WASHINGTON — The Centers for Disease Control and Prevention say the salmonella outbreak that sickened more than 1,440 people appears to be over.

A joint investigation by CDC and the Food and Drug Administration found strong evidence that jalapeno peppers were a major carrier of the bacteria, and that serrano peppers were also a carrier. The salmonella strain that caused the outbreak was traced back to a produce distribution center in Texas, and to a farm in Mexico that grew peppers.

The extensive probe found no contaminated tomatoes, but investigators say they cannot rule out that tomatoes might have been a carrier, particularly early on.

It was the largest outbreak of foodborne illness in the United States in the past decade.