Outbreaks Where Food Workers Have Been Implicated in the Spread of Foodborne Disease. Part 2. Description of Outbreaks by Size, Severity, and Settings

Abstract

This article is the second in a series of several by members of the Committee on the Control of Foodborne Illness of the International Association of Food Protection, and it continues the analysis of 816 outbreaks where food workers were implicated in the spread of foodborne disease. In this article, we discuss case morbidity and mortality and the settings where the 816 outbreaks occurred. Some of the outbreaks were very large; 11 involved more than 1,000 persons, 4 with more than 3,000 ill. The larger outbreaks tended to be extended over several days with a continuing source of infections, such as at festivals, resorts, and community events, or the contaminated product had been shipped to a large number of customers, e.g., icing on cakes or exported raspberries. There were five outbreaks with more than 100 persons hospitalized, with rates ranging from 9.9 to 100%. However, overall, the hospitalization rate was low (1.4%), and deaths were rare (0.11% of the 80,682 cases). Many of the deaths were associated with high-risk persons (i.e., those who had underlying diseases, malnutrition, or both, as in a refugee camp, or young children), but a few occurred with apparently healthy adults. An analysis of the settings for the food worker-related events showed that most of the outbreaks came from food service facilities (376 outbreaks [46.1%]), followed by catered events (126 outbreaks [15.4%]), the home (83 outbreaks [10.2%]), schools and day care centers (49 [6.0%]), and health care institutions (43 outbreaks [5.3%]). However, many cases resulted from relatively few outbreaks (< 30 each) associated with community events (9,726), processing plants (8,580), mobile/temporary service (5,367), and camps/ armed forces (5,117). The single most frequently reported setting was restaurants, with 324 outbreaks and 16,938 cases. Improper hygienic practices in homes, on picnics, or at community events accounted for 89 of the 816 outbreaks. There were 18 outbreaks associated with commercial travel in air flights, trains, and cruise ships over several decades, although only the last seems to be a major concern today. Sixteen outbreaks occurred where food, primarily produce, was harvested and shipped from one country to another. Sometimes the presence of an infected worker preparing food was only one of several factors contributing to the outbreak.

Human Astroviruses

“…HAstVs cause asymptomatic infections in children and adults (61,93), and asymptomatic food workers are more often implicated in gastroenteritis outbreaks than symptomatic food handlers (227). It is critical to ascertain the significance of asymptomatic as well as presymptomatic and postsymptomatic HAstV shedding in the transmission of food-borne infections.…”

Assessment of Hygienic Practices and Microbiological Quality of Food in an Institutional Food Service Establishment

“…Food may be contaminated with harmful bacteria, either directly by an infected food handler, or indirectly through contact with a food contact surface that has been contaminated by an infected food handler. Foods which will not be cooked before being eaten are of greater risk because cooking is a process that would kill many of the bacteria present [50]. Additionally, 96% of the food handlers did not know that microbes can be found on the skin, and in the mouth and nose of healthy looking individuals.…”

“…Food handling personnel play important role in ensuring food safety throughout the chain of food production, processing, storage and preparation. Mishandling and disregard to hygienic measures on the part of the food handlers have been reported to introduce contaminant and pathogens that survive and multiply in sufficient numbers to cause illness in the consumer [19,50,73,75]. With regard to AMB, counts above 10 5 have been considered a potential risk for the presence of pathogens [76].…”

Year-Round Prevalence of Norovirus in the Environment of Catering Companies without a Recently Reported Outbreak of Gastroenteritis

“…Transmission by food handlers most likely occurs through contact of bare hands or contaminated surfaces with food, which has been studied in experimental settings (1,2). In a series of 3 recent papers reviewing published data from 816 food worker-related outbreaks occurring between 1927 and 2006, food service facilities, e.g., restaurants and hotels, were the settings most often implicated (15,26), and bare-hand contact with food followed by failure to properly wash hands was the factor associated with the involvement of the infected worker (27).…”