Cystic echinococcosis in cattle dairy farms: spatial distribution and epidemiological dynamics

A study monitoring cystic echinococcosis (CE) in adult dairy cattle from intensive livestock farms located in the municipality of Arborea (Sardinia, Italy) was carried out between 2012 and 2015. A retrospective study of veterinary reporting forms of post-mortem inspections in 10 different Italian slaughterhouses was also performed. In addition, data on viability and molecular characterisation of hydatid cysts removed from parasitised organs in cattle was carried out. A geographical information system (GIS) with data layers of the study area and the geo-referenced points of 160 cattle farms was constructed. CE was found in 21.9% (35/160) of the surveyed farms. The retrospective study revealed that 0.05% (13/23,656) of adult slaughtered animals (over one year of age) from Arborea had tested positive to CE. The results stratified per year showed the following CE prevalences: 0.09% (5/5673) in 2012; 0.02% (1/5682) in 2013; 0.08% (5/6261) in 2014; and 0.03% (2/6040) in 2015 (χ² with 3 degrees of freedom=3.81; P=0.282). The E. granulosus sensu stricto (formerly called G1 or sheep strain) was detected in all cysts subjected to molecular analysis. The GIS analysis showed that CE is fairly resilient in the Arborea territory where most of cattle farms are located, while a small cluster of cases was found located in the southeastern part of Arborea, close to districts where sheep farms are situated. The present survey reports the presence of CE in Sardinian dairy cattle intensive farms and suggests that the parasitic pressure of CE in the island continues to be very strong.