How Does E Coli Get in Ground Beef

The purpose of the Preparation Module is to estimate the occurrence and extent of Eastward. coli O157:H7 contamination in consumed basis-beef servings. The arroyo involves determining the frequency of exposure of consumers in different age groups to E. coli O157:H7 in basis beef served at and away from home. Six primary steps are evaluated: grinding of beefiness, ground-beef storage during processing or by the retailer or distributor; transportation to the home or to hotels, restaurants, and institutions (HRI); storage at dwelling or in HRI; cooking; and consumption. Consumption patterns are modeled every bit existence dependent on the historic period of the consumer and the location of the repast. Ground beef is consumed in many forms, only the FSIS draft take a chance assessment focuses on hamburger patties and on ground beefiness used as a major ingredient in beef-based foods (such as meatballs and meatloaf). The model does non include ground beefiness every bit a granulated ingredient (as in commercial meat sauce for spaghetti).

Cantankerous CONTAMINATION

A central issue for the committee in its review of the draft Preparation Module was the factoring in of the contributing influence of cantankerous contamination on man illness. Cantankerous contamination during preparation results when E. coli O157:H7 is transmitted from contaminated footing beef to such vehicles as other foods, food preparation and processing surfaces, and food handlers. Because of the highly infectious nature of the pathogen, which has an estimated low infectious dose of under 100 cells, vehicles cantankerous-contaminated through direct or indirect exposure to E. coli O157:H7-tainted raw basis beefiness are likely to be of import sources of human illness (Buchanan and Doyle, 1997).

A case-control analysis of desultory infection with E. coli O157:H7 by Mead et al. (1997) substantiates that notion. It determined that most sick persons in question had eaten hamburgers prepared at abode and that the main hazard factors associated with infection were food preparers who had not done their hands or piece of work surfaces after treatment raw basis beef. The investigators ended that in many instances hamburgers were non the direct vehicle of transmission of E. coli O157:H7, simply rather that transmission occurred more commonly when the food preparers' easily, contaminated past raw footing beefiness, were allowed to cross-contaminate other meal items or utensils. In a multistate outbreak of Due east. coli O157:H7 infection in 1995, cross contagion from raw ground beef was identified as the probable contributing cistron associated with eating cooked ground-beef sandwiches prepared at fast-food restaurants of a specific chain (CDC, 1996).

Although they did not address the issue of E. coli O157:H7 direct, ii studies released while the draft chance assessment was under development support the notion that cross contamination during nutrient preparation is an important risk factor for foodborne illness in full general. Audits International (2001) published a study of food-grooming practices that identified cross contamination (25% of failures) as the tertiary most-common critical violation¹ of good hygienic practices in the domicile. Previous Audits International studies had ranked it as the virtually common disquisitional violation, with a frequency of 71% in 1997 and 31% in 1999. Another study researching commercial and institutional food operations was prepared by the Nutrient and Drug Administration (FDA, 2000). Researchers at FDA found that xv% of fast-food restaurants and 44% of full-service restaurants examined were out of compliance with 1 or more items in the category "contaminated equipment/protection from contamination". Those items included whether raw animate being foods were separated from one another, whether raw and gear up-to-swallow foods were separated, and whether surfaces and utensils were cleaned or sanitized.

The Food Safety and Inspection Service (FSIS) of the United states of america Department of Agronomics (USDA) itself identifies cantankerous contamination during grooming as a significant cistron in food safe. Two of the four steps in USDA's Fight BAC!^two entrada—"Clean—launder hands and surfaces often" and "Dissever—don't cross-contaminate"—accost interventions intended to minimize information technology.

Still, the FSIS draft risk cess indicates that cross contagion in the preparation stage is outside the scope of the analysis (p. iii). Later (p.74), it states:

Currently, quantitative modeling of cross-contamination in foods is hampered by a dearth of evidence. Furthermore, cross-contamination pathways are potentially complex, and each pathway may require as much data regarding growth dynamics and cooking issue every bit the primary production of involvement. The model, notwithstanding, can serve equally a starting point for analyzing the effects of cross-contamination on human exposure to E. coli O157:H7.

The committee understands and respects the determination of the modelers to establish reasonable bounds on the reach of their work; it is a necessary office of any risk cess. Information technology observes, however, that cross contamination during preparation is an established, important adventure cistron; that the lack of data on its furnishings is no more astringent than the lack of data for some other parts of the draft model; and that further attention to cross contamination volition help to lay the groundwork for an analysis and improve place the data gaps that need to be filled past future research efforts.

The value of the gamble assessment in informing public health policy and supporting regulatory interventions volition exist increased if it is able to cistron in the effect of cantankerous contamination on Eastward. coli O157:H7 infections and mayhap address the influence of interventions. Simply equally important, the committee is concerned that the draft risk assessment may foster the inaccurate and misleading impression that proper cooking of ground beefiness will prevent all associated East. coli O157:H7 infections. If the model is used to simulate the effects of various interventions on human wellness outcomes, omission of this major route of infection could produce ambiguous results and potentially deficient policy decisions.

The commission recognizes that information are lacking on the extent to which diverse forms of exposure—whether direct (through contact with contaminated beef itself) or indirect (through contact with meat drippings or with surfaces that have previously been in contact with contaminated drippings or beef)—to E. coli O157:H7-tainted raw basis beef during storage, transportation, and meal-making touch infection. Nonetheless, that is not the only circumstance in the FSIS draft model in which there is a dearth of information. As noted elsewhere in the affiliate, for example, some estimates of the corporeality of raw ground beef consumed in subpopulations are derived from rather scanty data, and simplifying assumptions or conjectures are used in lieu of data in several steps of the Slaughter Module.

The committee also acknowledges that information technology may not now exist possible to model cantankerous contamination at a level of detail that would allow informed analysis of the efficacy of specific interventions. Nonetheless, it points out that the ability to specify the particulars of the myriad scenarios by which cross contamination with raw footing beef can occur is non a prerequisite for accounting for this take a chance gene in the model. Equally noted elsewhere in this review, the process of constructing a risk assessment necessarily results in the identification of disquisitional data gaps. With a better understanding of what information would be needed to perform more than-sophisticated modeling, USDA volition be in a better position to ascertain a research calendar.

In summary, disregarding the contribution of cross contagion of Due east. coli O157:H7-tainted raw ground beef to human illness weakens the draft risk assessment. The committee suggests that consideration exist given to factoring in cross contamination equally an additional step. If that is not possible, information technology recommends that the final FSIS hazard assessment highlight more than clearly the role of cross contamination in E. coli O157:H7 infection and emphasize the limitations in the model engendered by a conclusion to not gene information technology in.

MODELING IN THE PREPARATION MODULE

Information Selected for Apply and Means of Analysis Take Weaknesses

An of import limitation in modeling in the Preparation Module is the paucity of adequate or validated information regarding some components of the preparation steps. It leads to diminished conviction in estimates derived from these information.

I example is the modeling of storage times. There are no data that directly certificate the length of fourth dimension that basis beef is stored at refrigeration temperature. The draft uses storage temperature data of Audits International (1999) (Table 3-16 in the draft risk assessment) for home and HRI storage (Stride 4). However, those information were obtained from a super-market study in which temperatures were monitored from the retail distribution channel into the home, and it is inappropriate to extrapolate them to the whole of the HRI industry, considering the vast majority of ground beef distributed through the food-service segment of HRI is distributed frozen. Such basis beefiness is processed into patties that are transported frozen and cooked from the frozen state. Hence, it is important to recognize that the Audits International data are relevant but to retail products and a small portion of HRI ground beef. The vast majority of ground beef used in HRI is stored frozen, and so the storage-temperature profiles of the product would be much different from those of fresh ground beef stored in a home setting.

The FSIS draft hazard assessment does attempt to model the effects of freezing footing beefiness on E. coli O157:H7 cell numbers during storage and distribution (p. 83), assuming a compatible distribution of twenty–80% of ground beef is produced frozen. That guess, though, is so broad every bit to exist uninformative. The committee suggests that skilful stance exist sought regarding a more precise gauge and distribution and, if it is found useful, that it exist documented in the text and used in the model until data become bachelor. Whatsoever revised gauge should recognize that nearly ground-beefiness products used by the nutrient-service sector are stored frozen.

The commission recommends, in general, that more precise information regarding the percentage of basis beef that is stored and distributed frozen and cooked from the frozen country be obtained and used for determining estimates associated with frozen basis beefiness, especially that used past fast-food restaurants. A trade association, such every bit the American Meat Plant, could be a source of this information.

Differences in Cooking Practices Based on Location Are Not Appropriately Considered

Practices for cooking ground beef in the habitation, at fast-nutrient restaurants, and in other HRI facilities vary considerably; those of major concatenation fast-nutrient restaurants are well defined and validated to kill pathogens, whereas those used in the home are based largely on the appearance of the cooked product and may result in pathogen survival. A 2002 instance-command report conducted past the Centers for Illness Command and Prevention to place risk factors associated with sporadic E. coli O157 infections determined that eating hamburgers cooked in the domicile was a major risk factor (Kennedy et al., 2002), whereas an earlier case-control study based on data obtained through the aforementioned FoodNet system identified eating hamburgers served at table-service restaurants—but not restaurants of major fast-food chains—as a major risk gene (Kassenborg et al., 1998). The committee recommends that each location—the home, fast-nutrient restaurants, and the remainder of HRI facilities—where basis beefiness is cooked be modeled separately. That would necessitate that data on internal temperatures of cooked footing-beefiness patties be obtained or estimated for the 3 general locations. The Risk Characterization chapter in the draft correctly notes that "information on variability in food grooming behavior between consumers (home) and food preparers (HRI) are lacking" (p. 141) simply this does not necessarily foreclose modeling. The commission notes, for example, that most fast-food restaurants that cook patties from the frozen country would non encounter the wide variation in pretreatment storage conditions that was used in the draft to model cooking of ground beef and that variability in pretreatment storage conditions would more likely occur in ground beefiness cooked in homes.

Circumspection should be used in applying to the model the information of Jackson et al. (1996) regarding the mean reduction in E. coli O157:H7 in grilled ground-beef patties because some of their results (summarized in the draft's Tabular array 3-twenty) are counterintuitive. In that location are several observations where greater or equivalent Due east. coli O157:H7 populations were killed at 62.eight°C (145°F) than at 68.3°C (155°F). It is well established that the higher the temperature (to a higher place the maximal growth temperature), the greater the number of bacteria killed. Furthermore, pretreatment past freezing may increase the sensitivity of pathogens similar Eastward. coli O157:H7 to thermal inactivation. The Jackson et al. data contradict that: more E. coli O157:H7 were inactivated at equivalent cooking temperatures in patties previously held refrigerated at 3°C for nine hours than in patties held frozen at eighteen°C for eight days. The committee recommends that, until more than reliable data become available, D values ^three established for E. coli O157:H7 inactivation in ground beef be used to model the result of pretreatment storage conditions on rates of E. coli O157:H7 inactivation. The analysis should account for the varied fat content of basis beef used in the domicile, fast-nutrient restaurants, and other HRI environments.

Estimates of Amount of Raw Ground Beef Consumed Are Flawed

The draft model calculates that "cooking" does not yield any log reduction of Eastward. coli O157:H7 in iv–8% of basis beef servings. The explanation—described in a footnote (on p. 89)—is that the USDA's Continuing Survey of Food Intakes by Individuals (CSFII) information used every bit the sole reference reported that four people (three 25–64 years old and one less than 5 years old) consumed "raw" ground beef. For modeling purposes, the servings were considered to be a subset of servings that had no log reduction in Due east. coli O157:H7 during cooking (for case, grossly undercooked servings). That information is critical to understanding the rationale for the relatively loftier occurrence of no-log-reduction ground-beef servings. Because of the importance of log-reduction information for interpreting calculated estimates, the commission recommends that the cloth in the footnote be moved to the text afterwards the estimates that are presented as having no log reduction.

More important, uncomplicated extrapolation of data from the 1994–1996 and 1998 CSFII surveys for estimating the annual number of raw footing-beef servings is scientifically unfounded because of the minor number of observations bachelor in some subsets. Table 3-24 in the typhoon indicates that children 0–5 years old eat an estimated 522,315 servings of raw ground beef annually abroad from home simply none at dwelling house. That calculation is based on a unmarried observation, and confidence intervals are not included. The committee recommends that FSIS acknowledge that it lacks adequate information on the consumption of raw ground beef in the The states. Linear scaling of observations from one or a small number of individuals to the entire Us population is statistically inappropriate. The commission believes that in this circumstance expert judgment, with appropriate accounting for uncertainty, may be superior to using extant information and suggests that FSIS solicit such input in the brusque term. ⁴ For the longer term, the committee suggests that better data on raw-meat consumption be gathered and that research business relationship for the fact that some groups of individuals consume raw basis beef in traditional dishes or in keeping with cultural traditions. USDA'south Agronomical Marketing Service or manufacture sources may have boosted data bearing on this question.

Human Exposure to E. coli O157:H7 in Footing Beef Fails to Address Potentially Important Variables

The primary outputs of the FSIS draft Preparation Module are estimates of distributions that describe the prevalence of Eastward. coli O157:H7 in footing-beef servings prepared during the seasons in which Due east. coli O157:H7 is more than and less prevalent in cattle at slaughter. The Training Module relies solely on outputs of the Slaughter Module related to seasonal differences rather than using FSIS ground-beefiness sampling data. In addition, considering the major differences in handling of frozen footing beef and in cooking ground beefiness between fast-food restaurants and the abode, there may be substantial differences in distributions of E. coli O157:H7 in ground-beef servings, depending on the location where the meat is prepared, cooked, and consumed. The committee recommends that FSIS basis-beefiness sampling data be used to determine seasonal differences in E. coli O157:H7 contamination of ground beef and that inputs into the model be further differentiated on the basis of location of ground-beef preparation and consumption.

Insight into another potentially important variable is provided by the CSFII. The 1994–1996 data regarding ground-beef consumption, repro duced below in Table iv-1, suggests that both sexual practice and historic period are important in serving size. Age is factored in by the model, just sexual practice is not accounted for in the characterization of the quantity of ground-beef products consumed. The proceeds in precision from including sex is likely to be small compared with other elements for which data are weak or absent-minded. The commission suggests that the final chance assessment at least notation the possible role of sex for completeness and future reference.

Table 4-ane

Ground-beef quantity (g) consumed per eating occasion by age and sex (2-twenty-four hour period sample).

REFERENCES

• Audits International. 2001. Audits International 2000 Home Nutrient Safety Study.

• Buchanan RL, Doyle MP. 1997. Foodborne disease significance of Escherichia coli O157:H7 and other enterohemorrhagic Eastward. coli. Food Engineering science 51:69–75.

• CDC (Centers for Disease Command and Prevention). 1996. Outbreak of Escherichia coli O157:H7 infection Georgia and Tennessee June 1995. Morbidity and Mortality Weekly Study 45(12):249–251. [PubMed: 8965785]

• FDA (Food and Drug Administration). 2000. Written report of the FDA Retail Food Program Database of Foodborne Affliction Risk Factors. FDA Retail Food Program Steering Committee. August ten, 2000.

• Jackson, TC, Hardin Doctor, Acuff GR. 1996. Heat resistance of Escherichia coli O157:H7 in a nutrient medium and in ground beef patties equally influenced past storage and holding temperatures. Journal of Food Protection 59:230–237. [PubMed: 10463438]

• Kassenborg H, Hedberg C, Evans One thousand, Chin Chiliad, Fiorentino T, Vugia D, Bardsley M, Slutsker 50, Griffin P. 1998. Case-control study of desultory Escherichia coli O157:H7 infections in 5 FoodNet sites. Abstracts of the International Conference on Emerging Infectious Diseases, p. 50.

• Kennedy, MH, Rabatsky-Ehr T, Thomas SM, Lance-Parker Southward, Mohle-Boetani J, Smith One thousand, Keene W, Sparling P, Hardnett FP, Mead PS, and the EIP FoodNet Working Group. 2002. Risk factors for sporadic Escherichia coli O157 infections in the United States: A case-command study in FoodNet sites, 1999–2000. Abstracts of the International Conference on Emerging Infectious Diseases, p. 169.

• Mead PS, Finelli Fifty, Lambert-Fair MA, Gnaw D, Townes J, Hutwagner L, Barrett T, Spitalny K, Mintz E. 1997. Take chances factors for desultory infection with Escherichia coli O157:H7. Athenaeum of Internal Medicine 157(2):204–208. [PubMed: 9009977]

• Nauta MJ, Evers EG, Takumi M, Havelaar AH. 2001. Risk cess of Shiga-toxin producing Escherichia coli O157 in steak tartare in the Netherlands. Rijksinstituut voor Volksgezondheid en Milieu (RIVM). Written report 257851 003.

• Smiciklas-Wright H, Mitchell DC, Mickle SJ, Cook AJ, Goldman JD. 2002. Foods Normally Eaten in the U.s.: Quantities Consumed per Eating Occasion and in a Day, 1994– 1996. The states Department of Agriculture NFS Report No. 96-v, prepublication version. http://www​.barc.usda​.gov/bhnrc/foodsurvey/Products9496.html , accessed July 10, 2002.

• USDA (United states of america Section of Agriculture), Agronomical Research Service. 2000. Continuing Survey of Food Intakes by Individuals 1994–96, 1998. National Technical Information Service. CD-ROM. NTIS Accession no. PB2000-500027.

one

Critical violations are defined as weather or deportment that past themselves can cause foodborne disease.

2

Where "BAC" refers to leaner.

3

D (or decimal reduction) value is the amount of time in minutes required to reduce the number of organisms of a particular bacterium by xc% at a specified temperature. A 90% reduction—from x⁶ to ten⁵ colony-forming units, for example—is equivalent to a ane-log decrease.

iv

Faced with a like trouble in their hazard assessment of Shiga-producing E. coli O157 in steak tartare, Dutch researchers convened an expert solicitation workshop to gauge values for parameters for which no data were found (Nauta et al., 2001).

reedried1993.blogspot.com

Source: https://www.ncbi.nlm.nih.gov/books/NBK221093/

Share this post