Validation of the natural sedimentation technique in the diagnosis of chronic fasciolosis

• Published in: Parasitology international Vol. 101; p. 102889
• Main Authors: Rojas-Moncada, Juan, Torrel-Pajares, Téofilo, Vargas-Rocha, Luis
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2024
• Subjects: Animals; Cattle; Cattle Diseases - diagnosis; Cattle Diseases - parasitology; Chronic Disease; Chronic fasciolosis; Diagnostic technique; Fasciola hepatica - isolation & purification; Fascioliasis - diagnosis; Fascioliasis - parasitology; Fascioliasis - veterinary; Feces - parasitology; Natural eggs sedimentation; Parasite Egg Count - methods; Parasite Egg Count - veterinary; Sensitivity; Sensitivity and Specificity; Sheep; Sheep Diseases - diagnosis; Sheep Diseases - parasitology; Specificity; Swine; Swine Diseases - diagnosis; Swine Diseases - parasitology; Specificity; Sensitivity; Diagnostic technique; Chronic fasciolosis; Natural eggs sedimentation
• ISSN: 1383-5769; 1873-0329
• DOI: 10.1016/j.parint.2024.102889

There are various diagnostic techniques available for chronic fasciolosis in ruminants. However, many of them exhibit low specificity and sensitivity, making them impractical for field use and in low-resource laboratories. The present study evaluates the usefulness of the Natural Sedimentation technique in diagnosing chronic fasciolosis in three domestic species conducted at the Laboratorio de Parasitología y Enfermedades Parasitarias, Facultad de Ciencias Veterinas, Universidad Nacional de Cajamarca. Fecal samples were collected from n = 323 cattle, n = 362 sheep, and n = 231 swine for Fasciola hepatica fecal egg counts. The visualization of adult parasites in animal livers post-mortem was considered the gold standard. Additionally, the sensitivity of the technique was evaluated using five different amounts of feces. In cattle, a sensitivity of 0.93 ± 0.03, specificity of 0.91 ± 0.06, positive predictive value of 0.96 ± 0.03, and negative predictive value of 0.86 ± 0.07 were obtained. In sheep, a sensitivity of 0.79 ± 0.05, specificity of 0.83 ± 0.07, positive predictive value of 0.90 ± 0.04, and negative predictive value of 0.66 ± 0.08 were observed. In swine, a sensitivity of 0.92 ± 0.06, specificity of 1.00 ± 0.00, positive predictive value of 1.00 ± 0.00, and negative predictive value of 0.96 ± 0.03 were found. There was no statistical difference in egg counts when using 1, 2, 3, 4, and 5 g of feces (p = 0.907). Furthermore, 1 to 688 fecal eggs of F. hepatica were counted in 1 g of feces. The Natural Sedimentation technique has both qualitative and quantitative applications with satisfactory results when using 1 g of feces in the diagnosis of chronic fasciolosis in domestic animals. Due to its simplicity, it can be implemented in field conditions and low-resource laboratories.