Assessment of the risk of salmonellosis from internally contaminated shell eggs following initial storage at 18 °C (65 °F), compared with 7 °C (45 °F).

In the U.S., chicken-breeder farms that supply hatcheries typically store and transport eggs intended for broiler production at a temperature of 18.3 °C (65 °F). However, in case of surplus, some of these eggs may be diverted to human consumption. According to the U.S. Food and Drug Administration's 'Egg Safety Final Rule,' shell eggs intended for human consumption are required to be held or transported at or below 7.2 °C (45 °F) ambient temperature beginning 36 h after time of lay. We adapted a risk assessment model developed by the U.S. Department of Agriculture's Food Safety Inspection Service, to quantify human exposure to Salmonella Enteritidis and the risk of human salmonellosis if eggs are held and transported at 18.3 °C for up to 5.5 days after time of lay, as has been observed when hatchery eggs are diverted to human consumption, rather than held and transported at 7.2 °C within 36 h after time of lay. Storage at 18.3 °C leads to considerable bacterial growth in internally contaminated eggs. The model predicted that more than 10% of internally contaminated eggs would remain contaminated after in-shell pasteurization resulting in a 5-log10 reduction, and that some bacteria would survive after home-cooking. The model predicted that, alternatively, eggs stored at 7.2 °C after lay would have limited bacterial growth prior to pasteurization, and Salmonella would be very unlikely to be present after pasteurization. The predicted risk of salmonellosis from the consumption of eggs held and transported at 18.3 °C and subsequently diverted to human consumption is 25 times higher than the risk when eggs are held and transported at 7.2 °C.

Dietary exposure and health risk assessment for 11 minerals and trace elements in Yaoundé: the Cameroonian Total Diet Study.

Dietary exposure to 11 elements was assessed by the Total Diet Study (TDS) method. Sixty-four pooled samples representing 96.5% of the diet in Yaoundé, Cameroon, were prepared as consumed before analysis. Consumption data were sourced from a household budget survey. Dietary exposures were compared with nutritional or health-based guidance values (HBGV) and to worldwide TDS results. Elevated prevalence of inadequate intake was estimated for calcium (71.6%), iron (89.7%), magnesium (31.8%), zinc (46.9%) and selenium (87.3%). The percentage of the study population exceeding the tolerable upper intake levels was estimated as <3.2% for calcium, iron, magnesium, zinc and cobalt; 19.1% of the population exceeded the HBGV for sodium. No exceedance of the HBGV for inorganic mercury was predicted in the population. The margin of exposure ranged from 0.91 to 25.0 for inorganic arsenic depending on the reference point. The "Fish" food group was the highest contributor to intake for calcium (65%), cobalt (32%) and selenium (96%). This group was the highest contributor to the exposure to total arsenic (71%) and organic mercury (96%). The "Cereals and cereal products" highly contributed to iron (26%), zinc (26%) and chromium (25%) intakes. The "Tubers and starches" highly contributed to magnesium (39%) and potassium (52%) intakes. This study highlights the dietary deficiency of some essential elements and a low dietary exposure to toxic elements in Yaoundé.

Virus inactivation on hard surfaces or in suspension by chemical disinfectants: systematic review and meta-analysis of norovirus surrogates.

Norovirus (NoV) infections are the leading cause of foodborne illness in the United States. Effective disinfection is important for controlling outbreaks caused by this highly infectious virus but can be difficult to achieve because NoV is very resistant to many common disinfection protocols. The inability of human NoV to replicate in tissue culture complicates NoV research, generally necessitating genome copy quantification, the use of surrogate viruses, or the use of other substitutes such as virus-like particles. To date, comprehensive comparisons among NoV surrogates and between surrogates and human NoV are missing, and it is not clear how best to extrapolate information from surrogate data. We conducted a systematic review and meta-analysis of comparisons of NoV surrogates with regard to their susceptibility to disinfection on hard surfaces or in suspension. Restricting our analysis to those studies in which two or more virus surrogates were compared allowed us to improve the signal-to-noise ratio in our analysis, similar to the epidemiological concept of matching. Using meta-analysis methods, our results indicate that hepatitis A virus, murine norovirus 1, and phage MS2 are significantly more resistant to disinfection than is feline calicivirus, but average differences in viral titer reduction appeared to be modest, 1.5 log PFU or less in all cases. None of the studies that compared surrogates and human NoV met our inclusion criteria, precluding a direct comparison between human NoV and NoV surrogates in this study. For all surrogates with sufficient data available to permit subgroup analyses, we detected strong evidence that the type of disinfectant impacted the relative susceptibility of the surrogates. Therefore, extrapolation of results between surrogates or from surrogates to human NoV must consider the type of disinfectant studied.

New data, strategies, and insights for Listeria monocytogenes dose-response models: summary of an interagency workshop, 2011.

Listeria monocytogenes is a leading cause of hospitalization, fetal loss, and death due to foodborne illnesses in the United States. A quantitative assessment of the relative risk of listeriosis associated with the consumption of 23 selected categories of ready-to-eat foods, published by the U.S. Department of Health and Human Services and the U.S. Department of Agriculture in 2003, has been instrumental in identifying the food products and practices that pose the greatest listeriosis risk and has guided the evaluation of potential intervention strategies. Dose-response models, which quantify the relationship between an exposure dose and the probability of adverse health outcomes, were essential components of the risk assessment. However, because of data gaps and limitations in the available data and modeling approaches, considerable uncertainty existed. Since publication of the risk assessment, new data have become available for modeling L. monocytogenes dose-response. At the same time, recent advances in the understanding of L. monocytogenes pathophysiology and strain diversity have warranted a critical reevaluation of the published dose-response models. To discuss strategies for modeling L. monocytogenes dose-response, the Interagency Risk Assessment Consortium (IRAC) and the Joint Institute for Food Safety and Applied Nutrition (JIFSAN) held a scientific workshop in 2011 (details available at http://foodrisk.org/irac/events/). The main findings of the workshop and the most current and relevant data identified during the workshop are summarized and presented in the context of L. monocytogenes dose-response. This article also discusses new insights on dose-response modeling for L. monocytogenes and research opportunities to meet future needs.

Produce consumption in the United States: an analysis of consumption frequencies, serving sizes, processing forms, and high-consuming population subgroups for microbial risk assessments.

A great variety of fruits and vegetables are available in the United States. These items are produced in various geographic regions by a diverse industry. Produce has been increasingly identified as a vehicle for disease outbreaks. Changes in consumption may explain this increase, but analyses of produce consumption are limited. Comprehensive assessments of the public health risks associated with produce depend on quantitative consumption data, including the population fractions and subgroups of consumers, the quantities consumed by these individuals, and the processing that occurs before consumption. Here, we provide an analysis of nationally representative consumption estimates by estimating consumption frequencies, serving sizes, and processing forms for a variety of produce commodities based on 1999 through 2006 data from "What We Eat in America," the dietary interview component of the National Health and Nutrition Examination Survey performed by the National Center for Health Statistics. Consumption patterns for fresh and heat-treated produce were assessed, compared with U.S. food availability estimates from the U.S. Department of Agriculture Economic Research Service (ERS), and combined with ERS data on temporal trends in food availability and nondomestic produce origins. To identify high-consuming population subgroups, we explored consumer habits and demographic predictors of fresh produce consumption (data available at www.foodrisk.org). Our analysis of common outbreak vehicles revealed limited temporal changes in food availability but frequent consumption as fresh commodities. In addition to providing quantitative consumption estimates for risk assessments, our data clearly show that produce consumption differs among fruits and vegetables, fresh and heat-treated foods, and demographic subgroups. These results are valuable for risk assessments and outbreak investigations and allow targeting of risk communication or interventions to those individuals at greatest risk.

Epidemiology of methicillin-resistant Staphylococcus aureus lineages in five major African towns: emergence and spread of atypical clones.

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Africa is poorly documented. From January 2007 to March 2008, we collected 86 MRSA isolates from five African towns, one each in Cameroon, Madagascar, Morocco, Niger and Senegal. Although one or two major clones, defined by the sequence type and staphylococcal cassette chromosome mec type, predominated at each site, genetic diversity (ten clones) was relatively limited in view of the large geographical area studied. Most of the isolates (n = 76, 88%) belonged to three major clones, namely ST239/241-III, a well-known pandemic clone (n = 34, 40%), ST88-IV (n = 24, 28%) and ST5-IV (n = 18, 21%). The latter two clones have only been sporadically described in other parts of the world. The spread of community-associated MRSA carrying the Panton-Valentine leukocidin genes is a cause for concern, especially in Dakar and possibly throughout Africa.

Epidemiology of methicillin-susceptible Staphylococcus aureus lineages in five major African towns: high prevalence of Panton-Valentine leukocidin genes.

The epidemiology of methicillin-susceptible Staphylococcus aureus (MSSA) in Africa is poorly documented. From January 2007 to March 2008, 555 S. aureus isolates were collected from five African towns in Cameroon, Madagascar, Morocco, Niger, and Senegal; among these, 456 unique isolates were susceptible to methicillin. Approximately 50% of the MSSA isolates from each different participating centre were randomly selected for further molecular analysis. Of the 228 isolates investigated, 132 (58%) belonged to five major multilocus sequence typing (MLST) clonal complexes (CCs) (CC1, CC15, CC30, CC121 and CC152) that were not related to any successful methicillin-resistant S. aureus (MRSA) clones previously identified in the same study population. The luk-PV genes encoding Panton-Valentine leukocidin (PVL), present in 130 isolates overall (57%), were highly prevalent in isolates from Cameroon, Niger, and Senegal (West and Central Africa). This finding is of major concern, with regard to both a source of severe infections and a potential reservoir for PVL genes. This overrepresentation of PVL in MSSA could lead to the emergence and spread of successful, highly virulent PVL-positive MRSA clones, a phenomenon that has already started in Africa.

Observational study of food safety practices in retail deli departments.

In order to improve the safety of refrigerated ready-to-eat food products prepared at retail deli departments, a better understanding of current practices in these establishments is needed. Food employees in deli departments at six chain and three independent retail establishments in Maryland and Virginia were observed, using notational analysis, as they prepared deli products for sale. The frequency of contact with objects and deli products before sale, hand washing and glove changing during preparation, and equipment, utensil, and surface cleaning and sanitizing was determined. Compliance with the U.S. Food and Drug Administration's 2005 model Food Code recommendations, which must be adopted by the individual state and local jurisdictions that are responsible for directly regulating retail establishments, was also assessed. Observations indicated there were a large number of actions for which hand washing was recommended at independent and chain stores (273 recommended of 1,098 total actions and 439 recommended of 3,073 total actions, respectively). Moreover, 67% (295 of 439) of the actions for which hand washing was recommended at the chain stores and 86% (235 of 273) of those at the independent stores resulted from employees touching non-food contact surfaces prior to handling ready-to-eat food. Compliance with hand washing recommendations was generally low and varied depending on store type with independent stores exhibiting lower compliance than chain stores (5 instances of compliance for 273 recommended actions and 73 instances of compliance for 439 recommended actions, respectively). Potential risk mitigation measures that may reduce the frequency of hand washing actions needed during ready-to-eat food preparation in retail deli departments are discussed. More research is needed to determine the impact of such measures on food safety.

[Illicit drug trade on the markets of Yaounde (Cameroon) and Niamey (Niger): characteristics of salesmen and quality of drugs]. / Le circuit informel des médicaments à Yaoundé et à Niamey: étude de la population des vendeurs et de la qualité des médicaments distribués.

This study characterizes salesmen and evaluates the drugs offer and quality of the drugs in the illicit selling network in Yaoundé (Cameroon) and Niamey (Niger). A sample of 75 and 124 drug salesmen working in these cities was questioned using a standardized questionnaire. The prescription of drugs and the advices provided by these poorly trained salesmen could have an important impact in term of public health: 32% and 67% of the salesmen in Yaoundé give systematically or occasionally advices regarding the prescription. The active substances are always present in the 153 drugs of our analysed sample, except for chloroquine-based drugs, among which 5/30 samples did not contain active substance. However, the rate of nonconformity is approximately 50% in the two cities. Complementary studies are needed to explore the origin of these nonconformities, between counterfeiting, low quality of the products provided by the factories, defects of conservation or instability of the formulations.

Dietary exposure to pesticide residues in Yaoundé: the Cameroonian total diet study.

Dietary exposure to pesticide residues was assessed in Yaoundé, Cameroon, using the total diet study (TDS) method. Sixty-three composite samples, representative of the foods as consumed in Yaoundé, were collected, prepared, and analysed for residues of pesticides including organochlorine, organophosphorous, and pyrethroids. A multi-residue method was used with a limit of detection (LOD) of 0.005 mg kg(-1). Additional analyses were performed for dithiocarbamates (LOD=0.050 mg kg(-1)), glyphosate (LOD=0.005 mg kg(-1)) and chlordecone (LOD=0.0008 mg kg(-1)) on certain composites samples. The overall contamination was low with 37 out of 46 pesticides below the LOD in all samples. The estimated upper bound (for values less than the LOD equal the LOD; and values less than the LOQ equal the LOQ) of the mean dietary exposures ranged from 0.24% (cypermethrin) to 3.03% (pirimiphos-methyl) of the acceptable daily intakes (ADIs) for pesticides for which at least one analysis was greater than the LOD. This study suggests a low dietary exposure to pesticide residues in Yaoundé.

Pulmonary tuberculosis in the Central Prison of Douala, Cameroon.

OBJECTIVE: To determine the prevalence of and factors associated with pulmonary tuberculosis (PTB) in an urban prison in sub-Saharan Africa. DESIGN: A cross-sectional survey. SETTING: The Central Prison of Douala, Cameroon. RESULTS: Two thousand four hundred and seventy four (87.4%) out of 2830 inmates underwent screening. Twenty seven (1.1%) of the inmates were under treatment for smear-positive PTB on commencement of the survey while 60 (2.4%) were diagnosed with smear and/or culture-positive PTB during the active case finding, resulting in a point prevalence of PTB of 3.5%. HIV seroprevalence in inmates without clinical signs of PTB was 111/1067 (10.4%) while it amounted to 6/24 (25%) in PTB patients. In multiple stepwise regression analysis, a low BMI, a prison stay of < or = 12 months, and a history of previous incarceration were positively associated with PTB. CONCLUSION: The study results confirm the high prevalence rates of PTB in prison populations and underscore the need for urgent preventive measures.

Use of Bayesian modelling in risk assessment: application to growth of Listeria monocytogenes and food flora in cold-smoked salmon.

An attempt to use a Bayesian approach to model variability and uncertainty separately in microbial growth in a risk assessment is presented. It was conducted within the framework of a French project aiming at assessing the exposure to Listeria monocytogenes in cold-smoked salmon. The chosen model describes the effect of time and temperature on bacterial growth. A Bayesian approach close to the one proposed by Pouillot et al. [Int. J. Food Microbiol. 81 (2003) 87] is used to estimate the variability and uncertainty of growth parameters from both literature data and data experimentally acquired during the project. Variability between strains and between products is taken into account. The growth of the food flora of cold-smoked salmon is also modelled by the same method. The results obtained for both models are used to predict the simultaneous growth of L. monocytogenes and food flora in cold-smoked salmon with a competitive model, expressing variability and uncertainty through a second-order Monte Carlo simulation.

Foodborne infections in France.

To quantify the impact of foodborne diseases on health, and set priorities for data collection, prevention and control of these diseases, we compiled and analyzed information from surveillance systems and other sources on the morbidity and mortality due to foodborne infectious diseases in mainland France in the last decade of the 20th century. Illness due to 13 bacteria, two viruses, and eight parasites were studied. The number of foodborne infections, hospitalizations, and deaths were estimated from multiple data sources. For each agent, several estimates were derived from the different sources. Estimates were ranked according to their plausibility, based on an assessment of the validity of the data source, and are presented as a "plausible interval" consisting of a low and high estimate. We estimate that these pathogens caused 10,200-17,800 hospitalizations per year. Salmonella is the most frequent cause (5,700-10,200 cases), followed by Campylobacter (2,600-3,500 cases) and Listeria (304 cases). Toxoplasmosis accounts for the majority of hospitalizations (426 cases) attributable to the studied parasitic infections. The number of deaths related to foodborne infection was estimated between 228 and 691. Bacterial pathogens account for the majority (191 to 652) of deaths of which 92 to 535 are attributable to salmonellosis, ranking as the first cause of death, and 78 to listeriosis, the second cause. Salmonella, Campylobacter, and Listeria are the main causes of severe foodborne illness in France. For several pathogens, data are insufficient to derive exact estimates of the disease burden. Nevertheless, it has been possible to derive plausible estimates for the majority, and to rank them according to their impact on public health.

Validation of in situ hybridisation and histology assays for the detection of the oyster parasite Marteilia refringens.

An in situ hybridisation technique has been developed for the detection of infection in oysters with Marteilia refringens with particular emphasis on light infections or confirmation of suspected cases by means of histology. Although validation of new diagnostic methods is usually achieved by comparison with standard techniques, in our case the sensitivity and specificity of the standard (histology) had not previously been established. Another point to consider is that surveillance and monitoring frequently target populations displaying different levels of prevalence under different field conditions. The objective of our study was to evaluate the sensitivity and specificity values of in situ hybridisation and histology for the detection of M. refringens, based on 3 populations of flat oysters, free of the disease and with mild and high levels of prevalence. A blind assay of 200 individuals from each population was performed using both techniques. Results were analysed by means of the classical approach and latent models (maximum likehood and Bayesian approach). Assumptions and results were found to vary slightly with the different statistical approaches. The more realistic estimate by the Bayesian approach shows a link between the level of prevalence and the sensitivity of the techniques. Values of sensitivity and specificity for histology were 0.7 and 0.99 respectively, and 0.9 and 0.99 respectively in the case of in situ hybridisation. Some uncertainty remains regarding these values because the study does not take into account the severity of infection or the developmental stages of the parasite actually present in each individual. This work provides valuable information with regard to the choice and potential use of those 2 diagnostic methods currently recommended by international standards.

Statistical procedures for calculating the residual virulence of Brucella abortus strain 19 (S19) and Brucella melitensis strain Rev 1 vaccines in mice: theoretical basis and practical applications.

Regular control of the biological quality of live Brucella abortus strain 19 (S19) and B. melitensis strain Rev 1 vaccines is essential for the successful management of ruminant brucellosis in affected countries. The reference procedures recommended by the OIE (World organisation for animal health) and the European Pharmacopoeia include the determination of residual virulence, expressed as the recovery time 50 (RT50), of the tested (problem) vaccine in a reference mouse model compared with the RT50 of the corresponding reference strains in the same assay. The underlying statistical procedure applied is based on a parallel line assay and a classical probit model. In practice, the currently recommended procedure for calculating the RT50 is based on a graphical method which has never been described in detail. This paper provides a full description of this graphical method with the aim of making the technique comprehensible and accessible to all interested biologists. The procedure is somewhat cumbersome and very few laboratories apply the OIE and European Pharmacopoeia recommendations on a regular basis. Moreover, since this reference graphical method shows some statistical inconsistencies, a dedicated internet interface has been developed to perform RT50 calculations and is now available free of charge on the web (www.afssa.fr/interne/rev2.html).

A point pattern model of the spread of foot-and-mouth disease.

The spatial spread of foot-and-mouth disease (FMD) is influenced by several sources of spatial heterogeneity: heterogeneity of the exposure to the virus, heterogeneity of the animal density and heterogeneity of the networks formed by the contacts between farms. A discrete space model assuming that farms can be reduced to points is proposed to handle these different factors. The farm-to-farm process of transmission of the infection is studied using point-pattern methodology. Farm management, commercial exchanges, possible airborne transmission, etc. cannot be explicitly taken into account because of lack of data. These latter factors are introduced via surrogate variables such as herd size and distance between farms. The model is built on the calculation of an infectious potential for each farm. This method has been applied to the study of the 1967-1968 FMD epidemic in UK and allowed us to evaluate the spatial variation of the probability of infection during this epidemic. Maximum likelihood estimation has been conducted conditional on the absence of data concerning the farms which were not infected during the epidemic. Model parameters have then been tested using an approximated conditional-likelihood ratio test. In this case study, results and validation are limited by the lack of data, but this model can easily be extended to include other information such as the effect of wind direction and velocity on airborne spread of the virus or the complex interactions between the locations of farms and the herd size. It can also be applied to other diseases where point approximation is convenient. In the context of an increase of animal density in some areas, the model explicitly incorporates the density and known epidemiological characteristics (e.g. incubation period) in the calculation of the probability of FMD infection. Control measures such as vaccination or slaughter can be simply introduced, respectively, as a reduction of the susceptible population or as a reduction of the source of infection.

Proposed criteria to determine whether a territory is free of a given animal disease.

This text describes the general principles underlying the concept of disease-free territory and the required statistical basis for the corresponding epidemiological surveillance operations. Among the essential points, it is emphasised that "disease-free" status should be given only under conditions substantiating the absence of infection (or infestation) and not simply on basis of a known low level of infection (or infestation). This manuscript also raises concerns about possible confusion that has arisen between the inevitable requirement to set a threshold on the level of detection of epidemiological surveillance tools, for economic reasons, and the acceptance of a level of infection (or infestation) that is known, but occurring below the accepted threshold, when according the official status of "territory-free from a given disease". In such a situation, it would be preferable to accord the status of "territory where the disease is in the process of eradication".

Non specific serological reactions in the diagnosis of bovine brucellosis: experimental oral infection of cattle with repeated doses of Yersinia enterocolitica O:9.

Eight heifers were orally infected with 4 x 10(9) colony forming units of a field cattle strain of Yersinia enterocolitica O:9 in a capsule, 5 days a week, for about 9 weeks (day 0-day 64 (D0-D64). The faecal shedding of Y. enterocolitica O:9 began on D5 for seven out of the eight challenged cattle with a high level of excretion during the first month, followed by a decrease till the day of slaughter (D76). Y. enterocolitica O:9 was not isolated from organs collected at slaughter. No clinical symptoms were observed. Hyperplasia of intestinal lymph formations was the sole microscopic lesions observed. Five animals showed a serological reaction against Brucella antigens in at least one of the following tests: Rose-Bengal test, complement fixation test, tube agglutination test or indirect ELISA (iELISA) tests. Only one animal showed a high level of serological response and a positive reaction in the dithiothreitol-microagglutination test. The observed variability in terms of individual sensitivity to the Y. enterocolitica O:9 infection is in agreement with the low individual prevalence rate and the transient serological reaction and faecal Y. entercolitica O:9 shedding observed in herds showing false positive serological reactions in brucellosis.

Risk factors for false-positive serological reactions for bovine brucellosis in Saône-et-Loire (France).

Since 1990, unusually high rates of false-positive serological reactions (FPSR) in bovine brucellosis screening have been observed in some countries of the European Union. The aim of this survey was to describe this phenomenon in a highly affected French Department, and to evaluate the links between some individual or herd factors and the occurrence of these FPSR. Before 1990, low backgrounds of FPSR were recorded (individual prevalence rate: less than 0.5 per 10,000). The phenomenon burst during the 1990-91 screening campaign, reached a peak in 1992-93 (50.5 per 10,000), and then decreased until the last studied campaign, 1995-96 (9.1 per 10,000). The phenomenon was transient and sporadic within a herd. At the herd-screening level, four assumed risk factors were isolated: (i) the probability of a herd-screening to be positive was closely and positively linked with the herd screening size; (ii) during a given screening campaign, the prevalence of FPSR decreased from December to November; (iii) the presence of at least one goat on the premises increased the risk for the 1992-93 and 1993-94 screening campaigns; and (iv) a previous FPSR in a given herd appeared to be a weak but significant risk factor. At the individual-animal level, herd size, sex and breed did not seem to be linked with FPSR appearance, while young animals were significantly more affected than older ones. However, global variations in herd or individual prevalences remained unexplained. The lack of link between FPSR and brucellosis is strengthened. The hypothesis of a widely spread causal agent with a low individual host susceptibility and/or a low probability of detecting FPSR animals can be supported by these results.

The Brucellin skin test as a tool to discriminate false positive serological reactions in bovine brucellosis.

Three experiments were performed in order to assess the diagnostic value of the Brucellin allergic skin test (AST) in a brucellosis false positive serological reactions (FPSR) context. First, 1259 cattle from 20 Brucella-free herds in a FPSR area were tested twice with AST to estimate its specificity. Secondly, AST and serological tests (complement fixation test [CFT], tube agglutination test, dithiothreitol-microagglutination test and ELISA) sensitivities were evaluated on 111 cattle positive to the Rose Bengal test (RBT) belonging to 15 Brucella-infected herds. Thirdly, AST was used in a field trial to discriminate FPSR from true brucellosis reactions. AST specificity in non-vaccinated cattle was very high (99.83%; confidence interval 95% [CI95%]: 99.67-99.96%). Skin thickening 72 h post-injection was significantly higher on vaccinated cattle (1.42 vs 0.15 mm). In this sub-population, AST specificity decreased significantly to 78% (CI95%: 68-87%). Individual sensitivity of AST relative to Rose Bengal test was 64% (CI95%: 54-72%), while all infected herds were AST positive (n = 15). When associated with CFT, it detected 95% (CI95%: 90-98%) of the infected cattle. These results were consistent with the field trial. In a FPSR context, AST was more specific than RBT or CFT. Therefore, this test could be used at herd level as a confirmation test, on cattle non vaccinated against brucellosis.