Salmonella in Imported Mangos: Shoeleather and Contemporary Epidemiologic Techniques Together Meet the Challenge

In this issue of Clinical Infectious Diseases, Sivapalasingam et al. [1] describe an elegant epidemiologic investigation of a mul-tistate outbreak of Salmonella enterica se-rotype Newport infection associated with mango consumption. The details of this investigation highlight a number of important issues demonstrating the substantial impact of recent changes in food processing and distribution on food safety, as well as the substantial contribution of modern tools to the traditional techniques of foodborne-disease epidemiologists. Foodborne disease is reported to cause 76 million illnesses, 325,000 hospitalizations , and 5000 deaths in the United States each year [2]. A variety of factors contribute to the changing epidemiology of foodborne disease, including aging of the US population, the emergence of new pathogens, and changes in what Ameri-cans eat and where they eat it [3, 4]. The per capita consumption of fresh fruits and vegetables is increasing [3], as is the proportion of foodborne disease outbreaks associated with fresh produce [4]. The produce sections of our local supermarkets have come to resemble an international bazaar. At some times during the year, 175% of the produce we eat is harvested outside of the United States and delivered to our tables within days [4]. Mangoes are not a regular part of the typical American diet, and their increasing popularity is likely attributable to both an increase in the cultural diversity of the United States population and the " globalization " of our food supply, with increasingly widespread and regular access to new foods. This investigation adds to the list of recent foodborne disease outbreaks attributable to imported produce, including strawberries, melons, raspberries , parsley, and coconut milk, among others [5–9]. Because the origins of our foods have changed, so also have the epidemiologic characteristics of the foodborne diseases that result. Most foods were once produced and distributed locally. The traditional " church picnic " foodborne outbreak had a readily apparent explosive onset among a well-defined group of neighbors. Local health department personnel could manage the event with a little help from a standard microbiology laboratory. In contrast, imported foodstuffs have a wide geographic distribution, and recent outbreaks have had subtle onsets, with relatively few cases that were geographically dispersed over several states and, as in the current instance, involving a product that previously might have gone unrecognized as a common source. The successful investigation of outbreaks provides a distinctive opportunity to identify new infectious agents, vehicles of transmission, …