Integrated management-based approach for surveillance and control of zoonoses in emerging livestock systems: South East Asia Pig & Poultry Partnership

Lead Research Organisation: University of Cambridge
Department Name: Veterinary Medicine

Abstract

Human populations repeatedly face new infectious disease challenges, many of which are of animal origin (zoonotic) and then become endemic in animal and human populations. These zoonotic risks may be worsened by rapid development and diversification of livestock production systems now occurring in low- and middle-income countries, especially in South East Asia. These emerging livestock systems (ELS) are linked to peoples' changing food consumption habits, economic status, aspirations and population shifts, and to political contexts. Key features of ELS include intensification of animal keeping, increased use of antibiotics, and extended supply chains - all of which can have disadvantages from a food safety perspective.

Headlines reasonably focus on the emerging zoonotic diseases, for example highly pathogenic influenza (HPAI), but it is the forgotten endemic zoonotic diseases, and primarily gastrointestinal (GI) infections that put the heaviest global burden on the health of poor people, and on productivity and profitability of their livestock (ILRI Report to DfID, 2012). It is estimated that zoonotic gastrointestinal disease, caused by bacteria such as Salmonella and Campylobacter and related antibiotic resistance, accounts for around 1 million human deaths per year globally with around 800 million people being affected, most of them children under five; a situation also reflected in our study countries Viet Nam and Myanmar which rank in the top 5 hotspots for rapidity and diversity of their ELS (ILRI report to DfID).

Our work tests the idea that diverse ELS, specifically pig and poultry production, upon which these people increasingly depend for food, are major sources of these infections. We also hypothesise that these zoonotic threats are impacted by the risk environment, and pathogen- and host-related factors and that these, in turn, will be affected by the scale and diversity of different ELS. Viet Nam and Myanmar are at different stages of rapid but different development trajectories and we will study these differences to support development of new One Health approaches.

Our proposal's aim is to exploit interdisciplinary expertise that includes social, biological, and governmental players from Myanmar, Viet Nam and UK to bring about step changes in pro-poor control measures using knowledge-driven and culturally relevant strategies that concomitantly improve animal health and productivity and thus improve and protect human health.

The objectives to achieve this aim involve parallel work in Viet Nam and Myanmar:
(1) To characterise pig and poultry production systems and supply chains.
(2) To characterise key stakeholders' existing perceptions and practices related to livestock disease, zoonotic risk and baseline preventive mechanisms.
(3) To identify the impact of different livestock systems on the prevalence and diversity of bacterial zoonotic infections and on antimicrobial resistance.
(4) To up-scale regionally accessible diagnostic laboratories
(5) To identify, pilot and evaluate appropriate and effective knowledge-based training programmes in ELS in Viet Nam and Myanmar, and consider how these might be translated to other contexts.

Our research will underpin improved food safety and wellbeing for consumers, improved economic security and health for food chain workers, community-level and environmental benefits from improved management of livestock intensification, evidence on which to base effective and culturally relevant policy for bacterial zoonosis control, pilot microbiology laboratories, infrastructure, and training as the basis for sustainable future surveillance for bacterial endemic zoonoses (to which surveillance for emerging zoonoses could be bolted), and zoonotic risk evaluation and control methods that can be adapted to other international contexts. Finally, the project provides novel academic insights into the role of interdisciplinary teams in tackling global health issues.

Technical Summary

Increasing consumption of meat in developing countries, especially in SE Asia, is leading to new demands on pig and poultry supply chains and emergence of new production networks. The zoonotic threats posed by these changes are largely unknown. The project will deliver interdisciplinary understanding of interactions between (1) meat production, the environment and supply practices, (2) socio-economic and export pressures, cultural understandings and perceptions of risk to humans and livestock, and (3) the infection dynamics and diversity of zoonotic infections and antimicrobial resistance determinants in these systems. This understanding will provide baseline knowledge and inform the design and evaluation of interventions intended to strengthen the safety and robustness of meat supply chains in ways that build on existing formal and informal practices and contexts, implementable in dynamic SE Asian settings.

Our aim is to exploit interdisciplinary expertise including social, biological, and governmental players from Myanmar, Viet Nam and UK to bring about step changes in pro-poor control measures using knowledge-driven and culturally relevant strategies that concomitantly improve animal health and productivity and thus improve and protect human health. The objectives to achieve this aim involve parallel work in Viet Nam and Myanmar:
(1) To characterise pig and poultry production systems and supply chains.
(2) To characterise key stakeholders' existing perceptions and practices related to livestock disease, zoonotic risk and baseline preventive mechanisms.
(3) To identify the impact of different livestock systems on the prevalence and diversity of bacterial zoonotic infections and on antimicrobial resistance.
(4) To up-scale regionally accessible diagnostic laboratories
(5) To identify, pilot and evaluate appropriate and effective knowledge-based training programmes in ELS in Viet Nam and Myanmar, and consider how these might be translated to other contexts.

Planned Impact

The following is a summary of the impacts, and routes for their delivery.
(1) Retail and subsistence consumer benefits through improved food safety and reduced prevalence of pig- and poultry-meat derived endemic bacterial zoonoses is a major impact target of our work. This will come through the uptake of training in knowledge-based management methods along the meat supply chain - from farm through butchery and retail, delivering safer products into consumers' homes. It will be assisted through shifts in government policy and legislation. Although much of this impact will come from earlier steps in the supply chain, our project includes the use and evaluation of consumer discussion groups allowing direct interaction training opportunities. Involvement of regional government in our consortium will enable fast-tracking of successful public health education programs for broader uptake.
(2) Our research will impact supply chain workers directly involved in our project (farmers, butchers, retailers) by offering improved economic stability through better animal health (including non-zoonotic infections) and productivity and reduced occupational exposure to bacterial zoonoses along the supply chains. This will be achieved through adaptations of the Farmer Field School Approach described in Pathways to Impact, with uptake on a larger scale being assisted by sDAH in Viet Nam and LBVD in Myanmar.
(3) At community level, we anticipate that methods to control the selection of antimicrobial resistance and its escape into local environments, watercourses and populations will be a significant impact. This will be achieved through farm-level training methods.
(4) A key area of impact will be at regional (policy implementation) and national governmental (policy development) level. At regional level we anticipate making a tangible step-change in infrastructure, capacity and training for surveillance and diagnostic investigation of bacterial endemic zoonoses of livestock and in-contact humans by up-scaling and up-skilling this capability. We anticipate that the laboratories we support in Myanmar and Viet Nam will obtain subsequent research funding, and that sDAH and LBVD will be convinced of the value in investing to maintain these capabilities. Our work also provides opportunities for interdisciplinary training of government (sDAH and LBVD) veterinary surgeons and epidemiologists for on-farm productivity assessment and intervention delivery. At national level we anticipate impacts in terms of influencing One Health policies across and between departments responsible for livestock and human health and for regulation of food safety surveillance, animal husbandry and health management recommendations. Finally, we see our new approach to designing bespoke training methods that account for risk perceptions as being an important impact leading to more effective results in government led training initiatives.
(5) At international level, we anticipate that outputs from our project will be taken up by non-governmental development, animal health and One Health agencies to enable translation of knowledge-based, culturally applicable training for reduction of endemic bacterial zoonoses in different countries. This will be achieved through, for example, collaborative support from FAO. In addition, we believe that the strong international consortium will encourage all participants in our project, from small-scale farmer to butcher to government official, to foster and cherish mutually valuable international linkages as sources of advice, support and friendship.
(6) The opportunity to build stronger teaching links between UK, VN and MM universities, veterinary and medical schools provides exciting opportunities for 2-way flow of One Health and development impacts at faculty and student levels. These opportunities will be facilitated by our partners at LBVD and sDAH.

Publications

10 25 50
 
Description Key initial findings from existing ZELS funded work in Myanmar, the Myanmar Pig Partnership:
There were 2 key aims for our original ZELS funded work in Myanmar, an interdisciplinary collaboration between LBVD - part of the Myanmar Ministry of Agriculture, Livestock and Irrigation, Dept. Veterinary Medicine at the University of Cambridge, the Institute for Development Studies at the University of Sussex, and Oxford University Clinical Research Unit (OUCRU) in Ho Chi Minh City. First, we set out to characterise the animal health, zoonotic and productivity risks in emerging pig-based production systems in the pig dense Yangon region, though a multi-disciplinary approach, considering:
- Supply chains along urban-rural transect and their social, economic, cultural dimensions of risk were studied using a range of methods including in depth interviews, discussion groups, and observation of practices.
- Risk perceptions and existing practices among farmers, traders, slaughter workers, pig meat retailers and consumers
- Microbiological, productivity and veterinary preventive health surveys of pigs and products (Salmonella, Strep. suis, drug resistance) on farms, at slaughter and at retail.
Second, we aimed to develop pro-poor, knowledge-driven, interventions that improve animal health, productivity, and or human health:
- Pilot and wider scale evaluation of interventions.
- Capacity building of farmers and veterinary officers
- Culturally sensitive training and identification of strategies for wider dissemination and/or uptake of outputs in policy and practice.

The original planned focus of the Myanmar Pig Partnership work was to understand how these changes in intensification in the risk environment affected the likelihood of zoonotic transfer between livestock and humans of endemic bacterial pathogens (Fig 1: right section, middle panel). We also wanted to seek insights into how these changes affected the dynamics of antimicrobial resistance. The results were intended to inform the design of integrated responses which could in theory be mounted at three levels (Fig 1, right panel): producers, frontline workers down supply chains and communities (knowledge-based management training, public engagement on zoonotic and related risks), national agencies (skill training, improved laboratories to support surveillance, advice on regulation, strengthening of national One Health networks) and internationally (strengthened regional linkages, training methodologies, contributing to learning on One Health approaches). Budget limitations led us, in consultation with ZELS Secretariat to focus microbiological sampling only on pig farms, slaughterhouses and retail, and to step back from our original plans to sample from human actors along the supply chain and also our plans to study the burden of human disease associated with pig production and consumption.

Despite a 9 months no-cost extension having been granted by BBSRC due to the effective paralysis of our Myanmar government partner LBVD during the presidential election and associated reorganisation of administration during 2015, the project is largely on track, with plans now at an advanced stage for the introduction of pilot interventions for participant farms in October 2018. The project has focused its interdisciplinary research efforts on 18 farms spread across 3 townships in the Yangon Region, each with a differing profile of intensification. We studied 8 mid-sized farms (30-70 head) in the rural township of Taikkyi, most distant from Yangon; we studied 8 larger farms in Hlegu township (70 - >7000 head), part of a peri-urban official 'livestock intensification zone'; and finally we studied 8 small farms (<30 head) in South Dagon township, a suburb of Yangon with many backyard producers. We were also able to gain access to one of Yangon's 2 large slaughterhouses (Yarthwargyi, S. Dagon, slaughtering more than 150 pigs per night) and 8 small slaughter houses (located across the 3 townships, slaughtering 1-2 pigs per night). Some key elements of the data are included here (presented at the Internal Pig Veterinary Congress, Chongqing, China 2018 by Hlaing May Than, and at the International Conference of Agircultral Economists, 2018 by Dr Ayako Ebata, as well as by other team members at ZELS network meetings) but it must be noted that analysis and preparation for publication is ongoing.

Data emerging from the intensive social science-based characterisation of supply chains included the following key points:
• Value chains are strongly market-based and consumers at retail markets have limited means for differentiating meat that is safer than other meat on offer (beyond colour and smell), thus there is no incentive for hygiene-based changes to practices on farms or at slaughter unless those changes also bring efficiency savings.
• Farmers, slaughter workers, retailers and consumers do not have functional understanding of the concept of zoonotic disease risks. Farmers, especially those with small numbers of animals and limited means, fear disease in their pigs more than those for humans because of the economic consequences of loss.
• Farmers' ability to access vets for advice on disease management is limited: they rely on many different sources for advice and expertise is variable. Only the very large farms have their own vets
• Antibiotics are not chosen and dosed to give best results from a veterinary point of view, not least because the product labels are in language that farmers and their non-veterinary advisors cannot read. This limits their effect and value and could worsen resistance.
• Risky practices identified for pig disease risk included boar rental, transport of pigs to farms without quarantine or disinfection and unhygienic castration.
• Risky practices for human disease included marketing sick pigs for human consumption.

Data emerging from the microbiological survey of participant farms and slaughterhouses (note, the survey of retail premises is ongoing) included the following key points:
• The prevalence of Salmonella enterica serovars was widespread across almost all farms in all townships with a statistically significant increase in S. Dagon, potentially associated with the increased reliance in that township on human food by-products and kitchen waste in pace of commercial pig diets. At the slaughterhouse, there was evidence for an overwhelming level of cross contamination during processing with carcass prevalence (i.e. what goes out to the consumer) much greater than caecal prevalence (i.e. what comes in with the pigs), and increased levels of carcass contamination recorded during the rainy season.
• The prevalence of Streptococcus suis was also widespread across all farms and townships studied, as was expected based on global prevalence data. However, we found S. suis on carcasses and, in our view significantly, in the blood of slaughter-pigs suggesting bacteraemia or septicaemia with a peak prevalence of 48% of all pigs sampled being positive in blood during the rainy season (n=31). Such findings have not been reported elsewhere and may reflect the tendency to market sick pigs, and the suboptimal conditions to which slaughter pigs are subjected in transport, lairage and slaughter.
• The antimicrobial resistance profiles for Salmonella obtained from farms showed a distinct pattern according to the township in which they were based. For example, AMR was most prevalent and diverse for isolates from the more intensive Hlegu township, where usage of a very wide range of antibiotic products was described, included antibiotics that should be restricted for human use. Conversely, isolates from farms in S. Dagon (smallest scale production) showed the lowest prevalence and diversity of AMR, again aligned with the available antibiotic usage data indicating relatively lower level of usage.

Data from the veterinary preventive health and productivity evaluation of farms included the following key findings:
• Biosecurity weaknesses were identified including boar rental, inadequate cleaning and disinfection of pig transport, mixing different sources of pigs without quarantine, and people movements.
• Productivity: There was generally poor data collection and storage by farmers about their pig farming enterprise and its profitability (noting that it was commonplace for smaller farmers to borrow money at 20% per month for purchase of weaners and inputs). Pigs were typically weaned at 7 weeks compared to the optimum of 4 weeks which allows for a swift onset of a full estrus and speedy return to pregnancy. A consequence of this was a typically prolonged wean-to-service interval reducing piglets weaned per sow per year. Castration was typically done at a later age than expected and this could be associated with losses due to poor hygiene and secondary ascending infections.
• Disease: Widespread with main problems being nervous, gut and respiratory disease. Mortality of up to 100% was not uncommon for individual farms and peaks in numbers of deaths occurred in summer and rainy seasons. There were no examples of diagnostic work being done to check causes of disease or antibiotic sensitivity.
• Vaccination: Classical Swine Fever is the only widely used vaccine, except on very large farms. Some farmers did not understand the risks of delaying vaccination.
• Medicines usage: Usage was not always recorded because it is illegal for non-vets to administer, yet this practice was believed to be taking place in an undetermined number of cases. Very large farms reported usage of a wide variety (<11) of products.

Data from the veterinary preventive health evaluation of slaughterhouses included the following key points:
• Slaughtering was done at night in all cases, with no chilling, and delivery of meat direct to retailers.
• Transport of pigs: Duration ranged from 2-3 hrs (small slaughterhouses) to 1 day (large slaughterhouses).
• Lairage: All lairages were cleaned but none were disinfected; duration of residence could be up to 72 hours; supply of feed and water for pigs was variable by premises.
• Slaughter line: Cleaning after each shift was variable and more frequently reported in small than large slaughterhouses. Disinfection was not reported in any premises.
• No food safety occupational health practices were reported such as hand washing, knife washing between carcasses, protective clothing, or use of hygienic surfaces for butchering.
• Official inspection: Ante and post-mortem only reported as being done in large slaughterhouses. Marking of rejected meat was reported as always done in large, but variably, in small slaughterhouses.

These outcomes were evaluated collectively and qualitatively by the interdisciplinary project partners to identify opportunities for intervention and following outline conclusions were made:
• Identified but not selected for intervention at current time:
o High prevalence of Salmonella on carcasses: Evidence of extensive cross-contamination, heavily market-dominated value chain, and lack of incentive for implementing hygienic practices indicated little opportunity for training in absence of strongly enforced food safety audit.
o Moderate prevalence of Salmonella in pigs on farms and at entry to slaughter. Most of this carriage was not associated with diarrhoea so there was little incentive for farmers to invest in reduction strategies. In addition, any improvements in Salmonella prevalence at farm level would be lost due to the high levels of cross-contamination at slaughter.
o High prevalence of pigs with blood culture positive at slaughter: Market forces currently encourage this. Veterinary diagnostic and treatment infrastructure is not yet able to support credible recommendation to retain and treat sick pigs to recovery.
• Selected for intervention:
o Antibiotic resistance: Pilot training on proper selection and dosage - for 1st line and follow-up treatments. Pilot access to laboratory diagnostics and sensitivity testing.
o Improvement in farmer livelihoods: Strategies to improve sow productivity (pigs weaned / sow / year) and increase survival of weaned pigs to slaughter age.

A pilot intervention plan for farmers is currently in development for implementation in October 2018 (see Figure 2) to run for an 18 month period, with a follow-up survey planned for 2019 to evaluate farmer opinions, productivity and antimicrobial resistance profiles. These interventions are intended to be ultimately self-sustaining if value can be demonstrated; mentoring will be provided to support this goal.


Figure 2. Farmer interventions, based on an 18-month long two-pronged pilot approach of Farm Management Workshop group discussions and demonstrations (to address emerging problems but also generic prioritised issues e.g. management of farrowing), alongside Veterinary Advisory Visits (to identify farm-specific opportunities for intervention).

Our work has identified the following opportunities which could effectively be addressed by the availability of additional funds:
1. Appropriately designed advice for consumers and pig meat supply chain actors on prevention of food borne and occupational zoonoses related to pig meat and pigs, respectively. The content and means of communication needs to be adjusted based on better understanding of the human disease burden for pig and pig meat associated zoonoses in Myanmar.
2. Appropriately channelled data sharing and interpretation with relevant policy makers and other key stakeholders in Myanmar. As examples, this includes existing data that might support regulatory overhaul of food safety measures at slaughter, identify points for improved implementation of existing protocols, and systematically generated data on antimicrobial resistance and antibiotics usage that might support Myanmar's National Action Plan on AMR.
3. Facilitate the build-up of international networks for pig veterinary expertise through an inaugural meeting of national and international pig veterinary specialists.
Exploitation Route Our work has identified the following opportunities which could effectively be addressed by the availability of additional funds:
1. Appropriately designed advice for consumers and pig meat supply chain actors on prevention of food borne and occupational zoonoses related to pig meat and pigs, respectively. The content and means of communication needs to be adjusted based on better understanding of the human disease burden for pig and pig meat associated zoonoses in Myanmar.
2. Appropriately channelled data sharing and interpretation with relevant policy makers and other key stakeholders in Myanmar. As examples, this includes existing data that might support regulatory overhaul of food safety measures at slaughter, identify points for improved implementation of existing protocols, and systematically generated data on antimicrobial resistance and antibiotics usage that might support Myanmar's National Action Plan on AMR.
3. Facilitate the build-up of international networks for pig veterinary expertise through an inaugural meeting of national and international pig veterinary specialists.
Sectors Agriculture, Food and Drink

 
Description Training of laboratory technicians from Yangon LBVD Veterinary Diagnostic Laboratory in routine microbiological methods including methods for antibiotic susceptibility testing. Training of Government veterinarians in preventive veterinary health practices for pig farmers in Yangon region.
First Year Of Impact 2017
Sector Agriculture, Food and Drink
Impact Types Policy & public services

 
Description Myanmar Pig Partnership Project Expansion
Amount £359,515 (GBP)
Funding ID BB/S013784/1 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 02/2019 
End 11/2020
 
Title Database of pig farm characteristics, productivity and antibiotics use in 3 townships in Yangon region, Myanmar 
Description A collection of data arising from 18 pigs farms of warring intensification, comprising basic characteristics, productivity, antibiotics usage. 
Type Of Material Database/Collection of data 
Year Produced 2016 
Provided To Others? Yes  
Impact The data base is still being built. 
 
Description Collaboration with Hayley MacGregor, University of Sussex 
Organisation University of Sussex
Country United Kingdom 
Sector Academic/University 
PI Contribution Cambridge has contributed bacterial genetic, and pig infectious disease and production disease, expertise to this collaboration.
Collaborator Contribution Dr MacGregor's group, University of Sussex, has contributed social science and medical anthropology expertise to this multidisciplinary project.
Impact None so far
Start Year 2015
 
Description Collaboration with Myanmar Livestock Breeding and Veterinary Department 
Organisation Ministry of Livestock, Fisheries and Rural Development
Country Myanmar 
Sector Public 
PI Contribution Cambridge brings expertise in bacterial genetics and pig health management.
Collaborator Contribution LBVD brings access to diverse pig meat supply chains and access to longitudinal sampling at farms, slaughter points and meat retail locations. LBVD provides field sampling teams.
Impact None so far.
Start Year 2015
 
Description Collaboration with Oxford Clinical Research Unit (OUCRU), Ho Chi Minh City 
Organisation University of Oxford
Department Oxford University Clinical Research Unit Vietnam (OUCRU)
Country Viet Nam 
Sector Academic/University 
PI Contribution Cambridge brings expertise in bacterial genetics, epidemiology and pig health management.
Collaborator Contribution OUCRU brings expertise, located in SE Asia, in practical microbiological laboratory diagnostics and epidemiology with focus on pig/poultry associated infectious agents and antibiotic resistance.
Impact None so far.
Start Year 2015
 
Description FAO Myanmar Office (Dr David Hadrill) 
Organisation Food and Agricultural Organisation (FAO)
Country Italy 
Sector Charity/Non Profit 
PI Contribution Strengthened relationships with Myanmar's LBVD in Yangon Region, specifically in relation to updated mapping of pig farm locations and slaughter points in 3 townships.
Collaborator Contribution Contribution though advisory board membership.
Impact None so far
Start Year 2015
 
Description Farmer workshops on optimum intervention strategies 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Study participants or study members
Results and Impact A workshop in each of 3 Townships in Yangon Region, working with farmers and their advisers to design and optimise intervention strategies.
Year(s) Of Engagement Activity 2018
 
Description Invited lectures at University of Veterinary Science, Yezin, Myanmar 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Lectures were provided on:
1. Optimisation of pig health and immunity in intensive production systems.
2. Zoonotic infections of pigs; epidemiology, diagnosis and prevention.
Year(s) Of Engagement Activity 2016
 
Description PIPA meeting (Participatory Impact Pathway Analysis), Yangon. July 2016 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact PIPA activity was undertaken to identify relevant actors along pig meat supply chains in Yangon Region, Myanmar. This allowed better refinement of useful research outcomes and targets.
Year(s) Of Engagement Activity 2016