Study of Animal's Viral Diseases
Complex Study on Possible Introduction of Extremely Dangerous Viral Diseases of Animals, Detection of Previously Unstudied Causative Agents, Development of Effective Means and Methods of Their Diagnosis and Specific Prophylaxis
Tech Area / Field
- AGR-DIS/Disease Surveillance/Agriculture
- AGR-VTH/Vaccines and Theraupetics/Agriculture
3 Approved without Funding
The Republican Government Enterprise on the basic of economic control rights “Research Institute for Biological Safety Problems” , Kazakstan, Gvardeiski
Project summaryThe objective of the project is complex study of possible introduction of agents causing extremely dangerous diseases of animals and detection of previously unstudied agents on the territory of the Republic of Kazakhstan as well as development of effective means and methods of diagnosis and prophylaxis of diseases.
The Republic of Kazakhstan is located between the states of Eastern Europe and Central Asia and that results in its key role in spread of infections reported both in Europe and in Asia. Exotic diseases of animals such as rinderpest, African swine fever, catarrhal fever of sheep (bluetongue) are not registered on the territory of the Republic of Kazakhstan but are of great danger for it and may be introduced from other countries through imported animals, livestock products, forage, migrating wild animals, by water routes and so on. Sheep pox and foot-and-mouth disease of farm animals are very dangerous too because their epizooties result in great economical losses.
The territory of the country is perse in its natural and geographic conditions, its fauna numbers a lot of species, seasonal migration routes of wild animals and fowl cross its spaces. Alongside with this mutual contacts with foreign countries has become more intensive last years. The above factors favour the intensive circulation of micro flora and make emergence of perse pathogenic microorganisms (including viruses) not registered here previously more possible. The findings of some studies show that infectious diseases of unknown etiology occur in the livestock population of the republic, some cases being unnoticed or unstudied.
Wild artiodactyls are susceptible to a number of viral infections including rinderpest, sheep pox and foot-and-mouth desease, and may serve the reservoir of these infections and origin of their dispersion through the vast territories. Injection methods of vaccination are not in practice acceptable for wild animals. Luring vaccines for peroral introduction are used mainly for immunization of predatory animals with constant area of habitation. For immunization of wild artiodactyls which change their migration routes in search of food aerosol method of vaccination with powder preparations is promising.
In the planned research work the following will be used:
– statistical data of veterinary accounts on morbidity and mortality of animals caused by dangerous viral diseases, including diseases with obscure etiology, and on number of animals susceptible to rinderpest, sheep pox and foot-and-mouth disease in boundary regions of the republic;
– information on ways of driving and transport of imported animals; on migration ways of wild animals in boundary regions of the republic;
– OIE and FAO information on rinderpest, sheep pox and foot-and-mouth disease outbreaks through the world;
– data on import of animal produce and forage.
The analysis of epizootological information will allow to determine possible ways and factors of introduction and dissemination of dangerous viral infections of animals. On the base of findings expedition travels will be organized to detail time and nature of disease manifestation in animals and fowl, to carry out clinicopathologicoanatomical investigation with simultaneous collection of biological materials (biomaterials) for isolation of a supposed viral agent.
The collected biomaterials will be analyzed in the SRAI by conventional virological methods to isolate possible agents of viral etiology. In the case of isolation of a pathogene (an isolate) not reported previously on the territory of Kazakhstan further biological and physical-chemical study will be executed to determine major properties of the virus, to locate it in viral classification and to certify it in detail. For isolation of infectious agents from collected biolmaterials cellular systems and laboratory animals will beused. At the same time optical and electron microscopy of samples, their serological (neutralization test, reaction of diffuse precipitation, complement fixation, haemagglutination, enzyme-linked immunosorbent assay) and molecular-biological analysis will be implemented. Density gradient centrifugation, ultracentrifugation, ion-exchange chromatography, ultrafiltration will be used for physical and chemical characterization of isolated agents. If previously unknown viruses or new serotypes of well-known microorganisms have been isolated, the pathogenicity spectrum, the range of sensitive animals and cell cultures, physical and chemical properties, virus cultivation and detection methods, resistance to environmental and inactivating chemical factors, reservoirs of these infective agents will be studied.In the course of the development of diagnosticals and conditions for indirect method of fluorescent antibodies (MFA), enzyme-linked immunoassay (ELISA) and some other likely methods for rapid laboratory diagnosis of rinderpest, sheep pox and foot-and-mouth disease various primary and continuous cell cultures, methods of producing immunoglobulins, conjugates and so on will be tested. Methods of rinderpest and sheep pox viruses isolation and concentration from objects under study will be tested to promote the development of the viruses indication methods.
In the process of the development of preventive means against rinderpest, sheep pox and foot-and-mouth disease methods of viruses cultivation in primarily tripsinized and continuous cell cultures (stationary, roller and in suspension) will be used. Various protective media on the base of protein-carbohydrate components for stabilization of virus immunobiological characteristics will be tested alongside with various methods of dehydration of viral suspensions (lyophilization and spraying). For the development of methods of vaccine application methods of inpidual immunization with inactivated foot-and-mouth disease vaccine and group immunization (aerosol, peroral) with live rinderpest and sheep pox vaccines will be tested.
Development of powder vaccines with high biological activity, fine-dispersed structure and sufficiently stable properties in aerosol is planned for study of possible aerosol vaccination of wild artiodactyls. While their developing the most effective ways of virus cultivation and concentraion will be used as well as of conservation and production of powder vaccines. For aerobiological characterization of vaccines and mastering of aerosol vaccination parameters cabinet and field trials will be executed. High power jet generator with system of torch aerosol generating will be used in the field trials on vaccination of chosen model animals. At the final step of studies experimental aerosol immunization of saigaks and yaks in their native environment with dispersion of aerosol vaccine from a helicopter is planned. The efficiency of aerosol immunization will be evaluated through blood sera assays and challenge infection of trapped animals in safety box of the SRAI.
As the result of the planned project studies:
– possible ways and factors of introduction and spread of extremely dangerous viral infections of animals (rinderpest, sheep pox, foot-and-mouth disease) will be determined;
– a list of pathogenes causing animal and fowl diseases not known in the republic earlier will be compiled, the geography of their occurrence will be determined and that will provide an opportunity of regular and special investigation aimed on the development of specific diagnostic and prevention means alongside with measures of control and eradication of mentioned diseases on the national scale;
– the diagnosticals and conditions for indirect MFA, ELISA and other promising assays for rapid laboratory diagnosis of rinderpest, sheep pox and foot-and-mouth disease will be developed as well as methods of indication of above agents in objects of veterinary supervision (water, hay, grain) to solve the problem of controlling the emergence and spread of mentioned infections through the territory of Kazakhstan;
– vaccines against rinderpest, sheep pox and foot-and-mouth disease as well as methods of their inpidual application and group immunization in cases of urgent epizootic situation (aerosol and peroral for vaccines against rinderpest and sheep pox) will be developed;
– possibility of aerosol immunization of wild animals including artiodactyls against rinderpest and sheep pox will be studied and method of their aerosol vaccination will be proposed;
– normative technological documentation for means and methods of diagnosis, indication and prophylaxis of diseases will be developed as well as recommendations on timely carrying out counterepizootic and preventive measures.