Mohammad Akhoundi

Background: Scabies remains a widespread parasitic skin disease with increasing reports of treatment failure associated with permethrin, the first‐line therapy. Emerging evidence suggests that genetic variation in the voltage‐gated sodium channel (VGSC) may be associated with reduced susceptibility to pyrethroids, although its contribution to clinical treatment failure in human scabies remains incompletely characterized. Objectives: To investigate the presence and frequency of knockdown resistance ( kdr ) gene mutations associated with permethrin treatment failure in S. scabiei collected from patients in multiple centres across Europe and Africa. Methods: Mite samples were obtained from patients with clinically diagnosed scabies in France, Belgium, Tunisia and Madagascar between 2023 and 2025. Genomic DNA was extracted and PCR amplification of the voltage‐sensitive sodium channel (VSSC) gene was performed, followed by bidirectional sequencing to identify single nucleotide polymorphisms (SNPs). Detected mutations were analysed and correlated with clinical treatment outcomes. Results: Out of 61 suspected cases, 45 were confirmed as scabies infestations. Molecular analysis identified three mutations—M918L, G733D and S916S—in 25 (55.5%) specimens, which were detected in patients with documented permethrin treatment failure. In contrast, 20 out of 45 patients without these mutations experienced successful treatment outcomes. M918L was the most frequent and widely distributed mutation. These genetic findings were consistent with the observed treatment ineffectiveness. This study is the first to report these mutations in Belgium, Tunisia and Madagascar. Conclusions: This pilot multicentre study identified an association between specific VGSC polymorphisms and documented permethrin treatment failure in human scabies. M918L, G733D and S916S represent candidate resistance‐associated variants, whereas the functional significance of the synonymous S916S substitution requires further investigation. Regarding the multifactorial nature of scabies treatment, the increasing occurrence of VGSC nucleotide substitutions highlights an emerging challenge in scabies management and underscores the urgent need for ongoing resistance monitoring, molecular surveillance and the development of alternative therapeutic strategies.

Climate-driven expansion of Leishmania infantum and its phlebotomine vectors is reshaping the geography of leishmaniasis across Europe, while surveillance systems remain largely dependent on labour-intensive trapping and pathogen screening. We propose a hypothesis-driven framework in which surface environmental DNA (eDNA) collected from sand fly resting microhabitats is analysed using duplex droplet digital PCR (ddPCR) targeting both vector and parasite DNA. The approach is not intended to replace conventional entomological surveillance but to function as a first-tier triage tool for identifying locations where targeted trapping and pathogen investigations should be prioritised.The hypothesis is based on three observations: (i) adult sand flies aggregate at predictable sheltered resting sites; (ii) infected sand flies may harbour substantial parasite burdens, with each Leishmania parasite containing thousands of kinetoplast minicircle copies; and (iii) biological residues deposited at resting sites may contribute detectable quantities of vector and parasite DNA to environmental surfaces. We therefore hypothesise that repeated occupation of resting microhabitats could generate environmental DNA signals reflecting local vector–parasite co-occurrence.We outline a tiered interpretation framework and a falsifiable validation pathway combining controlled insectarium experiments and field investigations. Particular emphasis is placed on distinguishing environmental detection of parasite DNA from evidence of active transmission and on defining the analytical and ecological conditions required for reliable signal interpretation.If validated, surface eDNA surveillance could provide a scalable spatial risk surveillance component within integrated One Health surveillance systems, helping to prioritise entomological investigations in newly exposed or under-surveyed regions. Beyond operational surveillance, this framework may contribute to addressing a recurrent challenge in neglected tropical diseases: distinguishing true emergence from delayed detection in areas where transmission has historically been overlooked.

Human lice are hematophagous ectoparasites of worldwide distribution and public health concern. Despite their medical importance, the genetic diversity of these ectoparasites remains poorly documented, with only one prior study conducted in France. In this study, we investigated the distribution and genetic diversity of human louse populations collected from patients referred to Avicenne Hospital, northern Paris, between 2019 and 2023. A total of 209 specimens, one per patient, were examined: 186 head lice ( Pediculus humanus capitis ), 11 body lice ( Pediculus h. corporis ), and 12 pubic lice ( Pthirus pubis ). Head lice predominated in women (82.3%), whereas body and pubic lice were more frequent in men (81.8% and 83.3%, respectively). Among head lice patients, 75.8% were children under 18 years, while all body lice patients and 83.3% of pubic lice patients were adults. Two infants with pubic lice were diagnosed, presumably infected by their parents, highlighting transmission risk among family members. Four pubic lice cases involved men who have sex with men. Phylogenetic analysis of cytochrome oxidase I ( COI ) sequences using the maximum likelihood method and comparison to GenBank sequences from multiple regions revealed genetic heterogeneity, with sequences clustering into three monophyletic clades (A, B and C). Clade C is reported for the first time in France. Body louse sequences clustered exclusively within clade A. Together with our previous work, this study represents the first epidemiological investigation of human lice infestation in a general French population, contrasting with earlier reports restricted to schoolchildren. Our findings also improve our understanding of human louse genetic diversity with implications for control strategies.

Human lice are obligate bloodsucking ectoparasites harbouring endosymbiotic bacteria essential for their survival. Despite the medical significance of human lice, their endosymbionts remain understudied, and knowledge about their species identity, prevalence and genetic diversity is largely limited. Head, body and pubic louse specimens' collection from infested patients of various origins between 2019 and 2023 enabled molecular screening for distribution and genetic diversity of bacterial endosymbionts through conventional PCR targeting two fragments of 16S‐rRNA. A total of 209 louse specimens isolated from infested patients, including 186 head lice, 11 body lice and 12 pubic lice were examined with 77.5%, 41.7% and 94.3% of the specimens found to be infested with Candidatus Riesia pediculicola, Candidatus Riesia pthiripubis and Wolbachia respectively. Inferred phylogenetic analysis of Candidatus Riesia and Wolbachia sequences revealed heterogeneity clustering into four and three clades respectively. No specific correlation was observed between these endosymbionts and lice ecological forms or geographical origin demonstrating that head, body and pubic lice share the same Candidatus Riesia and Wolbachia strains with independent adaptation and co‐evolution, except Candidatus Riesia pthiripubis which was identified exclusively in pubic lice. These phylogenetic results were aligned by network analysis. These findings could be helpful in evolutionary and biological control investigations.

Background: Checklists of zoological groups are useful to document species names in a specific area or even worldwide. They serve for various purposes, including ecological studies, conservation reports, policy and decision-making, and species identification. Phlebotomine sand flies (Diptera, Psychodidae) are the vectors of pathogens such as Leishmania, Bartonella and some arboviruses (Toscana, Naples, Sicily), and checklists for sand flies have primarily been published mainly for a state, department, or country. A checklist for American sand flies was published in 2017, but, until then, no effort has been made to compile a comprehensive list of species worldwide. The present study aims to fill this gap of knowledge. Methods: The present checklist is provided based on a literature overview and biological collections records and includes unpublished data from the authors. The species are presented according to the classification, then alphabetically by Eastern and Western Hemispheres. Distribution by country and type locality of each species are provided. Discussions on the taxonomic status or occurrence of each species are provided when needed. Results: A total of 23 genera in the Western Hemisphere, formerly the New World (Bichromomyia, Brumptomyia, Deanemyia, Dampfomyia, Edentomyia, Evandromyia, Expapillata, Hertigia, Lutzomyia, Martinsmyia, Micropygomyia, Migonemyia, Nyssomyia, Oligodontomyia, Pintomyia, Pressatia, Psathyromyia, Psychodopygus, Sciopemyia, Trichophoromyia, Trichopygomyia, Viannamyia, and Warileya) and 17 genera in the Eastern Hemisphere, formerly the Old World (Australophlebotomus, Chinius, Demeillonius, Grassomyia, Idiophlebotomus, Libanophlebotomus, Libanophlebotomites, Mesophlebotomites, Paleomyia, Parvidens, Phlebotoiella, Phlebotomiella, Phlebotomites, Phlebotomus, Sergentomyia, Spelaeomyia, Spelaeophlebotomus), including the fossil species, are listed herein. The updated list, excluding nomina dubia/species inquirenda includes 1063 sand fly species, with 549 and 514 species for New World and Old World, respectively. Only New Zealand and the Pacific Islands (excluding New Caledonia) do not record the presence of sand flies. The dataset for this study is publicly available in the SiBBr and GBIF. Conclusions: This is the first detailed list of valid names of phlebotomine sand flies worldwide, including records from each country where they have been documented. Graphical