Feline leishmaniasis : serological and molecular detection of an emergent disease in a non-endemic area of Northern Italy

Background. In recent decades feline leishmaniosis (FeL) has become an emerging disease, also in non- endemic areas for the canine infection. Objectives. This study updates the epidemiological status for FeL in cats in northern Italy and compares results with previous studies of the same feline population. Co-infections with feline retroviruses FIV and FeLV were also investigated. Material and Methods. Stray, shelter and owned cats from different cities in the Lombardy region of northern Italy, were prospectively randomly sampled between January 2020 and May 2021. A total of 255 cats were tested for L. infantum: 240/255 for antibodies by IFAT and 234/255 and 198/255 for Leishmania DNA by PCR on whole blood and lymph nodes, respectively. Rapid ELISA test was used to detect FIV or FeLV infection. Results. Overall, 26/255 (10.2%) cats tested positive for L. infantum: in 8/26 cats Leishmania DNA was found in popliteal lymph nodes (leishmania/ml range from 15 to 60), 6/26 were PCR positive on whole blood (leishmania/ml range from 5 to 80) and 15/26 IFAT seropositive at titers ranging from 1:80 to 1:320 (Table 1). Two Leishmania infected cats were also FIV+FeLV coinfected, another was FIV positive and one was FeLV positive. Conclusion. A high prevalence of FeL was found in a non-endemic area of northern Italy, with an increasing trend in infection rates.