Outbreaks Linked to Melons, United States, 2012-2021

Abstract

The Centers for Disease Control and Prevention (CDC), working closely with public health and regulatory partners, investigate outbreaks of foodborne illness. Outbreak investigations continue to identify melons as an important source of outbreak-associated illness. We characterized the epidemiology of outbreaks linked to melons from 2012 to 2021, summarized public health responses to these outbreaks, and identified potential opportunities for prevention efforts and interventions. We queried CDC's Foodborne Disease Outbreak Surveillance System (FDOSS) for all Salmonella, Escherichia coli (E. coli), and Listeria monocytogenes outbreaks linked to melons and collected data from the U.S. Food and Drug Administration's (FDA) Coordinated Outbreak Response & Evaluation (CORE) Network internal databases for information regarding outbreak investigations that involved FDA's evaluation and response activities. Descriptive statistics were calculated for outbreaks overall, by melon type, and by etiology, including the number of outbreaks, illnesses, hospitalizations, deaths, patient demographics including sex and age, outbreak duration, investigation duration, seasonality, serotypes, and food preparation and consumption settings. During 2012-2021, 18 outbreaks were linked to melons. The median number of outbreaks per year was 2 (range: 0-3); there were no melon-associated outbreaks reported in 2015. These 18 outbreaks resulted in 821 illnesses, 251 hospitalizations, and 10 deaths. More than half of the melon-associated Salmonella outbreaks in this reporting timeframe were linked to cantaloupe. Outbreak illnesses clustered in the U.S. Midwest and in outbreaks where the growing area was known, most were produced domestically (4/7, 57%), frequently grown in Indiana. Traceback and epidemiologic investigations demonstrated that contamination can occur at all points along the farm-to-fork continuum, requiring the need for pathogen control at every step.

Keywords: Foodborne Outbreak; Listeria; Melon; Salmonella.