Ultrasound as a monitoring tool for cystic echinococcosis in sheep

tAn ultrasound-based survey for cystic echinococcosis (CE) in sheep was carried out in Sar-dinia in 2012. The study was done on three farms (A, B, C) which had been pre-selectedfor different CE prevalence levels (A: >80%, B: 50–80%, C: <50%). In total, 129 sheep wereexamined on the farms using portable ultrasound equipment (A: n = 51, B: n = 30, C: n = 48).Within a period of 20 days after ultrasound examination, all sheep were slaughtered andunderwent a parasitological post-mortem examination for cysts in the liver and lungs. Withpost-mortem as gold standard, ultrasonography gave a test sensitivity of 88.7% and a speci-ficity of 75.9%, while the positive and negative predictive values were 81.8% and 84.6%,respectively. When only sheep with fertile cysts were considered, the sensitivity of thetest increased to 100%. We conclude that the ultrasound examination of the liver in sheep– using state-of-the-art technology – is a sensitive and specific diagnostic tool, which iscost-effective, highly appropriate for field use and requires only moderate time (no shav-ing required). The method can also be applied to other livestock species and will be usefultool in epidemiological studies, monitoring schemes and vaccination/control trials