Infectious diseases of saiga antelopes and domestic livestock in Kazakhstan Monica Lundervold ...

Infectious diseases of saiga antelopes and domestic livestock in Kazakhstan

Monica Lundervold University of Warwick, UK June 2001

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Chapter 1 Introduction This thesis combines an investigation of the ecology of a wild ungulate, the saiga antelope (Saiga tatarica, Pallas), with epidemiological work on the diseases that this species shares with domestic livestock. The main focus is on foot-and-mouth disease (FMD) and brucellosis. The area of study was Kazakhstan (located in Central Asia, Figure 1.1), home to the largest population of saiga antelope in the world (Bekenov et al., 1998). Kazakhstan's independence from the Soviet Union in 1991 led to a dramatic economic decline, accompanied by a massive reduction in livestock numbers and a virtual collapse in veterinary services (Goskomstat, 1996; Morin, 1998a). As the rural economy has disintegrated, the saiga has suffered a dramatic increase in poaching (Bekenov et al., 1998). Thus the investigation reported in this thesis includes ecological, epidemiological and socio-economic aspects, all of which were necessary in order to gain a full picture of the dynamics of the infectious diseases of saigas and livestock in Kazakhstan.

The saiga is an interesting species to study because it is one of the few wildlife populations in the world that has been successfully managed for commercial hunting over a period of more than 40 years (Milner-Gulland, 1994a). Its location in Central Asia, an area that was completely closed to foreigners during the Soviet era, means that very little information on the species and its management has been available in western literature.

The diseases that saigas share with domestic livestock have been a particular focus of this study because of the interesting issues related to veterinary care and disease control in the Former Soviet Union (FSU). Soviet Central Asia is only just opening up to the outside world, and the area is in rapid transition. Until very recently, little was known about their methods of animal husbandry, disease control and veterinary measures. The disease status of their animals and the state of veterinary research were not disclosed, either within the country or externally. Even now, a large proportion of the scientific literature is not in the public domain, and thus difficult to obtain. Of the literature that is available, most is in Russian and not accessible to western audiences. Within the western literature, there has been some work carried out on the disease-mediated interactions between livestock and wildlife (Christiansen & Thomsen, 1956; Anderson & Trewhella, 1985; Freeland &

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Boulton, 1990), but it is still a relatively under-researched field, and one that is receiving increasing recognition as important both for conservation and for livestock disease control. Figure 1.1

Map of Asia

Thesis Aims The study aimed to answer the following questions: •

What are the effects of recent socio-political changes in Kazakhstan on livestock husbandry and veterinary practices, and hence on disease prevalence in Kazakhstan?

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Are there effective disease control measures and monitoring programs operating at present in Kazakhstan?

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Foot-and-mouth disease and brucellosis have been reported in saiga. Are these diseases or other major viral diseases currently circulating in the saiga population?

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What are the key factors that should be included in a model of FMD dynamics in a saiga population?

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Are infectious diseases a cause for concern for the saiga population, or could they be so in the near future?

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How have the socio-political changes in Kazakhstan in the last decade affected the saiga antelope with respect to their relation with humans, and are these changes likely

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to have affected the interaction between livestock and saigas, through disease or other factors? •

If Kazakhstan embarks on a program to attempt eradication of brucellosis or FMD from the domestic livestock population, could saiga constitute a threat of failure to this program?

To attempt to answer these questions, baseline data were required. This necessitated collection of a large amount of information in the field: •

The current prevalence of major infectious diseases in the saiga population

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The current saiga population structure and ecology (sex ratio, age structure)

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The current prevalence of foot-and-mouth disease virus (FMDV) infection among domestic ruminants located in or close to saiga range areas and their current level of immunity against FMD, and the important factors that are associated with immunity

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The current prevalence of brucellosis infection among domestic ruminants located in or close to saiga range areas, and the important factors that are associated with infection

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The prevalence of other major infectious diseases among domestic ruminants located in or close to saiga range areas, and the important factors associated with infection

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Changes in disease control policies after independence

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Changes in the veterinary care of livestock after independence

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The reliability of official statistics

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Meteorological data for modelling the spread of FMD

Data were collected from two saiga populations, one of which is subject to heavy human pressure and the other of which is relatively undisturbed. This comparison allowed an assessment of the effects of human disturbance on saiga ecology and the prevalence of infectious diseases. Data were also collected for livestock from villages outside the saiga range, for comparative purposes and in order to assess veterinary procedures in the case of a disease outbreak. These data were then analysed using a range of laboratory methods, statistical and epidemiological models in order to provide answers to the questions listed above. The t-test was used to test the significance between means, and the ?2, MannWhitney U, Fisher exact and Kruskal-Wallis H tests (Mead & Curnow, 1983; Bland, 1987; Fowler et al., 1998) were used to test the significance between proportions, where p