Defining syndromes using cattle meat inspection data for syndromic surveillance purposes: a statistical approach with the 2005-2010 data from ten French slaughterhouses

Evaluating swine disease occurrence on farms using the state-space model based on meat inspection data: a time-series analysis

BACKGROUND

Data on abnormal health conditions in animals obtained from slaughter inspection are important for identifying problems in fattening management. However, methods to objectively evaluate diseases on farms using inspection data has not yet been well established. It is important to assess fattening management on farms using data obtained from slaughter inspection. In this study, we developed the state-space model to evaluate swine morbidity using slaughter inspection data.

RESULTS

The most appropriate model for each disease was constructed using the state-space model. Data on 11 diseases in slaughterhouses over the past 4 years were used to build the model. The model was validated using data from 14 farms. The local-level model (the simplest model) was the best model for all diseases. We found that the analysis of slaughter data using the state-space model could construct a model with greater accuracy and flexibility than the ARIMA model. In this study, no seasonality or trend model was selected for any disease. It is thought that models with seasonality were not selected because diseases in swine shipped to slaughterhouses were the result of illness at some point during the 6-month fattening period between birth and shipment.

CONCLUSION

Evaluation of previous diseases helps with the objective understanding of problems in fattening management. We believe that clarifying how farms manage fattening of their pigs will lead to improved farm profits. In that respect, it is important to use slaughterhouse data for fattening evaluation, and it is extremely useful to use mathematical models for slaughterhouse data. However, in this research, the model was constructed on the assumption of normality and linearity. In the future, we believe that we can build a more accurate model by considering models that assume non-normality and non-linearity.

Estimation of genetic parameters for visceral diseases of fattening Japanese Black cattle in Shimane Prefecture, Japan

In this study, the genetic parameters of major visceral diseases were estimated using the postmortem inspection records of 9057 fattening Japanese Black cattle in Shimane Prefecture, Japan, and the genetic correlation between visceral diseases and carcass traits was analyzed. There were six visceral diseases with a prevalence of 5% or higher, namely, pleurisy, pneumonia, bovine abdominal fat necrosis (BFN), rumenitis, hemorrhagic hepatitis, and perihepatitis. Variance components were estimated using the Gibbs sampling method, and the heritability of the visceral disease ranged from 0.07 to 0.49 for perihepatitis and BFN, respectively. Significant negative genetic correlations were identified between pleurisy and rib thickness (-0.32), BFN and carcass weight (-0.29), and BFN and rib eye area (-0.22). No significant genetic correlation was observed among the visceral diseases. The least squares analysis of variance suggested that some visceral diseases decrease the value of carcass traits. In particular, carcass weight and rib eye area in individuals with BFN were 11.7 kg and 1.87 cm2 lower than those of healthy cattle, respectively. Thus, it was inferred that genetic factors were involved in the visceral diseases of fattening Japanese Black cattle in Shimane Prefecture.

The Incidence of Liver Damage Found during Postmortem Examination at the Slaughterhouse

We monitored liver damage in cattle (cows, heifers, fattening bulls, and calves culled from the herd), pigs (sows, finishing pigs, and piglets culled from the farm), sheep (ewes and lambs), goats (does and kids), rabbits, and poultry (end-of-lay hens, broiler chickens, turkeys, domestic ducks, and domestic geese) in the period from 2010 to 2021. All animals (n = 1,425,710,143) reared on Czech farms and slaughtered at slaughterhouses in the Czech Republic were included in the analysis. We determined the total number of damaged livers for individual categories of animals and also analyzed separately the incidence of damage of acute, chronic, parasitic, and other origin. The overall incidence of liver damage was higher in adult animals compared to fattening animals in all species. In cattle and pigs, the incidence was also higher in young animals culled from the herd compared to fattening animals. When comparing adult animals by species, the incidence of liver damage was highest in cows (46.38%), followed by sows (17.51%), ewes (12.97%), and does (4.26%). When comparing fattening animals by species, the incidence was highest in heifers (14.17%) and fattening bulls (7.97 %), followed by finishing pigs (11.26%), lambs (4.73%), and kids (0.59%). When comparing young culled from the herd by species, it was higher in piglets (32.39%) than in calves (17.6 %), and when poultry and rabbits were compared, the incidence was highest in turkeys (3.38%), followed by ducks (2.20%), geese (1.09%), broiler chickens (0.08%), and rabbits (0.04%). The results indicate that fattening animals have a better liver condition than mature animals and that culled young have a worse liver condition than older fattening animals. Chronic lesions represented the dominant proportion of pathological findings. Parasitic lesions occurred, first and foremost, in animals grazed on meadows with likely parasitic invasion, i.e., in ewes (7.51%), lambs (3.51%), and heifers (1.31%), and in animals in which antiparasitic protection is limited in view of the protection of meat from antiparasitic residues, i.e., finishing pigs (3.68%). Parasitic damage to the liver was rarely detected in rabbits and poultry. The results obtained represent a body of knowledge for measures to improve the health and condition of the liver in food animals.

The Importance of the Slaughterhouse in Surveilling Animal and Public Health: A Systematic Review

From the point of public health, the objective of the slaughterhouse is to guarantee the safety of meat in which meat inspection represent an essential tool to control animal diseases and guarantee the public health. The slaughterhouse can be used as surveillance center for livestock diseases. However, other aspects related with animal and human health, such as epidemiology and disease control in primary production, control of animal welfare on the farm, surveillance of zoonotic agents responsible for food poisoning, as well as surveillance and control of antimicrobial resistance, can be monitored. These controls should not be seen as a last defensive barrier but rather as a complement to the controls carried out on the farm. Regarding the control of diseases in livestock, scientific research is scarce and outdated, not taking advantage of the potential for disease control. Animal welfare in primary production and during transport can be monitored throughout ante-mortem and post-mortem inspection at the slaughterhouse, providing valuable individual data on animal welfare. Surveillance and research regarding antimicrobial resistance (AMR) at slaughterhouses is scarce, mainly in cattle, sheep, and goats. However, most of the zoonotic pathogens are sensitive to the antibiotics studied. Moreover, the prevalence at the slaughterhouse of zoonotic and foodborne agents seems to be low, but a lack of harmonization in terms of control and communication may lead to underestimate its real prevalence.

The Value of Current Ante Mortem Meat Inspection and Food Chain Information of Dairy Cows in Relation to Post Mortem Findings and the Protection of Public Health: A Case for a More Risk-Based Meat Inspection

In this study, the contribution of the ante mortem (AM) inspection and the food chain information (FCI) to ensuring meat safety and public health was investigated, by evaluating the slaughterhouse findings of 223,600 slaughtered dairy cows in the Netherlands. The outcome of this study was that the ante mortem (AM) and post mortem (PM) inspections have a substantial overlap, and that with regard to food safety and public health in over 99% of cases the PM could even be omitted on the basis of the AM. In this study, the data provided by the dairy farmers on the current FCI forms contributed little to nothing with regard to the outcomes of AM and PM inspection. It is concluded that current meat inspection procedures need an update and a more risk-based approach needs to be adopted. Regarding this, the AM inspection of dairy cattle should remain, because it plays an important role in ensuring food safety (e.g., by preventing contamination of the slaughter line by excessively dirty animals, or animals with abscesses), monitoring animal welfare and in detecting some important notifiable diseases. The PM inspection, however, could in many cases be omitted, provided there is a strict AM inspection complemented by a vastly improved (automated) way of obtaining reliable FCI.

Perspectives of economic losses due to condemnation of cattle and buffalo carcasses in the northern region of Brazil

The work aims to study the economical losses of the condemnation of bovine and buffalo carcasses, in order to estimate the losses in animals slaughtered in Santarém-Pará, Brazil, between 2016 and 2018, with data obtained from the Municipal Department of Agriculture and Fisheries. Sex, age, origin, total number of animals slaughtered and causes of condemnation of carcasses were considered. All analyzes were performed in RStudio version 1.1.463. In this study, 71,277 bovine carcasses and 2,016 buffalo carcasses were inspected, of which 300 bovine and 71 buffalo were condemned. The highest prevalence of causes of condemnation in cattle was recorded for brucellosis (0.0020%) and tuberculosis (0.0019%). In buffaloes, tuberculosis (0.0307%) peritonitis (0,0019%) were the main causes of condemnations. Economical losses were more evident in females, for both species. The projection of economical losses related to the condemnation of carcasses showed a sharp growth for the next three years, if the average growth remains constant. The biggest projected loss was for bovine females, with an accumulated projection of $ 5,451.44. The smallest estimated loss was for buffalo males, projected at more than thirty-two thousand reais. The most important causes of condemnation report the diseases brucellosis and tuberculosis, as the ones with the greatest impact. In the buffalo species this was even more accentuated, even though the number of buffaloes slaughtered is more than 35 times smaller than the number of cattle.

Analysis of bovine postmortem condemnation data in France: Contributions from a comprehensive and standardised information system at the slaughterhouse

BACKGROUND

The condemnation of carcases and offal unfit for human consumption is a regulatory requirement at the slaughterhouse. Condemnation data, if comprehensive and standardised, can be a valuable source of information for risk-based inspection and decision making.

METHODS

The aim of this study was to analyse postmortem condemnation data that were recorded in all bovine slaughterhouses in mainland France from 1 January 2016 to 31 December 2020 in a comprehensive and standardised information system. The rates of and reasons for condemnation, as well as factors influencing rate variation, were investigated through descriptive analysis and multivariable logistic regression models.

RESULTS

The global, total and partial condemnation rates were 4.5%, 0.7% and 3.8% for adult cattle and 1.4%, 0.3% and 1.1% for calves, respectively. Reasons for condemnation varied with the animal category; for example, the three main reasons for total condemnation in adult cattle were serous infiltration of connective tissue (49% of condemned animals), congestive peritonitis (12.2%) and fibrinous peritonitis (10.9%), whereas the top three reasons for partial condemnation were unique abscess (21.9%), haemorrhagic infiltration (20.6%) and muscular sclerosis (17.4%). Condemnation rates were influenced by animal-related factors (sex, age, type of breed) and slaughterhouse-related factors (status, type, slaughter volume).

CONCLUSION

Our findings could usefully contribute to the continuous improvement of the harmonisation of inspection decisions and support the risk manager's strategy in the modernisation of official controls at the slaughterhouse.

Body condition scores, fluke intensity, liver pathology, and carcass quality of different dairy cattle genotypes infected with Fasciola species at high throughput abattoirs in South Africa

Milk is an essential commodity whose demand far exceeds supply. However, dairy animal productivity is constantly hampered by parasitic diseases such as fasciolosis, affecting milk production. Despite the negative impact of liver fluke on milk production, there is little information on liver fluke infection and associated abattoir losses (body weight, condition score, liver pathology, and carcass quality) in culled dairy cattle. This study aimed to determine body condition scores, fluke intensity, liver pathology, and carcass quality of different cattle genotypes infected with Fasciola species at three commercial abattoirs. A longitudinal study was conducted from September 2019 to October 2020 to determine body condition score, liver fluke intensity, liver pathology in 3065 dairy cattle slaughtered in CA1, CA2, and CA3, of the Eastern Cape Province South Africa. Liver fluke intensity significantly increased with cattle age (P < 0.0001). Cattle ≥ 7 years old (59.93 ± 6.42) and those 4 to 6 years old (49.78 ± 9.98) had higher infection than those 2 to 3 years old (27.55 ± 13.68). The liver fluke infection was significantly (P < 0.001) the highest when sampling was conducted in summer, followed by autumn and winter, and least for spring. The differences in carcass weights or body condition scores decreased by 0.99 units (P < 0.0001) or 0.97 units (P < 0.0001) respectively. Therefore, this study suggests that fluke infection could be responsible for considerable economic and production losses mainly due to condemnation and weight loss in dairy cattle. This study recommended a combination of holistic and grazing management to control infection rates in dairy herds.

Health status of slaughtered animals as indicated by postmortem inspection at slaughterhouses

The study focused on the comparison of health of cattle, pigs, sheep, goats, rabbits, poultry and ostriches slaughtered in slaughterhouses in the Czech Republic based on the occurrence of findings detected during a postmortem veterinary inspection in the period from 2010 to 2019. The level of health was expressed as the so-called PA index obtained by the ratio of the number of findings to the total number of observations (15) during the pathoanatomical examination in the slaughterhouse multiplied by one hundred. Mammals (cattle, pigs, sheep and goats) generally had a higher PA index than birds (domestic chickens, turkeys, ducks, geese, ostriches), with the exception of kids and rabbits. The highest PA index was found in cows (15.13) and piglets (12.18); whereas the lowest PA index was found in broiler chickens (0.102), rabbits, and geese (both 0.14). In poultry, the PA index values were below 1, with the exception of laying hens (PA index 2.165). A higher PA index was found in a group of adult animals (the PA index ranged from 2.17 to 15.13) and groups of young animals culled from farms (the PA index ranged from 10.79 to 12.18) than in fattened animals (the PA index ranged from 0.10 to 5.32). A comprehensive overview of the health condition of slaughtered animals enables the farmers, veterinarians, transporters and slaughterhouse operators to take appropriate and precisely targeted preventive measures, thereby increasing the animal welfare and health in the future while reducing the incidence of carcass damage.

Enhancing the value of meat inspection records for broiler health and welfare surveillance: longitudinal detection of relational patterns

Background

Abattoir data are under-used for surveillance. Nationwide surveillance could benefit from using data on meat inspection findings, but several limitations need to be overcome. At the producer level, interpretation of meat inspection findings is a notable opportunity for surveillance with relevance to animal health and welfare. In this study, we propose that discovery and monitoring of relational patterns between condemnation conditions co-present in broiler batches at meat inspection can provide valuable information for surveillance of farmed animal health and welfare.

Results

Great Britain (GB)-based integrator meat inspection records for 14,045 broiler batches slaughtered in nine, four monthly intervals were assessed for the presence of surveillance indicators relevant to broiler health and welfare. K-means and correlation-based hierarchical clustering, and association rules analyses were performed to identify relational patterns in the data. Incidence of condemnation showed seasonal and temporal variation, which was detected by association rules analysis. Syndrome-related and non-specific relational patterns were detected in some months of meat inspection records. A potentially syndromic cluster was identified in May 2016 consisting of infection-related conditions: pericarditis, perihepatitis, peritonitis, and abnormal colour. Non-specific trends were identified in some months as an unusual combination of condemnation reasons in broiler batches.

Conclusions

We conclude that the detection of relational patterns in meat inspection records could provide producer-level surveillance indicators with relevance to broiler chicken health and welfare.

Added Value of Meat Inspection Data for Monitoring of Dairy Cattle Health in the Netherlands

Meat inspection records of one large cattle slaughterhouse were analyzed to evaluate the added value of slaughterhouse data for cattle health surveillance in the Netherlands. Data were available from January 2015 to September 2018, consisting of 467,361 meat inspection records. Analyses included (1) an assessment of the representativeness of the cattle herds in the slaughterhouse data in relation to the cattle herd population in the Netherlands, and (2) multivariable analyses to quantify associations between meat inspection findings and farm of origin characteristics, and the trends in time of the findings in slaughtered cattle. Ninety percent of the meat inspection records originated from dairy cattle therefore this paper only presents the results of dairy herds (N = 422,194 cattle). The dairy herds in the slaughterhouse data seemed representative for the Dutch dairy population although their regional coverage differed from the distribution of dairy herds in the Netherlands. Non-dairy herds were underrepresented in the slaughterhouse data which stresses the importance of the inclusion of data from other slaughterhouses that may be more specialized in slaughtering beef cattle. Inspection records were categorized into 15 indicators related to ante-mortem and post-mortem findings. Following multivariable analyses, seven indicators were deemed of added value to existing cattle health surveillance components, as they provided either new information or information regarding specific health problems.

Incidence of Characteristic Findings during Veterinary Carcass Inspections 2010-2019 in the Czech Republic and the Relation to the Level of Health and Welfare of Individual Classes of Cattle

Pathological findings in individual classes of cattle were assessed from the viewpoint of their localization and category. The objective of the study was to evaluate whether there are differences in the range and number of findings made between the individual classes of cattle. The results of veterinary inspections on 2,514,666 head of cattle slaughtered in the Czech Republic in the period 2010-2019 were used for the assessment. In terms of localization, the most frequent findings in cows were in the liver and pancreas (46.13%), the urinary tract (40.76%) and the lungs (36.23%). These findings also predominated in heifers and bulls, though they were recorded at lower frequencies (p < 0.01) than in cows. The most frequent pathological changes in heifers and bulls were chronic findings in the lungs (16.09% and 12.27%, respectively). The range of findings in calves differed significantly from other classes of cattle, primarily as the result of respiratory and diarrheal syndrome being the most frequent diseases in calves. Calves were the class of cattle most frequently diagnosed with findings in the lungs (44.89%), as well as other unclassified changes (24.43%) and overall changes (21.55%), which point to a systemic disorder of the organism. The results of this study confirmed the differing states of health in the individual classes of cattle and the differing health issues to which treatment and the prevention of the most frequently occurring infectious and non-infectious diseases must be adapted. Cattle welfare is affected not only by the level of health but also by the herd management and economics. This is confirmed by the range of findings, and the deterioration of living conditions especially in cows, likely because of great intensity of farming, but also in calves which suffered from emaciation or stunted growth.

A study on causes of cattle liver condemnation at an abattoir in Omdurman area, Khartoum State, Sudan

BACKGROUND

Information obtained from abattoirs on the causes of liver condemnation is important in preventing the spread of diseases and for promoting food security. The current study reviews three years (2009 to 2011) postmortem inspection records of cattle slaughtered at an abattoir in Omdurman, Khartoum State, Sudan. The aim was to determine the prevalence of diseases and conditions that lead to liver condemnation.

RESULTS

From a total of 234,175 cattle slaughtered, 8,910 (3.8%) livers were condemned due to several diseases/conditions mainly fasciolosis, cysticercosis, necrosis, abscess, calcification, hemorrhages, liver cirrhosis, hydatidosis, and other miscellaneous causes. Collectively, fasciolosis was the leading cause of liver condemnation and was responsible for 51.6 % of total liver condemnations followed by necrosis (18.6%), and cysticercosis (13.5%).

CONCLUSIONS

Because of their zoonotic nature, the observed high frequency of some detected diseases/conditions is thought to pose a public health risk among consumers. This survey could be used as a regional baseline for future monitoring of control programmers against these liver diseases.

Factors associated with cattle necropsy submissions in Switzerland, and their importance for surveillance

Pathology data have been reported to be important for surveillance, as they are crucial for correctly recognizing and identifying new or re-emerging diseases in animal populations. However, there are no reports in the literature of necropsy data being compared or complemented with other data. In our study, we compared cattle necropsy reports extracted from 3 laboratories with the Swiss fallen stock data and clinical data collected by the association of Swiss Cattle Breeders. The objective was to assess the completeness, validity and representativeness of the necropsy data, as well as evaluate potential factors for necropsy submission and how they can benefit animal health surveillance. Our results showed that, on average, 1% of Swiss cattle that die are submitted for post-mortem examinations. However, different factors influence cattle necropsy submissions, such as the age of the animal, the geographical location and the number of sick and/or dead animals on the farm. There was a median of five animals reported sick and two animals reported dead within 30 days prior to a necropsy submission, providing quantitative evidence of a correlation between on farm morbidity/mortality and post-mortem examination. Our results also showed that necropsy data can help improve the accuracy and completeness of health data for surveillance systems. In this study, we were able to demonstrate the importance of veterinary pathology data for AHS by providing quantitative evidence that necropsied animals are indicative of farms with important disease problems and are therefore critically important for surveillance. Furthermore, thanks to the amount of information provided by combined data sources, the epidemiology (e.g. season, geographic region, risk factors) of potential diseases can be analysed more precisely and help supporting animal health surveillance systems.

Prevalence of Bovine Tuberculosis in Slaughtered Cattle in Sicily, Southern Italy

Simple Summary

Mycobacterium bovis is a Gram-positive, acid-fast bacterium responsible for disease in cattle and in several other domestic and wild animal species, also representing a prominent cause of morbidity and mortality in humans. In Italy, the incidence of bovine tuberculosis (bTB) in cattle has been progressively reduced throughout the years; however, the disease still remains widespread in Southern Italy, with the highest prevalence rates recorded in Sicily. Specific eradication programs have been established, with herd testing and post-mortem inspection at the slaughterhouse used as diagnostic procedures to obtain epidemiological data on bTB prevalence. The concomitant use of these procedures is essential in epidemiological surveillance programs, and although data on disease prevalence at herd level are systematically collected and used for epidemiological surveillance in Sicily, data from post-mortem inspection are scant. Therefore, the current survey aimed to investigate the prevalence of bTB in cattle in Sicily during two different three-year periods, using data from meat inspections and histopathological methods. Results obtained show that even though bTB occurrence in cattle was well reduced over the years, the disease still remains widespread in this region, posing severe implications for public health and a prominent economic impact on the livestock industry.

Abstract

Post-mortem inspection in slaughterhouses plays a key role in the epidemiological surveillance of infectious diseases, including bTB. This study assessed the prevalence of bTB in cattle in Sicily during two different three-year periods (2010–2012; 2017–2019), using data from meat inspections and histopathological methods. Out of 100,196 cattle, 5221 (5.21%) were diagnosed with tuberculous lesions. Higher prevalence of bTB was recorded during the triennium 2010–2012 (6.74%; n = 3692) compared to the triennium 2017–2019 (3.36%; n = 1529), with a decreasing trend in annual occurrence throughout the study period and a heterogenous proportion of infected cattle among the Sicilian provinces (p < 0.01). Lower rates of infection were recorded in animals aged <12 months and >84 months (p < 0.0001). Pearson’s chi square analysis revealed a higher localization of lesions in the thoracic cavity (p < 0.0001). Gathered findings show that even though bTB occurrence in cattle was greatly reduced over the years, the disease still remains widespread in Sicily, also posing severe implications for public health.

Identification of production chain risk factors for slaughterhouse condemnation of broiler chickens'

Slaughterhouse condemnation of broiler chickens results from identification of polymorphic pathological conditions during meat inspection from arrival and on the slaughter line. While conditions that result in condemnation are multifactorial, identification of factors that are common for a number of categories could be valuable for developing strategies to reduce total condemnation. This study aimed to identify those condemnation categories that were most common in batches of broiler chickens and to determine and compare associated risk factors. In the first step, retrospective meat inspection records for 55,918 broiler batches from one large broiler integrator for 2015-2017 were used for association rules analysis. Results identified a network of nine associated condemnation categories: whole carcass condemnation for ascites, abnormal colour, perihepatitis, cellulitis, hard breast, tumours and dead on arrival, and liver only and heart only most often associated with hepatitis and pericarditis, respectively. Secondly, a longitudinal study collected data on 109 explanatory variables from broiler parental flocks to slaughterhouse characteristics between January 2015 and December 2017. Condemnation outcome data were obtained from meat inspection records for 539 broiler batches participating in the study. Parental flock-, rearing farm-, shed- and transport-level risk factors were assessed for each outcome using mixed-effects multivariable Poisson regression including shed and farm as random effects. A Poisson regression tree method was used as the first step to identify variables most relevant for analysis and comparison across the outcomes. No single production factor was associated with all nine of the condemnation outcomes investigated in this study, although some were shared across multiple outcomes: age of parental flock at time of lay, flock-level Campylobacter spp. frequency, broiler chick weight at seven days of age, weight at slaughter, type of broiler removal (i.e. thinning, final depopulation), catcher team, number of birds per transport crate, slaughterhouse shift number, and type of slaughterhouse line. Broiler chickens removed during final depopulation were at greatest risk of condemnation. Condemnation rates for cellulitis and tumours were found to be higher in broilers inspected by night shift at the slaughterhouse. Discovery of an apparent protective effect of a higher number of broilers per transport crate was unexpected. These findings provide information for the broiler industry on production chain factors that might be amenable to targeted intervention to improve future efforts for control of condemnation.

Economic impact of the liver condemnation of cattle infected with Fasciola hepatica in the Peruvian Andes

Fasciolosis is a zoonotic food- and waterborne infection related to great economic losses on ruminant production. In order to determine the prevalence of bovine liver condemnations due to fasciolosis in an abattoir at the Central Andes of Peru, we evaluated the records of an authorized slaughterhouse in Huancayo, at 3300 m above sea level, over 16 months. Subsequently, the average weights of condemned viscera and carcasses were also estimated to determine the direct and indirect economic losses. Fasciolosis was the main cause of liver condemnation, with a prevalence of 55.72% (3926/7046; CI 95%: 56.88-54.56%). The livers infected were more than double the amount of livers supplied to markets in this period. Although the average price of liver in the Peruvian Andes is very cheap, approximately 16.45 tons of livers were destroyed, estimating a direct economic loss of US$ 35,080 (CI 95%: US$ 29,178-40,938). The indirect loss due to decreased body weight gain (calculated using 10% of the average weight of a healthy animal carcass) was estimated at US$ 354,570 (CI 95%: US$ 387,908-US$ 321,227). Fasciolosis is an important zoonotic disease that threatens food security in the Andean region, with major repercussions on the income of the livestock industry and the availability of cheap protein sources.

Comparison of Finnish meat inspection records and average daily gain for cattle herds differing in Mycoplasma bovis test-status

Detecting Mycoplasma bovis on cattle farms represents a challenge in the absence of an outbreak or cases of M. bovis mastitis, yet identification of an infection is essential to control the spread of the disease successfully. The objectives of this study were: (1) to determine whether meat inspection records can aid identification of cattle farms supporting M. bovis infection, and (2) to compare the average daily weight gain estimated from carcass weight for cattle originating from farms differing in M. bovis test-status. Meat inspection records were collected from two abattoirs in 2015; 80 677 animals in total. All the dairy and mixed breed cows and bulls used for meat production were categorized according to known M. bovis infection status of the farms from which the cattle were derived; positive, contact or control farms. The associations between animals from different M. bovis categories and lung lesions of bulls and cows (pneumonia and pleuritis), identified during meat inspection, and estimated average daily gain (ADG) of bulls, were investigated. The odds ratios for lung lesions, especially pleuritis, were higher in M. bovis test-positive or contact farms compared with control farms. Additionally, odds ratios for pleuritis were higher among animals from M. bovis test-positive farms and animals from contact slaughtering farms originating from M. bovis-free rearing farms. Bulls originating from M. bovis test-positive farms had higher estimated average daily gain than cattle from control farms. Meat inspection records can be used alongside other methods to detect M. bovis-positive farms where M. bovis causes lung lesions.

Parasitic infections as major cause of abattoir condemnations in cattle slaughtered at an Ethiopian abattoir: 10-year retrospective study

Abattoirs are vital for gathering information on animal diseases and protecting the public from consuming infected or unhygienic meat. To assess the major reasons for organ and carcass condemnations and their financial implications, we reviewed 10-year abattoir records of slaughtered bovines between January 2005 and December 2014 at Kombolcha ELFORA abattoir, north-east Ethiopia. Of the 46,913 cattle slaughtered during that period, 17,963 (38.3%) had at least one disease condition. Lungs (10.67%) and liver (25%) were the most affected and condemned organs, followed by heart (1.53%), head (0.56%), tongue (0.17%) and kidney (0.32%). The major conditions responsible for condemnation were fasciolosis (49.89%), hydatid cyst (55.55%), pericarditis (78.2%), hydronephrosis (35.8%), abscess (71.7%) and abscess (43.9%), in liver, lung, heart, kidneys, head and tongue, respectively. The direct financial losses incurred from organ and carcass condemnation over the 10-year period amounted to ETB 1,219,399 (USD 61,946.9), with parasitic diseases such as fascioliasis and hydatidosis accounting for ETB 256,837.5 (USD 13,047.64) and ETB 170,827.5 (USD 8678.23) in losses, respectively. This study describes a significant loss of cheap and reliable sources of protein due to non-utilization of infected organs or carcasses, emphasizing the need to implement integrated approaches in disease surveillance and control programmes.

The annual, temporal and spatial pattern of Setaria tundra outbreaks in Finnish reindeer: a mechanistic transmission model approach

Background

In northern Finland (Lapland), reindeer are reared as semi-domesticated animals. The region has a short summer season of 2–3 months, yet reindeer are infected with the mosquito-borne filarioid parasite Setaria tundra. The infection causes peritonitis and perihepatitis, which cause significant economic losses due to reduced body weight of infected animals. The objective of this study was to: (i) describe the spatial and temporal pattern of outbreaks in three different areas across Finnish Lapland; and (ii) construct a temperature-driven mechanistic transmission model to quantify the potential role of temperature on intensity of S. tundra transmission in reindeer.

Methods

We developed a temperature-driven transmission model able to predict the number of S. tundra potentially transmitted from an infectious reindeer. We applied the model to the years 2004–2015, and compared the predictions to the proportion of reindeer whose livers were condemned due to S. tundra infection at the time of slaughter.

Results

The mean proportion of liver condemnation increased in reindeer slaughtered in late autumn/winter compared to earlier dates. The outbreaks were geographically clustered each year but there were no fixed foci where outbreaks occurred. Larger outbreaks were recorded in the southern regions of reindeer-herding areas compared to the central or northern parts of Lapland. Our model showed that temperatures never allowed for transmission of more than a single generation of S. tundra each season. In southern (Kuusamo) and central (Sodankylä) Lapland, our model predicted an increasing trend from 1979 to 2015 for both the duration of the effective transmission period of S. tundra (P < 0.001) and for the potential number of L3 S. tundra larvae being transmitted from an infectious reindeer (P < 0.001).

Conclusions

The effective transmission period for S. tundra in reindeer is very short in Lapland, but it increased over the period studied. Only one generation of S. tundra can be transmitted in one season among reindeer in Lapland. Increasing temperatures may facilitate a range expansion and increasing duration of effective transmission period for S. tundra.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-3159-z) contains supplementary material, which is available to authorized users.

Characterization of the Temporal Trends in the Rate of Cattle Carcass Condemnations in the US and Dynamic Modeling of the Condemnation Reasons in California With a Seasonal Component

Based on the 2016 National Cattlemen's Beef Association statistics, the cattle inventory in the US reached 93.5 million head, from which 30.5 million were commercial slaughter in 2016. California ranked fourth among all the US states that raise cattle and calves, with 5.15 million head and approximately 1.18 million slaughtered animals per year. Approximately 0.5% of cattle carcasses in the US are condemned each year, which has an important economic impact on cattle producers.In this study, we first described and compared the temporal trends of cattle carcass condemnations in all the US states from Jan-2005 to Dec-2014. Then, we focused on the condemnation reasons with a seasonal component in California and used dynamic harmonic regression (DHR) models both to model (from Jan-2005 to Dec-2011) and predict (from Jan-2012 to Dec-2014) the carcass condemnations rate in different time horizons (3 to 12 months).Data consisted of daily reports of 35 condemnation reasons per cattle type reported in 684 federally inspected slaughterhouses in the US from Jan-2005 to Dec-2014 and the monthly slaughtered animals per cattle type per states. Almost 1.5 million carcasses were condemned in the US during the 10 year study period (Jan 2005-Dec 2014), and around 40% were associated with three condemnation reasons: malignant lymphoma, septicemia and pneumonia. In California, emaciation, eosinophilic myositis and malignant lymphoma were the only condemnation reasons presenting seasonality and, therefore, the only ones selected to be modeled using DHRs. The DHR models for Jan-2005 to Dec-2011 were able to correctly model the dynamics of the emaciation, malignant lymphoma and eosinophilic myositis condemnation rates with coefficient of determination (Rt2) of 0.98, 0.87 and 0.78, respectively. The DHR models for Jan-2012 to Dec-2014 were able to predict the rate of condemned carcasses 3 month ahead of time with mean relative prediction error of 33, 11, and 38%, respectively. The systematic analysis of carcass condemnations and slaughter data in a more real-time fashion could be used to identify changes in carcass condemnation trends and more timely support the implementation of prevention and mitigation strategies that reduce the number of carcass condemnations in the US.

The value of necropsy reports for animal health surveillance

BACKGROUND

Animal health data recorded in free text, such as in necropsy reports, can have valuable information for national surveillance systems. However, these data are rarely utilized because the text format requires labor-intensive classification of records before they can be analyzed with using statistical or other software. In a previous study, we designed a text-mining tool to extract data from text in necropsy reports. In the current study, we used the tool to extract data from the reports from pig and cattle necropsies performed between 2000 and 2011 at the Institute of Animal Pathology (ITPA), University of Bern, Switzerland. We evaluated data quality in terms of credibility, completeness and representativeness of the Swiss pig and cattle populations.

RESULTS

Data was easily extracted from necropsy reports. Data quality in terms of completeness and validity varied a lot depending on the type of data reported. Diseases of the gastrointestinal system were reported most frequently (54.6% of pig submissions and 40.8% of cattle submissions). Diseases affecting serous membranes were reported in 16.0% of necropsied pigs and 27.6% of cattle. Respiratory diseases were reported in 18.3% of pigs and 21.6% of cattle submissions.

CONCLUSIONS

This study suggests that extracting data from necropsy reports can provide information of value for animal health surveillance. This data has potential value for monitoring endemic disease syndromes in different age and production groups, or for early detection of emerging or re-emerging diseases. The study identified data entry and other errors that could be corrected to improve the quality and validity of the data. Submissions to veterinary diagnostic laboratories have selection biases and these should be considered when designing surveillance systems that include necropsy reports.

Identification and characterization of the Fasciola hepatica sodium- and chloride-dependent taurine transporter

The parasitic liver fluke Fasciola hepatica infests mainly ruminants, but it can also cause fasciolosis in people, who ingest the metacercariae encysted on plants. The drug of choice to treat fasciolosis is triclabendazole (TBZ), which has been on the market for several decades. This is also true for the other available drugs. Accordingly, drug-resistant flukes have been emerging at an increasing rate making it desirable to identify alternative drug targets. Here, we focused on the fact that adult F. hepatica persists in the hostile environment of the bile ducts of infected organisms. A common way to render bile acids less toxic is to conjugate them to taurine (2-aminoethanesulfonic acid). We cloned a transporter from the solute carrier-6 (SLC6) family, which was most closely related to the GABA-transporter-2 of other organisms. When heterologously expressed, this F. hepatica transporter supported the high-affinity cellular uptake of taurine (KM = 12.0 ± 0.5 μM) but not of GABA. Substrate uptake was dependent on Na+- and Cl- (calculated stoichiometry 2:1). Consistent with the low chloride concentration in mammalian bile, the F. hepatica transporter had a higher apparent affinity for Cl- (EC50 = 14±3 mM) than the human taurine transporter (EC50 = 55±7 mM). We incubated flukes with unconjugated bile acids in the presence and absence of taurine: taurine promoted survival of flukes; the taurine transporter inhibitor guanidinoethansulfonic acid abolished this protective effect of taurine. Based on these observations, we conclude that the taurine transporter is critical for the survival of liver flukes in the bile. Thus, the taurine transporter represents a candidate drug target.

Factors responsible for the post-slaughter loss of carcass and offal's in abattoirs in South Africa

Global demand for food is surging upward due to the expansion of human population. Hence food production and supply need to double with little or no waste to meet this demand. Food loss at any point in the farm to fork chain inhibits the stability of food security at household and national level. A retrospective (AR) and a post mortem meat inspection (PMMI) study to identify major causes of offal and carcass condemnation was conducted in three abattoirs namely, Adeliade, Queenstown and East London abattoirs represented as AD, QT, and EL respectively. The retrospective study revealed the main causes of tongue condemnation as abscess (0.08%, 0.03% and 0.05%) and actinobacillosis (0.02%, 0% and 0.02%) respectively. The spleen was condemned due to abscess (0.35%, 0.94% and 0.17%) and splenomegaly (0.21%, 0.55% and 0.2%). The heart was condemned due to cyst (0.24%, 0.36% and 0.2%) and inflammation (0.9%, 1.85%, and 0.75%). While the kidney, was condemned due to cyst (0.08%, 0.23% and 0.16%) and nephritis (0.94%, 1.01% and 1.18%). However, a greater percentage of condemnation was recorded during the active abattoir study. During the same period, partial carcass condemnations were mainly due to bruises (63.3%, 50.4% and 41.0%), abscess (7%, 6% and 14%) and improper evisceration (19%, 31% and 27%). The combined monetary loss due to offal's and carcass condemnation during the AR and PMMI study was estimated as ZAR 255194.4 (34191.5 USD) and ZAR 25958.8 (2570.2 USD) respectively. This study identified major causes of offals and carcass condemnation as abscess, bruises, actinobacillosis, cyst, inflammatory conditions and improper evisceration. It can be used as starting point information for early warning on livestock diseases of economic loss in South Africa.

Molecular and serological dynamics of Chlamydia pecorum infection in a longitudinal study of prime lamb production

BACKGROUND

Chlamydia pecorum is a globally significant livestock pathogen causing pathology and production losses. The on-farm infection and serological dynamics and the relevance of existing diagnostic tools for diagnosing C. pecorum in livestock remains poorly characterized. In this study, we characterized the antigen and antibody dynamics of this pathogen in a longitudinal study of prime lamb production, utilizing the infection focused C. pecorum-specific 16S rRNA qPCR assay and serology based chlamydial Complement fixation Test (CFT).

METHODS

The study consisted of 76 Border Leicester mixed sex lambs (39 females and 37 males) that were sampled bimonthly from 2-10 months of age in a commercial farm operating in Central NSW, Australia. Blood/plasma was analysed for CFT antibodies, and swabs from conjunctival, rectal and vaginal sites were analysed for C. pecorum shedding using qPCR. We assessed the temporal and overall dynamics of C. pecorum in lambs, including detailed description and comparison of qPCR and CFT, the timing of first detection by either diagnostic method, the lag between infection and antibody response; and the distribution of qPCR load and CFT antibody titre over time.

RESULTS

Over the study period, C. pecorum was highly prevalent (71.0% by qPCR, 92.1% by CFT, 96.0% by both), with 21.1% (16/76) lambs shedding ≥1, 000 qPCR copies/µl (denoted as high shedders). C. pecorum shedding (as evidence of infection) were first observed at two months of age (14.4%) with a significant peak of infection occurring at six months of age (34.2%), whereas seroconversions peaked at eight months of age (81.5%). 52.6% of C. pecorum qPCR and CFT positive lambs became qPCR negative by 10 months of age, indicating clearance of chlamydial infection. Although CFT is utilised for on-farm detection of active infection, we confirm that it lagged behind qPCR detection (average lag 1.7 ± 2.1 months) and that the proportion of qPCR positives simultaneously identified by CFT was low with 2/11 (18.1%), 0/13, 17/25 (68.0%), 5/7 (71.4%) and 1/10 (10.0%) concurrent seroconversions occurring at two, four, six, eight and 10 months of age, respectively.

DISCUSSION

This work reveals rapid rates of C. pecorum infection and widespread exposure during lamb production. The comparison of molecular and serological diagnostic agreement longitudinally, supports the use of qPCR as an important ancillary tool for the detection of active infections in conjunction with chlamydial CFT for routine veterinary diagnostics. Development of rapid Point-of-Care (POC) tools for diagnosing active infection would be valuable for producers and veterinarians.

A Smartphone-Based Application Improves the Accuracy, Completeness, and Timeliness of Cattle Disease Reporting and Surveillance in Ethiopia

Accurate disease reporting, ideally in near real time, is a prerequisite to detecting disease outbreaks and implementing appropriate measures for their control. This study compared the performance of the traditional paper-based approach to animal disease reporting in Ethiopia to one using an application running on smartphones. In the traditional approach, the total number of cases for each disease or syndrome was aggregated by animal species and reported to each administrative level at monthly intervals; while in the case of the smartphone application demographic information, a detailed list of presenting signs, in addition to the putative disease diagnosis were immediately available to all administrative levels via a Cloud-based server. While the smartphone-based approach resulted in much more timely reporting, there were delays due to limited connectivity; these ranged on average from 2 days (in well-connected areas) up to 13 days (in more rural locations). We outline the challenges that would likely be associated with any widespread rollout of a smartphone-based approach such as the one described in this study but demonstrate that in the long run the approach offers significant benefits in terms of timeliness of disease reporting, improved data integrity and greatly improved animal disease surveillance.

Seasonal prevalence, body condition score and risk factors of bovine fasciolosis in South Africa

Fasciolosis is an important zoonotic disease that is responsible for a significant loss in food resource and animal productivity. The objectives of this study were to determine the seasonal prevalence and risk factors associated with Fasciola infection in cattle. The results were obtained by coprology, antemortem and post-mortem survey of three abattoirs (HTPA1, n = 500, HTPA2, n = 400, and LTPA, n = 220). The seasonal prevalence of Fasciola infection was 10.4%, 12.8% and 10.9%, during summer, 11.2%, 10.8% and 8.6%, during autumn, 9.8%, 6.5% and 5.9% during winter and 8.2%, 7.8% and 5.9%, during spring in the three abattoirs HTPA1, HTPA and LTPA respectively. There was a significant association (p < 0.05) between the intensity of infection and body condition score (BCS) of cattle at each abattoir. Factors such as age [HTPA1 (OR = 3.6, CI = 1.2, 10.2), and LTPA (OR = 3.8, CI= 2.4, 6.1)], sex [LTPA (OR = 4.2, CI= 2.5, 7.0)], breed [HTPA2 (OR = 2.3, CI = 1.3, 4.1) and LTPA (OR = 2.5, CI= 1.3, 5.0)] and BCS had significant (p < 0.01-0.001) influence on the prevalence of fasciolosis. In conclusion, the infection with Fasciola spp was higher in the summer than in the winter; a positive association was established between the prevalence of fasciolosis and poor body condition in study animals. This study, therefore, suggests that fasciolosis could be causing substantial production losses, mainly due to cattle weight loss and liver condemnation.

Surveillance and diagnosis of zoonotic foodborne parasites

Foodborne parasites are a source of human parasitic infection. Zoonotic infections of humans arise from a variety of domestic and wild animals, including sheep, goats, cattle, camels, horses, pigs, boars, bears, felines, canids, amphibians, reptiles, poultry, and aquatic animals such as fishes and shrimp. Therefore, the implementation of efficient, accessible, and controllable inspection policies for livestock, fisheries, slaughterhouses, and meat processing and packaging companies is highly recommended. In addition, more attention should be paid to the education of auditors from the quality control (QC) and assurance sectors, livestock breeders, the fishery sector, and meat inspection veterinarians in developing countries with high incidence of zoonotic parasitic infections. Furthermore, both the diagnosis of zoonotic parasitic infections by inexpensive, accessible, and reliable identification methods and the organization of effective control systems with sufficient supervision of product quality are other areas to which more attention should be paid. In this review, we present some examples of successful inspection policies and recent updates on present conventional, serologic, and molecular diagnostic methods for zoonotic foodborne parasites from both human infection and animal‐derived foods.

Combining Slaughterhouse Surveillance Data with Cattle Tracing Scheme and Environmental Data to Quantify Environmental Risk Factors for Liver Fluke in Cattle

Liver fluke infection causes serious disease (fasciolosis) in cattle and sheep in many regions of the world, resulting in production losses and additional economic consequences due to condemnation of the liver at slaughter. Liver fluke depends on mud snails as an intermediate host and infect livestock when ingested through grazing. Therefore, environmental factors play important roles in infection risk and climate change is likely to modify this. Here, we demonstrate how slaughterhouse data can be integrated with other data, including animal movement and climate variables to identify environmental risk factors for liver fluke in cattle in Scotland. We fitted a generalized linear mixed model to the data, with exposure-weighted random and fixed effects, an approach which takes into account the amount of time cattle spent at different locations, exposed to different levels of risk. This enabled us to identify an increased risk of liver fluke with increased animal age, rainfall, and temperature and for farms located further to the West, in excess of the risk associated with a warmer, wetter climate. This model explained 45% of the variability in liver fluke between farms, suggesting that the unexplained 55% was due to factors not included in the model, such as differences in on-farm management and presence of wet habitats. This approach demonstrates the value of statistically integrating routinely recorded slaughterhouse data with other pre-existing data, creating a powerful approach to quantify disease risks in production animals. Furthermore, this approach can be used to better quantify the impact of projected climate change on liver fluke risk for future studies.

Animal health syndromic surveillance: a systematic literature review of the progress in the last 5 years (2011-2016)

This review presents the current initiatives and potential for development in the field of animal health surveillance (AHSyS), 5 years on from its advent to the front of the veterinary public health scene. A systematic review approach was used to document the ongoing AHSyS initiatives (active systems and those in pilot phase) and recent methodological developments. Clinical data from practitioners and laboratory data remain the main data sources for AHSyS. However, although not currently integrated into prospectively running initiatives, production data, mortality data, abattoir data, and new media sources (such as Internet searches) have been the objective of an increasing number of publications seeking to develop and validate new AHSyS indicators. Some limitations inherent to AHSyS such as reporting sustainability and the lack of classification standards continue to hinder the development of automated syndromic analysis and interpretation. In an era of ubiquitous electronic collection of animal health data, surveillance experts are increasingly interested in running multivariate systems (which concurrently monitor several data streams) as they are inferentially more accurate than univariate systems. Thus, Bayesian methodologies, which are much more apt to discover the interplay among multiple syndromic data sources, are foreseen to play a big part in the future of AHSyS. It has become clear that early detection of outbreaks may not be the principal expected benefit of AHSyS. As more systems will enter an active prospective phase, following the intensive development stage of the last 5 years, the study envisions AHSyS, in particular for livestock, to significantly contribute to future international-, national-, and local-level animal health intelligence, going beyond the detection and monitoring of disease events by contributing solid situation awareness of animal welfare and health at various stages along the food-producing chain, and an understanding of the risk management involving actors in this value chain.

Prevalence of lung lesions in slaughtered cattle in the Eastern Cape Province, South Africa

Information obtained from abattoirs on the causes of lung condemnation is important in preventing the spread of zoonotic diseases and for promoting food security. In this study, we assessed the causes of lung condemnation in cattle at three abattoirs represented as ANA, QTA and EBA to evaluate the financial losses associated with lung condemnation. A retrospective study (n = 51 302) involving the use of abattoir slaughter records of 2010-2012 and an active abattoir survey (n = 1374) was conducted from July to December 2013. The retrospective study revealed the main causes of lung condemnation as pneumonia (1.09%, 2.21% and 0.77%), emphysema (1.12%, 1.14% and 1.1.6%) and abscessation (0.71%, 1.06% and 0.77%), from ANA, QTA and EBA, respectively. The combined monetary loss because of lung condemnation during the period 2010 to 2012 was estimated as ZAR 85 158 (USD 7939) for the abattoirs surveyed. Conversely, during the active abattoir survey, agonal emphysema (15%, 15% and 23%) and improper eviscerations with faecal contamination (10%, 38% and 42%) were the major factors that led to lung condemnation at ANA, QTA and EBA, respectively. Other causes of lung condemnations were haemorrhage (10%) for QTA and pleurisy (12%) for EBA. The weight loss of lungs during the active abattoir survey was 6450 kg, while the associated monetary loss was estimated as ZAR 29 025 (USD 2706). This study identified major causes of lung condemnation as pleuritis, improper evisceration, pneumonia, abscesses, haemorrhages and lung worms and their associated monetary losses. The results of this study may be useful as baseline data for future comparison in similar surveys, for tracking of some zoonotic diseases affecting lungs and for further research in the Eastern Cape Province or other provinces of South Africa.

Pig Abattoir Inspection Data: Can It Be Used for Surveillance Purposes?

Statutory recording of carcass lesions at the abattoir may have significant potential as a resource for surveillance of livestock populations. Food Standards Agency (FSA) data in Great Britain are not currently used for surveillance purposes. There are concerns that the sensitivity of detection, combined with other issues, may make the outputs unreliable. In this study we postulate that FSA data could be used for surveillance purposes. To test this we compared FSA data with BPHS (a targeted surveillance system of slaughtered pigs) and laboratory diagnostic scanning surveillance (FarmFile) data, from mid-2008 to mid-2012, for respiratory conditions and tail bite lesions in pigs at population level. We also evaluated the agreement/correlation at batch level between FSA and BPHS inspections in four field trials during 2013. Temporal trends and regional differences at population level were described and compared using logistic regression models. Population temporal analysis showed an increase in respiratory disease in all datasets but with regional differences. For tail bite, the temporal trend and monthly patterns were completely different between the datasets. The field trials were run in three abattoirs and included 322 batches. Pearson’s correlation and Cohen’s kappa tests were used to assess correlation/agreement between inspections systems. It was moderate to strong for high prevalence conditions but slight for low prevalence conditions. We conclude that there is potential to use FSA data as a component of a surveillance system to monitor temporal trends and regional differences of chosen indicators at population level. At producer level and for low prevalence conditions it needs further improvement. Overall a number of issues still need to be addressed in order to provide the pig industry with the confidence to base their decisions on these FSA inspection data. Similar conclusions, at national level, may apply to other livestock sectors but require further evaluation of the inspection and data collection processes.

Liver fluke (Fasciola hepatica) infection in cattle in Northern Ireland: a large-scale epidemiological investigation utilising surveillance data

Background

Liver fluke (Fasciola hepatica) is a widespread parasite of ruminants which can have significant economic impact on cattle production. Fluke infection status at the animal-level is captured during meat inspection of all animals processed for human consumption within Northern Ireland. These national datasets have not been analysed to assess their utility in uncovering patterns in fluke infection at animal- and herd-levels in Northern Ireland.

Methods

We utilised a dataset of 1.2 million animal records from ~18,000 herds across 3 years (2011–2013) to assess animal- and herd-level apparent prevalence and risk-factors associated with fluke infection. Animal-level apparent prevalence was measured as the proportion of animals exhibiting evidence of fluke infection at slaughter; between herd-level infection prevalence was measured by binary categorisation of herds (infected or not). “Within herd” infection prevalence was measured using the proportion of animals within a herd that showed evidence of fluke infection per year (ranging from 0–100 %). “Within herd” infection prevalence at the herd level was investigated using multivariable modelling.

Results

At the animal level, the proportion of animals slaughtered that exhibited evidence of infection was 21–25 % amongst years. Across herds, the proportion of herds with at least one infected animal, varied between 61 and 65 %. However, there was a significant sampling effect at the herd-level; all herds where at least 105 animals slaughtered over the study period exhibited evidence of fluke infection (100 %). There was significant variation in terms of within-herd infection prevalence. Risk factors included herd type, long-term weather variation, geographic location (region) and the abattoir.

Conclusions

Liver fluke apparent prevalence was high at the herd-level across years. However, there was lower prevalence at the animal level, which may indicate significant variation in the exposure to fluke infection within herds. The proportion infected within-herds varied significantly in time and space, and by abattoir, herd-type and some weather variables. These data are a useful source of information on a widespread endemic disease, despite known limitations in terms of test performance (low sensitivity). As well as informing on the distribution and severity of liver fluke infection, these analyses will be used to investigate the effect of co-infection on risk for bovine tuberculosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1489-2) contains supplementary material, which is available to authorized users.

Chlamydia pecorum infections in sheep and cattle: A common and under-recognised infectious disease with significant impact on animal health

There is a growing recognition that infections of livestock by the obligate intracellular bacterium, Chlamydia pecorum, are more widespread than was previously thought. A range of diseases have been associated with this pathogen, with the most important manifestations including infectious arthritis, infertility, enteritis, reduced growth rates, mastitis, and pneumonia. C. pecorum infections have also been associated with sub-clinical disease, highlighting our lack of knowledge about its true economic impact on livestock producers. Diagnosis of C. pecorum infection is based on clinical findings, serology and histopathology, which are not necessarily implemented in subclinical or early stages of infection, thus potentially contributing to under-diagnosis and under-reporting of infections associated with this bacterium. Recent molecular epidemiology studies have revealed that C. pecorum is genetically diverse and that there may be an association between certain strains and disease in sheep and cattle. Antimicrobial treatment of affected animals has questionable efficacy, justifying development of chlamydia vaccines for livestock. This review summarises current knowledge of the prevalence and impact of C. pecorum infections in sheep and cattle and provides an update on attempts to improve detection, management and treatment of infections by this important obligate intracellular pathogen.

Spatio-temporal prevalence of porcine cysticercosis in Madagascar based on meat inspection

Background

Taenia solium cysticercosis is a parasitic meat-borne disease that is highly prevalent in pigs and humans in Africa, but the burden is vastly underestimated due to the lack of official control along the pork commodity chain, which hampers long-term control policies.

Methods

The apparent and corrected prevalences of T. solium cysticercosis were investigated in pork carcasses slaughtered and retailed in Antananarivo (Madagascar), thanks to a 12-month monitoring plan in two urban abattoirs.

Results

Overall apparent prevalence was estimated at 4.6 % [4.2 – 5.0 %]. The corrected overall prevalence defined as the estimated prevalence after accounting for the sensitivity of meat inspection was 21.03 % [19.18- 22.87 %]. Significant differences among geoclimatic regions were observed only for indigenous pigs, with an apparent prevalence estimated at 7.9 % [6.0 – 9.9 %] in the northern and western regions, 7.3 % [6.0 – 8.6 %] in the central region, and 6.2 % [4.7 – 7.8 %] in the southern region. In the central region, where both exotic and indigenous pigs were surveyed, indigenous pigs were 8.5 times [6.7 – 10.7] more likely to be infected than exotic improved pigs. Urban consumers were more likely to encounter cysticercosis in pork in the rainy season, which is a major at risk period, in particular in December. Differences between abattoirs were also identified.

Conclusion

Our results underline the need for improved surveillance and control programmes to limit T. solium cysticercosis in carcasses by introducing a risk-based meat inspection procedure that accounts for the origin and breed of the pigs, and the season.

Integrating novel data streams to support biosurveillance in commercial livestock production systems in developed countries: challenges and opportunities

Reducing the burden of emerging and endemic infectious diseases on commercial livestock production systems will require the development of innovative technology platforms that enable information from diverse animal health resources to be collected, analyzed, and communicated in near real-time. In this paper, we review recent initiatives to leverage data routinely observed by farmers, production managers, veterinary practitioners, diagnostic laboratories, regulatory officials, and slaughterhouse inspectors for disease surveillance purposes. The most commonly identified challenges were (1) the lack of standardized systems for recording essential data elements within and between surveillance data streams, (2) the additional time required to collect data elements that are not routinely recorded by participants, (3) the concern over the sharing and use of business sensitive information with regulatory authorities and other data analysts, (4) the difficulty in developing sustainable incentives to maintain long-term program participation, and (5) the limitations in current methods for analyzing and reporting animal health information in a manner that facilitates actionable response. With the significant recent advances in information science, there are many opportunities to develop more sophisticated systems that meet national disease surveillance objectives, while still providing participants with valuable tools and feedback to manage routine animal health concerns.

Syndromic surveillance system based on near real-time cattle mortality monitoring

Early detection of an infectious disease incursion will minimize the impact of outbreaks in livestock. Syndromic surveillance based on the analysis of readily available data can enhance traditional surveillance systems and allow veterinary authorities to react in a timely manner. This study was based on monitoring the number of cattle carcasses sent for rendering in the veterinary unit of Talavera de la Reina (Spain). The aim was to develop a system to detect deviations from expected values which would signal unexpected health events. Historical weekly collected dead cattle (WCDC) time series stabilized by the Box-Cox transformation and adjusted by the minimum least squares method were used to build the univariate cycling regression model based on a Fourier transformation. Three different models, according to type of production system, were built to estimate the baseline expected number of WCDC. Two types of risk signals were generated: point risk signals when the observed value was greater than the upper 95% confidence interval of the expected baseline, and cumulative risk signals, generated by a modified cumulative sum algorithm, when the cumulative sums of reported deaths were above the cumulative sum of expected deaths. Data from 2011 were used to prospectively validate the model generating seven risk signals. None of them were correlated to infectious disease events but some coincided, in time, with very high climatic temperatures recorded in the region. The harvest effect was also observed during the first week of the study year. Establishing appropriate risk signal thresholds is a limiting factor of predictive models; it needs to be adjusted based on experience gained during the use of the models. To increase the sensitivity and specificity of the predictions epidemiological interpretation of non-specific risk signals should be complemented by other sources of information. The methodology developed in this study can enhance other existing early detection surveillance systems. Syndromic surveillance based on mortality monitoring can reduce the detection time for certain disease outbreaks associated with mild mortality only detected at regional level. The methodology can be adapted to monitor other parameters routinely collected at farm level which can be influenced by communicable diseases.

Pilot simulation study using meat inspection data for syndromic surveillance: use of whole carcass condemnation of adult cattle to assess the performance of several algorithms for outbreak detection

The objective of this study was to assess the performance of several algorithms for outbreak detection based on weekly proportions of whole carcass condemnations. Data from one French slaughterhouse over the 2005–2009 period were used (177 098 slaughtered cattle, 0.97% of whole carcass condemnations). The method involved three steps: (i) preparation of an outbreak-free historical baseline over 5 years, (ii) simulation of over 100 years of baseline time series with injection of artificial outbreak signals with several shapes, durations and magnitudes, and (iii) assessment of the performance (sensitivity, specificity, outbreak detection precocity) of several algorithms to detect these artificial outbreak signals. The algorithms tested included the Shewart p chart, confidence interval of the negative binomial model, the exponentially weighted moving average (EWMA); and cumulative sum (CUSUM). The highest sensitivity was obtained using a negative binomial algorithm and the highest specificity with CUSUM or EWMA. EWMA sensitivity was too low to select this algorithm for efficient outbreak detection. CUSUM's performance was complementary to the negative binomial algorithm. The use of both algorithms on real data for a prospective investigation of the whole carcass condemnation rate as a syndromic surveillance indicator could be relevant. Shewart could also be a good option considering its high sensitivity and simplicity of implementation.

Comparison of whole carcass condemnation and partial carcass condemnation data for integration in a national syndromic surveillance system: the Swiss experience

We obtained partial carcass condemnation (PCC) data for cattle (2009-2010) from a Swiss slaughterhouse. Data on whole carcass condemnations (WCC) carried out at the same slaughterhouse over those years were extracted from the national database for meat inspection. We found that given the differences observed in the WCC and PCC time series, it is likely that both indicators respond to different health events in the population and that one cannot be substituted by the other. Because PCC recordings are promising for syndromic surveillance, the meat inspection database should be capable to record both WCC and PCC data in the future. However, a standardised list of reasons for PCC needs to be defined and used nationwide in all slaughterhouses.

Factors associated with offal, partial and whole carcass condemnation in ten French cattle slaughterhouses

The proportion of cattle with offal, partial or whole carcass condemnation could be a useful indicator for animal health syndromic surveillance purposes. It requires first highlighting the factors associated with condemnation in order to include them in a modeling process. This study aims to identify and quantify these factors. It was based on data from ten French cattle slaughterhouses from 2006 to 2010 (n=1,439,868 cattle). Multivariable multinomial logistic regression analyses were performed. Sex, age and slaughterhouse were the main effects for offal, partial and whole carcass condemnation and have to be taken into account when implementing syndromic surveillance systems based on meat inspection data. The presence of an error in cattle identification was identified as a potential indicator for a higher risk of condemnation and should be explored as a potential factor for risk-based meat inspection.

Evaluation of Swiss slaughterhouse data for integration in a syndromic surveillance system

BACKGROUND

We evaluated Swiss slaughterhouse data for integration in a national syndromic surveillance system for the early detection of emerging diseases in production animals. We analysed meat inspection data for cattle, pigs and small ruminants slaughtered between 2007 and 2012 (including emergency slaughters of sick/injured animals); investigating patterns in the number of animals slaughtered and condemned; the reasons invoked for whole carcass condemnations; reporting biases and regional effects.

RESULTS

Whole carcass condemnation rates were fairly uniform (1-2‰) over time and between the different types of production animals. Condemnation rates were much higher and less uniform following emergency slaughters. The number of condemnations peaked in December for both cattle and pigs, a time when individuals of lower quality are sent to slaughter when hay and food are limited and when certain diseases are more prevalent. Each type of production animal was associated with a different profile of condemnation reasons. The most commonly reported one was "severe lesions" for cattle, "abscesses" for pigs and "pronounced weight loss" for small ruminants. These reasons could constitute valuable syndromic indicators as they are unspecific clinical manifestations of a large range of animal diseases (as well as potential indicators of animal welfare). Differences were detected in the rate of carcass condemnation between cantons and between large and small slaughterhouses. A large percentage (>60% for all three animal categories) of slaughterhouses operating never reported a condemnation between 2007 and 2012, a potential indicator of widespread non-reporting bias in our database.

CONCLUSIONS

The current system offers simultaneous coverage of cattle, pigs and small ruminants for the whole of Switzerland; and traceability of each condemnation to its farm of origin. The number of condemnations was significantly linked to the number of slaughters, meaning that the former should be always be offset by the later in analyses. Because this denominator is only communicated at the end of the month, condemnations may currently only be monitored on a monthly basis. Coupled with the lack of timeliness (30-60 days delay between condemnation and notification), this limits the use of the data for early-detection.

A preliminary investigation of farm-level risk factors for cattle condemnation at the slaughterhouse: a case-control study on French farms

The financial impact of condemnation for farmers and the importance of efficiency in the meat inspection process to guarantee food safety are well known. Identifying farm-level risk factors for condemnation are useful in order to find a way for farmers to potentially reduce their condemnation rates and to build a risk-based farm classification for veterinary services to target both meat inspection and farms inspections. To our knowledge, this has not yet been done, probably due to a lack of available meat inspection data. A preliminary investigation was performed through a case-control study on 36 French farms, from a dairy production region to identify farm-level risk factors for high condemnation rates (i.e. more than 45% of cattle with at least one portion of the carcass condemned). Multivariable exact logistic regression was performed to take into account the small sample size. The final model identified two significant risk factors. The odds of having a high condemnation rate was at least twice as greater for farmers who did not adhere to the quality charter of an international retailer and was significantly higher when the most qualified worker on the farm had a degree in agriculture. This latter effect was unexpected and is reviewed in the discussion section. The protective effect of the quality charter could be explained by the annual control of farms performed to guarantee compliance with good farming practices in the adhering farms. It led us to believe that compliance with well known good farming practices could be a way for farmers to reduce their condemnation rates. This study is a preliminary investigation performed on a small sample size of farms that were mainly dairy farms. It is a first step for further investigations that need to be done on this topic at a larger scale to fill the current lack of knowledge.