Geographic Information Systems in Epidemiology – Ecology of Common Vole and Distribution of Natural Foci of Tularaemia

KORMAP geographic information system (GIS) was used to analyse the distribution and selected environmental factors related to population levels of Microtus arvalis (a potential reservoir host of F. tularensis) in the Czech Republic and the relation between M. arvalis populations and natural foci of tularaemia in the European hare. Maximum population levels of M. arvalis were in areas from 200 to 399 m above sea, of 40 to 60 days of snow cover annually and of 10 °C of mean annual air temperature. Warm and moderately warm climatic regions differed in the mean M. arvalis population level with high statistical significance (t = 4.97, P = 0.01). M. arvalis did not occur in the cold climatic region and areas of less than 4 °C of mean annual air temperature. The highest and lowest population densities were found in geographic areas of 1800 to 2000 h and up to 1600 h of annual sunshine duration, respectively. M. arvalis population density correlates with high statistical significance with the elevation above sea, annual sunshine duration and mean annual air temperature. It was, however, found that there is no correlation between M. arvalis levels and numbers of natural foci of tularaemia in the European hare (r = 0.0765, n = 396, t = 1.5228). In other words, tularaemia seems to be independent of M. arvalis population density. GIS are suitable for the State Veterinary Administration and they are becoming part of decision-making as knowledge on the geographical aspects of diseases including the distribution of reservoir hosts is essential for disease control. Microtus arvalis, geography of occurrence, population levels, environmental factors, Czech Republic, tularaemi