Maria Magdalena Alcover1, Asier Basurco2,3, Antonio Fernandez2,3, Cristina Riera1, Roser Fisa1, Ana Gonzalez3, Maite Verde2,3, Ana María Garrido3, Héctor Ruíz3, Andrés Yzuel2, Sergio Villanueva-Saz4,5. 1. Departament de Biologia, Salut I Medi Ambient, Facultat de Farmacia, Universitat de Barcelona, Barcelona, Spain. 2. Laboratorio de Inmunopatología Clínica, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain. 3. Departamento de Patología Animal, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain. 4. Laboratorio de Inmunopatología Clínica, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain. svs@unizar.es. 5. Departamento de Farmacología Y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, 50013, Zaragoza, Spain. svs@unizar.es.
Abstract
BACKGROUND: Feline leishmaniosis is a vector-borne parasitic disease caused by Leishmania spp. Leishmania infection in dogs is prevalent in the Mediterranean basin, but in other animals, such as cats, it could also play a role in the epidemiology of the disease. Information on the geographical distribution and epidemiological features of L. infantum infection in cats is scarce, particularly in urban stray cats living in regions where canine leishmaniosis is endemic. As diagnosis can be challenging, combining different serological and molecular methods is a useful approach. Our aim was to investigate the prevalence of infection of L. infantum in apparently healthy stray cats in an endemic region of Spain (Zaragoza city) using serological and molecular methods, and to compare the results of the different techniques. METHODS: The prevalence of Leishmania infection was studied in stray cats captured in urban and peri-urban areas of Zaragoza. Blood was collected from each animal for serology and molecular analysis. Three serological methods, namely the immunofluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) and western blot (WB), were used to detect L. infantum antibodies and a real-time PCR (qPCR) assay was used to detect L. infantum DNA. The results were analyzed by Fisher's exact test and Cohen's kappa statistic (κ) to assess the level of agreement between the diagnostic techniques. RESULTS: Serological analysis of blood samples from 180 stray cats revealed 2.2% (4/179) Leishmania infection positivity by IFAT, 2.8% (5/179) by ELISA and 14.5% (26/179) by WB. Leishmania DNA was detected by qPCR in 5.6% (10/179) of the cats. Sixteen cats (8.9%) tested positive by only one serological technique and four tested positive by all three serological methods used. The overall rate of infected cats (calculated as the number of cats seropositive and/or qPCR positive) was 15.6%, and only two cats tested positive by all the diagnostic methods. A significant association was found between male cats and a positive qPCR result. Comparison of the techniques revealed a fair agreement in seropositivity between blood qPCR and IFAT (κ = 0.26), blood qPCR and ELISA (κ = 0.24), WB and ELISA (κ = 0.37) and WB and IFAT (κ = 0.40). The highest agreement between seropositive results was between IFAT and ELISA (κ = 0.89), and the lowest was between blood qPCR and WB (κ = 0.19). The prevalence of the feline leukemia virus antigen was 4.49% (8/178 cats) and that of the feline immunodeficiency virus (FIV) antibody was 6.74% (12/178), while co-infection with both retroviruses was observed in one female cat (1/178). Leishmania ELISA and IFAT seropositivity were statistically associated with FIV status by the chi-square test. CONCLUSIONS: The results obtained in this study, using serological tests and qPCR, indicate the existence of L. infantum asymptomatic infection in apparently healthy stray cats in the city of Zaragoza, an endemic area in Spain.
BACKGROUND:Feline leishmaniosis is a vector-borne parasitic disease caused by Leishmania spp. Leishmania infection in dogs is prevalent in the Mediterranean basin, but in other animals, such as cats, it could also play a role in the epidemiology of the disease. Information on the geographical distribution and epidemiological features of L. infantuminfection in cats is scarce, particularly in urban stray cats living in regions where canine leishmaniosis is endemic. As diagnosis can be challenging, combining different serological and molecular methods is a useful approach. Our aim was to investigate the prevalence of infection of L. infantum in apparently healthy stray cats in an endemic region of Spain (Zaragoza city) using serological and molecular methods, and to compare the results of the different techniques. METHODS: The prevalence of Leishmania infection was studied in stray cats captured in urban and peri-urban areas of Zaragoza. Blood was collected from each animal for serology and molecular analysis. Three serological methods, namely the immunofluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) and western blot (WB), were used to detect L. infantum antibodies and a real-time PCR (qPCR) assay was used to detect L. infantum DNA. The results were analyzed by Fisher's exact test and Cohen's kappa statistic (κ) to assess the level of agreement between the diagnostic techniques. RESULTS: Serological analysis of blood samples from 180 stray cats revealed 2.2% (4/179) Leishmania infection positivity by IFAT, 2.8% (5/179) by ELISA and 14.5% (26/179) by WB. Leishmania DNA was detected by qPCR in 5.6% (10/179) of the cats. Sixteen cats (8.9%) tested positive by only one serological technique and four tested positive by all three serological methods used. The overall rate of infectedcats (calculated as the number of cats seropositive and/or qPCR positive) was 15.6%, and only two cats tested positive by all the diagnostic methods. A significant association was found between male cats and a positive qPCR result. Comparison of the techniques revealed a fair agreement in seropositivity between blood qPCR and IFAT (κ = 0.26), blood qPCR and ELISA (κ = 0.24), WB and ELISA (κ = 0.37) and WB and IFAT (κ = 0.40). The highest agreement between seropositive results was between IFAT and ELISA (κ = 0.89), and the lowest was between blood qPCR and WB (κ = 0.19). The prevalence of the feline leukemia virus antigen was 4.49% (8/178 cats) and that of the feline immunodeficiency virus (FIV) antibody was 6.74% (12/178), while co-infection with both retroviruses was observed in one female cat (1/178). Leishmania ELISA and IFAT seropositivity were statistically associated with FIV status by the chi-square test. CONCLUSIONS: The results obtained in this study, using serological tests and qPCR, indicate the existence of L. infantum asymptomatic infection in apparently healthy stray cats in the city of Zaragoza, an endemic area in Spain.
Authors: Ana O Franco; Clive R Davies; Adrian Mylne; Jean-Pierre Dedet; Montserrat Gállego; Cristina Ballart; Marina Gramiccia; Luigi Gradoni; Ricardo Molina; Rosa Gálvez; Francisco Morillas-Márquez; Sergio Barón-López; Carlos Alves Pires; Maria Odete Afonso; Paul D Ready; Jonathan Cox Journal: Parasitology Date: 2011-09-14 Impact factor: 3.234
Authors: Luiz F J Nascimento; Tatyane M Cirilo; Dharliton S Gomes; Ana Carolina A Gomes; Victor F S Lima; R Scher; S Jain; Ricardo T Fujiwara; Silvio S Dolabella Journal: Parasitol Res Date: 2021-11-11 Impact factor: 2.383