At least 275 people in 29 states and Washington, D.C., were sickened and one man died in a Salmonella outbreak linked to cucumbers grown in the Delmarva region of Maryland, according to a report from the U.S. Centers for Disease Control and Prevention (CDC) published Friday. This is the first public mention of the outbreak, which occurred between May 20 and Sept. 30, 2014. CDC began investigating the outbreak in August, when a cluster of Salmonella Newport illnesses showed up on PulseNet, the national database of transmittable diseases. Salmonella with that particular genetic code last appeared on PulseNet in an outbreak from 2006-2007 linked to tomatoes grown in the Delmarva region of Virginia. Thirty-four percent of patients were hospitalized. One elderly man was diagnosed with bacteremia and died. After CDC and local and state health officials traced the infections back to cucumbers grown at a farm in Delmarva — several months after harvest — they began testing soil and manure samples but couldn’t find any remaining contamination. However, investigators did learn that the farm applied poultry litter approximately 120 days before harvest. Historically, this genetic variety of Salmonella has only been associated with tomatoes grown in the region, with outbreaks occurring in 2002 (333 cases), 2005 (72), 2006 (115), and 2007 (65), with a suspected outbreak in 2010 (51). The exact source of the contamination, however, has eluded investigators. In the report, CDC said that the source of contamination “should be identified and mitigated to prevent future outbreaks.” Editor’s Note: This article originally reported that the cucumbers came from the Delmarva region of Virginia. That was incorrect. The contaminated cucumbers were grown in the Delmarva region of Maryland, while previous cases with the same Salmonella strain have been linked to tomatoes from the Delmarva region of Virginia.