As food-poisoning outbreaks sweep America, here's what an expert says pregnant women should refuse to eat

Listeria concerns mean that pregnant women shouldn't consume cheeses including brie, Camembert, Roquefort, feta, and Gorgonzola.

Precut and prewashed fruits and veggies have caused a number of issues already in 2018. McDonald's salads were linked to a parasitic illness outbreak that sickened more than 390 people, and an E. coli outbreak linked to romaine lettuce sickened at least 197 and killed five people.

"Not every lettuce leaf in the field is contaminated with E. coli, but some of them are," Marler said earlier this year regarding the risks of prewashed, bagged lettuce. "And when you mix and match it at a processing facility and chop it up, you get what you get."

Marler says raw milk "can be infected with all types of bacteria."

"Some argue that milk loses nutrients during pasteurization, but the risk from coli and other pathogens found in raw milk outweigh any possible benefits," he wrote on Food Safety News.

Raw, unpasteurized juice presents similar issues to raw milk.

"There's no benefit big enough to take away the risk of drinking products that can be made safe by pasteurization," Marler previously told Business Insider.

Eggs and products such as homemade Caesar salad dressing, mayonnaise, ice cream, custards, and hollandaise sauce have the potential to carry salmonella. In April, the FDA announced a recall of 206 million eggs over salmonella-contamination concerns.

Marler says he has seen more foodborne illnesses linked to shellfish in the past five years than in the two preceding decades.

According to Marler, global warming is heating up oceans and allowing microbial growth to thrive, which encourages the spread of foodborne illnesses like norovirus and vibrio infections.

Smoked seafood comes with listeria concerns, though canned and shelf-safe fish (such as tuna) is safe to eat. However, pregnant women and nursing mothers should avoid fish with high levels of mercury — not because of food-poisoning concerns, but because high mercury levels can harm brain development.

Stick to professionally canned jams while pregnant, Marler says. Home-canned goods can contain botulism, or be contaminated with other ways, as DIY canning operations don't have the same safety regulations as professional enterprises.

Because sprouts are grown in standing water, they are a prime spot for bacteria such as salmonella to thrive. Sprout-related outbreaks are common, with more than 30 bacterial outbreaks— primarily related to salmonella and E. coli — happening in the past two decades.