title: Cytological and molecular detection of Leishmania infantum in different tissues of clinically normal and sick cats.
abstract: Natural infection of domestic cats by Leishmania infantum (synonym: L. chagasi) has been demonstrated in several European, Latin American, and Asian countries, and the estimated prevalence of infection, based mainly on blood PCR, ranges from 0.3% up to 60.6%. In this study we aimed to: (a) estimate the prevalence of the infection by L. infantum in clinically normal cats (group A; n=50) and in cats with various clinical signs (group B; n=50), living in an endemic region, by both cytological examination of four different tissues (lymph node, skin, bone marrow, and conjunctiva) and by PCR in four different tissues (blood, skin biopsies, bone marrow, and conjunctiva); (b) compare the diagnostic sensitivity of the above methods and evaluate for possible associations between their results; and (c) investigate the possible associations between infection by L. infantum and signalment, living conditions, season of sampling, and health status of the cats. The prevalence of the infection in the study population was 41% and did not differ (P=0.839) between group A (42%) and B (40%) cats. Lymph node, skin, bone marrow and conjunctiva cytology was always negative. Therefore, the diagnosis of the infection was based only on PCR in blood, skin biopsy, bone marrow and conjunctiva, which was positive in 13%, 18.2%, 16% and 3.1% of the cats, respectively. PCR was positive in only one of the four tissues in 80.5% of the infected cats. The results differed (P=0.014) among the four tissues and were less frequently positive in conjunctiva compared to skin biopsies and bone marrow (P=0.007 for both comparisons), thus highlighting the need for multiple tissue PCR testing in order to minimize false-negative results. More PCR-positive cats were found when sampling was performed during the period of sandfly activity (odds ratio: 2.44; P=0.022). Also, in group B cats, the likelihood of PCR-positivity was higher (odds ratio: 3.93; P=0.042) among those presenting at least one systemic clinical sign that had been previously reported in cats with leishmaniosis.
authors.affiliation: Clinic of Medicine, Faculty of Veterinary Science, University of Thessaly, 224 Trikalon Str., GR-43100, Karditsa, Greece. Electronic address: mchatzis@vet.uth.gr.
authors.forename: Manolis K
authors.initials: MK
authors.lastname: Chatzis
authors.affiliation: Department of Anatomy and Physiology of Farm Animals, Faculty of Animal Science and Hydrobiology, Agricultural University of Athens, 75 Iera Odos, Votanikos, GR-11855, Athens, Greece.
authors.forename: Margarita
authors.initials: M
authors.lastname: Andreadou
authors.affiliation: Laboratory of Epidemiology, Biostatistics and Animal Health Economics, Faculty of Veterinary Science, University of Thessaly, 224 Trikalon Str., GR-43100, Karditsa, Greece.
authors.forename: Leonidas
authors.initials: L
authors.lastname: Leontides
authors.affiliation: Clinic of Medicine, Faculty of Veterinary Science, University of Thessaly, 224 Trikalon Str., GR-43100, Karditsa, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Kasabalis
authors.affiliation: Companion Animal Clinic (Medicine), School of Veterinary Medicine, Aristotle University of Thessaloniki, 11 Stavrou Voutyra Str., GR-54627, Thessaloniki, Greece.
authors.forename: Mathios
authors.initials: M
authors.lastname: Mylonakis
authors.affiliation: Companion Animal Clinic (Medicine), School of Veterinary Medicine, Aristotle University of Thessaloniki, 11 Stavrou Voutyra Str., GR-54627, Thessaloniki, Greece.
authors.forename: Alexandros F
authors.initials: AF
authors.lastname: Koutinas
authors.affiliation: Companion Animal Clinic (Medicine), School of Veterinary Medicine, Aristotle University of Thessaloniki, 11 Stavrou Voutyra Str., GR-54627, Thessaloniki, Greece.
authors.forename: Timoleon
authors.initials: T
authors.lastname: Rallis
authors.affiliation: Department of Anatomy and Physiology of Farm Animals, Faculty of Animal Science and Hydrobiology, Agricultural University of Athens, 75 Iera Odos, Votanikos, GR-11855, Athens, Greece.
authors.forename: John
authors.initials: J
authors.lastname: Ikonomopoulos
authors.affiliation: Clinic of Medicine, Faculty of Veterinary Science, University of Thessaly, 224 Trikalon Str., GR-43100, Karditsa, Greece.
authors.forename: Manolis N
authors.initials: MN
authors.lastname: Saridomichelakis
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000175:diagnosis* / Q000469:parasitology; D002415:Cats; D018314:Leishmania infantum / Q000235:genetics; D007896:Leishmaniasis / Q000175:diagnosis / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D016133:Polymerase Chain Reaction / Q000592:standards / Q000662:veterinary; D012680:Sensitivity and Specificity
keywords: Cat; Cytology; Greece; Leishmania infantum; PCR