HEALTH ALERT! Over 200 Million Eggs Have Been Recalled over a Salmonella Outbreak

With 200 million eggs recalled across nine states due to possible salmonella contamination, it's worth asking: How do eggs typically get infected, anyway?



The symptoms of downing salmonella — diarrhea, stomach cramps and fever among them — are painfully obvious, but how eggs pick up the bacteria is less clear, with infections able to occur both inside the chicken and after an egg is laid.



Last week's egg recall could be America's largest since 2010, when an Iowa-based outbreak sickened thousands and left farmers facing prison time. Later asked just how the eggs became infected, one of those farmers, Austin DeCoster, described the process as "complicated."



Salmonella can contaminate as few as one in 20,000 eggs, according to a federal estimate noted by Slate, and the salmonella most associated with food poisoning (Salmonella enteritidis) doesn't show symptoms in hens who lay eggs. Once infected — often by exposure rodents carrying salmonella — the bacteria can move into the hen's oviduct or ovary, infecting eggs as they form, according to the The New York Times Such contaminations are rare, the newspaper noted, and only a few of those eggs still hold the bacteria once laid.



But eggs remain vulnerable after being laid, too: Their shells are porous, meaning eggs rolling through a contaminated processing facility could still let bacteria climb right inside, according to Discovery.