Electronic data collection to enhance disease surveillance at the slaughterhouse in a smallholder production system.

Globally, meat inspection provides data for animal health surveillance. However, paper-based recording of data is often not reported through to higher authorities in sufficient detail. We trialled the use of an electronic meat inspection form in Kenyan slaughterhouses, in lieu of the currently used paper-based format. Meat inspectors in two ruminant slaughterhouses completed and submitted an electronic report for each animal slaughtered at their facility. The reports, which captured information on the animal demographics and any eventual condemnations, were stored in a central database and available in real-time. A stakeholder meeting was held towards the end of the study. Over the 2.75 year study period, 16,386 reports were submitted; a downward linear trend in the monthly submissions was noted. There was a week effect, whereby more reports were submitted on the market day. Of the slaughtered animals, 23% had at least a partial condemnation. The most frequently condemned organs were the liver, lungs and intestines; the primary reasons for condemnations were parasitic conditions. Lack of feedback and difficulty capturing animal origin information were the primary challenges highlighted. The study demonstrated that electronic data capture is feasible in such challenging environments, thereby improving the timeliness and resolution of the data collected.

The association between meat inspection codes, footpad lesions and thinning of broiler flocks in the Danish broiler production.

The foundation of the condemnation practices in Post-Mortem Inspection (PMI) of poultry should be based on up-to-date scientific evidence about the cause of infection and hence whether the lesions observed are of food safety, animal health or welfare concerns. This study aimed to investigate the association between meat inspection codes, footpad lesions, and thinning of flocks in Danish broiler production. The data set was based on the delivery of chicken flocks to one of the two larger chicken slaughterhouses in Denmark, representing 71 farms, 174 houses, and 4,068 flocks over three years from January 2016 to December 2018. Post-mortem condemnation data of slaughtered chickens recorded and stored in the Danish Quality Assurance System (KIK) database was used in the study. Five potentially causal models were developed to investigate whether there was an association between dermatitis, arthritis, systemic infection, emaciation, mortality and possible explaining factors` (footpad lesion, age at slaughter, scratches, ascites, systemic infection and thinning of the flock). These five ecological logistic regression models were analyzed with the three levels: farm, house, and flock. Data from a total number of 126,137,002 (N) slaughtered chickens recorded in KIK databases were used for modeling and analyses. The prevalence of condemned carcasses was 1.1 % (n = 1,420,812). Overall, 12 individual reasons for condemnation of carcasses were recorded. The most frequently observed reason for condemnation was skin disease (scratches and dermatitis) with a prevalence of 0.5 %. Prevalence of ascites was 0.2 %, discoloration 0.09 %, emaciation 0.09 %, hepatitis 0.09 % and arthritis 0.07 %. In the first model, dermatitis was shown to be positively associated with age at slaughter with an OR = 1.04 (CI95 %: 1.02-1.05), while arthritis was considered an intervening variable. Moreover, there was a small protective effect of thinning of the flock for first and second delivery. There was a positive association between arthritis and age at the time of slaughter with an OR = 1.13 (CI95 %: 1.12-1.15). Systemic infections were associated with scratches with an OR = 24.5 (CI95 %: 16.6-36.3) and footpad lesions with an OR = 1.007 (CI95 %: 1.006-1.008). Further modelling of emaciation and mortality was not considered because of unbalanced groups in the data probably caused by the fact that some condemnation codes were rare. We observed that the most common causal factors of condemnation in the systemic infection models were scratches and footpad lesion, therefore preventing and controlling such lesions could reduce losses. Specific management and environmental etiological factors of the main infections causing condemnation in Danish broilers should be determined.

Recalls of Foods due to Microbial Contamination Classified by the Canadian Food Inspection Agency, 2000 to 2017.

Recall of microbial-contaminated food products is an important intervention in preventing the transmission of foodborne illness. Here, we summarize the number and nature of foods recalled as a result of microbial contamination, classified by the Canadian Food Inspection Agency, for the period 1 January 2000 through 31 December 2017. A total of 10,432 food products were recalled from 2,094 recall events in Canada because of microbial contamination during this period. The meat, meat products and poultry category, followed by fishery and seafood products and nuts and edible seeds, contained the food products most commonly associated with microbial contamination. Most microbial-contaminated food products reported were recalled because of the presence bacterial pathogens. Salmonella contamination was responsible for the largest number of recall events, whereas Listeria monocytogenes contamination accounted for the greatest number of food products recalled because of microbial contamination. L. monocytogenes contamination was also most commonly associated with major food recall events, although records may be inflated because of an invested effort to prevent future L. monocytogenes outbreaks following a 2008 deli meat recall. The findings and data we present in this study will support future surveillance and analysis of microbial-contaminated food recalls in Canada.

Perfil higiênico-sanitário dos estabelecimentos de frutas comercializadas na “Feira da Cidade” do município de Ananindeua / PA / Hygienic-sanitary profile of the establishments of fruits marketed in the “City Fair” of the municipality of Ananindeua / PA

As feiras livres desenvolvem um ambiente favorável para a proliferação de microrganismos, acarretando problemas de risco à saúde pública. A pesquisa objetivou descrever o perfil higiênico-sanitário de estabelecimentos que comercializam frutas em uma feira no Município de Ananindeua/PA. O estudo realizou visita ao local e utilizou um check-list adaptado da legislação vigente. Avaliou-se três itens, subdividindo-os em tópicos de avaliação. Os estabelecimentos classificaram-se com porcentagem inferior a 50% dos itens atendidos. A partir dos elevados índices de inadequações, observou-se a necessidade de uma reestruturação através da implementação das Boas Práticas com a realização de cursos e palestras periódicos para garantir a segurança na comercialização das frutas nessa feira.

Spatio-temporal patterns and characteristics of swine shipments in the U.S. based on Interstate Certificates of Veterinary Inspection.

Domestic swine production in the United States is a critical economic and food security industry, yet there is currently no large-scale quantitative assessment of swine shipments available to support risk assessments. In this study, we provide a national-level characterization of the swine industry by quantifying the demographic (i.e. age, sex) patterns, spatio-temporal patterns, and the production diversity within swine shipments. We characterize annual networks of swine shipments using a 30% stratified sample of Interstate Certificates of Veterinary Inspection (ICVI), which are required for the interstate movement of agricultural animals. We used ICVIs in 2010 and 2011 from eight states that represent 36% of swine operations and 63% of the U.S. swine industry. Our analyses reflect an integrated and spatially structured industry with high levels of spatial heterogeneity. Most shipments carried young swine for feeding or breeding purposes and carried a median of 330 head (range: 1-6,500). Geographically, most shipments went to and were shipped from Iowa, Minnesota, and Nebraska. This work, therefore, suggests that although the swine industry is variable in terms of its size and type of swine, counties in states historically known for breeding and feeding operations are consistently more central to the shipment network.

A time-series approach for clustering farms based on slaughterhouse health aberration data.

A large amount of data is collected routinely in meat inspection in pig slaughterhouses. A time series clustering approach is presented and applied that groups farms based on similar statistical characteristics of meat inspection data over time. A three step characteristic-based clustering approach was used from the idea that the data contain more info than the incidence figures. A stratified subset containing 511,645 pigs was derived as a study set from 3.5 years of meat inspection data. The monthly averages of incidence of pleuritis and of pneumonia of 44 Dutch farms (delivering 5149 batches to 2 pig slaughterhouses) were subjected to 1) derivation of farm level data characteristics 2) factor analysis and 3) clustering into groups of farms. The characteristic-based clustering was able to cluster farms for both lung aberrations. Three groups of data characteristics were informative, describing incidence, time pattern and degree of autocorrelation. The consistency of clustering similar farms was confirmed by repetition of the analysis in a larger dataset. The robustness of the clustering was tested on a substantially extended dataset. This confirmed the earlier results, three data distribution aspects make up the majority of distinction between groups of farms and in these groups (clusters) the majority of the farms was allocated comparable to the earlier allocation (75% and 62% for pleuritis and pneumonia, respectively). The difference between pleuritis and pneumonia in their seasonal dependency was confirmed, supporting the biological relevance of the clustering. Comparison of the identified clusters of statistically comparable farms can be used to detect farm level risk factors causing the health aberrations beyond comparison on disease incidence and trend alone.

Analysis of the monitoring status of residual nitrite in meat products in China from 2000 to 2011.

The aim of this article was to analyze the monitoring status of nitrite in meat products consumed from 2000 to 2011 in 24 provinces, autonomous regions or direct-controlled municipalities in China. Statistical analyses were performed on the monitoring status including number, proportion, and distribution of 13,316 samples, of which 11,320 (85%) contained up to 2808.2mg/kg nitrite and 1996 (15%) contained no nitrite. A total of 10,299 samples (77%) qualified for GB/T 5009.33-2003, 2003; however, 3017 samples (23%) contained nitrite at levels higher than the national standard. The districts with high percentage of samples with no nitrite were Shanghai (49%), Beijing (47%), and Liaoning (30%). While the districts with high percentage of meat products containing nitrite at levels exceeding the national standard were Jiangxi (49%), Jiangsu (33%), Shandong (29%) and Sichuan (29%). Therefore, the status of residue nitrite in meat products is of concern.

The Effect of Inspection Announcement on the Outcome of Food Science Establishment Sanitary Health Evaluations.

This study evaluated whether a difference existed between one-hour and one-day notice on inspection announcements versus unannounced inspections on health inspection ratings of food establishments. Three hundred food establishments were randomly assigned into three sections of no announcement, one-hour announcement, or one-day announcement. Certified food inspectors performed routine inspections of these establishments for foodborne illness risk factors. Inspection results were analyzed using chi-square analysis. A significant interaction was found: those who had no notice were more likely to have an unsatisfactory outcome (4%) than establishments that had either one-hour or one-day notice (0%). One-hour notice did not result in a significant difference in outcome when compared with no notification. One-day notice did result in a significant difference in outcome when compared with no notification. This result suggests that one-hour notification is not a significant amount of time to impact the outcome of an inspection, but is sufficient to allow management to logistically prepare for an inspection and still maintain the objective of the inspection process.

Food Safety Program Performance Assessment in Tennessee, 2003-2011.

To assess food safety program performance, the Tennessee Department of Health conducted food service surveys of randomly selected establishments and reviewed routine inspection reports by environmental health specialists (EHSs) of the same facilities. The individual restaurant sanitation scores, along with types and frequencies of violations noted by the survey team, were compared with records from the previous year. In addition, EHSs were observed as they each performed two routine inspections. Survey team staff consistently marked more critical violations than did field EHS staff. Differences between survey teams and field EHS staff in marking critical violations were statistically significant for all 10 critical violations in the first review cycle, 8 in the second cycle, and 7 in the third cycle. Over the course of the review period, there was a small but measurable improvement in scoring by field EHS staff. Marking of critical violations increased, sanitation scores decreased, and discrepancies with survey teams in both areas decreased.

Effect of a Publicly Accessible Disclosure System on Food Safety Inspection Scores in Retail and Food Service Establishments.

The increased frequency with which people are dining out coupled with an increase in the publicity of foodborne disease outbreaks has led the public to an increased awareness of food safety issues associated with food service establishments. To accommodate consumer needs, local health departments have increasingly publicized food establishments' health inspection scores. The objective of this study was to estimate the effect of the color-coded inspection score disclosure system in place since 2006 in Columbus, OH, by controlling for several confounding factors. This study incorporated cross-sectional time series data from food safety inspections performed from the Columbus Public Health Department. An ordinary least squares regression was used to assess the effect of the new inspection regime. The introduction of the new color-coded food safety inspection disclosure system increased inspection scores for all types of establishments and for most types of inspections, although significant differences were found in the degree of improvement. Overall, scores increased significantly by 1.14 points (of 100 possible). An exception to the positive results was found for inspections in response to foodborne disease complaints. Scores for these inspections declined significantly by 10.2 points. These results should be useful for both food safety researchers and public health decision makers.

Restaurant inspection frequency: The RestoFreq Study.

OBJECTIVES: Foodborne illness is an important contributor to morbidity and health system costs in Canada. Using number of critical hazards as a proxy for food safety, we sought to better understand how to improve food safety in restaurants. We compared the current standard of annual inspections to twice-yearly inspections among restaurants "at risk" for food safety infractions. These were restaurants that had three or more elevated-risk inspection ratings in the preceding 36 months. METHODS: We conducted a two-arm randomized controlled trial between November 2012 and October 2014. The intervention was twice-yearly routine restaurant inspection compared to standard once-yearly routine inspection. Included were all restaurants within Saskatoon Health Region that were assessed as "at risk", with 73 restaurants in the intervention arm and 78 in the control arm. Independent sample t-tests were conducted between groups to compare: i) average number of critical hazards per inspection; and ii) proportion of inspections resulting in a rating indicating an elevated hazard. RESULTS: Over time we noted statistically significant improvements across both study arms, in number of both critical food safety hazards (decreased by 61%) and elevated-risk inspection ratings (decreased by 45%) (p < 0.0001). We observed no significant differences between the two groups pre- or post-intervention. CONCLUSION: Results suggest increasing the number of annual routine inspections in high-risk restaurants was not associated with a significant difference in measures of compliance with food safety regulations. Findings of this study do not provide evidence supporting increased frequency of restaurant inspection from annually to twice annually.

Boas práticas: ferramenta primordial para manter a qualidade dos supermercados de São Luis - MA / Good practices: a primordial tool to maintain the quality of supermarkets in São Luis - MA

O objetivo deste trabalho consistiu em relatar as boas práticas como ferramenta primordial para manter a qualidade dos supermercados de São Luís ­ MA. Foram avaliadas cinco redes de supermercados diferentes, através da aplicação de checklist baseado na Resolução nº 216/2004 ANVISA-MS, nos diversos setores, tais como, padaria/confeitaria, hortifruti, açougue, peixaria, frios e laticínios e mercearia. Com a análise realizada pode-se verificar que todos os supermercados avaliados apresentam inconformidades, sendo propostas ações corretivas para saná-las.

The objective of this study is to report food safety as a primary tool for maintaining the quality of supermarkets in Sao Luis - MA. We evaluated the sanitary conditions of five supermarket chains different by applying a "checklist" based on Resolution No. 216/2004 ANVISA-MS in various industries such as bakery / confectionery, grocery, butcher, fishmonger, cold meats and dairy and grocery store. The analysis was able to verify that all supermarkets have non-conformities, corrective actions being proposed to remedy them.

Yelp Versus Inspection Reports: Is Quality Correlated With Sanitation in Retail Food Facilities?

Consumer-generated restaurant review sites offer a wealth of information about dining options. These sites are based on consumers' experiences; therefore, it is useful to assess the relevance between restaurant review (for food quality) and retail food facilities (RFFs) inspection results (for sanitation) from health departments. This study analyzed New York City restaurant ratings on Yelp.com to determine if there was a relationship to RFFs' violation scores for those same facilities found on the New York City Department of Health and Mental Hygiene web pages. In addition, we assessed differences between RFFs defined on Yelp as quick service versus full service, and chains versus nonchains. Yelp ratings were found to be correlated only with sanitation in chain RFFs.

Comércio ambulante de alimentos: condições higiênico-sanitárias nos pontos de venda no município de Umuarama, Paraná, Brasil / Street food: hygienic and sanitary conditiions in outlets in the city of Umuarama, Paraná, Brazil / Comercio de alimentos callejero: condiciones higiénicas y sanitarias en puestos de ventas en la ciudad de Umuarama, Paraná, Brasil

A evolução no comércio de alimentos em vias públicas levou ao surgimento de um novo tipo de atividade econômica denominada comércio ambulante de alimentos ou street food, fazendo referência ao comércio de alimentos prontos e servidos. Denomina-se alimento servido, qualquer alimento ou bebida preparada e/ou vendida em ruas ou locais públicos, onde há etapas adicionais de preparo ou processamento. Este trabalho teve como objetivo traçar o perfil dos vendedores (idade, sexo, escolaridade) e analisar as condições higiênicas sanitárias do local do comércio ambulante de alimentos por meio da aplicação de check-list em 28 estabelecimentos de comércio ambulante de lanches no município de Umuarama, PR. Quanto ao perfil dos manipuladores de alimentos (vendedores ambulantes) 68% eram do sexo masculino e 32% do sexo feminino. Em relação à faixa etária, verificou-se que 57% apresentavam idade entre 36 e 50 anos, e 43% entre 18 e 35 anos, e nenhum acima de 51 anos. A formação escolar dos entrevistados variou entre primeira a quarta série com 18%, até a oitava série 43% e segundo grau completo com 39%. No que diz respeito ao tempo de serviço, 75% dos entrevistados atuavam na área a mais de seis anos, 14% até cinco anos e 11% até dois anos. Em relação às edificações e instalações, manipuladores e produção de alimentos, 63% apresentam não conformidade com a legislação, demonstrando que se faz necessária uma maior fiscalização por parte da Vigilância Sanitária local, além da realização de programas de capacitação em boas práticas de manipulação para os manipuladores.

The evolution of food trade on the street has led to the rising of a new type of economic activity known as street food, which is the food ready to be served and eaten. Served food means any kind of food or beverage prepared and/or sold in streets or public places where there are additional preparation or processing steps. This study aimed to analyze the hygienic and sanitary conditions of street food through the application of a checklist on 28 street trading locations in the city of Umuarama, PR. Regarding the profile of food handlers (street vendors), 68% are male and 32% are female. In terms of age, 57 % were aged between 36 and 50 years old, while 43% were aged between 18 and 35 years, and none was older than 51. Schooling of the respondents ranged from 18% attending 1st to 4th year of elementary school, 43% attending the 8th year of elementary school, and 39% finishing high school. Regarding time on the job, 75% of the respondents worked in the area for more than six years, 14% up to five years, and 11% up to two years. Regarding facilities, handlers and food production, 63% were non-compliant with the legislation, showing the need for a greater inspection by the local Health Surveillance agency, as well as holding training programs in good handling practices for food handlers.

La evolución del comercio de alimentos en vías públicas llevó a la aparición de un nuevo tipo de actividad económica, conocido como comercio de alimentos callejero o street food, haciendo referencia al comercio de alimentos preparados y servidos. Se llama alimento servido, cualquier alimento o bebida preparada y/o vendida en las calles o lugares públicos, donde hay etapas adicionales de preparo o procesamiento. Este estudio tuvo como objetivo buscar el perfil de los vendedores (edad, sexo, escolaridad) y analizar las condiciones higiénicas y sanitarias de locales de ventas de alimentos callejeros, a través de la aplicación de lista control en 28 establecimientos callejeros en la ciudad de Umuarama, PR. En cuanto al perfil de los manipuladores de alimentos (vendedores ambulantes), 68% son del sexo masculino y 32% del sexo femenino. Cuanto a la edad, se encontró que 57% tenía entre 36 y 50 años, y 43% entre 18 y 35 años, y no más de 51 años. La educación escolar de los encuestados osciló entre el 1º y 4º año de la primaria 18%, hasta 8º año de la primaria 43%, la enseñanza secundaria completa 39%. Con respecto al tiempo de trabajo, 75% de los encuestados trabajan en el área hace más de seis años, 14% hasta cinco años y 11% hasta dos años. En relación a las edificaciones e instalaciones, manipuladores y producción de alimentos, 63% presentan incumplimiento con la legislación, demostrando que se hace necesaria una fiscalización mayor por parte de la Vigilancia Sanitaria local, además de realización de programas de capacitación en buenas prácticas de manipulación para los manipuladores.

The effect of follow-up inspections on critical violations identified during restaurant inspections.

Follow-up inspections are recommended by the Food and Drug Administration as a tool to verify corrections to violations cited during restaurant inspections. The effectiveness of follow-up inspections as a tool in reducing critical violations is unknown, however. The purpose of the authors' study was to assess whether a serious violation that leads to a follow-up inspection reduces the probability of specific critical violations occurring during the next routine inspection. Outcome measures included poor personal hygiene, improper holding temperatures, substandard equipment cleanliness, potential cross contamination, and improper sanitizer concentration. The risk of having a violation increased for all targeted critical violations during inspections conducted after a follow-up inspection compared to restaurant inspections without a prior follow-up, when adjusting for restaurant type, inspector experience, and season.

Risk factors for whole carcass condemnations in the Swiss slaughter cattle population.

We used meat-inspection data collected over a period of three years in Switzerland to evaluate slaughterhouse-level, farm-level and animal-level factors that may be associated with whole carcass condemnation (WCC) in cattle after slaughter. The objective of this study was to identify WCC risk factors so they can be communicated to, and managed by, the slaughter industry and veterinary services. During meat inspection, there were three main important predictors of the risk of WCC; the slaughtered animal's sex, age, and the size of the slaughterhouse it was processed in. WCC for injuries and significant weight loss (visible welfare indicators) were almost exclusive to smaller slaughterhouses. Cattle exhibiting clinical syndromes that were not externally visible (e.g. pneumonia lesions) and that are associated with fattening of cattle, end up in larger slaughterhouses. For this reason, it is important for animal health surveillance to collect data from both types of slaughterhouses. Other important risk factors for WCC were on-farm mortality rate and the number of cattle on the farm of origin. This study highlights the fact that the many risk factors for WCC are as complex as the production system itself, with risk factors interacting with one another in ways which are sometimes difficult to interpret biologically. Risk-based surveillance aimed at farms with reoccurring health problems (e.g. a history of above average condemnation rates) may be more appropriate than the selection, of higher-risk animals arriving at slaughter. In Switzerland, the introduction of a benchmarking system that would provide feedback to the farmer with information on condemnation reasons, and his/her performance compared to the national/regional average could be a first step towards improving herd-management and financial returns for producers.

Authenticity of food products in the Polish market checked during 2005-2012.

BACKGROUND: Food fraud/adulteration has ever increasingly become a dominant food issue of the modern world in both developed and developing countries. It is presumed that globalisation is mainly one of the underlying reasons. OBJECTIVES: To assess and analyse the occurrence of food fraud on the Polish market during 2005-2012. MATERIAL AND METHODS: Adulteration of foodstuffs was determined from official food inspections carried out by the Agricultural and Food Quality Inspection (IJHARS) in 2005-2012. On average, foodstuff manufacturers inspected ranged from 1300 companies in 2011 to 3000 in 2006. The amount of results so collected, allowed a meaningful assessment to be thus made of food fraud on the Polish market. RESULTS: Food fraud was found to vary in the Polish market for the specific areas researched (ie. organoleptic properties, physico-chemistry and labelling) as well as in the agri-food sector. Levels of food fraud were not significantly different to those observed in other countries. CONCLUSIONS: Appropriate control measures, at both national and international levels, are thereby indicated to halt the adulteration of foodstuff products that constitute a health hazard or pose a life-threat to consumers as well as constituting a financial fraud.

Evaluation of the US Army Institute of Public Health Destination Monitoring Program, a food safety surveillance program.

The Destination Monitoring Program, operated by the US Army Public Health Command (APHC), is one component that supports the APHC Veterinary Service's mission to ensure safety and quality of food procured for the Department of Defense (DoD). This program relies on retail product testing to ensure compliance of production facilities and distributors that supply food to the DoD. This program was assessed to determine the validity and timeliness by specifically evaluating whether sample size of items collected was adequate, if food samples collected were representative of risk, and whether the program returns results in a timely manner. Data was collected from the US Army Veterinary Services Lotus Notes database, including all food samples collected and submitted from APHC Region-North for the purposes of destination monitoring from January 1, 2013 to December 31, 2013. For most food items, only one sample was submitted for testing. The ability to correctly identify a contaminated food lot may be limited by reliance on test results from only one sample, as the level of confidence in a negative test result is low. The food groups most frequently sampled by APHC correlated with the commodities that were implicated in foodborne illness in the United States. Food items to be submitted were equally distributed among districts and branches, but sections within large branches submitted relatively few food samples compared to sections within smaller branches and districts. Finally, laboratory results were not available for about half the food items prior to their respective expiration dates.

Bovine tuberculosis slaughter surveillance in the United States 2001-2010: assessment of its traceback investigation function.

BACKGROUND: The success of tracing cattle to the herd of origin after the detection and confirmation of bovine tuberculosis (TB) lesions in cattle at slaughter is a critical component of the national bovine TB eradication program in the United States (U.S.). The aims of this study were to 1) quantify the number of bovine TB cases identified at slaughter that were successfully traced to their herd of origin in the U.S. during 2001-2010, 2) quantify the number of successful traceback investigations that found additional TB infected animals in the herd of origin or epidemiologically linked herds, and 3) describe the forms of animal identification present on domestic bovine TB cases and their association with traceback success. RESULTS: We analyzed 2001-2010 data in which 371 granulomatous lesions were confirmed as bovine TB. From these 114 bovine TB cases, 78 adults (i.e. sexually intact bovines greater than two years of age), and 36 fed (i.e. less than or equal to two years of age) were classified as domestic cattle (U.S. originated). Of these adults and fed cases, 83% and 13% were successfully traced, respectively. Of these traceback investigations, 70% of adult cases and 50% of fed cases identified additional bovine TB infected animals in the herd of origin or an epidemiologically linked herd. We found that the presence of various forms of animal identification on domestic bovine TB cases at slaughter may facilitate successful traceback investigations; however, they do not guarantee it. CONCLUSIONS: These results provide valuable information with regard to epidemiological traceback investigations and serve as a baseline to aid U.S. officials when assessing the impact of newly implemented strategies as part of the national bovine TB eradication in the U.S.

Optimal Food Safety Sampling Under a Budget Constraint.

Much of the literature regarding food safety sampling plans implicitly assumes that all lots entering commerce are tested. In practice, however, only a fraction of lots may be tested due to a budget constraint. In such a case, there is a tradeoff between the number of lots tested and the number of samples per lot. To illustrate this tradeoff, a simple model is presented in which the optimal number of samples per lot depends on the prevalence of sample units that do not conform to microbiological specifications and the relative costs of sampling a lot and of drawing and testing a sample unit from a lot. The assumed objective is to maximize the number of nonconforming lots that are rejected subject to a food safety sampling budget constraint. If the ratio of the cost per lot to the cost per sample unit is substantial, the optimal number of samples per lot increases as prevalence decreases. However, if the ratio of the cost per lot to the cost per sample unit is sufficiently small, the optimal number of samples per lot reduces to one (i.e., simple random sampling), regardless of prevalence. In practice, the cost per sample unit may be large relative to the cost per lot due to the expense of laboratory testing and other factors. Designing effective compliance assurance measures depends on economic, legal, and other factors in addition to microbiology and statistics.