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.

No abstract

Canine leishmaniosis is a disease caused by Leishmania infantum, a vector-borne parasite. Due to the zoonotic potential of canine leishmaniosis, infected dogs must be identified. Serological assays are the most common methods for the detection of L. infantum infection in dogs used in veterinary practice. The aim of the study was to assess the performance of a rapid immunochromatographic test ( FAST est LEISH ® , MEGACOR Diagnostik) for the detection of specific antibodies to that of the L. infantum in dog sera. The results were simultaneously compared using a commercial brand of indirect immunofluorescence antibody test and an in-house enzyme-linked immunosorbent assay as references. Between the two reference tests, 232 serum samples out of 244, produced concordant results while 12 exhibited discordant results. Of the 232 concordant samples, 121 were classified as L. infantum seropositive, and 111 samples were previously classified as L. infantum seronegative by a combination of the reference assays. All samples that were seropositive by the reference tests were also positive according to the rapid test, and only one sample that was seronegative according to the two reference assays was positive according to the rapid test. Compared with the reference tests, the rapid test sensitivity was 100%, specificity was 99.1%, accuracy was 99.6%, Cohen’s kappa coefficient was 0.99, and the area under receiver operating characteristic curve was 0.995. The FAST est LEISH ® is a rapid, qualitative in-clinic test with high sensitivity and specificity. Electronic supplementary material The online version of this article (10.1186/s13028-019-0473-1) contains supplementary material, which is available to authorized users.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Dirofilaria immitis is an endemic mosquito-borne pathogen widely spread throughout Europe as well as North and South America. Infection by D. immitis has been reported in domestic ferrets, although little is known about the occurrence and the epidemiological features of this nematode in this species. The aim of the present retrospective study was to assess the prevalence of D. immitis antibodies using an in-house enzyme-linked immunosorbent assay specifically developed for use in ferrets. One hundred and eighty-six serum samples were obtained from the Province of Valencia (Spain), an area endemic for dirofilariosis. Of the 186 serum samples included in the study, 27 (14.51%) were classified as D. immitis seropositive and 159 samples as D. immitis seronegative. The results provide valuable information on the seroprevalence of D. immitis infection in domestic ferrets in an area endemic for this vector-borne pathogen. The presence of seropositive ferrets should be taken into account and preventive measures should be implemented, including the possibility of serological screening for the early detection of Dirofilaria antibodies as a serological marker of exposure. This is the first study that demonstrates the presence of D. immitis exposure in ferrets in Spain. Veterinarians working in endemic areas should be aware of this infection in ferrets and their susceptibility.