Impact of Geographical Factors on the Spread of Animal Brucellosis in the Republic of Kazakhstan T ⁎ Bolat A
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Comparative Immunology, Microbiology and Infectious Diseases 67 (2019) 101349 Contents lists available at ScienceDirect Comparative Immunology, Microbiology and Infectious Diseases journal homepage: www.elsevier.com/locate/cimid Impact of geographical factors on the spread of animal brucellosis in the Republic of Kazakhstan T ⁎ Bolat A. Yespembetova, Nazym S. Syryma, , Marat S. Syzdykovb, Andrey N. Kuznetsovb, Zhumagali K. Koshemetova, Assiya K. Mussayevac, Sovetzhan Z. Basybekovc, Serik G. Kanatbayevc, Altynbek T. Mankibaevd, Canapya M. Romashevd a Research Institute for Biological Safety Problems, Kazakhstan b M. Aikimbayev Kazakh Scientific Centre for Quarantine and Zoonotic Diseases, Kazakhstan c Kazakh Scientific Research Veterinary Institute, Kazakhstan d Kazakh national agrarian university, Kazakhstan ARTICLE INFO ABSTRACT Keywords: In Latin and Central America and in most Asian countries, brucellosis remains an insufficiently studied disease. Cattle This study aims to determine the national and regional incidence of brucellosis among cattle (cows) and small Brucellosis ruminants (sheep, goats) in the Republic of Kazakhstan, as well as to identify the effect of climatic and geo- Epizootiology graphical factors on the incidence rates. Thematic maps were created in an open geographic information system Geographic information system QGIS version 2.8. in order to identify the natural and socio-economic factors that influence the spread of the Infection disease overlay method was used. Local cluster analysis was used in order to identify additional causes of the disease. Findings show the following values of Pearson correlation between the overall population and the number of animals infected: 0.68 for cows, p ≤ 0.005, and 0.56 for sheep and goats, p ≤ 0.03. Thus, the larger the heard in a given area, the greater likelihood of having brucellosis. Data processing reveals that Kazakhstan has almost twice as many regions good for cattle breeding as regions that are good for the small ruminants farming. The correlation variables for cattle and small ruminants are approximately the same. On the basis of the performed research the author proposes to amend the accepted methodology of epidemiology surveillance by the methods based on spatial (geographical) analysis. It is also proposed to adjust the process of breeding cattle and small ruminants considering the additional health recommendations that take into account the geographical aspects of the spread of the disease. 1. Introduction clinics [4], methods of diagnosis [5] and veterinary and sanitary measures [6]. At the same time, there is quite extensive global research Brucellosis of farm animals was a widespread ubiquitous infection practice of using interdisciplinary and especially geospatial research in the past. But nowadays epizootic situation for this disease is still method [6–11]. Geographic information systems (GIS) have been suc- quite tense in many regions, mainly in the countries of Central, South- cessfully used for allocation of spatial clusters that are of interest to East, and Asia Minor, the Mediterranean, some countries of Africa and explore and determine aetiology of the diseases [11–13], as well as for South America [1]. the study of patterns of spatial and temporal distribution of micro- In the context of globalisation and the global division of labour biological plague [14], hypodermatosis [15], foot-and-mouth disease forces, there is an increase in the exchange of goods between the states, [16] and others. including agricultural products. Since brucellosis can persist for quite a The work itself was carried out in 2004–2010 and the relationship long time in animal products that go for export, there is a probability between animal and human diseases as well as the impact of geo- that the infected food products can get into the retail trade [2,3]. graphical factors on the epizootic situation were studied. Mainly there are neighbouring countries in the risk zone, which are There is a common belief that the spread of brucellosis is affected members of the Customs Union. largely by economic and geographic factors, i.e. factors caused by Most studies of brucellosis have purely medical orientation: disease human activity. At the same time, physical and geographical factors ⁎ Corresponding author. E-mail addresses: [email protected], [email protected] (N.S. Syrym). https://doi.org/10.1016/j.cimid.2019.101349 Received 2 March 2018; Received in revised form 9 August 2019; Accepted 30 August 2019 0147-9571/ © 2019 Elsevier Ltd. All rights reserved. B.A. Yespembetov, et al. Comparative Immunology, Microbiology and Infectious Diseases 67 (2019) 101349 (climate, weather) do not have a tangible impact on the disease in- 2.3. Methods of clustering cidence because animals are being taken care of. The contradiction lies in the fact that particularly the physical and geographical factors can Graphic overlay method was used to detect spatial consistent pat- influence the type of agricultural activity, determining the economic terns of spread of the disease and the dependence of the latter on the efficiency of the stable cattle farming, and pasturing cattle. natural and socio-economic factors [20]. It involved maps creation and Kazakhstan is the second largest country among the former Soviet comparison of the received images with each other and with other maps republics. It is rich with diverse landscapes, from prevailing deserts, previously published. Initial data for the maps were calculated by semi-deserts, plateaus, and steppes to mountain ranges, and this implies averaging of the statistics received at different times in order to mini- a broad range of environmental conditions. The country has a sharply mise the impact of climate factors and accidental releases (surges). On continental temperate climate, with sharp changes in temperature both the basis of the processed data mapping indices were determined, during the day and during the year. Such conditions, with a limited which will facilitate the identification of these consistent patterns [21]. number of grazing areas, create a generally unfavorable scenario for the Graph-analytic method (spatial and temporal analysis) also involves livestock production in Kazakhstan. The global warming observed in the use of maps, but with smaller units of mapping and data compiled recent decades leads to an increase in climate aridisation and thereby to on year. For these maps, you can identify the so-called "hot" point – the even greater reduction of pasture areas. Despite the above factors, an- separate districts, which can be a source of spread of the disease and imal husbandry remains one of the priority sectors in the Republic [17]. "cold spots" that may become the subject of study for disease control. Livestock disease monitoring is a mandatory function of public services. The dynamics of the last enables to evaluate the effectiveness of anti- However, there are no reports on the national situation and the relevant epizootic measures, namely the presence of regions with increased data are not analysed from the perspective of geographical, social and morbidity that re-emerged after their successful recovery. This method other factors [18]. Among other regions in the world that are relatively of research will clarify the causes of the spread of animal brucellosis in well-studied, Kazakhstan remains a “blind spot” and this is despite the the Republic of Kazakhstan. fact that Kazakhstan is located at the intersection of important trade Method of cartograms with graduated colours of quantities in order routes connecting Asia and Europe [19]. From this perspective, in- to display parameters of cartographic representation (mapping) has vestigating the incidence of brucellosis in Kazakhstan is relevant. been selected for several reasons. First reason is that the economic and This study aims to determine the national and regional incidence of geographic data are usually summarised according to the adminis- brucellosis among cattle (cows) and small ruminants (sheep, goats) in trative division units. Secondly, a significant portion of the available the Republic of Kazakhstan, as well as to identify the effect of climatic cartographic material also uses administrative divisions. Only the and geographical factors on the incidence rates. physical and geographical indicators have different units of mapping. 2.4. Statistical analysis 2. Materials and methods The differences between variables were considered significant at 2.1. Research design, setting p ≤ 0.05. The levels of significance are described separately. To analyse the differences, the following methods were used: the Fisher’s two- The diagnostic study was carried out by techniques of classic ser- sample t-test for independent samples, the Pearson's correlation coef- ology – Rose Bengal test (RBT), agglutination test (AT), complement ficients, and the PCA analysis. Statistical calculations were conducted fixation test (CFT), and enzyme-linked immunosorbent assay (ELISA). using the Past v. 3.0 software. Changes over time in the epizootic situation in terms of brucellosis Public services that are involved in the brucellosis monitoring was analysed, based on presented data and the values of basic epizootic system, provided collected information in the form of tables. For its indicators. The risk assessment was based on the number of animals collection and processing, electronic spreadsheet of Libre Office with brucellosis, discovered in a certain area. package was used. The smoothed risk figures of livestock