The cause of the recent Salmonella outbreak my have been the irrigation water that was used in watering serrano peppers ( serrano peppers are a variety of chili pepper similar to the jalapeno but hotter ) at a Mexican farm. 

The people made sick by a strain called "Salmonella Saintpaul" were found in 43 states, the District of Columbia and Canada. At least 242 have been hospitalized, although federal health officials say only the elderly, infants and people with weakened immune system need to avoid raw peppers from Mexico.

Earlier, the FDA announced it had discovered salmonella on a jalapeño imported from Mexico at The Agricola Zarigosa produce distribution center in McAllen, Texas.

Initially, tomatoes seemed the most likely source of the outbreak. The FDA told consumers to avoid certain raw tomatoes on June 7, prompting grocery chains and some restaurants nationwide to stop offering them.  Likewise, no one should eat raw serrano peppers from Mexico, Herndon said. 

They however, still can't rule out tomatoes.

Whether it is from the peppers or tomatoes they say the contaminated water  is the most promising lead they have had.

You can go to the CDC, Centers for Disease Control, web site to learn about salmonella and its symptoms.

It is scary when it isn't safe to eat fruits and vegetables.

Source.