title: Serological cross-reactivity of three commercial in-house immunoassays for detection of Dirofilaria immitis antigens with Spirocerca lupi in dogs with benign esophageal spirocercosis.
abstract: The nematode Spirocerca lupi infects dogs and is endemic in Israel. It leads to formation of esophageal nodules and neoplasia. Infection is diagnosed by coproscopy, endoscopy and radiography. Dirofilaria immitis causes heartworm disease in dogs, and has a world-wide distribution, but autochthonous infection has never been detected in Israel. Infection is confirmed based on identifying D. immitis microfilariae, in concentrated blood specimens by microscopy (Knott's test or other tests) and serological tests specifically detecting circulating adult worm antigens. In the first part of this study, sera from dogs definitively diagnosed with esophageal spirocercosis by endoscopy were examined using three in-house immunoassays for detecting D. immitis antigen, and were positive in 2/19 (10.5%), 5/35 (14.3%) and 14/48 (29.2%) dogs, in assays 1 to 3, respectively, with no statistical difference between assays (P=0.08). Next, sera from 32 additional dogs with confirmed esophageal spirocercosis, which were confirmed to be negative for D. immitis and Dirofilaria repens DNA using a sensitive high-resolution melt PCR were tested using assay 3 and 8/32 (25%) were positive. These results demonstrate serological cross-reactivity between D. immitis and S. lupi in blood samples of dogs. In areas where the distributions of both nematodes overlap, this cross-reactivity should be considered when dog are screened for heartworm disease.
authors.affiliation: Koret School of Veterinary Medicine, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 761001, Israel. Electronic address: itamar.aroch@mail.huji.ac.il.
authors.forename: Itamar
authors.initials: I
authors.lastname: Aroch
authors.affiliation: Koret School of Veterinary Medicine, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 761001, Israel.
authors.forename: Alicia
authors.initials: A
authors.lastname: Rojas
authors.affiliation: Koret School of Veterinary Medicine, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 761001, Israel.
authors.forename: Paul
authors.initials: P
authors.lastname: Slon
authors.affiliation: Koret School of Veterinary Medicine, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 761001, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Lavy
authors.affiliation: Koret School of Veterinary Medicine, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 761001, Israel.
authors.forename: Gilad
authors.initials: G
authors.lastname: Segev
authors.affiliation: Koret School of Veterinary Medicine, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 761001, Israel.
authors.forename: Gad
authors.initials: G
authors.lastname: Baneth
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000097:blood*; D003429:Cross Reactions; D018509:DNA, Helminth / Q000235:genetics / Q000302:isolation & purification; D004183:Dirofilaria immitis / Q000302:isolation & purification*; D004283:Dog Diseases / Q000175:diagnosis / Q000469:parasitology*; D004285:Dogs; D003576:Electron Transport Complex IV / Q000235:genetics; D004935:Esophageal Diseases / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D007118:Immunoassay / Q000379:methods / Q000662:veterinary*; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D017205:Spirurida Infections / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D013802:Thelazioidea / Q000302:isolation & purification*
chemical_list: D000947:Antigens, Helminth; D018509:DNA, Helminth; D003576:Electron Transport Complex IV
keywords: Canine; Diagnosis; Dirofilaria repens; Dirofilariasis; Heartworm disease; Serology; Spirocercosis