An extensive survey of North American catostomid fishes yielded insights into the diversity, host specificity and phylogenetic relationships of monopisthocotylans belonging to Pseudomurraytrematidae. Parasites were recorded from 14 of 16 host species surveyed. In total, 22 species of Anonchohaptor, Icelanonchohaptor and Pseudomurraytrema were collected, including 7 new species. Most species were recovered from gills, whereas two Icelanonchohaptor species were found on fins. Phylogenetic analyses based on 28S rDNA support the monophyly of Pseudomurraytrematidae and its sister relationship to Diplectanidae. Within the family, Pseudomurraytrema asiaticum – a parasite of the East Asian fish Myxocyprinus asiaticus – was recovered as sister to the clade of Nearctic pseudomurraytrematids, a placement that may reflect geographic and host-associated separation. The remaining Pseudomurraytrema species parasitize North American Catostominae and form a well-supported clade sister to the clade comprising species of Anonchohaptor and Icelanonchohaptor, primarily associated with Ictiobinae. Under this topology, Pseudomurraytrema, as currently circumscribed, may be paraphyletic. Relationships between morphologically similar species of Anonchohaptor and Icelanonchohaptor remain unresolved: in the 28S tree, Anonchohaptor is paraphyletic (with Icelanonchohaptor nested within it), whereas the concatenated 18S–ITS1–28S analyses recover a single clade with Icelanonchohaptor (2 spp.) sister to the remaining species of Anonchohaptor. The parasite phylogeny broadly reflects host relationships, though several incongruences point to historical host switching. Morphological data also support the monophyly of Pseudomurraytrematidae via a synapomorphic male copulatory organ (U-shaped copulatory tube with a submedial spine, 3-ramus accessory piece), indicating structural conservatism within this family.

The probability that a disease will manifest is highly variable. Susceptibility to disease is influenced by genetic background, environment and lifestyle choices. In this review, we put forward the premise that evolution of disease susceptibility may be partially influenced by the interaction of divergent pathogen DNA-binding proteins with variable binding sites in the host genome. The hypothesis put forward is derived from recent data obtained from work on the protozoan parasite, Theileria annulata, together with related evidence from viral and bacterial pathogens that have been postulated to modulate host epigenome architecture. The pathogen proteins highlighted have the potential to mimic functions of mammalian epigenome organisers linked to a range of disease syndromes. It is feasible, therefore, that the evolutionary relationship between pathogen and host impacts susceptibility to a range of conditions, such as autoimmune disorders and cancer, which are not directly linked to pathogen infection.

Recently, the WHO published a Target Product Profile for a diagnostic test for cutaneous leishmaniasis (CL) and a Roadmap to 2030 for Neglected Tropical Diseases. The documents highlight that existing diagnostic tools for CL are insufficient, whilst setting clear goals for improved sensitivity and reduced cost. The need for species typing in diagnostics is also becoming more pressing with the emergence of drug-resistance, especially of Leishmania tropica. Serological tests are unable to do this, while techniques that can, like PCR, require complex and expensive machinery. Isothermal assays like LAMP offer a promising solution, but more work also remains, as few species-specific LAMP assays have been developed thus far and CL in Ethiopia is particularly neglected. Additionally, since the COVID-19 pandemic, many cheap isothermal diagnostic devices have been produced, which have yet to be tested in the diagnosis of CL. Finally, artificial intelligence presents another avenue for rapid diagnosis by image analysis. In this comprehensive review, we examine the opportunities and challenges inherent to diagnostic development for CL, a priority undertaking that still faces many developmental hurdles.

Hippoboscoidea flies exhibit highly specific ectoparasitic relationships with bats, shaped by both intrinsic factors (e.g. bat behaviour) and extrinsic factors (e.g. land use). Understanding the dynamics of these parasite–host interactions is essential for uncovering co-evolutionary patterns and informing conservation strategies. To this end, we studied bat–fly interactions across different elevations in a montane forest of Amazonas, northern Peru. The most abundant bats were Carollia brevicauda, C. perspicillata and Sturnira oporaphilum, while Paraeuctenodes similis and Trichobius joblingi were the most common flies. Most flies exhibited monoxenous host specificity. Bat–fly interaction networks revealed high modularity and specialization at both local and regional scales. Modules typically grouped bat species of the same genus or subfamily, suggesting that phylogenetic constraints and roosting behaviour may shape those interaction patterns. Nestedness within modules (compound structure) emerged in the aggregated regional network, aligning with the integrative hypothesis of specialization. Although network structures were broadly similar across sites, species turnover contributed to subtle differences in module composition and specialization. These differences were congruent with the changes in species roles of certain bats and flies. This study represents the first of its kind in Peru and addresses significant knowledge gaps in the ecology of bat–fly interactions in the Neotropics.

Leishmaniasis is a neglected parasitic disease responsible for significant morbidity and mortality. Currently, there is no vaccine approved for clinical use. Therefore, controlling infections in infected individuals depends on interventions to prevent infected female sand flies from biting humans, treatment of clinical infections or alternative treatment methods. This review focuses on the types of vaccine developed to control leishmaniasis and which vaccines have made it through to clinical trials. It also discusses the role CRISPR technology may play in improving vaccine candidates design.

The northern hookworm, Uncinaria stenocephala, is the primary hookworm infecting dogs in temperate regions, but red foxes (Vulpes vulpes) are also frequent hosts. The extent to which fox-derived U. stenocephala contributes to canine transmission remains unclear. In this study, we assembled complete mitochondrial genomes (mitogenomes) from two adult U. stenocephala worms collected from red fox and two mitogenomes recovered via genome skimming from dog faecal egg isolates. Comparative analysis revealed >99% identity across all U. stenocephala mitogenomes with no discernible genetic differences for dog- and fox-derived U. stenocephala, supporting their conspecificity. Phylogenetic analysis confirmed paraphyly of the genus Uncinaria and clear distinction of U. stenocephala from the badger hookworm U. criniformis, resolving historical taxonomic ambiguity. We applied a 3% nucleotide divergence threshold to assess species boundaries across hookworm mitogenomes, confirming potential cryptic diversity in Necator americanus, U. sanguinis and A. caninum. Our findings demonstrate the utility of genome skimming for recovering hookworm mitogenomes from faecal samples and highlight the need for broader mitogenomic characterization across hookworm taxa to refine taxonomy and understand host associations.

Heartworm disease is a serious acquired parasitic infection caused by Dirofilaria immitis that can cause severe lung manifestation, heart failure, and other organ damage in dogs. We hereby present a case of a seven-year-old, intact male which was submitted to treatment of heartworm disease with doxycycline and a single dose of injectable moxidectin. Three weeks later the dog presented an acute coughing, hemoptysis and marked dyspnea and was admitted to the Hospital Veterinário Popular de Mossoró, a private veterinary hospital located in Mossoró, Rio Grande do Norte, Brazil. Some hours after the admission, the dog showed a severe coughing episodes with progressive expectoration and subsequently profuse bloody discharge. At this time, two live worms were coughed out. The nematodes specimens (1 male and 1 female) were collected from bronchial mucus, and morphologically and molecularly identified as D. immitis. A fragment of 635 bp of the cytochrome oxidase C subunit 1 gene was sequenced and deposited at the GenBank database (Accession number: PV729978). The treatment of heartworm disease can be complex, and the veterinarian must evaluate each case individually to determine the best treatment protocol. Veterinarian practitioners must be aware about the risk of this presentation and intervene properly to keep dogs’ welfare.

Pentanchids (Elasmobranchii) are among the most species-rich groups of chondrichthyans. In the North Atlantic Ocean, the Icelandic catshark [Apristurus laurussonii (Saemundsson)], white ghost catshark (Apristurus aphyodes Nakaya & Stehmann), and mouse catshark [Galeus murinus (Collett)] are commonly found in deepwater habitats. However, information on their parasite communities remains scarce. This study provides the first comprehensive characterization of the metazoan parasite communities of the 3 pentanchid species. In total, 56 specimens were collected in Icelandic waters at depths of 466–1322 m between 2023 and 2024 and examined using standardized parasitological protocols, including morphological and molecular methods. Infection patterns were assessed in relation to size, maturity, body condition and capture area of hosts. Parasite intensities in all sharks ranged from 2 to 227 individuals, comprising 15 different taxa and resulting in 27 new parasite–host records, some of which likely representing new species. Eight out of 9 commonly found parasites did not display a high degree of host-specificity, indicating similar feeding habits, niche preferences, and trophic position of these sympatric species. Nonetheless, multivariate analyses revealed significant differences in the structure and composition of their parasite assemblages, with some parasites representing indicator species and occurring more abundantly and frequently in a certain deepwater catshark species. In addition, significant small-scale geographic differences were detected. At a broader geographical scale, North Atlantic pentanchids showed higher parasite richness and diversity, and lower dominance compared to standardized data from Mediterranean counterparts. Ecological factors underlying these patterns on host–parasite dynamics in (deepwater) cat sharks are discussed.

Infectious diseases result from multiple interactions among microbes and hosts, but community ecology approaches are rarely applied. Manipulation of vector populations provides a unique opportunity to test the importance of vectors in infection cycles while also observing changes in pathogen community diversity and species interactions. Yet for many vector-borne infections in wildlife, a biological vector has not been experimentally verified, and few manipulative studies have been performed. Using a captive colony of fruit bats in Ghana, we conducted the first study to experimentally test the role of bat flies as vectors of Bartonella species. We observed changes in the Bartonella bacteria community over time following the decline of bat flies and again after their subsequent restocking. Reduced transmission rates led to microbial community changes attributed to ecological drift and potential species sorting through interspecific competition mediated by host immunity. We demonstrate that forces maintaining diversity in communities of free-living macroorganisms act in similar ways in communities of symbiotic microorganisms, both within and among hosts.