Leishmania infantum-specific IFN-? production in stimulated blood from cats living in areas where canine leishmaniosis is endemic

Priolo, Vito; Martínez-Orellana, Pamela; Pennisi, Maria Grazia; Masucci, Marisa; Prandi, David; Ippolito, Dorotea; Bruno, Federica; Castelli, Germano; Solano-Gallego, Laia

PCR results based on cat provenience and clinical status are summarized in Table 2 . Only 9 cats (5%) were Leishmania-PCR positive (Fig. 1 ) and the median parasite load was 60 L. infantum amastigotes/ml [(25-75) = 10-128.5]. Leishmania-PCR positive cats were more frequently positive by serology (89% by IFAT and 78% by ELISA) than Leishmania-PCR negative cats (13% by IFAT and 7% by ELISA) (Fisher's exact test, P<0.0001 ). In addition, antibody level measured by IFAT (Mann-Whitney U-test, Z = 86.5, P < 0.0001) and ELISA (Mann-Whitney-U test, Z = 219, P < 0.0001) of Leishmania-PCR positive cats was significantly higher when compared to Leishmania-PCR negative cats. Moreover, a positive correlation was found between PCR and ELISA (Spearman's correlation coefficient, r s = 0.272, P = 0.0001) with an agreement of 86.1% (Cohen's kappa coefficient = 0.25, i.e. fair agreement) as well as a positive correlation between PCR and IFAT (Spearman's correlation coefficient, r s = 0.347, P = 0.0001) with an agreement of 80.1% (Cohen's kappa coefficient = 0.18, i.e. slight agreement). No other differences were found in positive PCR prevalence according to variables under study.