Economic costs and trade impacts of microbial foodborne illness

This article presents the economic costs of foodborne diseases for selected countries, the approaches used to calculate these costs, and a discussion on the interaction between microbial food safety issues and international trade in food. The human illness costs due to foodborne pathogens are estimated most completely in the United States of America, where, each year, 7 foodborne pathogens (Campylobacter jejuni, Clostridium perfringens, Escherichia coli O157:H7. Listeria monocytogenes, Salmonella, Staphylococcus aureus, and Toxoplasma gondii) cause an estimated 3.3-12.3 million cases of foodborne illness and up to 3900 deaths. These 7 pathogens are found in animal products and cost the United States an estimated $6.5-$34.9 billion (1995 US$) annually. The presence of foodborne pathogens in a country's food supply not only affects the health of the local population, but also represents a potential for spread to pathogens to visitors to the country and to consumers in countries which import food products. With more complete data on foodborne illnesses, deaths, costs and international trade rejections in each country, indicators could be developed by which changes in food safety can be monitored.     

Foodborne illness in the elderly

The elderly (> or = 65 years of age) are more susceptible to morbidity and mortality from foodborne-induced gastroenteritis than younger individuals. Several factors contribute to the increased susceptibility to foodborne infections as well as other infections in elderly populations. These include an age-associated decrease in humoral and cellular immunity, age-related changes in the gastrointestinal tract (decreased production of gastric acid and decreased intestinal motility), malnutrition, lack of exercise, entry into nursing homes, and excessive use of antibiotics. Data from foodborne outbreaks associated with nursing homes indicate that the elderly are more likely to die from foodborne Campylobacter, Clostridium perfringens, Escherichia coli O157:H7, Salmonella, and Staphylococcus aureus infections than the general population. Infections by Salmonella species are the most common cause of illness and death in nursing homes with Salmonella enteritidis as the major cause of both morbidity and mortality. While it is impossible to turn back the clock, practicing a healthy life-style with regular exercise, maintaining a balanced diet, receiving regular health care, paying attention to personal hygiene, and monitoring food preparation and handling should lead to a reduced incidence of foodborne and other infections in the elderly.     

Quantitative risk assessment: an emerging tool for emerging foodborne pathogens

New challenges to the safety of the food supply require new strategies for evaluating and managing food safety risks. Changes in pathogens, food preparation, distribution, and consumption, and population immunity have the potential to adversely affect human health. Risk assessment offers a framework for predicting the impact of changes and trends on the provision of safe food. Risk assessment models facilitate the evaluation of active or passive changes in how foods are produced, processed, distributed, and consumed.     

Food poisoning. Causes, remedies, and prevention

Food producers and consumers must continue to take precautions against foodborne diseases, and early diagnosis and appropriate treatment of these illnesses are essential. Food products and water can become contaminated with microorganisms and toxins that make people ill, and the very young, the elderly, and immunocompromised individuals are especially susceptible. Education of healthcare providers, food handlers, and the public is critical in reducing the incidence and spread of foodborne illness. Changes in eating habits and lifestyle and increased availability of both domestic and imported foods have made food hazards a more complex public health issue. Although most foodborne illnesses can be avoided by safe food handling procedures (see box on page 134), risk reduction is very important at every step from source to table. A concerted effort is needed to ensure continuing safety of the food supply in the United States while also assuring access to a wide variety of healthful foods. Time will tell whether consumers will accept irradiation of meats. If accepted, irradiation could rank in importance with pasteurization of milk and chlorination of water as a public health measure.     

An outbreak of Salmonella mikawasima associated with doner kebabs

During October 1992 an increase in the number of isolates of Salmonella mikawasima, a rare serotype, was noted including a cluster of nine cases in the South West Thames region. A case control study was conducted and univariate analysis showed a statistical association between illness and eating at take-away A for cases compared with household controls (P = 0.003) and with neighbourhood controls (P = 0.0245). Cases were also more likely to have eaten kebabs than were controls or average take-away A customers, implicating doner kebabs as the most likely vehicle of infection. Plasmid profile analysis of the nine cases' isolates showed them to be indistinguishable and to be characterized by a single plasmid of approximately 60 MDa. The original source of the Salmonella mikawasima contamination was not determined, but food preparation practices for kebabs at take-away A were insufficient to protect against illness if contaminated. This outbreak was only recognized because of the unusual serotype, but could be an indication of a more widespread problem with doner kebabs.     

The regulation of progesterone and hCG production from placental cells by interleukin-1beta

Recent outbreaks of foodborne illness and studies by expert groups have established the need for fundamental change in the United States meat and poultry inspection programme to reduce the risk of foodborne illness. The Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA) has embarked on a broad effort to bring about such change, with particular emphasis on the reduction of pathogenic micro-organisms in raw meat and poultry products. The publication on 25 July 1996 of the Final Rule on pathogen reduction and hazard analysis and critical control point (HACCP) systems was a major milestone in the FSIS strategy for change. The Final Rule provides a framework for change and clarifies the respective roles of industry and government in ensuring the safety of meat and poultry products. With the implementation of this Final Rule underway, the FSIS has been exploring ways in which slaughter inspection carried out under an HACCP-based system can be changed so that food safety risks are addressed more adequately and the allocation of inspection resources is improved further. In addition, the FSIS is broadening the focus of food safety activities to extend beyond slaughter and processing plants by working with industry, academia and other government agencies. Such co-operation should lead to the development of measures to improve food safety before animals reach the slaughter plant and after products leave the inspected establishment for distribution to the retail level. For the future, the FSIS believes that quantitative risk assessments will be at the core of food safety activities. Risk assessments provide the most effective means of identifying how specific pathogens and other hazards may be encountered throughout the farm-to-table chain and of measuring the potential impact of various interventions. In addition, these assessments will be used in the development and evaluation of HACCP systems. The FSIS is currently conducting a quantitative risk assessment for eggs, and several surveys and studies are being performed to supply data needed to conduct other risk assessments. The FSIS has established a food safety research agenda which will fill data gaps.     

Psychological stress, occurrence of cancer and cause-specific mortality]

Psychological stress has been claimed to contribute to the onset of cancer and to increase mortality from a number of nonmalignant diseases. We investigated the effect of a genuine psychological stressor, i.e. cancer in a child, on the incidence of cancer and mortality from nonmalignant diseases of 11,231 parents in a Danish nationwide population-based study. The children were identified from records in the Danish Cancer Registry for the period 1943-1985; their parents were identified from population registers. Overall, 1665 parental malignancies were diagnosed from the date the cancer of the child was reported through 1992, as compared with 1702 expected from national incidence rates, to yield standardized incidence ratios of 1.0 (95% confidence interval, 0.9-1.0) for all parents, 1.0 for mothers and 1.0 for fathers. No excess mortality was seen from causes associated with allergic illness, autoimmune conditions, chronic illness or changes in behaviour. Our data provide no support for the hypothesis of an association between psychological stress and the incidence of cancer or mortality from nonmalignant diseases. We conclude that the human organism is highly adaptable, even to extreme psychological stress.     

Sensitive populations: who is at the greatest risk?

The purpose of this article was to review the existing literature to define those groups of individuals who would be at the greatest risk of serious illness and mortality from water and foodborne enteric microorganisms. This group was found to include the very young, the elderly, pregnant women, and the immunocompromised. This segment of the population currently represents almost 20% of the population in the United States and is expected to increase significantly by the beginning of the next century, because of increases in life-span and the number of immunocompromised individuals. More than half of documented deaths from gastroenteritis and hepatitis A illness occur in the elderly in developed countries. The overall case fatality ratio for foodborne bacterial gastroenteritis outbreaks in nursing homes is 10 times greater than the general population. Pregnant mothers suffer from a case fatality ratio from hepatitis E infections ten times greater than the general population during waterborne disease outbreaks. Enteric diseases are most common and devastating among the immunocompromised. Cryptosporidium is a serious problem among patients with acquired immuno-deficiency syndrome (AIDS). Cancer patients undergoing chemotherapy and transplant patients, are also at significantly greater risk of dying from enteric viral infections than the general population. This review indicates the need for consideration of enhanced protection for certain segments of the population who will suffer the most from food and waterborne pathogens.     

Strain differences in histopathologic, hematologic, and blood chemistry changes induced in mice by a technical and a purified preparation of 2,4,5-trichlorphenoxyacetic acid

Including controls, 978 mice were studied. On days corresponding to days 6 through 14 of pregnancy, groups of pregnant and nonpregnant CD-1 mice and male and nonpregnant female dihybrid cross F2 mice received by gavage 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) ranging in dosage from 30 to 140 mg/kg. Some groups received a technical preparation containing 97.9 +/- 0.4% 2,4,5-T and some a purified preparation containing 99 +/- 0.3% 2,4,5-T. Mice were sacrificed when they became moribund and at 1, 2, 4, 6, 8, and 11 days after beginning treatment. Sick or moribund mice sacrificed after 2-9 doses of 2,4,5-T often showed severe myocardial lesions, hypocellularlity of the bone marrow, and depletion of lymphocytes in the thymus, spleen or lymph nodes. They also showed marked hematologic and blood chemistry changes. Treated mice remaining healthy showed few or no lesions or blood chemistry changes, but often developed a mild anemia attributable to a hemolytic effect of 2,4,5-T. The incidence of animals becoming moribund was less than 1% in the CD-1 mice, including those given 140 mg/kg, and 53-82% in groups of male and female F2 mice receiving 120 mg/kg 2,4,5-T. The incidence of moribund mice tended to be higher in male than in female F2 mice and in those given the purified compound. These findings indicate that impairment of maternal health by severe lesions early in gestation is not the primary cause of an increase in incidence of fetal abnormalities observed in mice given 2,4,5-t. they also indicate that the lesions are due primarily to 2,4,5-T, rather than contaminants in the technical preparation, and illustrate the importance of using more than one strain of mouse in a toxicologic or teratologic study.     

Treatment of hyperthyroidism with radioactive iodine

Treatment of hyperthyroidism with RAI has been performed for more than a half century with efficacy and safety. For its optimal use, the physician must employ appropriate patient selection criteria and clinical judgment concerning pretreatment patient preparation. The dose of the 131I needed remains an area of uncertainty and debate; thus far, it has not been possible to resolve the trade-off between efficient definitive cure of hyperthyroidism and the high incidence of post-therapy hypothyroidism. Early side effects are uncommon and readily manageable. Other than the need for long-term monitoring and, in most cases, lifelong L-T4 treatment, late adverse consequences of this treatment remain only conjectural. The available follow-up studies support the current majority opinion of North American thyroid specialists that RAI treatment is an excellent choice for most hyperthyroid patients.     

Prevalence and follow-up of psychiatric diseases in internal medicine departments

While several surveys have shown that psychiatric disorders are common in non-psychiatric hospital departments, information on the course of psychiatric morbidity during the hospital stay is still lacking. Therefore, in two medical hospital departments in Austria we investigated the course of illness in 265 patients staying in the hospital for more than four weeks. Patients were interviewed using the Clinical Interview Schedule. At admission, prevalence of all psychiatric disorders was 46.0%. During the four weeks after admission, mentally well were discharged from hospital more frequently than mentally ill. Among those staying in the hospital after four weeks, prevalence was 51.4%. In the intervening period, the incidence (9.5%) was slightly lower than the rate of remission (12.4%). At both assessments, organic mental illness was the most frequent diagnosis followed by neurotic and adjustment disorders. Thus, in spite of the slightly higher rate of remission than incidence, the overall psychiatric prevalence increased during the first four weeks after admission because of the earlier discharges of the mentally well. In conclusion, our results show that point-prevalence surveys not regarding disease course give an incomplete impression of psychiatric morbidity in non-psychiatric hospital departments.     

Epidemiology and control of egg-associated Salmonella enteritidis in the United States of America

The isolation rate for Salmonella enterica serotype Enteritidis (SE) in humans in the United States of America (USA) increased from 1,207 sporadic isolates identified in 1976 (0.6 isolates/100,000 population) to 10,201 identified in 1995 (4.0/100,000 population). The proportion of reported Salmonella isolates which were SE increased from 5% to 25% during the same time period. In 1990, 1994, and 1995, SE was the most commonly reported reported Salmonella serotype in the USA. Much of this increase has been associated with the consumption of contaminated shell eggs. An examination of the results of a United States Department of Agriculture (USDA) survey of spent hens at slaughter and unpasteurised liquid egg at breaker plants (liquid egg processors) in 1991 and 1995 reveals an increase in the prevalence of SE isolates overall and in most regions of the USA. SE phage type 4 (pt 4), the predominant SE phage type in other parts of the world, has emerged in the egg industry in the western USA concurrent with a sharp increase in the number of sporadic human SE pt 4 isolates in California and Utah. Research on the molecular structure and virulence of SE pt 4 isolates from the USA as compared with isolates from other parts of the world (human and poultry) should be a priority. A comparison of DNA from pt 4 isolates from the USA and Europe may provide information about the potential threat to public health and poultry in the USA from this phage type. Some regional success in the reduction of human illness as a result of SE control efforts is apparent. The Pennsylvania Egg Quality Assurance Program has shown progress in reducing SE infection in participating flocks. At a national level, however, neither the incidence of human illness due to SE nor the prevalence of SE in flocks and unpasteurised liquid eggs have decreased significantly, despite the implementation of the USDA 'trace back' regulation from 1990 to 1995, and intensified efforts to educate food handlers and to enforce safe food handling practices. More effort is needed to control SE at every stage of the egg continuum, from production through to consumption. A risk-reduction approach, with barriers to the introduction and multiplication of the pathogen throughout the farm-to-table continuum, is the most practical method for reducing human illness from SE in shell eggs at present. An effective long-term solution will require interdisciplinary efforts involving government, industry, consumers, and academics. Interventions should be developed and evaluated in compliance with the potential for reducing the risk to human health and cost-effectiveness.     

Ontogeny of glycoprotein gB-specific antibody and neutralizing activity during natural cytomegalovirus infection

Food allergy is a group of distinct clinico-pathological entities that have an immunological basis in common, and in which an abnormal or exaggerated immunological response to a specific food leads to disease. Some clinical pictures involving multiple organ system (anaphylaxis) are potentially fatal. The data on the incidence, prevalence, mortality rate and food products involved in food-induced anaphylaxis and the evolution of food sensitization compared with changes in eating habits are not very reliable. In the present study we analysed, over a period of 9 years (1984-1992), a group of 580 patients with pathological reactions to foods, 60 of which presented severe, near-fatal reactions. We sought the etiologic components and food sensitization in comparison with the principal tendencies of food consumption in France. Food products most frequently incriminated in anaphylactic reactions are not of a primary nutritional importance: celery (30%), crustaceans (17%), fish (13%), peanuts (12%), mango (6%), mustard (3%), but they are often hidden allergens in commercial foods. The sensitization to food products in the group of 580 patients reveals, in decreasing order of frequency: wheat (39%), peanuts (37%), crab (34%), celery (30%), soy (30%). Compared with previous data, the frequency of sensitization to different foods has changed; for instance, the sensitizations to wheat, soy, peanuts, celery, mustard, rice, are definitely increasing. The increased consumption and more attentive clinical research may be the reasons for this evolution. For products such as egg and pork, the data are stable and parallel with consumption, whilst for other products like milk and other dairy products, the increased consumption is accompanied by a decrease of the incidence of sensitization. The reactivity to some allergens may be affected by the way of preparing the food.     

Food-borne streptococcal epidemics

Approximately two days after a high school final year farewell party a striking number of pupils and teachers became ill with pharyngitis. The regional public health medical office carried out a questionnaire study with a control group of younger pupils. The regional food control unit studied the preparation and handling at food. Some bacterial cultures received from general practitioners were identified by the regional clinical-microbiological laboratory. Seventy-six percent of the 216 exposed pupils who answered (94% response rate) against 15% of 238 answering in the control group (83% response rate) became ill. The peak incidence was two days after the party. The infectious agent was beta-haemolytic streptoccoci group-A, T-type 25. A salad made of pasta and vegetables that were not cooked and handled properly must have been the vehicle of infection although no salad was left for cultivation. Salads made of pasta must be prepared with great care and effectively cooled. When suspecting a food-borne epidemic, clinicians should immediately inform the regional public health medical office, and the municipal food control unit must take part in the investigations. It is important that bacterial cultures are identified by the regional clinical-microbiological laboratory. It should be considered to make it mandatory that the involved personnel accepts clinical examination and microbiological sampling in cases of suspected food-borne infection.     

Under-reporting of work-related disorders in the workplace: a case study and review of the literature

Accurate reporting of work-related conditions is necessary to monitor workplace health and safety, and to identify the interventions that are most needed. Reporting systems may be designed primarily for external agencies (OSHA or workers' compensation) or for the employer's own use. Under-reporting of workplace injuries and illnesses is common due to a variety of causes and influences. Based on previous reports, the authors were especially interested in the role of safety incentive programmes on under-reporting. Safety incentive programmes typically reward supervisors and employees for reducing workplace injury rates, and thus may unintentionally inhibit proper reporting. The authors describe a case study of several industrial facilities in order to illustrate the extent of under-reporting and the reasons for its occurrence. A questionnaire and interview survey was administered to 110 workers performing similar tasks and several managers, health, and safety personnel at each of three industrial facilities. Although less than 5% of workers had officially reported a work-related injury or illness during the past year, over 85% experienced work-related symptoms, 50% had persistent work-related problems, and 30% reported either lost time from work or work restrictions because of their ailment. Workers described several reasons for not reporting their injuries, including fear of reprisal, a belief that pain was an ordinary consequence of work activity or ageing, lack of management responsiveness after prior reports, and a desire not to lose their usual job. Interviews with management representatives revealed administrative and other barriers to reporting, stemming from their desire to attain a goal of no reported injuries, and misconceptions about requirements for recordability. The corporate and facility safety incentives appeared to have an indirect, but significant negative influence on the proper reporting of workplace injuries by workers. A variety of influences may contribute to under-reporting; because of under-reporting, worker surveys and symptom reports may provide more valuable and timely information on risks than recordable injury logs. Safety incentive programmes should be carefully designed to ensure that they provide a stimulus for safety-related changes, and to discourage under-reporting. A case-control study of similar establishments, or data before and after instituting safety incentives, would be required to more clearly establish the role of these programmes in under-reporting.     

The frequency of unsuspected minor illness or injury in intoxicated patients

OBJECTIVE: To determine the frequency of unsuspected minor illness or injury in a group of patients frequently seen in the ED for acute intoxication. METHODS: The medical records of the 20 patients seen most frequently in the ED for acute intoxication in 1993 were reviewed for the number of ED visits for intoxication, the number of associated documented episodes of minor trauma or illness, the extent of ED workup of discovered illness or injury, and patient disposition from the ED. RESULTS: The 20 study patients were evaluated in the ED 1,858 times in 1993 for acute intoxication, a mean of 92.5 visits/patient (+/- 26.6). The most frequent injury was minor trauma above the neck, occurring a mean of 9 times (+/- 3.6) in each of the study patients during 1993. Evaluation included repeated neurologic examinations and frequent radiography of the cervical spine (n = 80), skull (n = 5), facial bones (n = 6), and mandible (n = 5). A limited number of head CT scans also were done (n = 8). The most frequent minor illnesses were gastritis (n = 7), managed with hydration, and mild hypothermia (n = 6), managed with passive rewarming. CONCLUSIONS: The incidence of unsuspected minor illness or injury in this patient group was substantial. While most unsuspected medical problems had little clinical significance, some were potentially dangerous, and some necessitated hospitalization (e.g., hypothermia, hematemesis, and respiratory depression).     

Pup cannibalism: One aspect of maternal behavior in golden hamsters.

In 5 experiments with a total of 157 golden hamsters (Mesocricetus auratus), examination of the role of 6 factors (e.g., extreme litter size, illness of pups, and lack of maternal experience) generally held to affect incidence of litter cannibalism in the golden hamster revealed little influence of any of them on frequency of pup destruction. More than 75% of mothers in all conditions examined cannibalized a portion of their litters during the 1st few days postpartum. Termination of cannibalism was found to result both from reduction in litter size, consequent upon destruction of young, and from changes in the internal state of the mother following parturition. The outcome of additional studies indicated that mothers maintain litter size at an individually determined value, behaviorally compensating for experimental alterations in pup number. Results are interpreted as indicating that pup cannibalism in hamsters is an organized part of normal maternal behavior which allows an individual female to adjust her litter size in accord with her capacity to rear young in the environmental conditions prevailing at the time of her parturition. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Safety evaluation of amino peptidase enzyme preparation derived from Aspergillus niger

An amino peptidase enzyme preparation obtained from Aspergillus niger was subjected to a series of toxicological tests to document the safety for use as a processing aid for food. The enzyme preparation was examined for subacute and subchronic oral toxicity, and mutagenic potential. No evidence of oral toxicity or mutagenicity was found. Administration of the amino peptidase enzyme preparation at doses of 500, 1000 and 2000 mg/kg body weight/day for 90 days did not induce noticeable signs of toxicity. The no-observed-adverse-effect level (NOAEL) of the enzyme preparation in the subchronic toxicity study was 2000mg/kg body weight/day (equivalent to 1152 PHEA units/kg body weight/day). It can be concluded that no safety concerns were identified in the studies conducted with this amino peptidase enzyme preparation derived from Aspergillus niger and produced under controlled fermentation conditions.     

Quantitative risk assessment for Escherichia coli O157:H7 in ground beef hamburgers

Quantitative Risk Assessment (QRA) is a methodology used to organize and analyze scientific information to estimate the probability and severity of an adverse event. Applied to microbial food safety, the methodology can also help to identify those stages in the manufacture, distribution, handling, and consumption of foods that contribute to an increased risk of foodborne illness, and help focus resources and efforts to most effectively reduce the risk of foodborne pathogens. The term Process Risk Model (PRM) is introduced in this paper to describe the integration and application of QRA methodology with scenario analysis and predictive microbiology to provide an objective assessment of the hygienic characteristics of a manufacturing process. The methodology was applied to model the human health risk associated with Escherichia coli O157:H7 in ground beef hamburgers. The PRM incorporated two mathematical submodels; the first was intended to described the behaviour of the pathogen from the production of the food through processing, handling, and consumption to predict human exposure. The exposure estimate was then used as input to a dose-response model to estimate the health risk associated with consuming food from the process. Monte Carlo simulation was used to assess the effect of the uncertainty and variability in the model parameters on the predicted human health risk. The model predicted a probability of Hemolytic Uremic Syndrome of 3.7 x 10(-6) and a probability of mortality of 1.9 x 10(-7) per meal for the very young. These estimates are likely high for all hamburger meals, but may be reasonable for the home-prepared hamburgers described by this model. The efficacy of three risk mitigation strategies were evaluated by modifying the values of the predictive factors and comparing the new predicted risk. The average probability of illness was predicted to be reduced by 80% under a hypothetical mitigation strategy directed at reducing microbial growth during retail storage through a reduction in storage temperature. This strategy was predicted to be more effective than a hypothetical intervention which estimated a plausible reduction in the concentration of E. coli O157:H7 in the feces of cattle shedding the pathogen and one aimed at convincing consumers to cook hamburgers more thoroughly. The conclusions of this approach are only accurate to the extent that the model accurately represents the process. Currently, uncertainty and ignorance about the hygienic effects of the individual operations during production, processing, and handling limit the applicability of a PRM to specify HACCP criteria in a quantitative manner. However, with continuous improvement through stimulated research, a PRM should encompass all available information about the process, food, and pathogen and should be the most appropriate decision-support tool since it represents current knowledge.