Geospatial Mapping of Early Cases in Multistate Foodborne Disease Outbreaks: A Strategy To Expedite Identification of...

From 1998 to 2008, produce-related illness outbreaks accounted for roughly one-half of reported foodborne outbreaks in the United States. In 2013, Mexico accounted for approximately 50 and 30% of the monetary value of all vegetables and fruits, respectively, imported into the United States. We used historical import data to examine the correlation between the port of entry for five implicated produce vehicles from five multistate outbreaks and the geospatial and temporal distribution of illnesses in the corresponding outbreaks in the United States. For comparison, we analyzed the geospatial and temporal distribution of cases from two U.S. multistate outbreaks associated with domestically grown produce. The geospatial distribution of illnesses in the two outbreaks linked to domestic produce differed from that of the import-related produce outbreaks. The results of our pilot study suggest that geospatial distribution of early-onset cases may be used to identify ports of entry for produce likely to be responsible for causing multistate outbreaks in the United States and that targeted sampling of produce items from these ports of entry may expedite identification of an outbreak vehicle.