That's hardly amazing; I've known since I was a child that the main source of salmonella was eggs and possibly raw chicken. In fact, I'd have been hard-pressed to name another place you could get it.
This is almost always either because (a) the vegetables are fertilized with manure (organic vegetables, in particular, carry a higher risk of fecal contamination and associated diseases) or because (b) they're processed and packed in contaminated facilities. It is a self-fulfilling irony of the regulatory regime that vegetable-processing plants, which are more likely to be contaminated, are subject to less stringent safety standards than their meat- and poultry-processing counterparts.
0. http://google2.fda.gov/search?site=FDAgov-recalls&client...
If so, reducing/eradicating endemic chicken salmonella might also remove it from the manure.
http://www.webmd.com/food-recipes/food-poisoning/news/201209...