Robyn G. Alders

Participatory epidemiology: approaches, methods, experiences.

Participatory epidemiology (PE) is an evolving branch of veterinary epidemiology which uses a combination of practitioner communication skills and participatory methods to improve the involvement of animal keepers in the analysis of animal disease problems, and the design, implementation and evaluation of disease control programmes and policies. This review describes the origins of PE and how the application of PE requires attention to both a participatory approach and participatory methods, supported by triangulation of data with conventional veterinary diagnostic methods. The review summarizes the various adaptations and uses of PE, including the design of primary veterinary service delivery systems, veterinary research and disease surveillance. In contrast to conventional data collection methods, an integral aspect PE is the concept of applying and evaluating new disease control programmes or surveillance systems in partnership with animal owners. In the developing regions where PE has been most commonly used, this action-orientated approach raises important challenges for veterinary institutions with limited financial resources. Information derived from PE studies can also question longstanding disease control policies and norms, nationally and internationally.

Village poultry: still important to millions, eight thousand years after domestication

Village poultry make a significant contribution to poverty alleviation and household food security in many developing countries. This contribution by village poultry to livelihoods can also support HIV/AIDS mitigation and wildlife conservation initiatives. Appropriate interventions focussing on the factors limiting productivity of the different production systems must be tailored according to country and local conditions. The contrast between the type of support in relation to the production systems that might be promoted in export-oriented countries such as Thailand, in comparison to others such as Mozambique and Lao PDR is discussed. A review of the benefits and costs of inputs comparing small scale commercial poultry and scavenging village poultry production systems in different countries taking into account the bio-risks for each production system demonstrates the overall efficiency of the village production system and provides an insight into why this system has continued to thrive into the 21st century.

Participatory Disease Surveillance and Response in Indonesia: Strengthening Veterinary Services and Empowering Communities to Prevent and Control Highly Pathogenic Avian Influenza

Abstract The participatory disease surveillance and response (PDSR) approach to highly pathogenic avian influenza (HPAI) in Indonesia has evolved significantly from the participatory disease surveillance (PDS) system developed for rinderpest eradication in Africa and Pakistan. The first phase of the PDSR project emphasized the detection and control of HPAI by separate PDS and participatory disease response teams primarily in sector 4 poultry at the household level. Lessons learned during the first phase were taken into account in the design of the second phase of the project, which has sought to further strengthen management of disease prevention and control activities by improving technical approaches, increasing active participation of key stakeholders, including local and central governments, and focusing on the village level. The ongoing evolution of the PDSR program aims to establish a sustainable community-based program within provincial and district livestock services that enhances the prevention and control of not only HPAI, but also other zoonotic and priority animal diseases.

The Australian village poultry development programme in Asia and Africa

Village poultry play a vital role in many poor rural households. They provide scarce animal protein (in the form of meat and eggs) and can be sold/bartered to meet essential family needs such as medicine, clothes and school fees. They also provide manure and pest control as well as being used in traditional ceremonies. Village poultry are generally owned and managed by women and children and improving their production can provide the first step out of poverty for the rural poor. The Australian Centre for International Agricultural Research (ACIAR) has supported village poultry research in many countries since 1984. This research has had some significant outcomes including: the control of Newcastle disease (ND) using Australian derived live thermotolerant vaccines in a variety of poultry production systems in several countries; description and quantification of the scavenging feed resource base of low input/low output systems; development of gender-sensitive extension materials and methodologies suitable for use in remote rural areas in Asia and Africa; and the development and registration of a new duck plague vaccine in Vietnam. The thermotolerant ND I-2 vaccine remains viable for periods away from the cold chain, can be administered by various routes and induces an acceptable level of protection under village conditions. The vaccine master seed, together with the ND Laboratory Manual, is made available without cost by ACIAR. In developing countries where ND is endemic, outbreaks regularly result in high mortalities and in countries where it is not endemic, sporadic outbreaks make vaccination advisable. The implementation of an effective ND control programme in countries in Africa and Asia has resulted in increased chicken numbers, increased household purchasing power, increased home consumption of chicken products and increased decision-making power for women. However, sustainable programmes for the control of ND in village chickens have been difficult to achieve, often due to limited appreciation by official agencies of the benefits of village poultry. Experience has shown that a sustainable ND control programme is composed of five essential components: a) an appropriate vaccine and vaccine technology; b) effective extension materials and methodologies that target veterinary and extension staff, community vaccinators and farmers; c) simple evaluation and monitoring systems; d) economic sustainability based on the commercialisation of the vaccine and vaccination services and the marketing of surplus chickens and eggs; and e) support and coordination by relevant government agencies for the promotion of vaccination programmes. Details of ND control in village poultry are provided on the ACIAR website, www.aciar.gov.au and by the Australian Agency for International Development www.ausaid.gov.au.

Effective communication: the key to efficient HPAI prevention and control

The current Highly Pathogenic Avian Influenza (HPAI) crisis, involving the H5N1 subtype, has developed quickly and has overwhelmed the human resource capacity of both international agencies and national governments in many affected countries. It has been recognized that the best way of preventing the emergence of a pandemic influenza virus of avian origin is to control the virus at source. The H5N1 subtype is now endemic in a number of countries and it has become clear that its control and eventual eradication will require a medium to long-term strategy involving multiple stakeholders. A common understanding of the problem and effective education and communication components are important elements of the control strategy. This paper reviews the challenges involved with the development of effective communication materials and methodologies for the wide range of partners involved in the prevention and control of HPAI, the communication lessons learnt to date and makes recommendations for improving the effectiveness and efficiency of communication activities in the future.

Impact of Avian Influenza on Village Poultry Production Globally

Village poultry and their owners were frequently implicated in disease transmission in the early days of the highly pathogenic avian influenza (HPAI) H5N1 pandemic. With improved understanding of the epidemiology of the disease, it was recognized that village poultry raised under extensive conditions pose less of a threat than intensively raised poultry of homogeneous genetic stock with poor biosecurity. This paper provides an overview of village poultry production and the multiple ways that the HPAI H5N1 pandemic has impacted on village poultry, their owners, and the traders whose livelihoods are intimately linked to these birds. It reviews impact in terms of gender and cultural issues; food security; village poultry value chains; approaches to biosecurity; marketing; poultry disease prevention and control; compensation; genetic diversity; poultry as part of livelihood strategies; and effective communication. It concludes on a positive note that there is growing awareness amongst animal health providers of the importance of facilitating culturally sensitive dialogue to develop HPAI prevention and control options.

Prevalence and evaluation of Hitchner B1 and V4 vaccines for the control of Newcastle disease in village chickens in Zambia

Abstract The seroprevalence of Newcastle disease (ND) in chickens in Zambia was 36.9% (based on the haemagglutination inhibition (HI) titres of 2000 blood samples). Seroprevalence varied between provinces, ranging from 29.2% in Northern Province to 51.3% in Copperbelt Province. A laboratory vaccine trial was conducted by administering the heat-tolerant V4 vaccine strain to one group of 20 birds intranasally with another 20 birds kept in contact. A second group of broilers was vaccinated with the Hitchner B1 vaccine strain, also with 20 incontact. birds. Four weeks after the second vaccination the birds were challenged by contact. The challenge virus was a local velogenic, viscerotropic ND virus. A non-vaccinated group of 16 birds was also challenged by contact and a further 25 by intranasal inoculation. All vaccinated chickens and chickens in contact with those vaccinated survived the challenge. In the control groups 39 of 41 chickens succumbed to the challenge. Vaccination with the heat-tolerant V4 vaccine gave slightly higher HI titres than vaccination with B1 vaccine.

Technically sound and sustainable Newcastle disease control in village chickens: lessons learnt over fifteen years.

Village chickens can be found in all developing countries and play a vital role in the livelihood strategies of many poor rural households. The implementation of effective village poultry production programmes in Asia, Africa and Latin America has resulted in increased poultry numbers, household purchasing power, home consumption of poultry products and decision-making power for women. The rapid and wide geographical spread of highly pathogenic avian influenza subtype H5N1 has drawn attention to the neglect of village poultry health. This crisis has presented an opportunity to invest in improved village poultry husbandry that can make a positive contribution to human development in rural areas across a range of endeavours including: empowerment of women (increased productivity, knowledge, participation in community life as vaccinators, etc); HIV/AIDS mitigation; wildlife conservation through a reduction in bushmeat consumption; improved understanding of disease transmission, prevention and control, human nutrition and hygiene; and, most importantly building trust between communities and government agencies. Key recommendations to support technically sound and sustainable Newcastle disease control programmes in village chickens include encouraging veterinary pharmaceutical manufacturers to develop and observe a code of conduct that supports the supply of appropriate vaccine with an adequate shelf life, giving instructions in local languages, using temperature indicators in vaccine containers and discouraging the payment of commission on the purchase of vaccine. Quality assurance activities should be built into all vaccination programmes to improve cost-efficiency, and should include post-vaccination serological monitoring of a representative sample of birds, especially when a new vaccine or new disease control programme is introduced. Also required is the participation of farmers (male and female) in monitoring and evaluating the effectiveness of vaccination campaigns; and active collaboration with the Ministries of Agriculture, Health and Education in village poultry improvement programmes.

An assessment of chicken husbandry including Newcastle disease control in rural areas of Chibuto, Mozambique.

This paper describes the management practices of village poultry in Chibuto and the impact of the Newcastle disease vaccination program conducted between January 2005 and August 2008. A 51-question survey was conducted in 11 villages involved in the Newcastle disease vaccination program in Chibuto, Mozambique. The mean flock size was significantly higher in households that provided their chickens with feed (15.0) than chickens that only scavenged (8.7; P = 0.0001). The mean flock size was significantly higher in households with vaccinated chickens (16.9) than those with unvaccinated chickens (10.0; P = 0.0005). The average number of chicks hatched during the most recent brooding was significantly higher in households that fed their chickens (9.2) than chickens that only scavenge (6.9; P = 0.0335). The mean hatch rate was significantly higher in households with vaccinated chickens (0.8) than those with unvaccinated chickens (0.7; P = 0.0324). It was determined that unvaccinated chickens are approximately five times more at risk to die of Newcastle disease (odds ratio = 4.79). This study supported the efficacy of the I-2 Newcastle disease vaccine as shown by the increased average flock size and decreased incidence of chicken mortality due to Newcastle disease. The level of farmer involvement and ongoing commitment by community vaccinators suggest that the Chibuto vaccination program is likely to be sustainable in the medium- to long-term.

Lymphocyte subpopulations in lymph and blood draining from the uterus and ovary in sheep

Lymphocyte subsets in utero-ovarian peripheral lymph and uterine and jugular venous blood were analysed with the aid of monoclonal antibodies, polyclonal antisera and flow microfluorometry. The proportion of various lymphocyte subpopulations, as determined by monoclonal antibodies (mAbs) and polyclonal antisera, was found to vary between utero-ovarian peripheral lymph and jugular and uterine venous blood. T cell levels were higher in utero-ovarian peripheral lymph (approx. 80% CD5+, 50% CD4+ and 23% CD8+) than peripheral blood (approx. 55% CD5+, 18% CD4+ and 12% CD8+). Conversely, in lymph, 10% of lymphocytes were B cells compared to 30% in blood. There were 20-30% MHC II+ cells in utero-ovarian peripheral lymph and 40-50% in blood. The level of CD45R+ cells in utero-ovarian peripheral lymph was low (2%) compared to peripheral blood (approx. 55% in pregnant and 25% in non-pregnant ewes). The proportion of lymphocyte subpopulations in lymph was similar for pregnant and non-pregnant ewes. However, some differences in levels in peripheral blood were evident between uterine and jugular venous blood and pregnant and non-pregnant ewes. CD4+ cells were higher in the uterine vein (14%) than in the jugular vein (11%) of pregnant ewes. The uterine and jugular veins in pregnant ewes contained approx. 50% MHC II+ cells compared to 30% in non-pregnant ewes. Likewise, the proportion of CD45R+ cells was higher in uterine and jugular venous blood of pregnant ewes (approx. 58%) compared to non-pregnant ewes (around 25%).