Analysis of tomato and jalapeño and Serrano pepper imports into the United States from Mexico before and during a National Outbreak of Salmonella serotype Saintpaul infections in 2008.

Case-control studies conducted during a multistate outbreak of Salmonella enterica serotype Saintpaul infections in 2008 revealed associations between illness and the consumption of jalapeño peppers, Serrano peppers, and tomatoes. Traceback investigations of implicated jalapeño and Serrano peppers led to farms in Tamaulipas and Nuevo León, Mexico. We conducted a novel analysis of a U.S. Food and Drug Administration database of tomatoes and jalapeño and Serrano peppers imported from Mexico during the first half of 2008 to describe the temporal and spatial flow of these items into the United States. Shipments of all three produce items followed a south-to-northwest corridor; 87% of peppers and 97% of tomatoes produced in Mexican states located west of the Sierra Madre Occidental were transported to ports in California and Arizona, and 90% of peppers and 100% of tomatoes produced in states east of the Sierra Madre Occidental were transported to ports east of Arizona. We found a significant correlation between state-specific infection rates and quantity of imported Mexican jalapeño and Serrano peppers to U.S. states by the first-level consignee but not for imported Mexican tomatoes. We localized production regions of interest by finding that quantities of both peppers and tomatoes imported from the states of Nuevo León and Tamaulipas were correlated with infection rates. In outbreaks possibly caused by agricultural commodities, analysis of import databases may foster a better understanding of growing seasons, harvest sites, shipment itineraries, and consignee destinations, thereby adding valuable insight into findings derived from epidemiologic studies.