preparation surfaces and food storage spaces

Dirty dishes piling up near food

High pressure hoses used for cleaning spraying into food prep areas

Too much acid in solutions used to soak and treat vegetables

Employees not washing their hands between tasks

Inadequate hot water at some sinks

Sanitizer to clean surfaces accidentally sprayed onto foods

Employee clothing touching foods

These violations affected at least the following ready meals:

Pesto pasta

Mushroom quesadillas

Egg salad

Anything with chives and beets

Couscous

Quinoa cakes

Anything with leafy salad greens

Chicken, turkey and other meats

Enchiladas

Salad dressings

Whole Foods reps say they've addressed all of the problems listed in the letter and they don't know why the FDA didn't acknowledge these changes when they sent the letter months later.

FDA reps say Whole Foods' response efforts up to this point have been inadequate, in part because Whole Foods management has not yet shared a plan for forcing this facility to comply with FDA regulations in the future. Last year, Whole Foods recalled deli pasta and curry chicken made at the same kitchen due to listeria contamination.

Listeria is especially harmful to pregnant women, who are 13 times more likely to develop listeriosis if they come in contact with it – though in general the risk is still very low. Unlike most other bacteria, listeria enters the bloodstream directly, and it can pass through the placenta, potentially causing miscarriage, stillbirth, preterm birth and meningitis in newborns.

Common listeriosis symptoms include fever over 100.6°F, muscle pain, backache, headache and diarrhea. If you think you've been exposed to listeria, call your doctor and seefor more info