Using the Electronic Foodborne Outbreak Reporting System (eFORS) to improve foodborne outbreak surveillance, investigations, and program evaluation.

Challenges exist in comparing foodborne disease outbreaks (FBDOs) across states due to important differences in reporting practices and investigations. Variables such as FBDO size, population size, number of tourists, and suspected etiology are important to consider when interpreting FBDO data. Analysis of eFORS data can be valuable in improving state FBDO investigations. From 2000 to 2005, Florida reported a greater proportion of FBDOs, with two cases per outbreak, than the U.S. as a whole (40.4% in Florida vs. 17.2% in the U.S.). Reporting a higher rate of small FBDOs provided more opportunities for public health interventions but contributed to a lower agent confirmation rate (17.0% in Florida vs. 42.2% in the U.S.). While the Electronic Foodborne Outbreak Reporting System's (eFORS) database brought great improvements in national FBDO surveillance, as with any complex surveillance system, considerable knowledge and specialized expertise is required to properly analyze and interpret the data, especially because there is a large variation in state reports to eFORS.

Cryptosporidiosis outbreak in a Nassau County, Florida, return travel group from Ireland, May 24, 2006-June 4, 2006.

The Nassau County Health Department (NCHD) in Florida investigated an outbreak of gastrointestinal (GI) illness in a returning choral group who toured Ireland from May 24 to June 4, 2006. The travel group, consisting predominantly of retirees, had performed at several churches and at a dinner theater in Ireland. The NCHD administered a telephone questionnaire to 40 of the 41 group members to examine possible water exposures; common meals; and food, travel, and clinical histories. The results of the questionnaire showed that 29 people met the case definition for the outbreak. Five stool samples from travel group members tested positive for Cryptosporidium parvum, a species that is animal in origin and often spread through an environmental contamination with animal feces. All five positive samples were subtyped 11aA16G1R1b, a strain that scientists at the Centers for Disease Control and Prevention (CDC) Division of Parasitic Diseases detected twice in 2006 in other human specimens from Northern Ireland.

Use of molecular epidemiology to confirm a multistate outbreak of hepatitis A caused by consumption of oysters.

The 39 oyster consumption-related cases of hepatitis A reported in 2005 represent the first large outbreak of hepatitis A associated with shellfish consumption in the United States in >15 years. This is the first outbreak investigation in which an identical hepatitis A virus sequence was obtained from both the implicated food product and case patients.

Outbreak bias in illness reporting and case confirmation in ciguatera fish poisoning surveillance in south Florida.

OBJECTIVE: Ciguatera fish poisoning is a potentially life-threatening disease caused by eating coral reef fish contaminated with ciguatoxins and is the most common marine poisoning. However, existing surveillance systems capture few cases. To improve regional ciguatera surveillance in South Florida, this study compared ciguatera illnesses in the Florida Poison Information Center-Miami (FPICM) call database to ciguatera cases in the Florida Department of Health (FDOH) disease surveillance systems. METHODS: Univariate and multivariate logistic regression were used to identify predictors of when FPICM reported ciguatera illnesses to FDOH and whether FDOH confirmed reported ciguatera cases. RESULTS: FPICM staff preferentially reported ciguatera illnesses that were of shorter duration (adjusted odds ratio [AOR] = 0.84 per additional illness day; 95% confidence interval [CI] 0.74, 0.97); outbreak-associated (AOR = 7.0; 95% CI 2.5, 19.5); and clinically more severe (AOR = 21.6; 95% CI 2.3, 198.5). Among ciguatera illnesses reported to FDOH, outbreak-associated illnesses were more likely than single, sporadic illnesses to become confirmed surveillance cases (crude OR = 11.1; 95% CI 2.0, 62.5). CONCLUSIONS: The over-representation of outbreak-associated ciguatera cases underestimates the true contribution of sporadic illnesses to ciguatera disease burden. This bias should be considered when evaluating surveillance systems that include both outbreak-associated and sporadic illness reports.

Assessing the effectiveness of food worker training in Florida: opportunities and challenges.

The task of measuring the effectiveness of food worker training has historically met with many challenges. This paper considers various approaches and utilizes trends in foodborne-outbreak contributing factors to evaluate a recent change in Florida's food worker training. Results show that subsequent to training, the relative incidence of many factors that contribute to foodborne outbreaks actuay increased, while the relative incidence of other factors decreased. The overall rate of foodborne outbreaks associated with the contributing factors that the authors studied decreased subsequent to training. Results of this analysis must be interpreted with caution because of multiple confounding factors; however, it became apparent that both increases and decreases in the occurrence of contributing factors could be used to focus future training material on areas of food handler practices in which it is needed. Further work needs to be done to estabish the most useful methods and approaches for assessing effectiveness and hence the public health impact of food worker training.

An outbreak of typhoid Fever in Florida associated with an imported frozen fruit.

An outbreak of typhoid fever in Florida involving at least 16 persons during the winter of 1998-99 was investigated using case-control, environmental, and laboratory methods. The genomic profiles of Salmonella serovar Typhi (Salmonella Typhi) isolates from the 15 confirmed case subjects were identical. Consumption of fruit shakes made with frozen mamey, a tropical fruit, was significantly associated with illness (matched odds ratio, 7.6; 95% confidence interval, 1.4-81.4). Laboratory testing showed that the fruit was heavily contaminated with fecal coliforms; no Salmonella Typhi was isolated. The frozen mamey was prepared in plants in Guatemala and Honduras. No further cases occurred after the frozen product was recalled. As our nation's food sources become increasingly globalized, the risk of outbreaks of exotic diseases linked to contaminated imported food will increase. This outbreak highlights the need for new approaches to ensure the safety of our food supply.