Monitoring of Insecticide Resistance Mutations and Pathogen Circulation in Sand Flies from Emilia-Romagna, a Leishmaniasis Endemic Region of Northern Italy

Abstract

The continuously expanding distribution of sand flies, proven vectors of Leishmania and of several phleboviruses, is a growing public health issue in Europe. Especially in Italy, visceral leishmaniasis (VL) is occurring with increasing incidence northward, in previously non-endemic provinces. Around the globe, disease elimination efforts largely focus on sand fly vector insecticidal control, often leading to the development of resistance. In Emilia-Romagna (ER), northern Italy, insecticides are heavily applied for agricultural and mosquito control, but not specifically against sandflies. Here, we investigated the sand fly species composition in certain environmental settings in ER provinces and monitored the presence of pyrethroid resistance mutations and pathogen circulation. Phlebotomus perfiliewi, a dominant vector of Leishmania infantum, was detected almost exclusively in the region. No mutations in the voltage-gated sodium channel gene, e.g., knock-down resistance mutations I1011M, L1014F/S, V1016G, or F1020S, were recorded. Pathogen monitoring revealed that almost 40% of the tested sand fly pools were positive for Leishmania, while the presence of Toscana and Fermo phleboviruses was also observed in much lower frequencies (≤3% positive pools). Regular epidemiological and entomological monitoring, alongside resistance surveillance, is highly recommended to ensure the sustainability and efficiency of vector control interventions.

Human Cutaneous Leishmaniasis in North Africa and Its Threats to Public Health: A Statistical Study Focused on Djelfa (Algeria)

“…This, in turn, prompted the government to implement a sand fly control program, ultimately resulting in a decrease in case rates [42]. This was the situation in our research, where CL cases gradually declined to 33 cases in 2009, then fluctuated with increases and decreases, justifiable to some extent by the excessive use of insecticides in the health sector as well as on farms, which contributed to the development of insecticide resistance in the disease vectors [43]. Additionally, inadequate sanitation and irregular household garbage disposal, combined with the construction of rural houses from mud with wall cracks, facilitate the breeding of phlebotomine sand flies [44,45].…”

Molecular monitoring of insecticide resistance in major disease vectors in Armenia

“…Mosquito species were molecularly identified as previously described [ 28 , 29 ]. Briefly, members of Cx.…”

“…Anopheles mosquitoes were molecularly differentiated by partial amplification of the ITS2 and mitochondrial cytochrome c oxidase I gene (COI) [ 32 , 33 ]. Sand fly species discrimination was performed based on the COI genomic fragment, as previously described [ 29 , 34 ].…”

Comparative genomics uncovers the evolutionary dynamics of detoxification and insecticide target genes across 11 phlebotomine sand flies

“…Recent monitoring studies have suggested that kdr mutations are typically absent from Phlebotomus species in Greece and Italy (Balaska et al, 2023). Nonetheless, the kdr (L995F and L995S) mutations have been recorded in Ph.…”