Alfalfa sprouts, clover sprouts and bean sprouts are delicious, in my (and possibly only my) humble opinion. But, like lettuce, they are prone to contamination and served raw. Right now, the U.S. is in the middle of a multi-state outbreak of E. coli linked to clover sprouts served at Jimmy John’s, a U.S. sandwich franchise.
Jimmy John’s stopped serving the sprouts, but if you have any sprout leftovers the U.S. Centers for Disease Control (CDC) is advising you to chuck them. More importantly, though, contamination of sprouts is fairly common, and a lot of experts on infectious disease or public health simply don’t eat them.
Just saying, Infectious Disease folks don't
a) eat sprouts
b) take cruise ships
c) take antibiotics when we don't need them
Current events may back us up here https://t.co/jjNM4FYV4S
— Infectious Diseases (@InfectiousDz) February 26, 2020
The issue is, unfortunately, inherent to the way sprouts are grown. Whether you buy them or sprout your own, they are kept moist and warm for several days, making perfect conditions for growing bacteria.
In Australia, there have been a number of Salmonella outbreaks related to sprouts due to the fact they're usually eaten raw.
The NSW Food Authority says "while all raw and lightly cooked – still crunchy – sprouts can pose some risk, alfalfa, mung bean and clover sprouts are most commonly linked to food poisoning."
That means that if the seeds for the sprouts are contaminated with Salmonella or E. coli, those bacteria can grow as the sprouts grow and make you sick. Washing does not get rid of the bacteria. Cooking does, but it destroys the fresh crunchy texture that is probably the whole reason you wanted sprouts in the first place. Knowing that, you may decide it’s safer not to eat sprouts at all.