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

Aga Khan University, Pakistan
PLoS ONE (Impact Factor: 3.23). 02/2011; 6(2):e16579. DOI: 10.1371/journal.pone.0016579
Source: PubMed


In 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.
We 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.
Jalapeño 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.

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Available from: Samir V Sodha, Oct 09, 2015
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    • "Historically foodborne disease outbreaks including outbreaks caused by various Salmonella serotypes have been most frequently caused by consumption of foods of animal origin, but more recently an increased number of foodborne outbreaks have been associated with consumption of fresh fruits and vegetables [29-31]. In a U.S. multistate outbreak investigation, public health authorities identified a link between raw jalapeño pepper consumption and Salmonella Saintpaul infections [32]. "
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    ABSTRACT: Background Identifying risk factors for Salmonella Enteritidis (SE) infections in Ontario will assist public health authorities to design effective control and prevention programs to reduce the burden of SE infections. Our research objective was to identify risk factors for acquiring SE infections with various phage types (PT) in Ontario, Canada. We hypothesized that certain PTs (e.g., PT8 and PT13a) have specific risk factors for infection. Methods Our study included endemic SE cases with various PTs whose isolates were submitted to the Public Health Laboratory-Toronto from January 20th to August 12th, 2011. Cases were interviewed using a standardized questionnaire that included questions pertaining to demographics, travel history, clinical symptoms, contact with animals, and food exposures. A multinomial logistic regression method using the Generalized Linear Latent and Mixed Model procedure and a case-case study design were used to identify risk factors for acquiring SE infections with various PTs in Ontario, Canada. In the multinomial logistic regression model, the outcome variable had three categories representing human infections caused by SE PT8, PT13a, and all other SE PTs (i.e., non-PT8/non-PT13a) as a referent category to which the other two categories were compared. Results In the multivariable model, SE PT8 was positively associated with contact with dogs (OR=2.17, 95% CI 1.01-4.68) and negatively associated with pepper consumption (OR=0.35, 95% CI 0.13-0.94), after adjusting for age categories and gender, and using exposure periods and health regions as random effects to account for clustering. Conclusions Our study findings offer interesting hypotheses about the role of phage type-specific risk factors. Multinomial logistic regression analysis and the case-case study approach are novel methodologies to evaluate associations among SE infections with different PTs and various risk factors.
    BMC Public Health 10/2012; 12(1):866. DOI:10.1186/1471-2458-12-866 · 2.26 Impact Factor
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    • "l . , 2006 Europe 2007 Salmonella Baby spinach 354 Denny et al . , 2007 North America , Europe 2007 Salmonella Basil 51 Pezzoli et al . , 2007 Australia , Europe 2007 Shigella sonnei Baby carrots 230 Lewis et al . , 2007 Europe 2007 Salmonella Alfalfa sprouts 45 Emberland et al . , 2007 USA , Canada 2008 Salmonella Peppers 1442 ( 2 ) CDC , 2008b ; Mody et al . , 2011 USA , Canada 2008 E . coli O157 : H7 Lettuce 134 Warriner and Namvar , 2010 UK 2008 Salmonella Basil 32 Elviss et al . , 2009 USA 2008"
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    ABSTRACT: ncreased consumption, larger scale production and more efficient distribution of fresh produce over the past two decades have contributed to an increase in the number of illness outbreaks caused by this commodity. Pathogen contamination of fresh produce may originate before or after harvest, but once contaminated produce is difficult to sanitize. The prospect that some pathogens invade the vascular system of plants and establish “sub-clinical” infection needs to be better understood to enable estimation of its influence upon risk of human illness. Conventional surface sanitation methods can reduce the microbial load, but cannot eliminate pathogens if present. Chlorine dioxide, electrolyzed water, UV light, cold atmosphere plasma, hydrogen peroxide, organic acids and acidified sodium chlorite show promise, but irradiation at 1 kGy in high oxygen atmospheres may prove to be the most effective means to assure elimination of both surface and internal contamination of produce by pathogens. Pathogens of greatest current concern are Salmonella (tomatoes, seed sprouts and spices) and Escherichia coli O157:H7 on leafy greens (spinach and lettuce). This review considers new information on illness outbreaks caused by produce, identifies factors which influence their frequency and size and examines intervention effectiveness. Research needed to increase our understanding of the factors influencing microbial safety of fresh produce is addressed.
    Food Microbiology 05/2012; DOI:10.1016/ · 3.33 Impact Factor
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    • "egg-industry-facts-sheet). Fresh produce is particularly vulnerable to contamination during the " farm to fork " process and fresh eggs can be contaminated easily with SE through cracks in the shell by contact with chicken feces or by transovarian infection (Howard et al., 2011). These events could have contributed to the observed increases of foodborne outbreaks (Altekruse, Cohen, & Swerdlow, 1997), including recent Salmonella outbreaks in the US involving jalapeno peppers in 2008 (Mody et al., 2011) and a large multistate outbreak of SE that was associated with contaminated eggs (http://www. in 2010. "
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    Food Research International 04/2012; 48(1):202. DOI:10.1016/j.foodres.2012.03.009 · 2.82 Impact Factor
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