Leishmania infantum and Dirofilaria immitis infections in Italy, 2009–2019: changing distribution patterns

Abstract

Background: For long time, canine leishmaniosis (CanL) was considered endemic in the southern, central, and insular regions of Italy, whereas heartworm disease (HW) caused by Dirofilaria immitis was considered endemic in the northern region and in the swampy Po Valley. Following the reports of new foci of both diseases, in this study we update the distribution patterns and occurrence of new foci of CanL and HW discussing the main drivers for the changes in the epidemiology of these two important zoonotic canine vector-borne diseases.Methods: Based on the statistical analyses of serological assays (n = 90,633) on L. infantum exposure and D. immitis infection performed by two reference diagnostic centres in Italy over a ten-year period (2009-2019) irrespective of the anamnesis of dogs. The distribution patterns of both parasites are herein presented along with the occurrence of new foci.Results: Results highlighted the changing distribution patterns of L. infantum vs D. immitis infection in Italy. CanL is endemic in some areas of northern regions and HW has endemic foci in central and southern regions and islands. Significant differences in L. infantum exposure and HW infection prevalence among the study macroareas were detected. The overall results of the positive tested samples were 28.2% in southern Italy and islands, 29.6% in central Italy and 21.6% in northern Italy for L. infantum and 2.83% in northern Italy, 7.75% in central Italy and 4.97% in southern Italy and islands for HW. HW positivity significantly varied over years (χ 2 = 108.401, df = 10, P < 0.0001), gradually increasing from 0.77% in 2009 to 8.47% in 2016-2017.Conclusions: New potential epidemiological scenarios are discussed according to a range of factors (e.g. environmental modifications, occurrence of competent insect vectors, transportation of infected animals to non-endemic areas, chemoprophylaxis or vector preventative measures), which may affect the current distribution. Overall, the results advocate for epidemiological surveillance programmes, more focussed preventative and control measures even in areas where few or no cases of both diseases have been diagnosed.

Comparison of Diagnostic Tools for the Detection of Dirofilaria immitis Infection in Dogs

“…In the last two decades, reports of clinical cases of heartworm (HW) infection in dogs have increased even in non-endemic areas with new endemic foci detected in the Mediterranean region [ 8 , 9 , 10 ]. However, several studies have recorded a large variability in prevalence data [ 11 , 12 , 13 ], which depends on epidemiological factors (e.g., presence and abundance of competent vectors and absence of chemoprophylaxis treatments) as well as on the diagnostic methods employed.…”

Molecular characterization of Leishmania species from stray dogs and patients in Saudi Arabia

“…in Qatar [35], L. tropica in Iran [26,36] and Israel [37,38] and by L. major in Iraq [23] and Israel [25], which are in agreement with the current study. Though CL is endemic in many parts of Saudi Arabia, the paucity of data concerning the relationship between the disease, the vectors and reservoirs is a major hindrance to understand the transmission cycles in endemic areas, considering that the distribution patterns can easily change through the years in speci c geographic areas [39]. Data herein provided contribute to ll existing gaps in order to increase the alert by the Ministry of Health in Saudi Arabia in preventing outbreaks and the spread of CL.…”

Parasitemia and its daily variation in canine leishmaniasis

“…Canine leishmaniasis (CanL), caused by Leishmania infantum , is an important zoonotic vector-borne disease, endemic in many countries all over the world (Alvar et al 2012 ). In the past 10 years, CanL is of increasing concern in many regions of the Mediterranean basin, including Italy, since it spreads in previously non-endemic areas in relationship to the sandfly vectors (Mendoza-Roldan et al 2020 ). Leishmania spp.…”