Spatial modeling of oestrosis in sheep in Guantánamo province, Cuba

Oestrosis is a myiasis caused by larvae of the fly Oestrus ovis (Linné 1761, Diptera: Oestridae) that occurs worldwide. Oestrosis was first reported in Cuba in the middle of the 1990s in the municipality of Imías, Guantánamo province. Determining the spatial pattern and risk factors for the disease might be useful to help explain the disease occurrence and select options for disease surveillance and control. In the present study, the number and distribution of affected premises was shown to have been similar throughout the period studied (2006-2010). The disease was found to occur mostly in the southern and western parts of the province with high dispersion in an east-west direction over the period of study. Three “hotspots” (Getis-Ord Gi*) were identified in the province in which there was an increased risk of disease occurrence. Geographically Weighted Logistic Regression was used to test associations between environmental variables and disease occurrence. Results demonstrated that areas with lower mean annual rainfall, higher mean temperature, and higher sheep density had the highest risk of disease occurrence. High risk areas are mostly located in the western zone (El Salvador, Niceto Pérez and Guantánamo municipalities) and also in the central zone (coast of San Antonio del Sur and Imías). The associations between oestrosis cases and local environmental characteristics varied geographically within the study area. These results might be useful to improve disease surveillance and control. Treatment of animals in these “hotspots”, as well as in other places where the risk is higher should be prioritized to more efficiently reduce the harmful impact of this disease.