Survey of Biosecurity Protocols and Practices Adopted by Growers on Commercial Poultry Farms in Georgia, U. S. A

Making the invisible visible: Effectiveness of a training program to increase awareness and biosecurity compliance in poultry barn anterooms, using glowing substances

Biosecurity is the cornerstone of prevention strategies to limit infectious pathogen spread between poultry farms. However, poor compliance of biosecurity measures is often observed when entering or exiting barns. The lack of knowledge, understanding, risk perception or technical skill are often described for anteroom-related biosecurity errors (i.e., not respecting anteroom zoning in relation to changing boots, clothing, and hand sanitation). In this study, we designed and assessed the efficacy of an intervention aiming at improving biosecurity compliance in anterooms, using substances glowing under ultraviolet light, which mimic microbiological contamination. Training exercises offered in a single session were proposed to 145 participants with an interest in animal farming (veterinary students, agricultural students, poultry farmers and poultry farm advisors). The exercises' efficacy was assessed by measuring the change in attitude and intentions of participants about specific biosecurity measures. The participants' attitudes and intentions were quantified using a questionnaire before and after training. The change in score was assessed in a multivariate linear regression model to measure the effect of various parameters on this change. The attitudes and intentions of participants were statistically improved (p < 0.05) and were affected by the initial attitude and intention score, the gender of the participants and the status of the participant (type of student or activity in the poultry industry). The use of this exercise material, perceived as playful and engaging, could be included in the framework of biosecurity training for all stakeholders of the poultry industry.

How Do Flemish Laying Hen Farmers and Private Bird Keepers Comply with and Think about Measures to Control Avian Influenza?

Competent authorities of many countries, including Belgium, impose control measures (preventing wild bird access to feeders and water facilities, indoor confinement of captive birds, or fencing off outdoor ranges with nets) on professional and non-professional keepers of birds to prevent the spread of avian influenza (AI). Flemish laying hen farmers (FAR, n = 33) and private keepers of captive birds (PRI, n = 263) were surveyed about their opinion on and compliance with AI measures legally imposed during the most recent high-risk period before this survey in 2021. Participants answered questions on a 5-point Likert scale (1 = the worst, 3 = neutral, and 5 = the best). FAR indicated better compliance with the AI measures than PRI, except for net confinement. FAR indicated that they and other poultry farmers complied better with AI measures than PRI. Additionally, PRI indicated that they better complied than other PRI keepers. FAR regarded the AI measures as more effective than PRI. To prevent the spread of AI more effectively, national authorities could focus on information campaigns explaining to private bird keepers the need for the various control measures that they impose. If these campaigns fail, local authorities may need stricter enforcement or alternative ways to increase compliance.

Development and use of Biocheck.UGent™ scoring system to quantify biosecurity in conventional indoor (turkey, duck, breeder) and free-range (layer and broiler) poultry farms

To assess and enhance the application of biosecurity measures in poultry farming, an objective measurement tool (Biocheck.UGent™) was already available for broiler and layer. This study describes the development, validation and application of a risk-based weighted scoring tool for breeder, turkey, duck, free-range layer and free-range broiler production. In collaboration with an expert panel (n= 38), five different questionnaires were developed, following the format of the existing Biocheck.UGent scoring tools. Weights were attributed to external (7-9 subcategories) and internal (3-4 subcategories) biosecurity categories, as well as to the corresponding individual questions within each subcategory. The biosecurity measures were prioritized and weighed based on their relative importance in preventing disease transmission. Upon completion of the questionnaire, and upload of all answers to the Biocheck.UGent website, the algorithm generates a biosecurity score varying between ''0'' which equals the total absence of any biosecurity measure up to ''100'' which refers to full application of all biosecurity measures. The final scoring systems are available online (https://biocheckgent.com/en) for free and have been used to assess biosecurity in 70 breeders, 100 turkeys, 23 ducks, 16 free-range broilers, and 15 free-range layer farms originating from 12 countries so far. On average, the overall biosecurity score (mean ± std. dev) was 78 ± 7 % for breeders, 73 ± 11 % for turkeys, 71 ± 8 % for ducks, 73 ± 8 % for free-range layers and 70 ± 13 % for free-range broilers. There were significant differences (p < 0.05) in biosecurity (both at the overall and subcategory levels) across different poultry types. The overall farm biosecurity score for breeders was significantly higher than that for turkey (p <.001) and duck production (p = 0.001). External biosecurity levels were highest in breeders in comparison to turkeys (p < 0.001), ducks (p = 0.008) and broiler free-range (p = 0.005). There was a notable difference in internal biosecurity levels between duck and turkey (p = 0.041) production as well. The study contributed to the poultry biosecurity database which allows benchmarking of the biosecurity levels of the users' farm results to national or international averages, indicating room for improvement and aiding to motivate stakeholders to enhance their biosecurity levels.

In silico and PCR Screening for a Live Attenuated Salmonella Typhimurium Vaccine Strain

The application of live attenuated Salmonella Typhimurium vaccines has significantly helped control Salmonella in poultry products. Because the U.S. Department of Agriculture-Food Safety Inspection Service (USDA-FSIS) scores all Salmonella as positive, regardless of serovar, attenuated vaccine strains that are identified at processing contribute negatively toward Salmonella performance standards. This study was designed to determine the incidence of a live attenuated Salmonella serovar Typhimurium vaccine identified in broiler products by FSIS and to develop a PCR assay for screening of isolates. Salmonella Typhimurium short-read sequences from broiler samples uploaded to the National Center for Biotechnology Information (NCBI) Pathogen Detection database by the USDA-FSIS from 2016 to 2022 were downloaded and assembled. These were analyzed using the Basic Local Alignment Search Tool (BLAST) with a sequence unique to field strains, followed by a sequence unique to the vaccine strain. The PCR assays were developed against field and vaccine strains by targeting transposition events in the crp and cya genes and validated by screening Salmonella serovar Typhimurium isolates. Between 2016 and 2022, 1708 Salmonella Typhimurium isolates of chicken origin were found in the NCBI Pathogen Detection database, corresponding to 7.99% of all Salmonella identified. Of these, 104 (5.97%) were identified as the vaccine strain. The PCR assay differentiated field strains from the vaccine strain when applied to isolates and was also able to detect the vaccine strain from DNA isolated from mixed serovar overnight Salmonella enrichment cultures. Live attenuated Salmonella vaccines are a critical preharvest tool for Salmonella control and are widely used in industry. With forthcoming regulations that will likely focus on Salmonella Typhimurium, along with other serovars, there is a need to distinguish between isolates belonging to the vaccine strain and those that are responsible for causing human illness.

Assessment of biosecurity measures in commercial poultry farms of Rajshahi district in Bangladesh

The application of biosecurity measures in the poultry sector are essential. Developing and implementing daily biosecurity activities are considered effective methods to prevent infectious diseases on poultry farms. Appropriate farm settings and management reduce the possibility of disease transmission between farms. This study aimed to assess the current biosecurity status of commercial poultry farms in the Rajshahi district of Bangladesh. A cross-sectional study was conducted from June to November 2021, involving 204 poultry farmers in the Rajshahi district, using a multistage sampling technique. Data were collected through face-to-face interviews using a semi-structured questionnaire. The statistically significant (p < 0.05) results found were: most farmers reported that the visitors could not access their farms (broiler vs. layer: 68.1%, 77.0%). A higher proportion of broilers compared to layer farms used company's supplied feed (81.2% vs. 66.7%). A higher proportion of layer (97.8%) farms cleaned the farm's litter within 24 h compared to broiler farms (72.5%). Broiler farms had better records animal mortality than layer farms (76.8% vs. 60.0%). More layer (96.3%) farms compared to broiler (87.0%) farms implemented a vaccination program. The findings of this study revealed that biosecurity measures are well-practiced and implemented in most broiler and layer farms in this region except in a small number of farms. Government authorities should strictly enforce and monitor biosecurity measures in farms that do not practice essential biosecurity measures.

Effect of biosecurity-based interventions on broiler crude mortality rate at an early stage of production in the small-scale farming system in Bangladesh

BACKGROUND

Biosecurity-based interventions are important health strategies for the control of infectious disease and improve productivity in broiler. There are various reasons why broilers die at the early stages of production; however, biosecurity measures are crucial in reducing the risk of disease prevalence and can therefore affect the overall deaths in a flock for a specific period (crude mortality rate [CMR]).

OBJECTIVES

This study was designed to determine the current biosecurity situation on small-scale broiler farms in Bangladesh and its relationship to the CMR during the early stages of production.

METHODS

A cross-sectional observational study was conducted on small-scale broiler farms (N = 57) located in peri-urban areas of Chattogram and Pabna districts of Bangladesh. Descriptive and predictive statistical analyses were performed to estimate the frequency of categorical variables and their effect on CMR.

RESULTS

The findings indicated that around 80% of small-scale broiler farms lacked adequate biosecurity measures. Both on day 1 (p = 0.012) and on days 2-14 (p = 0.003), flocks with inadequate biosecurity had considerably higher median CMRs. Farms that were near the neighbourhood used wood shavings as bedding, offered tube well/shallow well or supply line water, maintained a brief empty period (≤5 days) before introducing new flocks and began using antibiotics on day 1 all had significantly higher CMR at both days 1 and 2-14.

CONCLUSIONS

The findings point to the necessity of implementing stringent biosecurity measures in broiler production in locations where there is a shortage, which can lower the burden of arbitrary antibiotic usage and will lower total production costs due to crude mortality and management-related issues.

Quantitative and qualitative analysis of antimicrobial usage and biosecurity on broiler and Sonali farms in Bangladesh

Antimicrobial use (AMU) is a major contributing factor to the rising threat of antimicrobial resistance (AMR) in human and animals. To control AMR, indiscriminate antibiotic use needs to be restricted, preventive measures such as biosecurity must be prioritized and proper action plans must be implemented. This study aimed to quantify and associate AMU and biosecurity status of broiler and Sonali farms in Bangladesh. Data on all antimicrobial treatments administered during a batch production cycle and antimicrobials purchased over a year were collected from 94 conventional broiler and 51 Sonali (cross-breed) farms from the northern and southeast regions of Bangladesh. Flock-level AMU was quantified using Treatment Incidence (TI) per 100 days based on the Defined Daily Dose (TI_DDDvet) expressing the number of days per 100 animal-days at risk that the flock receives a standard dose of antimicrobials. The biosecurity status (external and internal) of these farms was assessed by means of the Biocheck.UGent scoring system and the correlation between biosecurity and TI_DDDvet were assessed by Pearson's correlation coefficients. Median flock TI_DDDvet was 60 and 58 for broilers and Sonali flocks, indicating that the birds were treated around 60% and 58% of their lifetime with an antimicrobial dose, respectively. Minimum and maximum values of TI_DDDvet ranged from 18 -188 and 31-212 in broilers and Sonali, respectively. Fluoroquinolones, sulfonamides, tetracyclines and aminopenicillins were the most frequently used antimicrobial classes. The mean external and internal biosecurity scores were 39% and 61% for broilers and 44% and 61% for Sonali, respectively. There was a statistically significant difference in the external biosecurity score in broiler farms in the two regions (p ≤ 0.001), whereas, the internal biosecurity score was borderline not statistically significantly different (p = 0.065). The biosecurity score was negatively correlated with AMU in broiler and sonali farms both for external (R² =-0.38; -0.36) and internal biosecurity (R² =-0.33; -0.32), respectively. As most of the farmers treated their birds with antimicrobials for a very large part of the production, it could be concluded that there is a high overuse of antimicrobials both in broiler and Sonali poultry production in Bangladesh. This study also highlighted a low level of farm biosecurity practices. Overuse of antimicrobials and low level of biosecurity practice may be due to a lack of knowledge, ignorance, avoid loss and/or lack of monitoring by governmental agencies. Therefore, urgent action is required to increase awareness and biosecurity levels and to reduce AMU in these production systems.

A cross-sectional survey for the assessment of biosecurity measures in small-scale duck farms in Qalyoubia, Egypt: Comprehensive evaluation and procedural recommendations

Background and Aim: Biosecurity implementation is fundamental to combating diseases and antibiotic resistance. Therefore, this study aimed to examine the correlation between the implementation of biosecurity measures in small-scale duck farms and the incidence of infectious diseases that threaten the duck industry. Materials and Methods: Twenty small-scale duck farms of different breeds and production stages were collected as representative samples, focused on two districts in the Qalyoubia governorate, which possesses high-density small-scale farms. A 30-point structured questionnaire was designed to assess the level of biosecurity measures implemented in the sampled farms. These farms were examined for bacterial infection by cultivation, typing, and antibiotic sensitivity tests, in addition to molecular techniques for detecting suspected viral diseases. Results: The results showed that the farms had high or low levels of biosecurity; only 25% possessed high-level biosecurity. Bacteria, including Salmonella, Escherichia coli, Staphylococcus, and Pasteurella, were isolated from all sampled farms. High rates of antimicrobial resistance-reaching up to 100% were observed against some drugs. However, viral causative agents, including HPAI-H5N8, duck viral hepatitis, and goose parvovirus, were isolated from only five farms. Conclusion: The lack of commitment to biosecurity implementation, particularly personal hygiene, was observed in most sampled farms. Increasing the level of biosecurity reduced the incidence of mixed infections. Keywords: antibiotic resistance, bacterial agents, biosecurity, co-infections, small-scale duck farms, viral diseases.

Development and implementation of a risk assessment tool for broiler farm biosecurity and a health intervention plan in the Netherlands, Greece, and Cyprus

Preventing pathogens from entering and spreading on farms is the first step in reducing health problems. For this study a BiosEcurity Assessment Tool was developed to identify strengths and weaknesses in biosecurity on broiler farms, which was used as a starting point to formulate tailor-made health plans to improve broiler health and reduce antimicrobial use. Farms were divided into 3 separate areas according to associated biosecurity risk; high disease risk external areas (red zone), medium risk service areas (orange zone), and the clean and highly secure access-restricted green zone. In the Netherlands, Cyprus, and Greece, 13, 15, and 7 broiler houses were monitored for 4 production cycles (2 preintervention and 2 postintervention cycles). At the start of the study the BiosEcurity Assessment Tool assessment was performed and a health plan was made in consultation with the veterinarian. After the second cycle a start was made with the implementation of the health plan. Overall, the biosecurity level in the green and orange zones were significantly higher in the Netherlands compared to Greece and Cyprus, but there was no difference for the red zone or the transition zones between the countries. The interventions in the health plans were mostly directed towards those measures that could be implemented in the short term and with low costs in the green zone. In Cyprus a decrease in antimicrobial use was found postintervention. This was not the case in Greece and the Netherlands. In Cyprus and Greece footpad lesion improved after interventions were implemented, although this may have been an effect of season. In Dutch farms no improvement was detected, but both antimicrobial use and footpad lesions were lower at the start of the study compared to Cypriot and Greek farms. In conclusion, the BEAT shows to be a promising tool to assess biosecurity risks on broiler farms. The biosecurity assessment in combination with the farm specific health plans could contribute to antimicrobial reduction on broiler farms.

Assessing farm biosecurity and farmers' knowledge and practices concerning antibiotics and antibiotic resistance in poultry and pig farms in Southern Togo

Background and Aim:

Several factors contribute to the unusual incidence of antibiotic resistance, which is now a primary public health concern. However, failure in managing preventive and therapeutic antibiotic use on farms is one of the most crucial factors. Therefore, this study aimed to evaluate the biosecurity of farms, farmers’ competence, and practices related to antibiotics and their resistance in poultry and pig rearing in Togo.

Materials and Methods:

Through a cross-sectional survey, 121 commercial poultry farmers and 97 commercial pig farmers were questioned to evaluate the biosecurity of farms and farmers’ competence and practices related to antibiotics and antibiotic resistance. Descriptive analyses, including the evaluation of proportions, were carried out. In addition, results from qualitative factors were evaluated in a defined grid and totaled up to assess cleanliness measures, awareness, and behavior regarding antibiotics and their resistance.

Results:

The results demonstrated that most farmers working on poultry farms had a university education, while most working on pig farms had secondary education. Most poultry (69%) and pig (44%) farms were of small sizes (<1000 animals in poultry and <10 animals in pig farming). The footbaths were used in just 51% of poultry farms and 4% of pig farms, respectively, with 37% and 82% of poultry and pig farms having inadequate levels of hygiene. In poultry farms, respiratory issues and periodic decline in egg-laying were the main problems. Simultaneously, skin disorders (scabies) and plagues (African swine fever) were the primary health constraints in pig farming. Tetracycline is the most commonly used antibiotic by farmers. However, in poultry and pig farms, 21% and 67% of farmers were unaware of antibiotics. In addition, 39% and 57% were unaware of antibiotic resistance. Poultry and pig farmers’ competence were substantially linked to their education level. Poultry farmers demonstrated better practices, including procuring antibiotics based on veterinary prescriptions (63%) and they knew where antibiotics should be bought (90%). Nevertheless, 43% of farmers asserted unpleasant activities – no application for laboratory testing (93%) and use of antibiotics for prevention (82%). In pig farming, most farmers (69%) reported inadequate incidents of the use of antibiotics.

Conclusion:

This study identified a crucial non-compliance with biosecurity measures and good practices toward antibiotic use on many farms. Therefore, training of farmers is mandatory for safe livestock products.

Assessing Biosecurity Compliance in Poultry Farms: A Survey in a Densely Populated Poultry Area in North East Italy

Biosecurity in poultry farms represents the first line of defense against the entry and spread of pathogens that may have animal health, food safety, and economic consequences. The aim of this study was to assess biosecurity compliance in poultry farms located in a densely populated poultry area in North East Italy. A total of 259 poultry farms (i.e., broilers, turkeys, and layers) were surveyed between 2018 and 2019 using standardized checklists, and differences in biosecurity compliance between the poultry sectors and years (only for turkey farms) were tested for significance. Among the three sectors, turkey farms showed the highest compliance. Farm hygiene, infrastructure condition, cleaning and disinfection tools, and procedures were the biosecurity measures most complied with. Some deficiencies were observed in the cleanliness of the farm hygiene lock in broiler farms, as well as the presence of the house hygiene lock in broiler and layer farms and an adequate coverage of built-up litter in turkey and broiler farms. In conclusion, this study highlighted a generally high level of biosecurity in the visited poultry farms (probably due to the stringent national regulation and the integration of the poultry industry) and identified some measures that still need to be improved.

Risky business in Georgia's wild birds: contact rates between wild birds and backyard chickens is influenced by supplemental feed

Backyard chickens are increasingly popular, and their husbandry varies widely. How backyard chickens are housed may influence the accessibility of chicken feed and water to wild birds, and thus, the contact rates between both groups. Increased contacts have implications for pathogen transmission; for instance, Newcastle disease virus or avian influenza virus may be transmitted to and from backyard chickens from contaminated water or feed. Given this potentially increased pathogen risk to wild birds and backyard chickens, we examined which wild bird species are likely to encounter backyard chickens and their resources. We performed a supplemental feeding experiment followed by observations at three sites associated with backyard chickens in North Georgia, USA. At each site, we identified the species of wild birds that: (a) shared habitat with the chickens, (b) had a higher frequency of detection relative to other species and (c) encountered the coops. We identified 14 wild bird species that entered the coops to consume supplemental feed and were considered high-risk for pathogen transmission. Our results provide evidence that contact between wild birds and backyard chickens is frequent and more common than previously believed, which has crucial epidemiological implications for wildlife managers and backyard chicken owners.

The Role of Biosecurity in the Control of Campylobacter: A Qualitative Study of the Attitudes and Perceptions of UK Broiler Farm Workers

Campylobacter is the leading cause of human bacterial diarrhoeal disease worldwide, with poultry meat products contributing to a large proportion of cases. Due to the ubiquitous presence of Campylobacter in the poultry farm environment, biosecurity is the main area for intervention to prevent colonisation of commercial broiler chicken flocks. However, research has repeatedly demonstrated that farmers' uptake of biosecurity recommendations is often poor. This study explored farmers' attitudes towards biosecurity and identified barriers to effective implementation of biosecurity protocols. Semi-structured interviews were conducted with 1–3 members of staff on each of 16 broiler farms; 6 owned by, and 10 contracted to, 3 different UK poultry integrators. In total, 28 interviewees participated, including farm owners, managers, and workers, with a range of industry experience. Thematic analysis of the interviews revealed high levels of recognition amongst broiler farmers of the importance of Campylobacter and the responsibility of the whole farm-to-fork chain within the poultry industry to reduce Campylobacter contamination of chicken meat for the benefit of public health. Participants' self-reported awareness and implementation of biosecurity has improved significantly following the industry-wide focus on Campylobacter control. However, there are frustrations with the industry's approach to tackling Campylobacter and the heavy burden of responsibility that has been put on interventions at the farm-level. There was also scepticism amongst participants as to the effectiveness of current biosecurity measures in the reduction of Campylobacter. Nevertheless, the interviewees' recognition of the benefit of improved biosecurity on broiler health and welfare and other important targets, such as reducing antimicrobial usage, leaves a legacy of which the UK broiler industry can be proud. There is scope for further farmer education about the evidence supporting biosecurity interventions, particularly in the control of Campylobacter, and a need to establish more effective channels of communication. Furthermore, to give all players within the industry agency and investment in industry targets, contributions from all levels should be permitted in the design of future biosecurity interventions. Biosecurity compliance may be improved through collaborative efforts, such as participatory and co-design practises, to facilitate knowledge co-creation and exchange.

Biosecurity measures in French poultry farms are associated with farm type and location

The severe impact of recently reported Highly Pathogenic Avian Influenza (HPAI) outbreaks have emphasized the need to better monitor biosecurity practices among the different French poultry production systems. Between October 2016 and September 2018, a large national cross-sectional study was carried out in France to assess biosecurity levels in high-risk poultry farms and identify farm biosecurity profiles, using Multiple Correspondence and Hierarchical Cluster Analyses. Results indicate that there is substantial room for improvement in cleaning and disinfection, anteroom management and delimitation of farm and production units for more than 50 % of the 1,004 analyzed farms. The farm biosecurity profile showing the highest level of biosecurity included commercial intensive poultry farms (gallinaceous poultry farms, in North-Western France), and those with a recent history of HPAI outbreak (duck farms, in South-Western France). The farms biosecurity profiles showing the lowest level of biosecurity included farms with multiple species (duck and gallinaceous poultry) or multiple production types (broilers and egg-layers), located in regions with a lower poultry density and without a recent history of HPAI outbreak. Outcomes provide support to adapt biosecurity improvement and inspection plans.

Characterization of commercial poultry farms in Mexico: Towards a better understanding of biosecurity practices and antibiotic usage patterns

Mexico is one of the world’s major poultry producing countries. Two significant challenges currently facing the poultry industry are the responsible and judicious use of antimicrobials, and the potential occurrence of infectious disease outbreaks. For example, repeated outbreaks of highly pathogenic avian influenza virus subtype H7N3 have occurred in poultry since its first detection in Mexico in 2012. Both of these challenges can be addressed through good husbandry practices and the application of on-farm biosecurity measures. The aims of this study were: (i) to assess the biosecurity measures practiced across different types of poultry farms in Mexico, and (ii) to collect information regarding antimicrobial usage. A cross-sectional study was carried out through on-farm interviews on 43 poultry farms. A multiple correspondence analysis was performed to characterize the farms based on their pattern of biosecurity practices and antimicrobial usage. Three clusters of farms were identified using an agglomerative hierarchical cluster analysis. In each cluster, a specific farm type was predominant. The biosecurity measures that significantly differentiated the visited farms, thus allowing their clusterization, were: the use of personal protective equipment (e.g. face masks, hair caps, and eye protection), the requirement for a hygiene protocol before and after entering the farm, the use of exclusive working clothes by staff and visitors, footbath presence at the barn entrance, and the mortality disposal strategy. The more stringent the biosecurity measures on farms within a cluster, the fewer the farms that used antimicrobials. Farms with more biosecurity breaches used antimicrobials considered critically important for public health. These findings could be helpful to understand how to guide strategies to reinforce compliance with biosecurity practices identified as critical according to the farm type. We conclude by providing certain recommendations to improve on-farm biosecurity measures.

Quantitative assessment of biosecurity in broiler farms using Biocheck.UGent in Central Luzon, Philippines

The biosecurity status of 397 broiler farms in Central Luzon, the highest poultry meat-producing region in the Philippines, was assessed using Biocheck.Ugent. This online biosecurity assessment tool quantifies biosecurity level or compliance of surveyed farms. The system generates scores that reflect the current biosecurity status of each farm in terms of the different external and internal biosecurity measures being implemented in each farm. It was initially developed for pigs and broilers but recently is available for layers, swine, and cattle (beef, dairy, and veal). The overall biosecurity score of broiler farms in Central Luzon was 71.2%, with average external and internal biosecurity scores of 68.5 and 77.2%, respectively. Bataan had the highest biosecurity scores (76.5%) compared with the other 6 provinces. This was also true for the external and internal biosecurity scores of the province, with mean scores of 72.1 and 80.1%, respectively. Of the 11 subcategories of external and internal biosecurity that were assessed, purchase of day-old chicks, feeds and water supply, supply of materials, cleaning and disinfection, and materials between compartments had scores higher than the global scores. Low scores were generated from transport of live animals and infrastructure and biological vectors. The mean biosecurity score of farms with traditional/conventional type of housing was 7.8% lower than that with tunnel vent housing. Every year as the farm gets older, there was a corresponding drop of 0.2% in the biosecurity score. Biosecurity measures are in place in broiler farms in the country. However, there were areas with low scores which need to be prioritized to improve and upgrade the farms' biosecurity status. To date, this is the first quantitative assessment of biosecurity in broiler farms in the Philippines. High biosecurity scores may entail greater protection from disease incursion.

Estimating the level of disease risk and biosecurity on commercial poultry farms in New Zealand

Aims: To collect baseline data on the contact risk pathways and biosecurity practices of commercial poultry farms in New Zealand, investigate the relationship between the farm-level disease contact risks and biosecurity practices, and identify important poultry health concerns of producers. Methods: A cross-sectional survey of all registered New Zealand commercial poultry operations was conducted in 2016 collecting information on farm demographics, biosecurity practices, and contact risk pathways. Survey responses were used to generate an unweighted subjective disease risk score based on eight risk criteria and a subjective biosecurity score based on the frequency with which producers reported implementing seven biosecurity measures. Producer opinions towards poultry health issues were also determined. Results: Responses to the survey response were obtained from 120/414 (29.0%) producers, including 57/157 (36.3%) broiler, 33/169 (19.5%) layer, 24/55 (44%) breeder, and 6/32 (19%) other poultry production types. Median disease risk scores differed between production types (p < 0.001) and were lowest for breeder enterprises. The greatest risk for layer and broiler enterprises was from the potential movement of employees between sheds, and for breeder enterprises was the on- and off-farm movement of goods and services. Median biosecurity scores also differed between production types (p < 0.001), and were highest for breeder and broiler enterprises. Across all sectors there was no statistical correlation between biosecurity scores and disease risk scores. Producers showed a high level of concern over effectively managing biosecurity measures. Conclusions: The uptake of biosecurity measures in the commercial poultry farms surveyed was highly variable, with some having very low scores despite significant potential disease contact risks. This may be related to the low prevalence or absence of many important infectious poultry diseases in New Zealand leading farmers to believe there is a limited need to maintain good biosecurity as well as farmer uncertainty around the efficacy of different biosecurity measures. Further research is needed to understand barriers towards biosecurity adoption including evaluating the cost-effectiveness of biosecurity interventions.

The role of farm business type on biosecurity practices in West Java broiler farms

Biosecurity is important to prevent introduction and spread of infectious diseases, including Highly Pathogenic Avian Influenza (HPAI). HPAI is currently endemic in Indonesia and it has triggered the adoption of a biosecurity policy. Although there is anecdotal evidence about the level of biosecurity on Indonesian broiler farms, formal evidence is lacking, as well as knowledge about determinants of low biosecurity levels. This paper has two main objectives: 1) to assess the levels of biosecurity measures across different farm business types, and (2) to analyze the determining factors, with a special reference to farm business type, for the level of biosecurity and the availability of biosecurity infrastructure in the West Java poultry farms. A multi-stage sampling procedure was applied to collect data from approximately 400 broiler farmers in four districts in West Java province, namely Ciamis, Tasikmalaya, Subang and Sukabumi. Data were collected through farmer interviews and direct observation at the farms. The Biosecurity Control Score (BCS), consisting of 16 practice indicators, and the Farm Infrastructures for Biosecurity (FIB) list consisting of 16 building or physical set-ups as biosecurity facilities were used to assess the level of biosecurity. Determinants of biosecurity measures were analyzed via tobit regression analysis. The results show that the BCS was associated with the total number of birds per cycle, and risk perception (P < 0.05). The BCS was significantly (P < 0.05) higher for the farm business types 'independent farming', 'price contract farming' and 'company' compared to the 'makloon contract farming' business type (farming for a fee). Physical set-ups as farm infrastructure for biosecurity (FIB) were associated with the total number of birds per cycle, and with risk perception (P < 0.05). FIB was significantly (P < 0.05) higher for the farm business types 'independent farming', 'price contract farming' and 'company' compared to makloon contract farming. The results of this study suggest that business types play a significant role in determining biosecurity practices; a makloon contract farm (farming for a fee) tends to have a lower level of biosecurity than other business types due to lack of incentives. Consequently, in developing incentives for improved biosecurity measures. policymakers should encourage farm registration, and at the same time develop incentives that support the independent and price contract farming.

Using lamb sales data to investigate associations between implementation of disease preventive practices and sheep flock performance

Although the UK is the largest lamb meat producer in Europe, there are limited data available on sheep flock performance and on how sheep farmers manage their flocks. The aims of this study were to gather evidence on the types of disease control practices implemented in sheep flocks, and to explore husbandry factors associated with flock productivity. A questionnaire focusing on farm characteristics, general husbandry and flock health management was carried out in 648 farms located in the UK over summer 2016. Abattoir sales data (lamb sales over 12 months) was compared with the number of breeding ewes on farm to estimate flock productivity (number of lambs sold for meat per 100 ewes per farm per year). Results of a multivariable linear regression model, conducted on 615 farms with complete data, indicated that farms vaccinating ewes against abortion and clostridial agents and administering a group 4/5 anthelmintic to ewes (as recommended by the Sustainable Control of Parasites in Sheep Initiative) during quarantining had a greater flock productivity than farms not implementing these actions (P<0.01 and 0.02, respectively). Flocks with maternal breed types had higher productivity indexes compared with flocks with either pure hill or terminal breeds (P<0.01). Farms weighing lambs during lactation had greater productivity than those not weighing (P<0.01). Importantly, these actions were associated with other disease control practices, for example, treating individual lame ewes with an antibiotic injection, weaning lambs between 13 and 15 weeks of age and carrying out faecal egg counts, suggesting that an increase in productivity may be associated with the combined effect of these factors. This study provides new evidence on the positive relationship between sheep flock performance and disease control measures and demonstrates that lamb sales data can be used as a baseline source of information on flock performance and for farm benchmarking. Further research is needed to explore additional drivers of flock performance.

Charles KM, Bonney PJ, Malladi S, Culhane M, Goldsmith TJ, Halvorson DA, Cardona CJ. Analysis of geographic location and pathways for influenza A virus infection of commercial upland game bird and conventional poultry farms in the United States of America

BACKGROUND

Avian influenza (AI) is an infectious viral disease that affects several species and has zoonotic potential. Due to its associated health and economic repercussions, minimizing AI outbreaks is important. However, most control measures are generic and mostly target pathways important for the conventional poultry farms producing chickens, turkeys, and eggs and may not target other pathways that may be specific to the upland game bird sector. The goal of this study is to provide evidence to support the development of novel strategies for sector-specific AI control by comparing and contrasting practices and potential pathways for spread in upland game bird farms with those for conventional poultry farms in the United States. Farm practices and processes, seasonality of activities, geographic location and inter-farm distance were analyzed across the sectors. All the identified differences were framed and discussed in the context of their associated pathways for virus introduction into the farm and subsequent between-farm spread.

RESULTS

Differences stemming from production systems and seasonality, inter-farm distance and farm densities were evident and these could influence both fomite-mediated and local-area spread risks. Upland game bird farms operate under a single, independent owner rather than being contracted with or owned by a company with other farms as is the case with conventional poultry. The seasonal marketing of upland game birds, largely driven by hunting seasons, implies that movements are seasonal and customer-vendor dynamics vary between industry groups. Farm location analysis revealed that, on average, an upland game bird premises was 15.42 km away from the nearest neighboring premises with birds compared to 3.74 km for turkey premises. Compared to turkey premises, the average poultry farm density in a radius of 10 km of an upland game bird premises was less than a half, and turkey premises were 3.8 times (43.5% compared with 11.5%) more likely to fall within a control area during the 2015 Minnesota outbreak.

CONCLUSIONS

We conclude that the existing differences in the seasonality of production, isolated geographic location and epidemiological seclusion of farms influence AI spread dynamics and therefore disease control measures should be informed by these and other factors to achieve success.

Assessment of biosecurity practices and development of a scoring system in swine farms using item response theory

Brazil is the fourth largest producer and exporter of pork in the world, but has never reported yet the occurrence of some economically important diseases such as porcine reproductive and respiratory syndrome (PRRS) and porcine epidemic diarrhea (PED). Most of the swine farms in Brazil are characterized by intensive production being part of large integrated companies, where biosecurity practices help to prevent the introduction and spread of disease-causing infectious agents. The assessment of biosecurity in farms is not straightforward because of the large number of practices that constitute an on-farm biosecurity program. It is therefore necessary to combine the measurement of several parameters in order to characterize the level of biosecurity on a given farm. Thus, the objective of the study was to develop a biosecurity score to estimate the biosecurity level (theta or θ) in swine farms using the item response theory (IRT) and explore the relationship between the scores and independent variables. The IRT is a latent trait method extensively used in other fields, and offers the advantage to quantify the latent trait, here the biosecurity level, and to identify the practices that discriminate the farms avoiding the use of extensive questionnaires and redundant questions. In this study, 604 farms were evaluated in the main swine production regions of the state of Rio Grande do Sul, Brazil. Thirty-five practices were considered in order to quantify the biosecurity level on a given farm. After a recursive process 14 practices were selected to compose the biosecurity score to estimate the biosecurity level (θ). The variables identified with greater capacity of distinguishing the farms as to their biosecurity level were if the farm has 'feed bin outside of the barn limit (external feed loading)', has 'perimetral fence around the farm or barn', and if 'transit of trucks inside the farm is prohibited'. The biosecurity level was associated with some independent variables, e.g. the farm operation type, the integrated company and some owner characteristics. In addition, the results demonstrated that biosecurity practices related to management (internal biosecurity) are adopted with higher frequency compared to segregation and sanitation practices (external biosecurity). The IRT model proved useful and valid to estimate the biosecurity level in swine farms. Moreover, the biosecurity score described here has a relatively low number of items, which makes the application of this tool easier and faster compared to other previously described biosecurity assessment.

Weed hygiene practices in rural industries and public land management: Variable knowledge, patchy implementation, inconsistent coordination

Weed management science and practice largely focuses on eradicating, containing and reducing existing weed populations; the focus is on plants in situ. More recently, the redefinition of biosecurity to include weeds has seen greater attention paid to preventing the introduction of weeds to previously uninfested areas within countries. Thus weed hygiene has come to the fore, with a growing number of publications recommending a diverse range of practices to minimise the spread of weeds across farm, regional and state boundaries. Yet little is known about the uptake of weed hygiene practices. The aim of this paper is to evaluate the extent to which best practice weed hygiene is being implemented on, across and along private and public lands. Telephone interviews were conducted with 54 private and public land managers, weed contractors, and agricultural transport operators in New South Wales, Australia. Vehicle hygiene was commonly undertaken across all stakeholder groups when it was consistent with other goals, requirements or norms. Other practices, such as sequencing harvesting from least to most weedy paddocks or including weed hygiene clauses in contracts were often known, but rarely practiced because of the onerous labour and financial costs or concerns about social etiquette. Individual commitment to weed hygiene efforts were also undermined by intra and inter-organisational coordination challenges. Public debate and assessment are needed on the benefits and costs to society of weed hygiene compared to in situ weed control to determine where best to invest limited time and resources.

Biosecurity practices on foie gras duck farms, Southwest France

On-farm biosecurity can be assessed by analyzing patterns of practices to better tailor technical advice to producers. Given their close contact with environmental and wildlife disease reservoirs, free-range duck farms are exposed to multiple risk factors of pathogen exposure that are rare or absent in indoor production. The recurrent emergence of Highly Pathogenic Avian Influenza (HPAI) viruses in Southeast Asia and Europe has emphasized the importance of farm-level biosecurity on free-range duck farms. This study was conducted on 46 French duck farms. The farms were visited and an 80-question survey was administered to assess biosecurity practices. Patterns of practices were explored with multiple correspondence analysis and hierarchical cluster analysis. Farms were assigned to one of three clusters in which specific farm types were overrepresented: farms specialized in rearing to grow-out phases and open-circuit full cycle (i.e., all production phases on the farm) farms in cluster 1, closed-circuit full cycle farms in cluster 2, and farms specialized in gavage in cluster 3. Differences in practices might be linked with differences in production constraints. This study provides a baseline assessment of biosecurity practices on foie gras duck farms in Southwest France and will help efforts to adapt biosecurity programs to farm types.

Scoring biosecurity in European conventional broiler production

Good biosecurity procedures are crucial for healthy animal production. The aim of this study was to quantify the level of biosecurity on conventional broiler farms in Europe, following a standardized procedure, thereby trying to identify factors that are amenable to improvement. The current study used a risk-based weighted scoring system (biocheck.ugent ®) to assess the level of biosecurity on 399 conventional broiler farms in 5 EU member states. The scoring system consisted of 2 main categories, namely external and internal biosecurity, which had 8 and 3 subcategories, respectively. Biosecurity was quantified by converting the answers to 97 questions into a score from 0 to 100. The minimum score, "0," represents total absence of any biosecurity measure on the broiler farm, whereas the maximum score, "100," means full application of all investigated biosecurity measures. A possible correlation between biosecurity and farm characteristics was investigated by multivariate linear regression analysis. The participating broiler farms scored better for internal biosecurity (mean score of 76.6) than for external biosecurity (mean 68.4). There was variation between the mean biosecurity scores for the different member states, ranging from 59.8 to 78.0 for external biosecurity and from 63.0 to 85.6 for internal biosecurity. Within the category of external biosecurity, the subcategory related to "infrastructure and vectors" had the highest mean score (82.4), while the subcategory with the lowest score related to biosecurity procedures for "visitors and staff" (mean 51.5). Within the category of internal biosecurity, the subcategory "disease management" had the highest mean score (65.8). In the multivariate regression model a significant negative correlation was found between internal biosecurity and the number of employees and farm size. These findings indicate that there is a lot of variation for external and internal biosecurity on the participating broiler farms, suggesting that improvements are possible. Since the subcategory "visitors and staff" scored the lowest, better education of broiler farmers and their staff may help to improve overall biosecurity on broiler farms in Europe.

Public health concerns of highly pathogenic avian influenza H5N1 endemicity in Africa

Highly pathogenic avian influenza virus (HPAIV) H5N1 was first officially reported in Africa in 2006; thereafter this virus has spread rapidly from Nigeria to 11 other African countries. This study was aimed at utilizing data from confirmed laboratory reports to carry out a qualitative evaluation of the factors responsible for HPAI H5N1 persistence in Africa and the public health implications; and to suggest appropriate control measures. Relevant publications were sought from data banks and repositories of FAO, OIE, WHO, and Google scholars. Substantiated data on HPAI H5N1 outbreaks in poultry in Africa and in humans across the world were mined. HPAI H5N1 affects poultry and human populations, with Egypt having highest human cases (346) globally. Nigeria had a reinfection from 2014 to 2015, with outbreaks in Côte d'Ivoire, Ghana, Niger, Nigeria, and Burkina Faso throughout 2016 unabated. The persistence of this virus in Africa is attributed to the survivability of HPAIV, ability to evolve other subtypes through genetic reassortment, poor biosecurity compliance at the live bird markets and poultry farms, husbandry methods and multispecies livestock farming, poultry vaccinations, and continuous shedding of HPAIV, transboundary transmission of HPAIV through poultry trades; and transcontinental migratory birds. There is, therefore, the need for African nations to realistically reassess their status, through regular surveillance and be transparent with HPAI H5N1 outbreak data. Also, it is important to have an understanding of HPAIV migration dynamics which will be helpful in epidemiological modeling, disease prevention, control and eradication measures.

A Simulation-Based Evaluation of Premovement Active Surveillance Protocol Options for the Managed Movement of Turkeys to Slaughter During an Outbreak of Highly Pathogenic Avian Influenza in the United States

Risk management decisions associated with live poultry movement during a highly pathogenic avian influenza (HPAI) outbreak should be carefully considered. Live turkey movements may pose a risk for disease spread. On the other hand, interruptions in scheduled movements can disrupt business continuity. The Secure Turkey Supply (STS) Plan was developed through an industry-government-academic collaboration to address business continuity concerns that might arise during a HPAI outbreak. STS stakeholders proposed outbreak response measure options that were evaluated through risk assessment. The developed approach relies on 1) diagnostic testing of two pooled samples of swabs taken from dead turkeys immediately before movement via the influenza A matrix gene real-time reverse transcriptase polymerase chain reaction (rRT-PCR) test; 2) enhanced biosecurity measures in combination with a premovement isolation period (PMIP), restricting movement onto the premises for a few days before movement to slaughter; and 3) incorporation of a distance factor from known infected flocks such that exposure via local area spread is unlikely. Daily exposure likelihood estimates from spatial kernels from past HPAI outbreaks were coupled with simulation models of disease spread and active surveillance to evaluate active surveillance protocol options that differ with respect to the number of swabs per pooled sample and the timing of the tests in relation to movement. Simulation model results indicate that active surveillance testing, in combination with strict biosecurity, substantially increased HPAI virus detection probability. When distance from a known infected flock was considered, the overall combined likelihood of moving an infected, undetected turkey flock to slaughter was predicted to be lower at 3 and 5 km. The analysis of different active surveillance protocol options is designed to incorporate flexibility into HPAI emergency response plans.

"Catch 22": Biosecurity awareness, interpretation and practice amongst poultry catchers

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Barriers to good biosecurity during catching are investigated using mixed methods.

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Awareness of biosecurity is assessed using a Watch-&-Click hazard awareness survey.

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Time pressure and lack of equipment are important causes of lapses in biosecurity.

Campylobacter contamination of chicken on sale in the UK remains at high levels and has a substantial public health impact. This has prompted the application of many interventions in the supply chain, including enhanced biosecurity measures on-farm. Catching and thinning are acknowledged as threats to the maintenance of good biosecurity, yet the people employed to undertake this critical work (i.e. ‘catchers’) are a rarely studied group.

This study uses a mixed methods approach to investigate catchers’ (n = 53) understanding of the biosecurity threats posed by the catching and thinning, and the barriers to good biosecurity practice. It interrogated the role of training in both the awareness and practice of good biosecurity. Awareness of lapses in biosecurity was assessed using a Watch-&-Click hazard awareness survey (n = 53). Qualitative interviews (n = 49 catchers, 5 farm managers) explored the understanding, experience and practice of catching and biosecurity.

All of the catchers who took part in the Watch-&-Click study identified at least one of the biosecurity threats with 40% detecting all of the hazards. Those who had undergone training were significantly more likely to identify specific biosecurity threats and have a higher awareness score overall (48% compared to 9%, p = 0.03). Crucially, the individual and group interviews revealed the tensions between the high levels of biosecurity awareness evident from the survey and the reality of the routine practice of catching and thinning. Time pressures and a lack of equipment rather than a lack of knowledge appear a more fundamental cause of catcher-related biosecurity lapses. Our results reveal that catchers find themselves in a ‘catch-22′ situation in which mutually conflicting circumstances prevent simultaneous completion of their job and compliance with biosecurity standards.3 Hence, although education about, and enforcement of, biosecurity protocols has been recommended, our findings suggest that further reforms, including changing the context in which catching occurs by improving the equipment and other resources available to catchers and providing more time for biosecurity, will be essential for successful implementation of existing biosecurity protocols.

Biosecurity and geospatial analysis of mycoplasma infections in poultry farms at Al-Jabal Al-Gharbi region of Libya

Geospatial database of farm locations and biosecurity measures are essential to control disease outbreaks. A study was conducted to establish geospatial database on poultry farms in Al-Jabal Al-Gharbi region of Libya, to evaluate the biosecurity level of each farm and to determine the seroprevalence of mycoplasma and its relation to biosecurity level. A field team of 7 Veterinarians belongs to the National Center of Animal Health was assigned for data recording and collection of blood samples. Personal information of the producers, geographical locations, biosecurity measures and description of the poultry farms were recorded. The total number of poultry farms in Al-Jabal Al-Gharbi Region is 461 farms distributed in 13 cities. Out of these, 102 broiler farms and one broiler breeder farm (10 houses) which were in operation during team visit were included in this study. Following collection of blood, sera were separated and tested by Enzyme-linked immunosorbent assay (ELISA) for the presence of antibodies against Mycoplasma (General antigen for M. gallisepticum and M. synoviae). The seroprevalence of Mycoplasma in the region was 28% (29 poultry farms out of 103 were infected). About 50% (23 out of 47) of poultry farms located in Garian city were infected with Mycoplasma and one significant cluster of Mycoplasma infection in the city was identified. Low level of biosecurity was found in poultry farms of the region. Out of the 103 farms included, 63% of poultry houses has a ground of soil and 44% of them has uncoated walls which may influence the proper cleaning and disinfection. Almost 100% of the farms are at risk of exposure to diseases transmitted by wild birds such as avian influenza and Newcastle disease due to absence of wild birds control program. Although, 81% of the farms have entry restrictions, only 20% have disinfectants at entry which increase the risk of exposure to pathogens. The results of this study highlight the weakness points of biosecurity measures in poultry farms of Al-Jabal Al-Gharbi region and high seroprevalence of mycoplasma. Data collected in this study will assist the Veterinary authorities to apply effective disease control strategies.

Appraisal of Chicken Production with Associated Biosecurity Practices in Commercial Poultry Farms Located in Jos, Nigeria

A questionnaire-based study of chicken production system with on-farm biosecurity practices was carried out in commercial poultry farms located in Jos, Nigeria. Commercial and semicommercial farms had 75.3% and 24.5% of 95,393 birds on 80 farms, respectively. Farms using deep litter and battery cage systems were 69 (86.3%) and 10 (12.5%), respectively. In our biosecurity scoring system, a correct practice of each indicator of an event scored 1.00 and biosecurity score (BS) of each farm was the average of the scores of biosecurity indicators for the farm, giving BS of zero and 1.00 as absence of biosecurity and optimal biosecurity, respectively. Semicommercial farms had higher BS than commercial farms. The flock size did not significantly (p > 0.05) affect the mean BS. Disease outbreaks correlated (r = -0.97) with BS, showing a tendency of reduction of disease outbreaks with increasing BS. Outbreaks were significantly (p < 0.05) associated with deep litter system. In conclusion, the chicken production system requires increased drive for excellent biosecurity practices and weak points in the biosecurity could be ameliorated by extension of information to farmers in order to support expansion of chicken production with robust biosecurity measures that drastically reduce risk of disease outbreak.

Risk assessment as a tool for improving external biosecurity at farm level

Background

Biosecurity routines at herd level may reduce the probability of introduction of disease into the herd, but some measures may be regarded as expensive and cumbersome for the farmers. Custom-made measures based on individual farm characteristics may aid in improving the actual application of on-farm biosecurity.

The aim of the study was to provide a tool for calculating the effects of different biosecurity measures and strategies on the individual farm level.

A simple model was developed to assess the risk of disease introduction and the need for biosecurity measures in individual farms. To illustrate the general applicability of the tool, it was applied to theoretical examples of Swedish cattle and pig farms and diseases endemic in those animal species in the EU, in two scenarios with different between-farm contact patterns.

Results

The model illustrated that the most important factors affecting the risk, and the effect of biosecurity measures such as quarantine routines and protective clothing, were the frequency of between-farm contacts and prevalence of the disease. The risk of introduction as well as the effect of biosecurity measures differed between farm types and disease transmission routes. Adapting contact patterns to mitigate a specific disease risk was as important as biosecurity measures for some farm types, but the largest effect was seen when combining biosecurity measures with more planned contact patterns.

Conclusions

The risk assessment model proved useful for illustrating the risk of introduction of endemic diseases and the mitigating effect of different biosecurity measures on farm level. Model outputs could be used to justify prioritisation of measures or adapting contact patterns. The theoretic exercise of adjusting model inputs and comparing outputs may help veterinary advisors to understand farm-specific risks and motivate farmers to improve biosecurity in their individual farm, as it can be tailored to each farmer’s needs and preferences.

Evaluating the risk of avian influenza introduction and spread among poultry exhibition flocks in Australia

Some practices undertaken by poultry exhibitors, such as allowing wild birds to contact domestic birds, the high frequency of bird movements and the lack of appropriate isolation for incoming birds, pose a risk for disease introduction and spread. The aim of the current study was to quantitatively assess the probability of introduction of low pathogenic avian influenza (LPAI) viruses from wild waterfowl into poultry exhibition flocks and the subsequent spread to other poultry flocks. Exposure and consequence assessments, using scenario trees and Monte Carlo stochastic simulation modelling, were conducted to identify potential pathways of introduction and spread and calculate the probabilities of these pathways occurring. Input parameters were estimated from two recently conducted cross-sectional studies among poultry exhibitors in Australia (Dusan et al., 2010; Hernández-Jover et al., 2013) and other scientific literature. According to reported practices of poultry exhibitors and the LPAI prevalence in wild birds in Australia, this assessment estimates a median (5-95%) probability of exposure of a bird kept by a poultry exhibitor of 0.004 (0.003-0.005). Due to the higher susceptibility of infection of turkeys and waterfowl, this probability is higher in flocks keeping these bird species than in those keeping chickens or pigeons only. Similarly, once exposure has occurred, establishment of infection and subsequent spread are more likely in those flocks keeping waterfowl and turkeys than in those keeping chicken and pigeons only. Spread through movement of birds is the most likely pathway of spread, followed by contaminated fomites, wild birds and airborne spread. The median probability of LPAI spread through movement of birds in flocks keeping waterfowl and turkeys was estimated to be 0.280 (0.123-0.541) and 0.230 (0.104-0.421), respectively. A lower probability was estimated for chicken (0.087; 0.027-0.202) and pigeon (0.0003; 3.0×10(-5)-0.0008) flocks. The sensitivity analysis indicates that the prevalence of LPAI in wild waterfowl and the probability of contact of domestic birds with wild waterfowl are the most influential parameters on the probability of exposure; while the probability of spread is mostly influenced by the probability of movement of birds and the probability of the exhibitor detecting and reporting LPAI. To minimize the potential risk of AI introduction and spread, poultry exhibitors should prevent contact of domestic birds with wild birds, and implement appropriate biosecurity practices. In addition, adequate extension services are required to improve exhibitors' abilities to recognize diseases and reporting behaviour.

The development of poultry farms risk assessment tool for avian influenza in Imo State, Nigeria

This study validated the content of a questionnaire that will be used for risk stratification in poultry farms in Imo State, Nigeria. The questionnaire was developed from avian influenza risk domains peculiar to poultry farms in Nigeria. The questionnaire was verified and modified by a group of five experts with research interest in Nigeria's poultry industry and avian influenza prevention. The questionnaire was distributed to 30 poultry farms selected from Imo State, Nigeria. The same poultry farms were visited one week after they completed the questionnaires for on-site observation. Agreement between survey and observation results was analyzed using the kappa statistic and rated as poor, fair, moderate, substantial, or nearly perfect; internal consistency of the survey was also computed. The mean kappa statistic for agreement between the survey and observations (validation) ranged from 0.06 to 1, poor to nearly perfect agreement. Eight questions showed poor agreement, four had a fair agreement, two items had moderate agreement, nineteen survey questions had substantial agreement and ten questions had nearly perfect agreement. Out of the 43 items in the questionnaire, 32 items were considered validated with coefficient alpha >0.70.

Factors associated with introduction of infectious laryngotracheitis virus on broiler farms during a localized outbreak

We analyzed factors involved in the introduction of infectious laryngotracheitis (ILT) virus (ILTV) onto broiler farms during a localized outbreak in an immunologically naive broiler population. The outbreak occurred in the state of Mississippi, United States in 2002-2003. From the responses to a retrospective survey questionnaire administered via personal interviews, 181 farm-level risk factors were defined and analyzed for their association with ILTV introduction using logistic regression. There were 27 case farms (93% of all the infected broiler farms) and two sets of controls: farms matched to the cases by location and those randomly selected among the broiler farms in Mississippi. We found that farm suppliers such as gas company representatives, who are likely to visit other farms, and farm-workers who visit other chicken farms, are likely vehicles of ILTV introduction onto broiler farms. These risks can be greatly reduced by following biosecurity procedures, in particular if farm workers bathe and change footwear prior to entering broiler houses on their own farm. Footbaths for farm visitors can provide a false sense of security during an ILT outbreak when, indeed, other practices such as plastic boots or changing boots are more effective in preventing ILTV transmission. Sharing of equipment used for removal of caked broiler litter between subsequent flocks may also serve as an important vehicle of ILTV transmission. During the 2002-2003 outbreak, shared litter removal equipment was associated with ILTV transmission despite a requirement being put in place for litter decontamination. We also found that tunnel-ventilated broiler houses with inlets toward a neighboring poultry farm are more likely to get infected with ILTV. In addition to this analysis, the data collected provide a good overview of the actual practices and deficiencies of biosecurity undertaken on broiler farms in this part of the United States.

Avian influenza transmission risks: analysis of biosecurity measures and contact structure in Dutch poultry farming

In the 2003 epidemic of highly pathogenic avian influenza in Dutch poultry, between-farm virus transmission continued for considerable time despite control measures. Gaining more insight into the mechanisms of this spread is necessary for the possible development of better control strategies. We carried out an in-depth interview study aiming to systematically explore all the poultry production activities to identify the activities that could potentially be related to virus introduction and transmission. One of the between-farm contact risks that were identified is the movement of birds between farms during thinning with violations of on-farm biosecurity protocols. In addition, several other risky management practices, risky visitor behaviours and biosecurity breaches were identified. They include human and fomite contacts that occurred without observing biosecurity protocols, poor waste management practices, presence of other animal species on poultry farms, and poor biosecurity against risks from farm neighbourhood activities. Among the detailed practices identified, taking cell phones and jewellery into poultry houses, not observing shower-in protocols and the exchange of unclean farm equipment were common. Also, sometimes certain protocols or biosecurity facilities were lacking. We also asked the interviewed farmers about their perception of transmission risks and found that they had divergent opinions about the visitor- and neighbourhood-associated risks. We performed a qualitative assessment of contact risks (as transmission pathways) based on contact type, corresponding biosecurity practices, and contact frequency. This assessment suggests that the most risky contact types are bird movements during thinning and restocking, most human movements accessing poultry houses and proximity to other poultry farms. The overall risk posed by persons and equipment accessing storage rooms and the premises-only contacts was considered to be medium. Most of the exposure risks are considered to be similar for layer and broiler farms. Our results, including those on farmer opinions, are relevant for the communication with farmers and poultry-related businesses about practices and risks. We conclude by providing recommendations for improvement of control strategies.

The cost-benefit of biosecurity measures on infectious diseases in the Egyptian household poultry

Increased animal intensification presents with increasing risks of animal diseases. The Egyptian household poultry is peculiar in its management style and housing and this present with particular challenges of risk of infection to both the flock and humans. Biosecurity remains one of the most important means of reducing risks of infection in the household poultry, however not much information is available to support its feasibility at the household level of production. In this study financial feasibilities of biosecurity were modeled and evaluated based on certain production parameters. Risks of particular importance to the household poultry were categorized and highly pathogenic avian influenza H5N1 was the most risky disease while people-related risk was the most important risk category. It was observed that basic biosecurity measures were applicable in the household poultry and it would be 8.45 times better to implement biosecurity than to do nothing against HPAI H5N1; 4.88 times better against Newcastle disease and 1.49 times better against coccidiosis. Sensitivity analyses proved that the household poultry project was robust and would withstand various uncertainties. An uptake pathway for basic biosecurity was suggested. The outcome of this work should support decisions to implement biosecurity at the household sector of poultry production.