Economic impact of a nationwide outbreak of salmonellosis: cost-benefit of early intervention

The economic burden of a Salmonella Thompson outbreak caused by smoked salmon in the Netherlands, 2012-2013

Background

In 2012, the Netherlands experienced the most extensive food-related outbreak of Salmonella ever recorded. It was caused by smoked salmon contaminated with Salmonella Thompson during processing. In total, 1149 cases of salmonellosis were laboratory confirmed and reported to RIVM. Twenty percent of cases was hospitalised and four cases were reported to be fatal. The purpose of this study was to estimate total costs of the Salmonella Thompson outbreak.

Methods

Data from a case-control study were used to estimate the cost-of-illness of reported cases (i.e. healthcare costs, patient costs and production losses). Outbreak control costs were estimated based on interviews with staff from health authorities. Using the Dutch foodborne disease burden and cost-of-illness model, we estimated the number of underestimated cases and the associated cost-of-illness.

Results

The estimated number of cases, including reported and underestimated cases was 21 123. Adjusted for underestimation, the total cost-of-illness would be €6.8 million (95% CI €2.5-€16.7 million) with productivity losses being the main cost driver. Adding outbreak control costs, the total outbreak costs are estimated at €7.5 million.

Conclusion

In the Netherlands, measures are taken to reduce salmonella concentrations in food, but detection of contamination during food processing remains difficult. As shown, Salmonella outbreaks have the potential for a relatively high disease and economic burden for society. Early warning and close cooperation between the industry, health authorities and laboratories is essential for rapid detection, control of outbreaks, and to reduce disease and economic burden.

Economic Cost of a Listeria monocytogenes Outbreak in Canada, 2008

Estimates of the economic costs associated with foodborne disease are important to inform public health decision-making. In 2008, 57 cases of listeriosis and 24 deaths in Canada were linked to contaminated delicatessen meat from one meat processing plant. Costs associated with the cases (including medical costs, nonmedical costs, and productivity losses) and those incurred by the implicated plant and federal agencies responding to the outbreak were estimated to be nearly $242 million Canadian dollars (CAD, 2008). Case costs alone were estimated at approximately $2.8 million (CAD, 2008) including loss of life. This demonstrates the considerable economic burden at both the individual and population levels associated with foodborne disease and foodborne outbreaks in particular. Foodborne outbreaks due to severe pathogens, such as Listeria monocytogenes and those that result in product recalls, are typically the most costly from the individual and/or societal perspective. Additional economic estimates of foodborne disease would contribute to our understanding of the burden of foodborne disease in Canada and would support the need for ongoing prevention and control activities.

Economic evidence on the health impacts of climate change in europe

BACKGROUND

In responding to the health impacts of climate change, economic evidence and tools inform decision makers of the efficiency of alternative health policies and interventions. In a time when sweeping budget cuts are affecting all tiers of government, economic evidence on health protection from climate change spending enables comparison with other public spending.

METHODS

The review included 53 countries of the World Health Organization (WHO) European Region. Literature was obtained using a Medline and Internet search of key terms in published reports and peer-reviewed literature, and from institutions working on health and climate change. Articles were included if they provided economic estimation of the health impacts of climate change or adaptation measures to protect health from climate change in the WHO European Region. Economic studies are classified under health impact cost, health adaptation cost, and health economic evaluation (comparing both costs and impacts).

RESULTS

A total of 40 relevant studies from Europe were identified, covering the health damage or adaptation costs related to the health effects of climate change and response measures to climate-sensitive diseases. No economic evaluation studies were identified of response measures specific to the impacts of climate change. Existing studies vary in terms of the economic outcomes measured and the methods for evaluation of health benefits. The lack of robust health impact data underlying economic studies significantly affects the availability and precision of economic studies.

CONCLUSIONS

Economic evidence in European countries on the costs of and response to climate-sensitive diseases is extremely limited and fragmented. Further studies are urgently needed that examine health impacts and the costs and efficiency of alternative responses to climate-sensitive health conditions, in particular extreme weather events (other than heat) and potential emerging diseases and other conditions threatening Europe.

Costs of two alternative Salmonella control policies in Finnish broiler production

Background

Costs and benefits of two Salmonella control policies for broiler production were described and compared. The control options were the Zoonosis Directive 92/117/EC and the more intense strategy, the Finnish Salmonella Control Programme (FSCP).

Methods

The comparison included the Salmonella control costs in primary and secondary production and the direct and indirect losses due to Salmonella infections in humans in 2000.

Results

The total annual costs of the FSCP were calculated to be 990 400 EUR (0.02 €/kg broiler meat). The average control costs in the broiler production chain were seven times higher with the FSCP than with the Zoonosis Directive alone. However, the public health costs were 33 times higher with the Zoonosis Directive alone. The value of one prevented loss of life per year exceeded the annual control costs of the FSCP.

Conclusion

Due to significant savings in public health costs compared to costs of FSCP, the FSCP was found to be economically feasible.

Ability of Shiga toxin-producing Escherichia coli and Salmonella spp. to survive in a desiccation model system and in dry foods

In order to determine desiccation tolerances of bacterial strains, the survival of 58 diarrheagenic strains (18 salmonellae, 35 Shiga toxin-producing Escherichia coli [STEC], and 5 shigellae) and of 15 nonpathogenic E. coli strains was determined after drying at 35 degrees C for 24 h in paper disks. At an inoculum level of 10(7) CFU/disk, most of the salmonellae (14/18) and the STEC strains (31/35) survived with a population of 10(3) to 10(4) CFU/disk, whereas all of the shigellae (5/5) and the majority of the nonpathogenic E. coli strains (9/15) did not survive (the population was decreased to less than the detection limit of 10(2) CFU/disk). After 22 to 24 months of subsequent storage at 4 degrees C, all of the selected salmonellae (4/4) and most of the selected STEC strains (12/15) survived, keeping the original populations (10(3) to 10(4) CFU/disk). In contrast to the case for storage at 4 degrees C, all of 15 selected strains (5 strains each of Salmonella spp., STEC O157, and STEC O26) died after 35 to 70 days of storage at 25 degrees C and 35 degrees C. The survival rates of all of these 15 strains in paper disks after the 24 h of drying were substantially increased (10 to 79 times) by the presence of sucrose (12% to 36%). All of these 15 desiccated strains in paper disks survived after exposure to 70 degrees C for 5 h. The populations of these 15 strains inoculated in dried foods containing sucrose and/or fat (e.g., chocolate) were 100 times higher than those in the dried paper disks after drying for 24 h at 25 degrees C.

An insidious nosocomial outbreak due to Salmonella enteritidis

OBJECTIVES

To investigate an increase in the number of Salmonella enteritidis isolates detected in a large hospital to ascertain whether it was due to a nosocomial source, to identify the mechanisms of transmission, and to institute effective control measures to prevent future episodes.

DESIGN

Observational study, survey of all microbiological samples positive for S. enteritidis detected in the hospital, outbreak investigation, and review of the literature.

SETTING

A tertiary-care teaching hospital for adults in Barcelona, Spain.

RESULTS

During a 7-month period from May to November 1998, we identified 22 inpatients with S. enteritidis infection for whom nosocomial acquisition was strongly suspected. The attack rate was 0.138 per 1,000 patient-days. All affected patients were immunosuppressed and overall mortality was 41% (9 of 22). A sample of a meal cooked in the kitchen was culture positive for S. enteritidis. All isolates shared the same antibiotic susceptibility pattern and all except one shared the same pulsed-field gel electrophoresis (PFGE) pattern, but PFGE could not differentiate between outbreak-related and control strains. After compliance with kitchen hygiene procedures was emphasized and cleansing was intensified, no more cases were detected.

CONCLUSIONS

Apparently, sporadic cases of S. enteritidis may be part of an outbreak with a low attack rate. A small but persistent inoculum affecting only individuals with special predisposition for Salmonella infection might account for this. Suspicion should be raised in hospitals and institutions with a highly susceptible population.

Economic impact of an Escherichia coli O157:H7 outbreak in Japan

We estimated the economic impact of an outbreak of foodborne diseases occurring from elementary school lunches in 1996 in which 268 persons in Iwate prefecture, Japan were infected with Escherichia coli O157:H7. This study assessed the impact of direct economic losses and indirect economic consequences due to this outbreak. The economic impact of the outbreak was estimated to be about 82,686,000 yen. The laboratory costs, about 21,204,000 yen, showed the highest ratio of the total cost of this outbreak (about 26%). Also, the cost of foodstuffs that were not purchased during the suspension of the lunch service (about 19%), personnel expenses paid to lunch service employees (about 17%), human illness costs (about 15%), and the repair costs of facilities (about 15%) showed up as a high ratio in the total cost, respectively. Because all patients were children, the productivity losses estimated were low as children were considered as dependants with no income. Instead, we estimated the lost income of the mothers of the children. The source of the contamination could not be identified. Therefore, no food industries suffered any setbacks where certain food items could not be used for daily consumption due to the outbreak.

Communicable disease and infection control: the surveillance contribution

In its much-publicized report (2000) the National Audit Office (NAO) has emphasized the important part surveillance plays in determining infection rates and infection control in general. Community nurses may be forgiven for pointing out that this report concentrates on hospitals, however it strongly recommends that surveillance be extended out into the community. This is a sensible move as studies quoted in the NAO report indicate that 50-70% of surgical wound infection occur during the post-discharge period. The boundaries between acute and primary care are becoming ever more blurred; increasing numbers of susceptible patients are being managed in the community and the number of invasive procedures carried out is rising in line with government policy. Action to control infection extends beyond the narrow boundaries of health care to involve the whole population, and although the idea of extending the surveillance of healthcare related infection from hospital to community settings appears to be relatively new, the surveillance of infectious diseases that occur in the community is not. It is, in effect, a key proactive infection control activity which facilitates targeted and effective infection control measures. This article aims to define and explain surveillance as it relates to infection control and communicable disease control in the community by using examples from history, the current Meningitis C vaccination programme and the surveillance of hospital-acquired infection in the USA.

Direct costs associated with a nosocomial outbreak of Salmonella infection: an ounce of prevention is worth a pound of cure

BACKGROUND

Nosocomial outbreaks of Salmonella infections in Australia are an infrequent but significant source of morbidity and mortality. Such an outbreak results in direct, measurable expenses for acute care management, as well as numerous indirect (and less quantifiable) costs to those affected, the hospital, and the wider community. This article describes the significant direct costs incurred as a result of a nosocomial outbreak of Salmonella infection involving patients and staff.

METHOD

Information on costs incurred by the hospital was gathered from a number of sources. The data were grouped into 4 sections (medical costs, investigative costs, lost productivity costs, and miscellaneous) with use of an existing tool for calculating the economic impact of foodborne illness.

RESULTS

The outbreak cost the hospital more than AU $120, 000. (US $95,000). This amount is independent of more substantial indirect costs.

CONCLUSION

Salmonella infections are preventable. Measures to aid the prevention of costly outbreaks of nosocomial salmonellosis, although available, require an investment of both time and money. We suggest that dedication of limited resources toward such preventive strategies as education is a practical and cost-effective option for health care facilities.

Incompleteness of statutory notification of bacterial gastro-intestinal infection

A study was made of all potentially statutorily notifiable bacterial infections diagnosed in faecal samples submitted from symptomatic patients to a single microbiology laboratory during a six-month period. Salmonella spp, Campylobacter spp or Shigella spp were isolated from 167 patients and 51% of these were formally notified (54% of general practice patients and 47% of hospital patients). Forty-seven percent of cases of food-poisoning (Salmonella spp. and Campylobacter spp) were notified as were 70% of cases of shigella infections. Notification was made on average 9.4d after sending a specimen to the laboratory. A questionnaire used to ascertain the reasons for non-notification in 80 of 85 cases elicited replies in respect of 78 patients. Four patients infected with Salmonella spp or Campylobacter spp were said not to have been suffering from food-poisoning. A variety of reasons was given for failing to notify the others, the most common were forgetfulness, not receiving the result of the specimen, or believing someone else had made the notification.

Salmonella virchow PT 26 infection in England and Wales: a case control study investigating an increase in cases during 1994

An increase in the number of human isolates of Salmonella virchow phage type (PT) 26 in England and Wales during 1994 was investigated. A national case control study was conducted which included 88 cases and 182 controls. The cases were mostly young adults (median age 26) and 13 (15%) were admitted to hospital. Acquisition of S. virchow PT 26 was associated with the consumption of any chicken (OR 2.5, CI 1.1-5.8), of chicken curry from restaurants and take aways (OR 2.9, CI 1.4-6.1), and of some other diverse types of pre-prepared chicken (OR 3.8, CI 1.9-7.6). Halal chicken was associated (P = 0.006) with illness in a subset. There were negative associations with contact with animals (OR 0.47, CI 0.23-0.95) and with the consumption of chicken cooked whole (OR 0.37, CI 0.21-0.66). The increase in S. virchow PT 26 may be due to changing epizoology and may be an indicator of what will become the dominant salmonella strain in poultry in future years. The increasing incidence of S. virchow PT 26 is of particular concern because of its association with more invasive disease in humans.

Estimating the economic benefits of avoiding food-borne risk: is 'willingness to pay' feasible?

In this paper, the results of a pilot study of willingness to pay (WTP) to avoid poultry-borne illness are reported. Through this, the problems of devising an economic measure of the 'intangible' benefits of prevention of food-borne risk are explored. The study is the first to allow those against a prevention policy (irradiation of poultry-meat) to register their WTP not to have the policy implemented. The study demonstrates that it is feasible to obtain answers to WTP questions from a self-selected sample. Future studies should ensure greater representativeness of respondents, that better information about benefits is provided to respondents and that an appropriate method of aggregation of benefits is used.

Climate change and the incidence of food poisoning in England and Wales

In recent years there have been several spells of high temperatures providing analogues for the conditions that might become more common as a result of the enhanced greenhouse effect. Statistical models were developed of the relationship between the monthly incidence of food poisoning and temperatures and these were then used to provide estimates of the possible effects of future warmer summers. Routinely collected data on the number of reported cases of food poisoning were analysed for the years 1982-1991. Regression analysis was used to establish the relationship between the monthly of food poisoning and temperatures of the same and the previous month. Published scenarios for future temperatures were applied to these statistical models to provide estimates of the possible impacts of warmer conditions. The monthly incidence of food poisoning was found to be significantly associated with the temperature of the same and of the previous month with the latter having the stronger effect. Using published data on the relationship between reported and actual numbers of cases of food poisoning, it is estimated that annually there might be an additional 179 000 cases of food poisoning by the year 2050 as a result of climate change. The observed relationship with the same month's temperature underlies the need for improvements in storage, preparation and hygiene close to the point of consumption. However, there was a much stronger relationship with the temperature of the previous month, indicating the importance of conditions earlier in the food production process. Improvements in areas such as animal husbandry and slaughtering may also be necessary to avoid the adverse effects of a warmer climate.

HACCP implementation in food businesses: the need for a flexible approach

There is a considerable literature on microbiological hazards which cause food-borne diseases and illnesses, and factors which influence their occurrence and growth in foods. Similarly, stages in the food chain where foods may be mishandled, and practices which often lead to outbreaks of food-borne diseases are well documented. Although these hazards and practices can be controlled in order to prevent or minimise risks to health, food-borne diseases have continued to present a serious challenge to public health. Because the traditional approaches of inspection and end-product testing have proved inadequate in tackling the problem of food-borne diseases, there is an urgent need to apply more rational and effective strategies. One such strategy is the Hazard Analysis, Critical Control Points (HACCP) system which is currently in international discussion. This paper examines the epidemiological basis for the application of HACCP to food safety control and describes its advantages. It is concluded that to realise the objectives of HACCP, a flexible and simple approach is needed in its practical application across food businesses. Any argument that the system cannot be applied without fully developed and well structured food systems will ultimately reduce its potential usefulness in food safety control.

The socio-economic impact of human Salmonella enteritidis infection

Recent government and public concern about the recorded increase in human salmonellosis in the UK and abroad has stimulated investigations of both the causes and consequences of these infections. This paper discusses the framework for economic analysis of food-borne disease and problems associated with the estimation of costs. A brief review of the literature in this area is given and the results of a national study of the costs of human salmonellosis in England and Wales are presented and used to estimate the likely costs of S. enteritidis infection.

The cost of infection in surgical patients: a case-control study

To determine the excess hospital cost attributable to hospital acquired infection in a UK hospital 67 surgical patients with hospital acquired infection (HAI) were matched with uninfected controls on the primary features of the first operative procedure and primary diagnosis, and on the secondary features of sex, age and surgical service. Costs were calculated from the hospital's unit costs for pathology, radiology and for the cost of one day's extra stay. The mean cost of one day of antibiotic therapy was also measured. In infected patients there was a significant increase in the length of hospital stay of 8.2 days with a mean extra cost per patient of 1041 pounds (P < 0.001). Microbiology, haematology, chemical pathology and radiology requests were all significantly increased with a mean extra cost per infected patient of 10.4 pounds, 7.8 pounds, 96. pounds, and 3.3 pounds, respectively. Antibiotic therapy contributed significantly to the extra costs (44 pounds per infected patient). The mean extra cost per patient was highest in orthopaedic patients (2646 pounds) and least in gynaecology patients (404 pounds). For the infections with significantly increased cost, multiple infections carried the greatest (3362 pounds), and urinary tract infections the least (467 pounds) cost. Hospital length of stay was the greatest contributor to the cost and accounted for 95% of the extra cost in orthopaedics, 94% in gynaecology and 92% in general surgery and urology. Antibiotic therapy was the second most significant contributor to cost and, with the exception of urinary tract infection and infections in gynaecology, was at least five times more per patient than requests for microbiology, haematology, chemical pathology or radiology.

Costs to affected individuals following an outbreak of food poisoning: a pilot study

This small pilot study surveyed the victims of an outbreak of food poisoning, in order to investigate the personal consequences which they suffered so as to identify costs, which are often ignored in economic analyses. A response rate of 88% was achieved. The results showed that an average of 10.5 days of illness was suffered by the affected individuals and there was a marked variation in the number of days of work missed. Housewives were identified as a group whose personal consequences are often omitted from economic studies and a variety of other costs were identified. The results should be borne in mind when undertaking future economic studies of food poisoning.

Tempting fate: control of communicable disease in England

Recent changes in the NHS have left many defects in the systems for the control of communicable diseases and infection and their surveillance and the management of outbreaks. Clear, explicit legislation is needed, placing the responsibilities on health authorities. New teams led by consultants need to be set up to investigate and manage outbreaks of communicable diseases of all types.

A large outbreak of human salmonellosis traced to a local pig farm

An outbreak of Salmonella typhimurium definitive type (DT) 193 affecting 206 persons occurred in July and August 1989 in a small town in northern England. A descriptive study suggested that cold meats including pork from a butcher's shop in the town were vehicles of infection. An analytical study of a cohort attending a function in the town showed a significant association between illness and consumption of cold roast pork supplied by the butcher's shop (P = 0.00000004). S. typhimurium DT 193 with the same antibiotic resistance pattern (to ampicillin, streptomycin, sulphonamides and tetracyclines) as the outbreak strain, and possessing a single plasmid of 80 MDa was isolated from samples of meat bought from the shop and implicated in illness, and from samples of pig faeces taken from the farm supplying the shop. It was concluded that inadequate processing of infected pork meat at the shop may have contributed to this outbreak but that cross contamination also played an important part in transmission. Control measures included a temporary closure of the shop and subsequent implementation of a detailed protocol for meat processing and monitoring of all procedures at the shop.

Cost-benefit analysis of a screening strategy for Salmonella enteritidis in poultry

Salmonella enteritidis is an emerging problem in several industrial countries. Outbreaks caused by this organism are almost always associated with the consumption of eggs and egg-products originating from infected poultry flocks. To reduce human infection, elimination of contaminated flocks could be considered. In this study we estimated the effectiveness of such a measure to reduce human infections. If poultry flocks are screened for S. enteritidis only once during their laying period, there is a 43.7% reduction in contaminated eggs. The effectiveness increases if the frequency of screening is increased, resulting in a 65.4% reduction in contaminated eggs after three screenings. The costs of this intervention strategy are determined by both the costs of screening and the economic losses of destroying poultry flocks.

The economic impact of poultry-borne salmonellosis: how much should be spent on prophylaxis?

Foodborne salmonellosis constitutes a major health problem in many countries. Moreover, the costs associated with salmonellosis could be considerable. There are thus strong arguments for preventive efforts. Ambitious, often government-sponsored, programmes aimed at preventing and controlling salmonellosis in for instance, poultry production represent one alternative to lower salmonellosis-related illness and economic costs. On the other hand, such comprehensive programmes are rather resource-demanding. From the economic point of view the key problem is to find the optimal level for prophylactic measures. The purpose of this study is to compare two different approaches to preventing poultry-borne salmonellosis among humans. We identify and compare the economic costs of illness due to poultry-borne salmonellosis and the costs of salmonella control in England and Wales and Sweden, respectively. An alternative option is then introduced: the concept of competitive exclusion (CE). Our results show that the cost of illness constitutes the major part of the total cost in England and Wales, whereas in Sweden, the control cost amounts to 95% of the total cost. By using the CE concept, the cost of illness due to poultry-borne salmonellosis in England and Wales could be reduced by at least GB pound 12.6 million. These advantages apply to individuals, producers, and to society, and we thus conclude that the CE concept is a very cost-effective way of using scarce resources.

The social and economic impact of salmonellosis. A report of a national survey in England and Wales of laboratory-confirmed Salmonella infections

This study presents the findings of a national survey of 1482 cases of salmonellosis reported to Environmental Health Departments in England and Wales between August 1988 and March 1989. A questionnaire survey of ill individuals and the environmental health officers who investigated them sought information about costs which were imposed upon public health authorities, the health sector, individuals and their families and the costs to the wider economy in terms of lost production. Costs of 996,339 pounds were identified. Over half (507,555 pounds) resulted from lost production due to sickness absence and more than a third (392,822 pounds) were costs to the public sector which resulted from health care and local authority investigation of cases. The remaining costs (95,962 pounds), although the smallest proportion of the total, indicated that salmonellosis can have a significant impact on affected individuals and their families.