Spatial and spatio-temporal analysis of human brucellosis in Iran.

Abstract

Brucellosis is an important public and veterinary health problem in Iran and poses enormous economic burdens and significant human morbidity. In order to better understand the epidemiology of the disease in Iran, yearly spatial distribution and possible hotspots of the disease have been investigated in this study. A cross-sectional survey was performed on 39 359 recorded cases during April 2009 to March 2012 throughout the country. Moran's I was applied to investigate the yearly patterns of the spatial distribution. Presence of possible hotspots was investigated using both local Moran's I and spatial and space-time scan statistics. Moran's I at county and province level showed that distribution of human brucellosis was regularly clustered. Both local Moran's I and spatial and space-time scan statistics detected significant hotspots of human brucellosis cases with high incidence rates. Hotspots were predominantly located in the west, northwest and northeast. Comparison of the population-based frequencies of human brucellosis in different elevation classes indicated the highest possibility of human brucellosis occurred in counties with high average altitudes (>2000 m). Human brucellosis continues to be a widespread challenge, especially in western and northwestern parts of Iran. The hotspots highlight the potential high risk areas requiring special plans and resources for monitoring and control of the disease.