Ineffective hand washing and the contamination of carrots after using a field latrine

A Critical Review of Parameters Relevant for Shiga Toxin-producing Escherichia coli and Listeria monocytogenes Risk Assessments of Leafy Greens

In the past decade, several quantitative models and risk assessments for Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes have been developed to guide the management of these pathogens in fresh produce. However, there is a need to collect and critically review the parameters used to guide their potential reuse in future risk assessments. This review (i) identifies 11 and 7 recently published quantitative models and risk assessments for STEC and L. monocytogenes, respectively, in leafy greens, (ii) summarizes parameters, and (iii) reviews the underlying data sources or mathematical formulas used. A total of 70 unique key parameters (55 and 25 for STEC and L. monocytogenes, respectively, 10 shared) were extracted from the reviewed models across five supply chain stages, including: Preharvest, Harvest, Processing, Presentation to Consumer (Retail or Foodservice Locations), and Consumer Handling. Primary growth, secondary growth, and dose-response equations and parameters for STEC and L. monocytogenes were also extracted. Additional literature reviews were performed if (i) certain key parameters were based on a single or a few data sources or (ii) key parameters were identified in a supply chain stage for one pathogen, but missing from the other. The critical summaries of parameters presented here (i) provide a resource for future risk assessments, (ii) help define future data collection needs, and (iii) represent a starting point for similar reviews focusing on other produce commodities and pathogens.

Scientific Evidence Supports the Use of Alcohol-Based Hand Sanitizers as an Effective Alternative to Hand Washing in Retail Food and Food Service Settings When Heavy Soiling Is Not Present on Hands

ABSTRACT

Suboptimal food worker health and hygiene has been a common contributing factor in foodborne disease outbreaks for many years. Despite clear U.S. Food and Drug Administration (FDA) Model Food Code recommendations for hand washing and glove use, food worker compliance with hand washing recommendations has remained poor for >20 years. Food workers' compliance with recommended hand washing guidelines is adversely impacted by a number of barriers, including complaints of time pressure, inadequate number and/or location of hand washing sinks and hand washing supplies, lack of food knowledge and training regarding hand washing, the belief that wearing gloves obviates the need for hand washing, insufficient management commitment, and adverse skin effects caused by frequent hand washing. Although many of the issues related to poor hand washing practices in food service facilities are the same as those in health care settings, a new approach to health care hand hygiene was deemed necessary >15 years ago due to persistently low compliance rates among health care personnel. Evidence-based hand hygiene guidelines for health care settings were published by both the Centers for Disease Control and Prevention in 2002 and by the World Health Organization in 2009. Despite similar low hand washing compliance rates among retail food establishment workers, no changes in the Food Code guidelines for hand washing have been made since 2001. In direct contrast to health care settings, where frequent use of alcohol-based hand sanitizers (ABHSs) in lieu of hand washing has improved hand hygiene compliance rates and reduced infections, the Food Code continues to permit the use of ABHSs only after hands have been washed with soap and water. This article provides clear evidence to support modifying the FDA Model Food Code to allow the use of ABHSs as an acceptable alternative to hand washing in situations where heavy soiling is not present. Emphasis on the importance of hand washing when hands are heavily soiled and appropriate use of gloves is still indicated.

HIGHLIGHTS

Antimicrobial Properties of Encapsulated Antimicrobial Natural Plant Products for Ready-to-Eat Carrots

The antimicrobial activity of natural antimicrobials (fruit extracts, essential oils and derivates), was assessed against six bacteria species (E. coli O157:H7, L. monocytogenes, S. Typhimurium, B. subtilis, E. faecium and S. aureus), two molds (A. flavus and P. chrysogenum) and a yeast (C. albicans) using disk diffusion method. Then, the antimicrobial compounds having high inhibitory capacity were evaluated for the determination of their minimum inhibitory, bactericidal and fungicidal concentration (MIC, MBC and MFC respectively). Total phenols and flavonoids content, radical scavenging activity and ferric reducing antioxidant power of selected compounds were also evaluated. Based on in vitro assays, five antimicrobial compounds were selected for their lowest effective concentration. Results showed that, most of these antimicrobial compounds had a high concentration of total phenols and flavonoids and a good anti-oxidant and anti-radical activity. In situ study showed that natural antimicrobials mix, applied on the carrot surface, reduced significantly the count of the initial mesophilic total flora (TMF), molds and yeasts and allowed an extension of the shelf-life of carrots by two days as compared to the control. However, the chemical treatment (mix of peroxyacetic acid and hydrogen peroxide) showed antifungal activity and a slight reduction of TMF.

Assessment of Food Safety Knowledge, Self-Reported Practices, and Microbiological Hand Hygiene Levels of Produce Handlers in Qatar

HIGHLIGHTS

Workers' hygiene is one of the most important risk factors in transferring pathogens to foods. Produce handlers lacked basic knowledge on personal hygiene and food safety. Produce handlers' hand hygiene levels were below set standards. This study is the first of its kind in the region; thus, it helps fill an existing knowledge gap.

Poor biosecurity could lead to disease outbreaks in animal populations

Human-mediated disease outbreaks due to poor biosecurity practices when processing animals in wild populations have been suspected. We tested whether not changing nitrile gloves between processing wood frog (Lithobates sylvaticus) tadpoles and co-housing individuals increased pathogen transmission and subsequent diseased-induced mortality caused by the emerging pathogen, ranavirus. We found that not changing gloves between processing infected and uninfected tadpoles resulted in transmission of ranavirus and increased the risk of mortality of uninfected tadpoles by 30X. Co-housing tadpoles for only 15 minutes with 10% of individuals infected resulted in ranavirus transmission and 50% mortality of uninfected tadpoles. More extreme mortality was observed when the co-housing infection prevalence was >10%. Our results illustrate that human-induced disease outbreaks due to poor biosecurity practices are possible in wild animal populations.

A unified framework for developing effective hygiene procedures for hands, environmental surfaces and laundry in healthcare, domestic, food handling and other settings

Hygiene procedures for hands, surfaces and fabrics are central to preventing spread of infection in settings including healthcare, food production, catering, agriculture, public settings, and home and everyday life. They are used in situations including hand hygiene, clinical procedures, decontamination of environmental surfaces, respiratory hygiene, food handling, laundry hygiene, toilet hygiene and so on. Although the principles are common to all, approaches currently used in different settings are inconsistent. A concern is the use of inconsistent terminology which is misleading, especially to people we need to communicate with such as the public or cleaning professionals. This paper reviews the data on current approaches, alongside new insights to developing hygiene procedures. Using this data, we propose a more scientifically-grounded framework for developing procedures that maximize protection against infection, based on consistent principles and terminology, and applicable across all settings. A key feature is use of test models which assess the state of surfaces after treatment rather than product performance alone. This allows procedures that rely on removal of microbes to be compared with those employing chemical or thermal inactivation. This makes it possible to ensure that a consistent "safety target level" is achieved regardless of the type of procedure used, and allows us deliver maximum health benefit whilst ensuring prudent usage of antimicrobial agents, detergents, water and energy.

Risk Assessment or Assessment of Risk? Developing an Evidence-Based Approach for Primary Producers of Leafy Vegetables To Assess and Manage Microbial Risks

Over the last 10 years, some high-profile foodborne illness outbreaks have been linked to the consumption of leafy greens. Growers are required to complete microbiological risk assessments (RAs) for the production of leafy crops supplied either to retail or for further processing. These RAs are based primarily on qualitative judgements of hazard and risks at various stages in the production process but lack many of the steps defined for quantitative microbiological RAs by the Codex Alimentarius Commission. This article is based on the discussions of an industry expert group and proposes a grower RA approach based on a structured qualitative assessment, which requires all decisions to be based on evidence and a framework for describing the decision process that can be challenged and defended within the supply chain. In addition, this article highlights the need for evidence to be more easily available and accessible to primary producers and identifies the need to develop hygiene criteria to aid validation of proposed interventions.