Salmonella is a food-borne bacteria that doesn’t discriminate, and this month it's eggs under the infectious-disease microscope. Remember when Salmonella was a tomato thing? A jalapeño problem? A peanut panic? But if you listened to the pig-headed Humane Society of the United States, you’d mistakenly believe vegetarian foods are exempt from carrying the bug.

By now we’re all aware of the ongoing recall of about 380 million eggs following a nationwide spike in cases of salmonella poisoning. And since every bit of news about animal protein has a corresponding HSUS press release, the animal rights group has already issued a statement from its favorite “Dr. Doom” spokesman.

Michael Greger, HSUS’s vegan public health expert, is stirring up panic to demand that egg farmers go “cage free” in order to reduce egg consumers’ salmonella risk. Here’s the central claim in HSUS’s press release (emphasis added):

Every scientific study published in recent yearsshows that confining hens in cages results in significantly increased Salmonella risk, including a 2010 study that found 7 times greater odds of Salmonella Enteriditis contamination in operations caging hens.

“Every scientific study” doesn’t leave a lot of wiggle room for interpretation. Not “most” studies, or “many” — but “every” study, they’re claiming, concludes that cage free (or abstaining from egg consumption, thus sparing the chickens) is the way to go. 

But is it true? The answer is a definitive “no.”

For starters, the 2010 study from the Veterinary Record journal—the only study that HSUS actually cites in its press statement—doesn’t offer such an unqualified conclusion. The study’s authors write that while there might be slightly less bacteria present in “cage free” flocks, that's mainly because the flocks are smaller. And there’s actually no way to tell whether that translates into any health risk to people.

So what other research has HSUS conveniently ignored? There’s the 2009 Swedish study found that bacteria levels among hens kept in "floor housing systems" (i.e., "cage free") were more than three times greater than those found where hens were kept in cages, mostly because cage-free hens are exposed to a lot more bacteria-laden dust. And HSUS also must have skipped over a 2008 study published in Japan’s Journal of Poultry Science that concluded: “No significant differences could be found in prevalence of Salmonella between laying hens reared in conventional and enriched cages and aviary." 

Back in the states, a 2005 study published in the U.S. journal Poultry Science compared salmonella levels in “aviary” (cage free) and “battery cage” housing systems with various methods of handling manure. It found: “The system with the lowest chance of infection was the cage system with wet manure.”

In other words, recent research puts a lot of bulletholes in HSUS’s “every scientific study” nonsense. Eggs may carry a tiny risk of bearing a contagion, but so have vegan fare like tomatoes and jalapeño peppers and peanut butter in the past. Which means HSUS’s moral imperative isn’t all it’s cracked up to be.