National Outbreak of Salmonella Serotype Saintpaul Infections: Importance of Texas Restaurant Investigations in Implicating Jalapeño Peppers

Abstract

BackgroundIn May 2008, PulseNet detected a multistate outbreak of Salmonella enterica serotype Saintpaul infections. Initial investigations identified an epidemiologic association between illness and consumption of raw tomatoes, yet cases continued. In mid-June, we investigated two clusters of outbreak strain infections in Texas among patrons of Restaurant A and two establishments of Restaurant Chain B to determine the outbreak's source.Methodology/Principal FindingsWe conducted independent case-control studies of Restaurant A and B patrons. Patients were matched to well controls by meal date. We conducted restaurant environmental investigations and traced the origin of implicated products. Forty-seven case-patients and 40 controls were enrolled in the Restaurant A study. Thirty case-patients and 31 controls were enrolled in the Restaurant Chain B study. In both studies, illness was independently associated with only one menu item, fresh salsa (Restaurant A: matched odds ratio [mOR], 37; 95% confidence interval [CI], 7.2–386; Restaurant B: mOR, 13; 95% CI 1.3–infinity). The only ingredient in common between the two salsas was raw jalapeño peppers. Cultures of jalapeño peppers collected from an importer that supplied Restaurant Chain B and serrano peppers and irrigation water from a Mexican farm that supplied that importer with jalapeño and serrano peppers grew the outbreak strain.Conclusions/SignificanceJalapeño peppers, contaminated before arrival at the restaurants and served in uncooked fresh salsas, were the source of these infections. Our investigations, critical in understanding the broader multistate outbreak, exemplify an effective approach to investigating large foodborne outbreaks. Additional measures are needed to reduce produce contamination.

Risk Factors Associated with Salmonella and Listeria monocytogenes Contamination of Produce Fields

“…For example, a Salmonella outbreak in 2005, associated with tomatoes, resulted in 459 illnesses across 21 U.S. states (7). In 2008, an outbreak of Salmonella, linked to jalapeno peppers, sickened approximately 1,500 individuals from 43 states, the District of Columbia, and Canada; this became the largest known outbreak of food-borne illness in the United States within the past decade (8). L. monocytogenes was responsible for a 2011 produce-borne outbreak in the United States, with 147 illnesses, 33 deaths, and 1 miscarriage, due to consumption of cantaloupe (9).…”

Scientific Opinion on the risk posed by pathogens in food of non-animal origin. Part 1 (outbreak data analysis and risk ranking of food/pathogen combinations)

“…Consumption of FoNAO not already identified as associated salmonellosis includes: vegetables including tomatoes and peppers (CDC, 2005;Greene et al, 2008;Gupta et al, 2007;Mody et al, 2011;SSI, 2011), fresh herbs (Elviss et al, 2009;Pezzoli et al, 2008), types of whole, fresh, pulped, frozen or juiced fruits (e.g. melons, oranges, papaya, mangoes) (CDC, 2006a(CDC, , 2010(CDC, , 2011b(CDC, , 2012a(CDC, , 2012bGibbs et al, 2009;Loharikar et al, 2012;Noel et al, 2010;Sivapalasingam et al, 2003;Vojdani et al, 2008); salads and other leafy greens (Barton Behravesh et al, 2011;CDC, 2006b;Gajraj et al, 2012;Nygard et al, 2008); nuts, seeds and derived products, e.g.…”

Microbial ecology of fresh vegetables

“…The pathogens most fre quently linked to vegetable-related outbreaks include bacteria (Salmonella, Escherichia coli) and viruses (norovirus, hepatitis A) (Painter et al, 2013). As an example, hot peppers were the source for a high profile salmonellosis out break in the US and Canada in 2008, leading to 1442 illnesses and two deaths (Mody et al, 2011). In addition, contaminated pre-packaged baby spinach caused a devastating E. coli O157:H7 outbreak in 2006 in the US, involving 199 cases and three deaths (CDC, 2006).…”