Highlights of 2010

Another important TAD is peste des petits ruminants (PPR), a highly contagious disease of sheep, goats and wildlife. With morbidity and mortality rates as high as 90-100% and 70-80% respectively in susceptible flocks, PPR can have a devastating impact on productivity. The disease ranges from Morocco to Tanzania in Africa, most of the Middle East, and several Central Asian countries and China. In the past PPR was overlooked because it was often confused with pasteurellosis or rinderpest, which it resembles clinically. The development of new, more sensitive and specific diagnostic tests, notably nucleic acid-based amplification techniques, has revealed a truer picture of the disease. Hence the number of PPR cases reported to the World Organisation for Animal Health (OIE) has dramatically increased over the past 10 years. Since small ruminants are the major livestock species kept by many of the worlds poor, it is vital that control of PPR should be integrated into poverty alleviation policies. Thus, in 2010, PPR was ranked by Chief Veterinary Officers as the most important livestock disease in the East African region. However, specific and sensitive nuclear related diagnostic tests are essential to enable the efficient control of PPR. This issue is being addressed by the IAEA coordinated research project (CRP) entitled “The Early and Sensitive Diagnosis and Control of Peste des Petits Ruminants (PPR)” (CRP D3.20.26) with the overall objective to develop, validate and transfer to MS sensitive, specific and rapid tests for the diagnosis of PPR to help them better manage and control the disease.

A specific objective was to evaluate and validate the gene amplification, reverse transcriptase-PCR (RT-PCR), method used in diagnosis. The outcome of an inter-laboratory proficiency ring-test, on the use and application of the RT-PCR technique organized by APHL showed that there was a clear need for counterparts to improve their implementation of the test. APHL has provided the necessary support to correct the problem and another ring-test is planned in 2011 to check for improvements. The isolation of PPRV from pathological samples into in-vitro cell culture is problematic and in most cases virus isolation requires many blind passages, taking several weeks. In a major advance for isolating the virus, last year APHL developed a new cell line by integrating the PPRV receptor gene of goat origin, into a monkey cell line. With this new cell line, PPRV can be isolated in less than one week. More recently, the PPRV receptor gene has been integrated into the genome of other cells including canine macrophages, sheep skin cells and goat kidney cells. Initial tests showed even greater improvement in isolation although the differentiation between infected and non-infected cells was difficult in the case of the canine macrophage cells.

In the future, more effort will be placed on designing rapid tests that can be used at the penside. To this end, a thermostable kit for the isothermal molecular diagnosis of TAD’s has been developed by APHL in cooperation with the University of Veterinary Medicine, Vienna (Vetmeduni Vienna) and a commercial company. This new Loop Mediated Amplification technology (LAMP) allows for the sensitive and highly specific diagnosis of pathogens even in the field. To cater for quality assurance, the test system was modified to a quantifiable platform, which allows the use of a simple tube scanner to run the assay and to read the results as a real-time curve and a melting curve for QC. This technology package is currently under evaluation in three CRP’s and a number of technical cooperation projects.

The production of vaccines by inactivation of the pathogen using ionizing radiation is a technique that is receiving increasing attention, since it offers a way of inducing protective immune responses that are superior to those produced by killed vaccines. The APHL is leading the development of such vaccines as part of a CRP “The Use of Irradiated Vaccines in the Control of Infectious Transboundary Diseases of Livestock (D3.20.29)”. Basic protocols for the attenuation of pathogenic trypanosomoses are being developed in support of participants from Kenya and India. Participants from other MS in the CRP are developing attenuated vaccines for the control of brucellosis, tropical theileriosis, anaplasmosis, fasciolosis and haemonchosis and protozoal diseases of farmed fish. The research network includes partners from Turkey, Iran, Georgia, Sudan, Ethiopia, Thailand, Sri Lanka, China and Argentina.

Stable isotope analysis of feathers from migratory wild birds associated with the spread of Highly Pathogenic Avian Influenza is beginning to reveal information on their origins. In association with the Austrian Institute of Technology GmbH, the FAO/IAEA Joint Centre measured feather stable isotope ratios in wild birds from Mongolia, Albania and Bulgaria. Stable isotopes of hydrogen (dD), oxygen (d18O), carbon (d13C) and sulphur (d34S) have been analyzed. Hydrogen is particularly useful in discriminating between different origins of birds. By relating the values obtained from dD stable isotope environmental findings, the feather isoscapes of birds from Mongolia point to their origins from three distinct areas; from very high latitudes (very depleted dD values), from high latitudes (depleted dD values), and low latitudes (enriched dD values). In contrast, feather samples from birds from Albania showed homogeneous values suggesting they came from one location in Albania. Most Bulgarian samples showed similar homogeneity, although there were indications that a small number of the birds originated from very high latitudes.

The Joint Centre provided funding from the CRP on “The early and rapid diagnosis of transboundary diseases (D3.20.25)” to the National Institute of Veterinary Research (NIVR) in Hanoi to enable it to validate a PCR disease detection system known as GeneSTAT that can provide results within an hour and can be used easily, even by unskilled workers, as training takes only a few minutes. The results of the successful tests for detection of Highly Pathogenic Avian Influenza were reported officially in Rome in May 2010. The support of the Joint FAO/IAEA Centre was crucial to the development of the system and it was possible to prove the platform in several other laboratories in addition to that in Vietnam.

Domestic chicken, especially indigenous stock provides a large proportion of animal protein for poor rural households in developing countries. However, the world poultry market is facing serious health and economic threats from recurrent outbreaks of contagious diseases. Firstly, commercially-bred animals that represent the greatest poultry genetic resource are likely to lose their innate genetic resistance through the long-term process of selection solely for advantageous production traits. Secondly, the actual health status of the commercial flocks is often unknown due to extensive vaccination programmes and veterinary drug abuse. Industrial-scale farms with thousands of birds thereby provide perfect opportunities for the rapid dissemination of any pathogenic organism. It should be possible to enhance the immunocompetence of chicken by using the existing rich sources of gene variants (alleles) that are associated with resistance to diseases, but the main obstacle in achieving this is the lack of knowledge on which genes in the chicken determine fitness and robustness of the individual.

The IAEA has now embarked on identification of markers that could be linked to disease resistance by undertaking the genetic characterization of indigenous chicken breeds. Information on breed characteristics and DNA samples were collected initially from indigenous chickens of Eastern European countries, including Poland, Bulgaria, Bosnia and Herzegovina, Macedonia and Montenegro but this has now been extended to other regions of the world. Among the breeds studied is the Green-legged Partridge, an indigenous Polish breed that lays eggs with lower cholesterol content and the Kadaknath – an Indian fowl whose meat is a rich source of iron. The study examined polymorphisms within loci involved in different immune function: the major histocompability complex (MHC), single nucleotide polymorphisms (SNPs) within key immune response genes, the interleukin 2 gene that is associated with production of an immunoregulatory cytokine responsible for macrophage activation and antibody production, and finally, a gene fragment including the Toll-like Receptor 7 a member of a specialized family of receptors that recognize pathogens and trigger immune responses.

Although indigenous goats in MS have been selected for advantageous traits and breed differentiation that suit them to local conditions, there is surprisingly little understanding of these characteristics at the genome level, especially when compared with other livestock. To improve our understanding of the genetic components of traits related to goat health, production and biology, there is an urgent need to construct a detailed goat genome map by construction of a whole-genome radiation hybrid panel. Some progress has been made on the construction of linkage and cytogenetic maps, although the density of mapped loci is low compared to those available for other domesticated livestock species. Radiation hybrid (RH) mapping can be used for integrating linkage maps and also serve as a link across species for comparative mapping. Therefore, it is of critical importance to construct a RH panel providing a resource for rapid and large-scale physical mapping of the goat genome. The IAEA has therefore participated, in collaboration with other institutes, in a project for the development and characterization of a goat (Capra hircus) whole-genome radiation hybrid panel (Goat RH5000). This goat RH map project will provide a fundamental tool for genomic research in the goat that will be useful for the entire research community through comparative genomic analyses with other species. A goat RH map will allow phenotypes of interest to be used for comparative analysis and gene discovery.

The production of high quality livestock and livestock products depends largely on the type of animals, management practices and environment. Moreover in the conditions found in many MS in developing countries it is essential that properly conceived and implemented programmes addressing these issues are formulated to ensure that the farmer achieves maximum benefit from the different inputs. The North West region of Cameroon was chosen for a project supported by Heifer International to increase milk production, but the advent of brucellosis and poor reproductive performance constrained the effort of the farmers. In order to more effectively target inputs, a government breeding centre, the Bambui Cattle Centre became involved in the programme. The IAEA, through a TC project, has provided technical assistance to the Centre including facilities that enable it to carry out artificial insemination (AI), pregnancy diagnosis using radioimmunoassay techniques and nuclear related tests for disease diagnosis thus providing the farmer with a comprehensive service to ensure the health and productivity of his cattle. More than 200 farms have been supported on issues relating to health, management, feeding and AI services.

Brucellosis has been controlled through a control programme, use of artificial insemination (AI) and culling of infected animals. The Bambui team also introduced innovative methods to enable the transport of semen in chilled containers, rather than in liquid nitrogen, a costly and scarce item in remote rural areas. The chilling processing requires the use of egg yolk and coconut water and the semen retains its viability for up to seven days under these conditions. The Centre also gives advice on improved feeding, processing milk to produce yoghurt and cheese in addition to the other veterinary services that provide the farmer with sound advice on ways to increase productivity. Farmers have readily accepted the new technologies and have seen their livelihoods increase substantially. The Centre plans to increase its activities to cover other regions of the country to enhance the impact on the farming community. Additionally, the Centre has trained veterinarians form Botswana, Burkina Faso, Madagascar and the Central African Public. This programme exemplifies how the efforts of the Sub-programme assist MS to improve livestock productivity and food security and reduce poverty.

Livestock is the pillar of the economy in Mongolia and the IAEA has supported the Mongolian State University of Agriculture and the Research Institute of Animal Husbandry to facilitate better nutrition and reproductive management using radioimmunoassay technologies to assess fertility and isotopic tracing and labelling methods to evaluate the nutritive value of feed. The Agency-supported introduction of blocks for urea molasses, medicated, nutrient and element concentrated feeds has had a profound effect on productivity. These initiatives, together with improved nutrition management such as investigating alternative feeds in different regions of Mongolia, farmers have been able to reduce their input costs by nearly 70% and the more effective use of feed crops has helped protect animals during the winter when feed resources are scarce. Increased skills in the use of artificial insemination have led to superior beef and milk production in cross breeding programmes between yaks and cattle.