Herd tests on meat livestock to protect consumers from zoonotic pathogens and chemical residues

Clinical veterinary work is of prime importance for the task of the veterinary food hygienist. This is particularly true of early clinical, allergological, serological and bacteriological examination of herds of meat livestock, as proposed by Bartels, Kampelmacher, Grossklaus and others. Such investigations would make it possible to diagnose latent types of zoonosis which would otherwise remain undetected during official meat inspection. The pathological and anatomical findings during meat inspection are also of clinical importance. To these must be added the necessary measures to eliminate toxicologically significant residues of pharmacologically active substances. On the basis of his own research the author presents proposals for herd tests which could help to promote, with improved safety, international trade in animal products for human consumption.

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Kurzfassung Die klinische Tätigkeit des Tierarztes beeinflusst wesentlich die Arbeit des tierärztlichen Lebensmittelhygienikers. Dies trifft besonders für die rechtzeitige klinische, allergologische, serologische und bakteriologisch-virologische Untersuchung von Schlachttieren in ihren Beständen zu, wie sie u. a. von Bartels, Kampelmacher und Grossklaus vorgeschlagen wurde. Sie soll u.a. die Diagnose inapparent verlaufender Zoonosen ermöglichen, die sonst im Rahmen der amtlichen Fleischuntersuchung unerkannt bleiben. Der pathologisch-anatomische Befund aus der Fleischuntersuchung ist zudem wichtig für den Kliniker. Hinzu kommen erforderliche Massnahmen zur Ausschaltung von toxikologisch relevanten Rückständen pharmakologisch wirksamer Substanzen. Anhand eigener Untersuchungen werden Vorschläge für sog. Bestandsuntersuchungen unterbreitet die in der Lage sein könnten, den internationalen Handel mit vom Tier stammenden Lebensmitteln sicherer zu gestalten und zu fördern.

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Resume L'action du vétérinaire praticien a une influence primordiale sur le travail du vétérinaire hygiéniste. Cela est particulièrement vrai pour l'examen clinique, allergologique, sérologique et bactériologique des animaux de boucherie, au niveau des élevages, proposé par des auteurs comme Bartels, Kampelmacher et Grossklaus. Il doit rendre possible le diagnostic des zoonoses inapparentes qui risqueraient de passer inapercues au stade de l'inspection des viandes. Du reste, le diagnostic anatomo-pathologique résultant de l'inspection des viandes est important pour le clinicien. Il faut ajouter les mesures nécessaires pour éliminer les résidus toxiques provenant de substances pharmacologiques actives. En se basant sur ses propres études, l'auteur fait des propositions pour des examens dits des troupeaux qui pourraient rendre plus sûr et plus efficace le commerce international des dentées d'origine animale.

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Riassunto L'attività del medico veterinario influenza sensibilmente il lavoro dell'igenista veterinario-alimentare. Questo vale in particolare per l'esame clinico, allergico, sierologico e batteriologico degli animali da macello negli allevamenti, proposti da autori quali Bartels, Kampelmacher e Grossklaus. Gli esami debbono permettere la diagnosi delle zoonosi inapparenti che rischierebbero di passare inosservate in fase di ispezione delle carni. Pertanto la diagnosi anatomo-patologica risultante dall'ispezione delle carni è importante anche per il clinico. A cio' si devono aggiungere misure atte ad eliminare i residui tossici provenienti dalle sostanze farmacologiche attive. Basandosi sui suoi studi, l'autore fa proposte relative agli esami detti di mandria che potrebbero rendere più sicuro e efficace il commercio internazionale degli alimenti di origine animale.

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This article was originally written in German. Copies of the German version may be obtained free of charge by writing to: Mr. J. Rodesch, Commission of the European Communities, DG XIII, Bâtiment Jean Monnet, Rue Alcide de Gasperi, Kirchberg, Luxembourg.     

Perceptions,practices, and consequences associated with foodborne pathogens and the feeding of raw meat to dogs

This study explored the impact of feeding raw meat to dogs on the fecal prevalence of several enteric bacterial zoonotic pathogens. Campylobacter jejuni was isolated from 1/42 (2.6%) raw meat-fed dogs. Salmonella enterica was isolated from 2/40 (5%) of the raw meat feeds, 6/42 (14%) raw meat-fed dog feces, none of the dogs that did not receive raw meat (P = 0.001), 4/38 (10.5%) of the vacuum cleaner waste samples from households where raw meat was fed, and 2/44 (4.5%) of vacuum cleaner waste samples from households where raw meat was not fed to dogs (P = 0.41). Responses to a questionnaire probing practices and beliefs regarding raw meat feeding that was administered to dog owners demonstrated that dog owners may either not be aware or refuse to acknowledge the risks associated with raw meat-feeding; thus, they may neglect to conduct adequate intervention strategies to prevent zoonoses among themselves and their families.     

A philosophy and approach to teaching the epidemiology of food-borne, waterborne, and zoonotic diseases

Faculty members from veterinary colleges that teach courses on food-borne, waterborne, and zoonotic diseases to non-veterinary students face unique challenges. The diversity of students' backgrounds, skills, and goals and the public nature of the science require some ingenuity in combining good science with the ability to communicate clearly in a variety of public forums. Drawing on pedagogical theory, the nature of the material, and the diverse abilities of the students, we have put together an effective teaching package for non-veterinary courses on these subjects, which includes a range of methods from outbreak investigations to town hall meetings and food diaries.     

动物与食物源病原菌的联系、健康影响及现状

生产人类蛋白食物的动物是许多食源性病原体的主要宿主,如弯曲杆菌、肠道沙门氏菌、大肠杆菌的和单核增生李斯特菌。本文综述了动物与食源性致病菌(如沙门氏菌、弯曲杆菌、志贺产毒素大肠杆菌)和单核细胞增生素的联系以及其影响和现状。这些致病菌将继续广泛的爆发和引起动物死亡,因为目前没有有效的干预措施将它们从动物和食品中消除。     

Evidence-based identification of the most important livestock related zoonotic diseases in Kampala, Uganda

Urban and peri-urban livestock farming in developing countries plays an important role in food security in cities; however it brings with it zoonotic risks. The present study was conducted to identify the most important livestock farming-related zoonotic diseases among the human population in urban and peri-urban areas of Kampala, Uganda and to assess the risks from such farming. A framework for identifying livestock farming-related significant zoonoses was developed. The process consisted of screening of medical record summaries for zoonotic diagnoses, selection of the zoonoses which are related to livestock farming, case estimation of the identified zoonoses and evidence-based reassurance of the importance of diseases. Medical records in the Mulago National Referral Hospital were used for the analysis. Leaders and residents of 75 Local Councils (LC1s: villages; 48 urban, 11 peri-urban and 16 rural) randomly selected in Kampala were interviewed for information regarding livestock farming systems, value chains and use of medical service units. Twelve zoonoses were identified in the screening and four out of them were related to livestock farming: animal sourced food-borne gastroenteritis, brucellosis, Taenia solium neuro-cysticercosis and Mycobacterium bovis tuberculosis. Livestock farming, value chain and severity of the diseases confirmed that all four diseases were important. Poor geographical correlation between animals in peri-urban and rural areas and patients in urban areas suggested that the majority of these zoonoses were caused by informally-marketed foods.     

Presence and incidence of food-borne pathogens in Australian chicken litter

1.?Litter samples were collected at the end of the production cycle from spread litter in a single shed from each of 28 farms distributed across the three Eastern seaboard States of Australia.

2.?The geometric mean for Salmonella was 44 Most Probable Number (MPN)/g for the 20 positive samples. Five samples were between 100 and 1000 MPN/g and one at 10⁵ MPN/g, indicating a range of factors are contributing to these varying loads of this organism in litter.

3.?The geometric mean for Campylobacter was 30 MPN/g for the 10 positive samples, with 7 of these samples being <100 MPN/g. The low prevalence and incidence of Campylobacter were possibly due to the rapid die-off of this organism.

4.?E. coli values were markedly higher than the two key pathogens (geometric mean 2?0 × 10⁵ colony forming units (cfu)/g) with overall values being more or less within the same range across all samples in the trial, suggesting a uniform contribution pattern of these organisms in litter.

5.?Listeria monocytogenes was absent in all samples and this organism appears not to be an issue in litter.

6.?The dominant (70% of the isolates) Salmonella serovar was S. Sofia (a common serovar isolated from chickens in Australia) and was isolated across all regions. Other major serovars were S. Virchow and S. Chester (at 10%) and S. Bovismorbificans and S. Infantis (at 8%) with these serovars demonstrating a spatial distribution across the major regions tested.

7.?There is potential to re-use litter in the environment depending on end use and the support of relevant application practices and guidelines.     

Children's farms in The Netherlands: hygiene and zoonotic pathogens

In 2004 the Food and Consumer Product Safety Authority (VWA) investigated the hygiene and hygiene facilities on 125 children's farms. In general, both the level of hygiene and the availability of hygiene facilities were good. A previous investigation, carried out in 2002, had highlighted a number of points for improvement, such as the need to improve hand-washing facilities. While the situation was better in 2004, it still did not meet the standard laid down by the VWA. The VWA aspires to achieve 100% implementation of the requirement that children's farms have a Code for Hygiene and an information board. Investigation of faecal samples collected in 2002 showed the presence of STEC O157 on 13 (10.2%) of the visited farms, Salmonella spp. on 19 (14.5%) and Campylobacter spp. on 74 (56.6%). These results show that there is a real risk of becoming infected with a zoonotic pathogen when visiting a children's farm. This emphasizes the importance of strict adherence to hygiene measures by workers and visitors on children's farms in The Netherlands.     

Cattle brucellosis in traditional livestock husbandry practice in Southern and Eastern Ethiopia,and its zoonotic implication

Background

Cattle brucellosis has significant economic and zoonotic implication for the rural communities in Ethiopia in consequence of their traditional life styles, feeding habits and disease patterns. Hence, knowledge of brucellosis occurrence in traditional livestock husbandry practice has considerable importance in reducing the economic and public health impacts of the disease.

Methods

A total of 1623 cattle sera were serially tested using the rose Bengal test as screening and complement fixation test as confirmatory tests. The Stata survey command was used to establish prevalences for the overall and individual variables, while potential risk factors for seropositivity were analyzed using a multivariable logistic regression analysis.

Results

The results showed that 3.5% (95% CI = 2.4, 4.5%) of the animals and 26.1% (95% CI = 18.6, 33.7) of the herds tested had antibodies against Brucella species. Village level seroprevalence ranged from 0% to 100%. A higher seroprevalence was observed in pastoral system than mixed farming although this variable was not significant in the final model. The final logistic regression model identified herd size; with large (odd ratio (OR) = 8.0, 95% CI = 1.9, 33.6) and medium herds (OR = 8.1, 95% CI = 1.9, 34.2) showing higher risk of Brucella infection when compared to small herds. Similarly, the odds of Brucella infection was higher in cattle aged above 4 years when compared to age groups of 1-2 (OR = 5.4, 2.1, 12.9) and 3-4 years (OR = 3.1, 95% CI = 1.0, 9.6). Herd level analysis of the risk factors revealed that large and medium herds as well as herds kept with multiple livestock species were at higher risk of acquiring Brucella infection. Brucellosis in traditional livestock husbandry practices certainly poses a zoonotic risk to the public, in consequence of raw milk consumption, close contact with animals and provision of assistance during parturition. Due to lack of diagnostic facilities and information on its occurrence, human brucellosis is most likely misdiagnosed for other febrile diseases prevailing in the areas and treated empirically.

Conclusions

The results of this study demonstrated that bovine brucellosis is widely prevalent in the study areas particularly in pastoral production system. Hence, the study suggests the need for implementing control measures and raising public awareness on prevention methods of brucellosis.     

Shedding of food-borne pathogens and microbiological carcass contamination in rabbits at slaughter

To obtain microbiological data from rabbits at slaughter, 500 fecal samples and 500 carcasses samples were examined. All samples tested negative for Listeria and Salmonella. Campylobacter were detected in two fecal samples. Of the 500 fecal samples, 45.8% tested positive for eae (intimin), 1.2% for stx (Shiga toxin), and 1.8% for both eae and stx. By colony hybridization, 56 eae positive Escherichia coli strains were isolated. Among them, 27 strains (48.2%) were of the serotypes O178:H7 and O153:H7, whereas 15 strains (26.8%) belonged to a serogroup that has not yet been described (O(CB10681):H7). All strains possessed intimin beta1 and the translocated intimin receptor (tir) capable of being tyrosine phosphorylated. None of the strains harbored the genes for Shiga toxins, EAST1 (astA), bundlin (bfpA), or the EAF plasmid. Slaughter rabbits therefore constitute a reservoir for certain atypical enteropathogenic Escherichia coli. On rabbit carcasses, average total bacterial counts accounted for 3.3 log CFU cm(-2). Enterobacteriaceae and coagulase positive staphylococci (CPS) were detected on 118 (23.6%) and 153 (30.6%) carcasses, respectively. Enterobacteriaceae and CPS counts of positive samples were mainly <1.5 log CFU cm(-2). Among 153 selected CPS isolates, 98.7% were identified as Staphylococcus aureus. None of the 151 isolated strains harbored the gene for methicillin resistance (mecA). Genes for staphylococcal enterotoxins (SE) were detected in 102 strains. The combinations of seg and sei (53 strains) and sed, seg, sei, and sej (27 strains) dominated.     

Infection control practices and zoonotic disease risks among veterinarians in the United States

OBJECTIVE-To assess the knowledge and use of infection control practices (ICPs) among US veterinarians. DESIGN-Anonymous mail-out population survey. PROCEDURES-In 2005 a questionnaire was mailed to US small animal, large animal, and equine veterinarians who were randomly selected from the AVMA membership to assess precaution awareness (PA) and veterinarians' perceptions of zoonotic disease risks. Respondents were assigned a PA score (0 to 4) on the basis of their responses (higher scores representing higher stringency of ICPs); within a practice type, respondents' scores were categorized as being within the upper 25% or lower 75% of scores (high and low PA ranking, respectively). Characteristics associated with low PA rankings were assessed. RESULTS-Generally, respondents did not engage in protective behaviors or use personal protective equipment considered appropriate to protect against zoonotic disease transmission. Small animal and equine veterinarians employed in practices that had no written infection control policy were significantly more likely to have low PA ranking. Male gender was associated with low PA ranking among small animal and large animal veterinarians; equine practitioners not working in a teaching or referral hospital were more likely to have low PA ranking than equine practitioners working in such institutions. CONCLUSIONS AND CLINICAL RELEVANCE-Results indicated that most US veterinarians are not aware of appropriate personal protective equipment use and do not engage in practices that may help reduce zoonotic disease transmission. Gender differences may influence personal choices for ICPs. Provision of information and training on ICPs and establishment of written infection control policies could be effective means of improving ICPs in veterinary practices.     

Ectoparasites of livestock in Europe and the Mediterranean region

Arthropod ectoparasites can have a major impact on the productivity and welfare of livestock. In recent years, many parts of Europe have seen important changes in the nature of animal husbandry and parasite control, which have increased the need for a precise understanding of the current distribution and prevalence of livestock ectoparasites. In some cases, these changes have been associated with moves towards increased productivity, such as higher-stocking densities, large-scale rearing units, indoor confinement, reduced genetic diversity and large-scale movement of animals and, in others, with a move towards organic farming. There have also been changes in parasite control, associated with the development of new parasiticides, such as the macrocyclic lactones, and concern over the continued use of some of the older neurotoxic compounds. These changes have been exacerbated by outbreaks of endemic disease, the threats of exotic disease introduction and fears of potential changes in arthropod distribution associated with climate change. This paper therefore, reviews the current status of livestock ectoparasites in Europe and the Mediterranean region.     

Knowledge, attitudes and practices of traceability among livestock traders in south-western Nigeria: implications for sustainable livestock industry

Livestock diseases and other animal health events are a threat to achieving sustainable livestock industry. The knowledge of trace-back and the practice of providing feedback on diseases encountered in slaughtered animals from the abattoir to the farm can help limit the spread as well as manage potential future incidents of such diseases. We assessed the knowledge, attitudes and practices of 200 willing livestock traders on traceability in Bodija Municipal Abattoir, south-western Nigeria. The results reveal that the majority of these traders had poor knowledge (79.5 %) and practices (74.0 %) of traceability, though 89.5 % demonstrated good attitudes. While 22.9 % knew that traceability could be an effective means to control diseases, only a lower proportion (9.0 %) knew the health status of the animals being purchased. Though 29.0 % reported the diseases encountered in their animals during slaughter to the farm, only 9.5 % followed up to ensure the farmers take steps at preventing further occurrence of the reported diseases. While age (p?=?0.000; 0.014) and education (p?=?0.000; 0.000) were both significant for good knowledge and attitudes, frequency of condemned cases (p?=?0.000) and length of years in the trade (p?=?0.004) were, respectively, significant for good knowledge and attitudes with none associated with practice. These poor levels of knowledge and practices of traceability are a threat to sustainable livestock industry, food security and human health; hence, there is an urgent need to institute national feedback mechanism on slaughtered animals in order to strengthen interventions against diseases at farm levels.     

Simultaneous occurrence of selected food-borne bacterial pathogens on bovine hides, carcasses and beef meat

The aim of this study was to determine the simultaneous occurence of Salmonella spp., L. monocytogenes, verotoxigenic E. coli (VTEC), and Campylobacter spp. in slaughtered cattle and in beef meat subjected for human consumption. A total of 406 bovine hides and 406 corresponding carcasses were used to collect the samples with a swab method after exsanguination and evisceration of animals, respectively. Furthermore, 362 beef meat samples were purchased in local retail shops over the same period of time as for the bovine samples. Food-borne bacterial pathogens were identified with standard ISO methods with some modification by the use of PCR for VTEC. The isolated bacteria were then molecularly speciated (Campylobacter), serotyped (L. monocytogenes) and characterized for the presence of several virulence marker genes (VTEC and Campylobacter). It was found that 49 hide (12.1%) and 3 (0.7%) carcass samples were contaminated with more than one bacterial pathogen tested. Most of the hides were positive for Campylobacter spp. and VTEC (27 samples) and Campylobacter spp. together with L. monocytogenes (12 samples). Eight bovine hides contained L. monocytogenes and VTEC while L. monocytogenes and Salmonella spp. were detected in one sample. Furthermore, 3 pathogens (Campylobacter spp., L. monocytogenes and VTEC) were simultaneously identified in one bovine hide tested. In case of bovine carcasses 2 samples contained Campylobacter spp. and VTEC whereas one carcass was positive for L. monocytogenes and VTEC. On the other hand, 10 out of 362 (2.8%) minced beef samples were contaminated with at least two pathogens tested. The majority of these samples were contaminated with L. monocytogenes and Salmonella spp. (6 samples). It was noticed that equal number of C. jejuni and C. coli were found, irrespective of the origin of the samples. Most of the strains possessed more than one pathogenic factor as identified by PCR. Molecular serotyping of L. monocytogenes revealed that the majority of the isolates (27 out of 31; 87.1%) belonged to 1/2a serogroup. It was found that most of the VTEC isolates possessed the Shiga toxin stx2 gene (12 strains) whereas only 2 strains were str1-positive. The eneterohemolysin and intimin markers were identified only in 7 and 2 isolates, respectively. PCR analysis revealed that 4 VTEC belonged to O91 serogroup, 2 strains were O145 and 1 isolate was identified as O113. None of the VTEC detected in the study was O157 serogroup.     

Veterinarian injuries associated with bovine TB testing livestock in Michigan, 2001

Testing all the cattle in an entire state with a uniform procedure for each animal affords an opportunity to relate human injury data to a known number of animals handled while carrying out a standardized procedure. Our objective was to describe the type and incidence density of injuries associated with TB-testing a large number of cattle herds, and to delineate the various factors associated with the risk of injury. A survey was mailed to all veterinarians (N = 259) who had completed at least five official bovine TB (bTB) herd tests in Michigan in 2001. We collected data regarding basic demographics and health status, work experience, veterinary specialty, and practice information. Each veterinarian was also requested to complete a separate injury questionnaire for each injury received while TB testing livestock in 2001. Accurate addresses were found for 247 eligible veterinarians, 175 (71%) of whom returned the survey. Thirty-six veterinarians reported a total of 53 injuries (10 major, 12 minor and 31 self-treated). Hands (29%) and legs (21%) were the anatomic locations most frequently injured, with sprains/strains (30%) and abrasion/contusion (30%) the most common types of injuries sustained. The overall incidence density of injuries was 1.9 per 10,000 animals tested. Female gender (RR = 3.3), being employed by the government (RR = 4.5), and smoking (RR = 6.0) were significantly associated with a higher rate of injury. Significant colliniearities were found between some risk factors associated with an increased rate of injury and participants thought 81% of their injuries could have been prevented. These results are explained by the administrative structure of the bTB testing program in Michigan, and the changing demographics of the veterinary workforce.     

Risk factors for bacterial zoonotic pathogens in acutely febrile patients in Mpumalanga Province,South Africa

Endemic zoonoses, such as Q fever and spotted fever group (SFG) rickettsiosis, are prevalent in South Africa, yet often undiagnosed. In this study, we reviewed the demographics and animal exposure history of patients presenting with acute febrile illness to community health clinics in Mpumalanga Province to identify trends and risk factors associated with exposure to Coxiella burnetii, the causative agent of Q fever, and infection by SFG Rickettsia spp. Clinical and serological data and questionnaires elucidating exposure to animals and their products were obtained from 141 acutely febrile patients between 2012 and 2016. Exposure or infection status to C. burnetii and SFG Rickettsia spp. was determined by presence of IgG or IgM antibodies. Logistic regression models were built for risk factor analysis. Clinical presentation of patients infected by SFG rickettsiosis was described. There were 37/139 (27%) patients with a positive C. burnetii serology, indicative of Q fever exposure. Patients who had reported attending cattle inspection facilities (“dip tanks”) were 9.39 times more likely to be exposed to Q fever (95% CI: 2.9–30.4). Exposure risk also increased with age (OR: 1.03, 95% CI: 1.002–1.06). Twenty‐one per cent of febrile patients (24/118) had evidence of acute infection by SFG Rickettsia spp. Similarly, attending cattle inspection facilities was the most significant risk factor (OR: 8.48, 95% CI: 1.58–45.60). Seropositivity of females showed a significant OR of 8.0 when compared to males (95% CI: 1.49–43.0), and consumption of livestock was associated with a decreased risk (OR: 0.02, 95% CI: 0.001–0.54). A trend between domestic cat contact and SFG rickettsiosis was also noted, albeit borderline non‐significant. In this endemic region of South Africa, an understanding of risk factors for zoonotic pathogens, including exposure to domestic animals, can help clinic staff with diagnosis and appropriate therapeutic management of acutely febrile patients as well as identify target areas for education and prevention strategies.     

Towards sustainable parasite control practices in livestock production with emphasis in Latin America

Endo and ectoparasites of domestic ruminants directly or indirectly contribute to reduce sustainability affecting food security in subsistence or small scale farming systems, food safety (food borne diseases and pesticide residues), environment (pesticides, pollution and ecotoxicity) and farmer's equity (limited or uneven access to relevant technical information/training). This is especially true for some regions of Latin America where there still are huge areas of natural grazing land for cattle, sheep and goats. Sustainable parasite control is not an absolute concept given the different regions and productive systems of the world and therefore, could have different levels of adoption and impact on farmers. This article develops a conceptual framework to better understand where each region or country is situated in terms of attaining a reasonable increase in animal production while preserving sustainability. Within this context the capacity to prioritize the target parasite species for control according to local epidemiology and production systems, the early diagnosis and monitoring of parasite resistance as well as the availability of well trained field professionals acquire a major role, creating an enabling environment for present and future decision support system approaches. Until new and different means of controlling parasites become available; the challenge is to utilize Good Animal Husbandry Practices and Integrated Parasite Management (IPM) principles in a pragmatic way allowing the rational use of pesticides.