It is clear that malaria, a disease caused by Plasmodium spp., has burdened humans throughout our evolutionary paths and remains one of the deadliest maladies to date. Yet, in sharp contrast to the consequence, the human–malaria interaction is a topic that archaeologists do not understand well. This is partially due to the technical difficulties in extracting evidence from archaeological contexts, and partially due to a dearth of interdisciplinary review on this parasite – valuable information is thus veiled by technical as well as linguistic barriers. This review synthesizes archaeological, biological and ecological evidence to explore such interaction on the east side of the Eurasian continent – namely, East, Southeast and South Asia. Materials under scrutiny involve published genetic analysis on pertinent malaria species, ancient Chinese historical/medical documents and osteoarchaeological data on relevant skeletal markers. We examine how the evolution of both Plasmodium and humans engaged in this theatre, and highlight the role played by malaria in driving human demographic shifts as well as the biological and even societal resilience of people to its exposure. Interestingly, humans, in creating favourable environments for us – for instance, watering fields for rice cultivation – had inadvertently yet systematically made it suitable for malaria transmission as well.

Dipylidium caninum is a globally distributed zoonotic cestode commonly found in dogs and cats. Recent molecular studies have identified 2 major, primarily host-associated genotypic clades. However, these findings are based on geographically restricted datasets and therefore may not capture the full extent of the species’ genetic diversity. Molecular data from many endemic regions remain scarce or entirely absent. In this study, D. caninum isolates collected from dogs in northern Ghana were characterized using partial fragments of the mitochondrial nad1 and cox1 genes. Parsimony analyses identified 4 haplotypes for cox1 and 7 for nad1. For both genes, the Ghanaian isolates clustered within the globally recognized canine and feline genotypic groups, with the canine genotype predominating. When integrated into the existing global dataset, the analyses resolved 3 well-supported phylogenetic clades, designated as genotypes: 1 canine-associated G1 and 2 feline–canine-associated genotypes G2a and G2b. This study provides the first molecular data for D. caninum from Ghana, West Africa, contributes to a broader understanding of the global population structure and establishes a basis for future investigations into the biogeography of this cestode.

Despite several recent studies, the helminth diversity of small mammals in South Africa remains poorly understood. During a survey conducted from 2023 to 2025 on the helminth assemblages of rodents in the Western Cape Province, South Africa, nematodes were collected from the stomach of a female Micaelamys namaquensis in the Nama-Karoo biome. For one of the nematode species identified, morphological characters, based on light and electron microscopy, corresponded to the genus Gastronodus: a short, heavily sclerotized buccal capsule armed with 6 teeth, the presence of 3 pairs of pedunculate postcloacal papillae as well as dissimilar and unequal spicules in males and a vulva situated at the level of the glandular oesophagus in females. The presence of 3, rather than 2, pairs of postcloacal pedunculate papillae distinguishes our specimens from the closely related genera Cylicospirura, Skrjabinocercina and Spirocerca. Furthermore, the presence of 4–5 vs 6–7 pairs of pedunculate precloacal papillae distinguishes them from their single currently recognized congener, Gastronodus strasseni sampled from Suncus murinus in India. Based on these results, we here describe Gastronodus karooensis n. sp. Phylogenetic analyses of the mtDNA cox1 gene suggest some affiliation with the genus Spirocerca and provide some support for their placement in the Spirocercidae. This is the first record of the genus Gastronodus in Africa. The description of a new species of Spirocercidae from M. namaquenis highlights the need for further studies as the nematode diversity in wild hosts in South Africa is currently underestimated.

Zoonotic parasites are a growing concern in regions where humans, domestic animals and wildlife live in close proximity. Understanding parasite communities overlap across hosts is essential for understanding transmission risks. In this study, we used sedimentation technique followed by microscopy, and molecular techniques for the identification of strongylid nematodes, Strongyloides, and protists in vervet monkeys (Chlorocebus pygerythrus, N = 75), household latrines (N = 25), dogs (Canis lupus familiaris, N = 25) and livestock (Ncows = 9, Ngoats = 7, Npigs = 9) at Lake Nabugabo, Uganda to compare parasite assemblages across hosts within the same habitat. We identified 33 unique parasite taxa with 18 in dogs, 14 in livestock and 10 each in vervets and latrine samples. There was a significant difference in the parasite infection rate between vervets (88%), latrines (24%), livestock (44%) and dogs (40%). Samples harboured at least 7 known genera of strongylid nematodes, with Ancylostoma, Murshidia and Oesophagostomum being the most prevalent. Protists diversity varied across hosts. Species-specific Cryptosporidium taxa occurred in dogs, goats (Capra aegagrus hircus) and pigs (Sus scrofa domesticus), and C. andersoni was detected in both dogs (4%) and cows (Bos taurus, 8%). Giardia intestinalis assemblage A was found in vervets (1.3%), dogs (16%) and latrine samples (12%). Enterocytozoon bieneusi occurred only in latrine samples, while Encephalitozoon sp. occurred only in vervets (4%). Our results show limited overlap between vervets and other hosts but highlight shared Giardia among animals and latrine samples, indicating key points of potential zoonotic transmission in this human-modified landscape.

In a parasitological survey conducted in 2025 at a fish farm in Kunming, southwest China, a new diplozoid species was discovered on Garra surgifrons, representing the first record of a diplozoid previously reported from fish within the genus Garra in China. Morphological and molecular evidence confirm that the new species is clearly differentiated from Paradiplozoon bingolensis, the only diplozoid previously reported from Garra fishes. Phylogenetic analyses place the new species at the basal position of Chinese Paradiplozoon species. Considering the natural distribution of its host in Yunnan province and adjacent areas of Myanmar and Laos, southwestern China and Southeast Asia may represent important centres of origin and diversification for East Asian Paradiplozoon species. This study highlights the underestimated diversity, host specificity and biogeographic structure of diplozoids in East Asia and underscores the need for expanded sampling in Yunnan and neighbouring Southeast Asian regions.

This is the first ultrastructural study of an adult tapeworm providing data on the morphological aspects of the pathways of lipid excretion via the tegumental surface and excretory system in the monozoic tapeworm Caryophyllaeus brachycollis (Janiszewska, 1953) from the chub Squalius tenellus (Heckel, 1843) obtained from a lake in the Bosnia-Herzegovina Federation. Our study has shown that the release of lipid droplets onto the parasite–host interface from the tegumental cytoplasm is carried out with the participation of tegumental vesicles, which clustered and fused with each other to form electron-lucent, membrane-bound sacs around lipid droplets. The ultrastructural pattern of the excretory bladder is presented for the first time for an adult tapeworm. In C. brachycollis, the syncytial epithelial lining of both the distal and proximal bladder is a derivative of the tegumental distal cytoplasm of the posterior body surface. Variations in the structural organization of both bladder parts were observed in the kinds of luminal microtriches and in the presence of large cytoplasmic protrusions in the proximal bladder. In C. brachycollis, the lipid droplets are released into the proximal bladder lumen via 10 collecting descending excretory ducts. In adult mature monozoic caryophyllidean tapeworms, an accumulation of a large number of sarcoplasmic lipid droplets is observed and their presence in the protonephridial cyrtocytes is revealed at the posterior body end, where there are the reproductive organs and ducts.

Parasitic worms have significant medical, veterinary and economic importance. Numerous studies have therefore addressed various aspects of parasitic worms’ biology. In contrast, the ploidy of parasitic worms remains comparatively understudied, despite a few known triploid species. Polyploidy is known to have phenotypic and genetic effects in animals, which can lead to changes at the evolutionary scale. The evolutionary consequences of polyploidy have been addressed in host–parasite systems; however, most studies have focused on the host perspective, with relatively few studies examining the parasitic side of the story. This review provides available information on the distribution of triploidy among parasitic worms, along with information on such aspects as reproduction, origin of triploidy and life history. Across 100 selected papers (out of 416 screened), triploidy was reported for 15 parasitic Platyhelminthes and 13 parasitic Nematoda. Most triploid species of parasitic worms (24 out of 28) were documented at the adult stage. Triploid lineages reported for the adult stage reproduce predominantly via parthenogenesis. Finally, the paper discusses the potential effects of ploidy variation for host–parasite dynamics and adaptation rates of parasitic worms. In particular, how parasitic worms adapt to their hosts despite potential constraints of asexuality. As well as whether triploid individuals outcompete diploid conspecifics when both ploidy levels coinfect the host, as could be expected if triploids have higher virulence.

This study reports the first rediscovery and redescription of Euclinostomum lauroi in more than 40 years, based on an adult specimen recovered from the oesophagus of a great white pelican (Pelecanus onocrotalus) in Lake Tana, Ethiopia. An integrative taxonomic approach combining detailed morphological examination and molecular analyses (ITS rDNA and COI mtDNA) was employed. Scanning electron microscopy revealed additional features, including the fine surface morphology of the cirrus and genital opening. The same host individual harboured 2 Clinostomum species, C. phalacrocoracis and C. tilapiae, for which updated morphological redescriptions are provided. The record of C. tilapiae represents a new geographical record for Ethiopia. These findings expand current knowledge of African clinostomid diversity and identify Lake Tana as an important hotspot of trematode biodiversity. The newly generated morphological and molecular data refine species boundaries within Euclinostomum and Clinostomum and support the use of integrative approaches to resolve persistent taxonomic uncertainties in clinostomid systematics.

Dientamoeba fragilis transmission is a basic aspect of this intestinal parasite’s biology that is poorly understood. Early historical reports reflecting the absence of a cyst are often cited as a central argument in debates supporting the lack of a D. fragilis cyst. While D. fragilis cysts have been described since Dobell’s original description, their existence is not universally accepted. Here, Dobell’s, Wenyon’s and Hoare’s collection of historical faecal smears stored at the Natural History Museum (London), dating back to the 1890s and the early 1900s, was examined for forms consistent with modern descriptions of D. fragilis cysts, and an example was found in 1 slide. Such rare forms were also detected during examination of stained faecal smears archived in the parasite reference laboratory collection at the United States Centers for Disease Control and Prevention. We discuss these observations in the context of literature describing cyst formation in parabasalids. Additionally, we report some incidental findings from past immunofluorescence experiments on cultured D. fragilis, which suggest differential staining that appears to correlate with life cycle stages. Considering published literature on the subject of D. fragilis cysts and the broader picture of cyst formation across diverse members of Parabasalia, we recommended that future investigations on D. fragilis transmission consider mounting evidence for the role of a true cyst despite its rarity in human faecal specimens. The factors leading to cyst formation and further characteristics of this life cycle stage require further study.

The current treatments for leishmaniasis come with various side effects and the risk of drug resistance. Nanoliposomal quercetin – paromomycin and clindamycin – is being explored as a new therapeutic approach to replace existing treatments. In this research, nanoliposomal was created using the ultrasonic thin-layer dispersion method and evaluated for its encapsulation efficiency, size and zeta potential. The average particle size in the nanoliposome containing quercetin – paromomycin and clindamycin – was 74.8 nm. The dispersibility indices were equal to 0.61. The zeta potential of the nanoliposome was 24.2 mV. EC50 levels of nanoliposomal quercetin (QN), nanoliposomal quercetin-paromomycin (QPN), quercetin-paromomycin and clindamycin (QPC), nanoliposomal quercetin-clindamycin and paromomycin (QCPN), paromomycin (P) against L. major promastigotes were 70 ± 2, 57 ± 2, 51 ± 9, 43 ± 8 and 41 ± 8  micromolar, respectively. There was no significant difference in the activity of liposomal formulations against L. major promastigotes. The topical application of all treatment groups compared to PBS and the untreated group caused significant reductions in the lesion sizes. The nanoliposomal quercetin – paromomycin and clindamycin – displayed a significant anti-leishmanial effect, showing promise as a potential candidate for treatment of cutaneous leishmaniasis.

Giardiasis remains a significant global health burden, constrained by limited diagnostic tools, the emergence of drug-resistant Giardia lamblia strains, and the absence of a licenced human vaccine. To address these critical gaps, this review provides a comprehensive functional analysis of the Giardia proteome, emphasizing molecular targets essential for the parasite’s survival and pathogenesis. We systematically examine the structural proteome, specifically the tubulin reservoir and the diverse giardin family (α-, β-, γ- and δ-giardins), elucidating their indispensable roles in the ventral disc attachment mechanism. Beyond structural components, we detail the ‘pathoproteome’, and moonlighting enzymes, highlighting how the secretome – including cathepsin B-like cysteine proteases (notably giardipain-1) and variant-specific surface proteins facilitate immune evasion and host intestinal epithelial damage. Furthermore, the review explores the metabolic and encystation proteomes, identifying unique enzymes such as carbamate kinase and fructose 1,6-bisphosphate aldolase that offer high therapeutic selectivity. By synthesizing these proteomic insights, this work identifies high-priority candidates for the development of next-generation therapeutics, prophylactic, and diagnostic interventions aimed at mitigating the global impact of this neglected disease.

Chagas disease (CD) is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi affecting more than 6 million people worldwide. Its treatment is based in old and toxic nitroderivative drugs necessitating for new alternatives. Imatinib (IMB) is a tyrosine kinase inhibitor used in cancer therapy, and previous reports demonstrate that some derivatives are active against T. cruzi justifying further synthesis screening of novel compounds derived from IMB. Our results demonstrate that all test derivatives are highly active against the intracellular forms of T. cruzi being similar or even more potent than the reference drug for CD – benznidazole (BZ). Besides, they were much more active than the parent molecule, displaying low EC90 values (<10 µm) and good selectivity indexes (>10), which are relevant characteristics of a novel hit compound for CD therapy. However, when screened against bloodstream trypomastigotes, only 1 derivative, named PLDC 23/19, was as active (EC50 = 18.8 µm) as BZ (EC50 = 18.8 µm), while the others did not show activity up to 20 µm.

Bat flies (Diptera: Nycteribiidae and Streblidae) are obligate blood-feeding ectoparasites of bats and are increasingly recognised for their potential role in host-specific co-evolution and disease transmission. Despite their ecological importance, the diversity, host associations and evolutionary relationships of bat flies in Australia remain poorly characterised. This study provides the first integrative assessment of nycteribiid bat flies parasitising Pteropus species in North Queensland, combining morphological taxonomy with cytochrome c oxidase subunit 1 (COX1) sequencing and phylogenetic analysis. A total of 304 bat flies were collected from 79 rescued pteropodids, representing three host species: the little red flying fox (Pteropus scapulatus), the black flying fox (Pteropus alecto) and the spectacled flying fox (Pteropus conspicillatus). Morphological examination of the bat flies identified two taxa, Cyclopodia australis and Cyclopodia albertisii, which were further confirmed by maximum likelihood phylogenetic analysis of COX1 sequences with distinct clade formations delineating species. C. australis was found almost exclusively on little red flying foxes. C. albertisii was mainly associated with both black flying foxes and spectacled flying foxes, with very limited association with the little red flying foxes. These findings underscore the utility of integrative taxonomic approaches in researching bat fly diversity and host specificity. They also highlight the potential for co-evolutionary divergence and emphasise the need for expanded geographic sampling and genomic analysis. This research provides critical baseline data for understanding ectoparasite biodiversity in Australia and contributes to future studies of host–parasite interaction, vector ecology and wildlife disease surveillance.

Host–parasite coevolution resulted in parasites optimizing their life cycle to obtain the most benefit from the host’s behaviour. In passerines, for instance, some parasite groups have found means to match their egg shedding rhythms with the hours of the day when hosts are most active. In other bird groups, such as shorebirds, whose active times are not determined by day–night cycles but by other external factors such as tidal or lunar cycles, it is not yet known whether their endoparasites exhibit any predictable pattern in their egg shedding rhythms. Here we used a simple wild-caught (captive) system, to provide a first approximation of the parasite egg shedding patterns in wintering Rufous-chested dotterels (Zonibyx modestus). We collected faeces every 2 hours over 10 days until completing a 24-hour cycle, which was coupled with continuous video recordings to determine their feeding and drinking habits. Contrary to our expectation, we showed that parasite egg shedding followed a cyclic pattern, characterized by 2 peaks: one at midnight and another in the afternoon. Importantly, this shedding pattern was not related to the birds’ feeding or drinking habits. We discuss possible environmental and physiological cues that parasites might use to trigger egg production, including the potential influence of tidal cycles on our results.

Environmental change can impact host–parasite interactions, but the effects of multiple stressors on parasites are rarely measured. Considering stressor interactions may allow parasitologists to evaluate how parasite burdens change in nature, where stressors rarely occur in isolation. This study aimed to understand how combined stressors such as warming, nutrients and pollution (i.e. metal concentrations) influence myxozoan prevalence and abundance in the Pearl River, Louisiana, USA. Fish were seined between 1963 and 2005 upstream and downstream of a pulp-mill outfall and were then preserved and accessioned into the Royal D. Suttkus Fish Collection of the Tulane University Biodiversity Research Institute. In 2024, we dissected 1188 fish individuals across 7 host species, and we identified myxozoans in 6 species. Six myxozoan genera were detected, including Chloromyxum, Henneguya, Myxidium, Myxobolus, Thelohanellus and Unicauda, with some novel host–parasite combinations. The abundance of Myxobolus infecting Carpiodes velifer gills declined by 86% over the study period, while the abundance of Myxobolus infecting Pimephales vigilax gills was significantly lower downstream of the pulp mill outfall. Among the drivers analyzed, temperature had a significant negative effect on this parasite’s abundance, metal concentrations had a positive effect, and these 2 drivers interacted. Our results highlight the differential susceptibility of wild fishes to myxozoan infections and the usefulness of museum collections for understanding historical change in myxozoan burdens in fish. Since stressor-driven changes in myxozoan abundance do not follow a single pattern across species, we expect a shift in freshwater myxozoan communities with progressing climate change and pollution.

Ricinid lice are exceptionally large-bodied relative to their hosts and tend to form small infrapopulations. They exhibit a more pronounced female bias (predominance of females) than most other lice. Sex ratios (SRs; the proportions of males) of 10 hummingbird-ricinid species pairs collected from South and North America were examined. There was a significant positive relationship between infrapopulation size and SR in 5 cases, and similar non-significant tendencies in 4 cases. Two formerly constructed hypotheses had been considered to explain this relationship. First, Wolbachia infections may account for the female bias, but male aggression during mating could elevate female mortality resulting in higher male proportions in large infrapopulations. Second, the Local Mate Competition (LMC) Hypothesis predicts that highly inbred infrapopulations should exhibit female-biased SRs. Small infrapopulations are likely to be inbred because of stronger genetic drift and are also more likely to originate from single infestations. Conversely, multiple infestations can generate larger and more outbred infrapopulations that are less affected by genetic drift, leading to a shift towards more balanced SRs. This results in a positive correlation between infrapopulation size (infestation intensity) and SR. Both hypotheses provide explanation for the positive association between infestation intensity and the proportion of males, although the LMC aligns more strongly with the actual values of the observed SR bias. Notably, the former hypothesis refers to the physiological mechanism, whereas the latter refers to the adaptive value of the SR bias. These 2 hypotheses are not mutually exclusive.

Fasciola hepatica infections in cattle often lead to significant production losses. Infection rates are expected to increase due to environmental changes at regional and global level which favour the life cycle of F. hepatica. This study aimed to identify environmental and herd factors associated with F. hepatica antibody positivity in bulk tank milk (BTM) of Dutch dairy cattle herds. In total, 10403 BTM samples were collected yearly in October, from 2018 till 2023. For each farm, monthly averages of weather factors and soil moisture level were obtained for the twelve months preceding October, along with soil type and number and grazing of dairy cows. Logistic regression analyses were performed retrospectively using generalized estimating equations, with continuous variables analysed as quartiles. The odds of F. hepatica antibody positivity in BTM are higher for farms on peat (OR 1.69, 95% CI [1.27, 2.24]) and heavy clay soils (OR 1.75, 95% CI [1.30, 2.35]) compared to those on sand soil. In addition, the odds of antibody positivity increased with higher monthly temperatures (December: ORQ1-Q4 2.94, 95% CI [1.94, 4.46]) and rainfall (November: ORQ1-Q4 2.33, 95% CI [1.62, 3.34]) at the end of the previous grazing season. Stratified analyses by soil type yielded results consistent with those across soil types. Weather patterns that favour the number of overwintering snails infected with F. hepatica seem to increase the infection risk for dairy cattle in the next grazing season, which highlights the potential of prediction tools that facilitate early detection of new F. hepatica infections.

The sambaqui (shellmounds) people are recognized as fisher-gatherers who inhabited the coastal regions of Brazil, with a subsistence on a diet composed of fish, molluscs, and plants. Paleoparasitological investigations in these open-air sites are challenged by the severe taphonomic processes affecting parasite vestige preservation. Previous palaeogenetic work reported parasite helminth infection by Ascaris sp. in an individual from Jabuticabeira II (JABII) sambaqui, located in the Santa Catarina state, Brazil (2890 ± 55 to 1805 ± 65 years BP). To expand our knowledge about helminth infections in sambaqui people, this study applied a palaeogenomics approach in JABII. Sediments from pelvic and sacral regions of 3 JABII individuals and environmental samples underwent ancient DNA extraction and cox1 gene PCRs. High-throughput sequencing data were compared to a custom-built reference database. The JABII dataset revealed reads that are mapped against plathelminth and nematode parasites. Plathelminth observations are probably attributable to pseudo-parasitism and are associated with the animal hosts identified within the JABII faunal assemblages. Two JABII individuals exhibited Anisakis simplex, Contracaecum osculatum, and Ascaris sp. Anisakids are common parasites of marine fish, crustaceans, and mammals that infect humans by consuming fish. Most of the fish identified at the JABII site are currently documented as being infected by Anisakidae. Ascaris sp. is verified in different JABII individuals from the previous study, confirming the spread of this soil-transmitted helminthiasis. The novel data herein agree with the subsistence of the JABII fisher-gatherers, the sedentary lifestyle and the faunal surroundings in the Southern coastal region of Brazil.

Naegleria fowleri, Acanthamoeba spp., Balamuthia mandrillaris and Sappinia spp. are free-living amoebae that can infect humans and cause serious disease; therefore, these organisms are commonly referred to as pathogenic free-living amoebae (pFLA). Diagnosis and treatment of pFLA infections have historically been very challenging. If a diagnosis is made, treatment regimens currently include a combination of antifungals, antimicrobials and anticancer agents that have, to date, proven to be of little help in resolving the disease. Discovery of new therapies is critical to reduce the >90% mortality rate for the brain infections that these microbes can cause. Molecular tools that allow for the study of gene function, generation of reporter cell lines and drug target validation would greatly improve drug discovery efforts. To date, transfection approaches for use with pFLA have been limited, hindering these types of molecular studies. Based on sequence comparisons, the pFLA harbour proteins that are involved in cargo delivery to the nucleus and DNA repair mechanisms, suggesting that fundamental pathways believed to be required for stable transfection are present. However, the amoebae lack homologs to genes connected to stable maintenance of transgenes and RNA interference in other systems. While these differences may limit our ability to alter gene expression, it is also possible that unrecognized components fulfill the roles of the missing homologs. Given the value of robust transfection approaches in drug discovery and gene function studies, resolving these mechanisms would be impactful, leading to improved understanding of amoebae biology and enhancement of drug discovery efforts.