Wendy has been really following a bad case of food poisoning so we don't want a repeat of that.
Here's what I found:
Beans can become contaminated with salmonella and E. coli naturally, while they're still on their parent plant. In that case the pathogens are physically located inside the bean, where they'll quickly begin to grow when the bean is sprouted. Improper handling and non-sterile utensils can also cause salmonella, E. coli and Listeria monocytogenes to establish colonies in bean sprouts. Even under refrigeration, they can quickly grow to levels that will cause illness
Sprouts are often eaten raw or lightly cooked in salads, stir-fries and as a garnish on pho and other Asian dishes. Eating them raw or minimally cooked permits any pathogens to survive until they reach your plate, potentially resulting in illness. For the highest level of food safety, bean sprouts should be blanched in boiling water for at least 30 seconds or in a steamer for at least 1 minute. To stop the cooking immediately afterward, and preserve as much of their crisp texture as possible, transfer the sprouts to a bowl of icewater until they're chilled. The blanched sprouts will shrink and will lose a small percentage of their vitamins, but will be safe to eat.
So we have blanched ours and going to have them for tea with salad (washed in filtered water). Fingers crossed.