Cross-sectional investigation on sheep sarcosporidiosis in Sardinia, Italy

• Sarcocystis spp., are among the most common parasites of livestock animals.
• Data on sheep sarcosporidiosis in Sardinia island have been updated.
• A cross-sectional investigation on macroscopic and microscopic species was performed.
• Improve knowledge on Sarcocystis spp. in Sardinia.

An epidemiological survey on sarcosporidiosis was carried out with a cross sectional investigation on macroscopic and microscopic Sarcocystis spp. in Sarda breed sheep slaughtered in different abbatoirs of Sardinia, Italy. For the macroscopic survey, muscular samples (diaphragm, abdominal and intercostals muscles, cutaneous muscles and muscles of the thigh) from 769 slaughtered Sarda sheep, oesophagus (n = 365) and laryngeal and pterygoid muscles (n = 521) were macroscopically investigated and Polymerase Chain Reaction (PCR) on selected macroscopic cysts was performed for a molecular identification of macroscopic Sarcocystis species. For the microscopic investigation 112 heart samples from slaughtered Sarda sheep were collected and investigated with two different protocols: unstained (compression) examination and a molecular technique. The overall prevalence of infection for macroscopic forms of sarcocysts was of 23.3% (179/769) with prevalences higher in the oesophagus (31.6%; 125/395) compared with the other investigated tissue type; two different morphotypes, classified as large oval (LO) macroscopic cysts, identified as Sarcocystis gigantea, and slender fusiform (SF) sarcocysts, were identified. The examination of heart samples revealed an overall prevalence of 77.7% (87/112) for Sarcocystis spp.; the nested-PCR analysis of heart samples allowed to identify the microscopic species, Sarcocystis tenella and Sarcocystis arieticanis, with prevalences of 95.5% (107/112) and 17.8% (5/112) respectively. Reported results highlight the high prevalence of Sarcocystis infection in the island and suggests the need of an improvement of control and prevention strategies for this parasitosis.