Schistosomiasis, a parasitic disease caused by Schistosoma species, remains highly prevalent in tropical regions, where it contributes significantly to hepatic and vascular complications. Despite the well-established role of parasitic eggs in driving inflammation and organ damage, the specific vascular mechanisms remain poorly understood. Given the role of angiogenesis and vascular remodelling in tissue repair, the angiopoietins (ANGs) could be promising biomarkers to evaluate disease progression. This study aims to explore the relationship between ANG levels with parasitic load in patients with schistosomiasis. In this cross-sectional study, 126 schistosomiasis patients were stratified into three groups based on parasitic egg burden: negative, low, and moderate/high. Demographic, clinical, and laboratory data were collected, and serum ANGs were quantified via enzyme-linked immunosorbent assays. Parasitic load was assessed through stool examination, quantifying the number of Schistosoma eggs per gram of faeces. Additional clinical parameters, including liver abnormalities and blood chemistry, were evaluated. The ANG-2 levels and the ANG-2/ANG-1 ratio were significantly elevated in patients with higher egg burdens, particularly in the moderate/high group. The ANG-2/ANG-1 ratio was notably higher in patients with hepatosplenic schistosomiasis. While systemic blood pressure and oxygen saturation showed no significant differences between groups, patients with elevated triglycerides had lower ANG-2 levels. Elevated ANG-2 levels and an increased ANG-2/ANG-1 ratio correlate with higher parasitic burdens, reinforcing their potential as biomarkers for disease severity. These findings underscore the role of egg-induced inflammation in schistosomiasis pathophysiology and suggest that ANGs could aid in early diagnosis and treatment decisions, particularly in populations with high parasitic loads.

In many areas of The Gambia, West Africa, population crowding in a degraded environment has forced close interactions of diurnal primate species with humans. We assessed intestinal parasitic infection prevalence and diversity in 4 diurnal non-human primate (NHP) species, Chlorocebus sabaeus, Erythrocebus patas, Papio papio and Piliocolobus badius across 13 sampling sites. The effect of human activity, determined by the human activity index, and NHP group size on parasite richness was assessed using a generalized linear mixed model (GLMM). The most common protozoa identified were Entamoeba coli (30%) and Iodamoeba buetschlii (25%). The most common helminths were Strongyloides fuelleborni (11%), Oesophagostomum spp. (9%) and Trichuris trichiura (9%). Two of six (6%) Cyclospora spp. infections detected sequenced as Cyclospora cercopitheci (both in C. sabaeus). The more arboreal P. badius trended towards a lower prevalence of intestinal parasites, although this was not statistically significant (χ2 P = 0.105). Human activity or group size did not have any significant effect on parasite richness for P. badius (P = 0.161 and P = 0.603) or P. papio (P = 0.817 and P = 0.607, respectively). There were insufficient observations to fit a GLMM to E. patas or C. sabaeus. Our reports present the richness and diversity of intestinal parasites in 4 diurnal NHPs in The Gambia, West Africa. Despite desertification and habitat loss, our results indicate that the prevalence and diversity of intestinal parasites in Gambian NHPs are seemingly unaffected by human activity. Further investigation with a larger dataset is required to better elucidate these findings.

Anisakis pegreffii and A. simplex (s.s.) are the two zoonotic anisakids infecting cetaceans as well as pelagic/demersal fish and squids. In European waters, A. pegreffii prevails in the Mediterranean Sea, while A. simplex (s.s.) in the NE Atlantic Ocean. Abiotic conditions likely play a significant role in shaping their geographical distribution. The Iberian Atlantic and Alboran Sea waters are sympatric areas of the two species. A total of 429 adults and L3 stage from both sympatric and allopatric areas were studied by a wide nuclear genotyping approach (including newly and previously found diagnostic single nucleotide polymorphisms (SNPs) at nuclear DNA (nDNA) and microsatellite DNA loci) and sequenced at mitochondrial DNA (mtDNA) cox2. Admixture between the two species was detected in the sympatric areas studied by STRUCTURE Bayesian analysis; NEWHYBRIDS revealed different categories of hybridization between the two species, representing approximately 5%. A tendency for F1 female hybrids to interbreed with the parental species at the geographical distribution limits of both species was observed. This finding suggests that hybridization occurs when the two parental species significantly differ in abundance. Mitochondrial introgression of A. simplex (s.s.) in A. pegreffii from Mediterranean waters was also detected, likely as a result of past and/or paleo-introgression events. The high level of genetic differentiation between the two species and their backcrosses indicates that, despite current hybridization, reproductive isolation which maintains evolutionary boundaries between the two species, exists. Possible causes of hybridization phenomena are attempted, as well as their evolutionary and ecological implications, also considering a sea warming scenario in European waters.

Host–parasite adaptation is crucial for evolutionary success of a parasite. The nematode Angiostrongylus cantonensis has a heterogenic life cycle involving molluscs as intermediate hosts and rats as definitive hosts. Several mollusc species are susceptible hosts of A. cantonensis, allowing the development of first-stage larvae (L1) into third-stage larvae (L3). Changes in the metabolism of infected molluscs have been demonstrated, disturbing regular routes and inducing host defence mechanisms. This study aimed to identify changes in the proteomic content of Phyllocaulis spp. mucus during A. cantonensis infection. Proteins were extracted from the mucus samples of infected and non-infected slugs and identified using liquid chromatography–tandem mass spectrometry. We found 26 up-regulated and 15 down-regulated proteins in infected slugs compared to non-infected slugs. Protein profiles are promising markers of parasite infection, and a better understanding of proteomic profiles during infection may help inform in vivo studies and promote new tools for the non-invasive identification of infected hosts.

Sarcoptic mange, caused by the Sarcoptes scabiei mite, is a highly transmissible skin condition affecting many mammalian species worldwide. South American camelids (SAC) have the highest reported prevalence of mange in South America, causing economic losses and posing a conservation threat to wild SAC. This study investigated mite diversity in SAC in Argentina and assessed relationships between known outbreak areas. Distinct epidemiologic scenarios were explored: the San Juan-La Rioja region, where a mange outbreak decimated wild SAC populations, and the Puna region of Jujuy, where domestic and wild SAC coexist and infections often occur. The mitochondrial gene cox1 and ten microsatellites were analysed from mites collected in five sampling events in Jujuy and four in San Juan-La Rioja between 2017 and 2023. A single cox1 haplotype was observed regardless of mite origin or host species. Comparison with partial cox1 sequences from other camelids worldwide showed little variation. Microsatellite markers revealed lower diversity in mites from San Juan-La Rioja compared to Jujuy. A single strain common to vicuñas and guanacos was identified in San Juan-La Rioja, while three strains were detected in Jujuy affecting vicuñas and/or domestic llamas. Some mites from Jujuy exhibited mixed genetic composition between the two regions, and results confirmed that domestic and wild SAC shared mite strains. This study enhances understanding of sarcoptic mange transmission among SAC species, contributing to vicuña and guanaco conservation and high-altitude livestock farming. Additionally, these findings provide support for the development of intersectoral management strategies to address this significant threat.

Haemosporidians constitute a monophyletic group of vector-borne parasites that infect a wide range of vertebrate hosts, including Neotropical lizards. The remarkable diversity of these host-parasite associations and inadequate research on certain parasite groups have resulted in controversial haemosporidian taxonomy. Herein, we rediscover erythrocytic and non-erythrocytic haemosporidians infecting golden tegus (Tupinambis teguixin) from Brazil and Colombia. The erythrocyte-inhabiting parasite belongs to Plasmodium sp., and the non-erythrocytic form was identified as Saurocytozoon tupinambi, previously attributed to the Family Leucocytozoidae. These non-pigmented haemosporidian parasites do not multiply in the blood. The relationships between the Saurocytozoon and Leucocytozoidae species were discussed for many years, especially during the 1970s. However, cytochrome b (cytb) sequences and the mitochondrial genomes recovered for this species strongly support classifying this parasite as a Plasmodium taxon. Therefore, we proposed a new combination for this parasite, Plasmodium (Saurocytozoon) tupinambi comb. nov., where Saurocytozoon is retained as a subgenus due to its distinct morphology. These results reinforce that a broader definition of Plasmodiidae must include saurian parasites that develop non-pigmented leucocytozoid-like gametocytes.

As part of a broad survey of the trematodes of damselfishes (Pomacentridae) in the tropical Indo-West Pacific, zoogonids were collected from multiple localities in Australia, New Caledonia, and French Polynesia. All zoogonid specimens collected were consistent with the subfamily Lecithostaphylinae, and morphological and molecular data (ITS2 and 28S rDNA, and cox1 mtDNA) were generated for most host-locality combinations to enable an integrative species delimitation. The collection comprised three species: Deretrema stratiotes n. sp. from four species of Abudefduf Forsskål from Ningaloo Reef in Western Australia, and two species consistent with the genus Lecithostaphylus Odhner, 1911 for which Innuptacola n. gen. is proposed based on phylogenetic and morphological distinction, the type-species I. gibsoni (Cribb, Bray & Barker, 1992) n. comb. (= L. gibsoni) from six species of Abudefduf in Ningaloo Reef, Queensland and New Caledonia, and I. torquata n. sp. from 12 pomacentrid species in Ningaloo Reef, the Great Barrier Reef in Queensland, and the Gambier Islands in French Polynesia. The new collection demonstrates that some zoogonid species are geographically widespread (from the Pacific Ocean to the Indian Ocean) and can infect a broad range of hosts (multiple genera within a family), whereas others are apparently geographically restricted and exhibit higher host-specificity (fishes within a single genus).

Helminth infection is highly prevalent in indigenous chickens reared in semi-scavenging/ scavenging systems in Bangladesh. Here, we estimated the prevalence of gizzard worm infection in indigenous chickens, the detection of the worm-induced pathologies, the development of ex vivo cultural protocol, and anthelmintic efficacy. We randomly collected and examined 390 chickens and isolated worms from the gizzard and proventriculus. The isolated worms were identified as Cheilospirura hamulosa Diesing, 1861. The overall prevalence of C. hamulosa was 33.1% (129 out of 390). Prevalence of the worm was almost similar in both sexes but significantly (p <0.05) higher in adult chickens (44.3%) and in the summer season (47.1%). In heavy infections, C. hamulosa destroyed the muscular layer of the gizzard. The presence of brown necrotic tissues and curd-like caseous materials was detected in the affected gizzards. In severe cases, the horny lining of the gizzard was inflamed, necrotized and marked by multiple holes and brick-red colored spots. Liquefied, fetid materials oozed out from the muscular layer in extensive cases. Histopathological examination showed marked infiltrations of eosinophils. In serum-supplemented M199 and DMEM, adult C. hamulosa survived well and reproduced. Levamisole (LEV) and ivermectin (IVM) efficiently killed the worm. However, albendazole (ABZ), mebendazole (MBZ) and piperazine (PPZ) did not kill the worms. Our results suggest that C. hamulosa is highly prevalent in semi-scavenging chickens in Bangladesh. LEV and IVM can be used to treat and control the infection in chickens.

Cryptic diversity, characterized by morphologically similar but genetically distinct species, poses significant challenges to traditional taxonomic methods. Within monogeneans parasitizing northwest African barbels, this complexity hampers species identification, limiting our understanding of diversity, distribution and evolutionary relationships. Supported by previously published genetic data, we morphologically delineate herein 9 Gyrodactylus species from Morocco. Newly described species include G. agnesei sp. nov. and G. benhoussai sp. nov. from Luciobarbus rabatensis, with the latter also found on Carasobarbus fritschii, and both G. deburonae sp. nov. and G. marruecosi sp. nov. from L. massaensis. Additionally, G. diakini sp. nov. and G. louiziae sp. nov. were identified from L. rifensis and L. yahyaouii, respectively. Pterocapoeta maroccana harboured G. pterocapoetai sp. nov., morphologically resembling G. shigoleyae sp. nov. from sympatric L. zayanensis. We also examined taxonomical discrepancies between Gyrodactylus species from L. ksibi and L. pallaryi, evaluated the status of previously described G. nyingiae and described G. qninbai sp. nov. from L. ksibi. Our findings highlight the conservative morphology in northwest African Gyrodactylus, characterized by an ancestral median ridge in the ventral bar membrane, similar to that found in species from Eurasia. Subtle phenotypic features, like bifurcations in dorsal bars and proportions of marginal hooks, serve as diagnostic traits. We further evidenced a potential host-switching event from northwest African to Iberian hosts, correlating with the region’s geological history and cyprinid dispersal events during intermittent closures of the Strait of Gibraltar. These insights illuminate the complex evolutionary processes driving gyrodactylid diversification in the West Mediterranean.

MicroRNAs (miRNAs), derived from extracellular vesicles (EVs) are circulating intercellular communicators which influence pathogenesis and could be used as potential diagnostic markers. In this study, plasma-derived EVs from Plasmodium knowlesi-infected patients (n = 13) and healthy individuals (n = 10) were isolated using size exclusion chromatography and ultracentrifugation. The presence of EVs was confirmed by transmission electron microscopy and Western immunoblotting, and quantified by nanoparticle tracking analysis. The EVs isolated from patients exhibited a larger size, accompanied by an elevated concentration of EVs. The relative expression levels of 8 human miRNAs were quantified using reverse transcriptase quantitative polymerase chain reaction. Compared to uninfected groups, hsa-miR-223-5p (P-value = 0.0002) and hsa-miR-486-5p (P-value = 0.025) were upregulated in P. knowlesi-infected patients. Bioinformatic analysis revealed that these miRNAs are predicted to target both human host and parasite genes, and they were found to be enriched in various malaria-related pathways. The areas under the receiver operating characteristic curve of hsa-miR-223-5p and hsa-miR-486-5p were 0.9154 and 0.8231, respectively, suggesting the potential of EV-miRNAs as diagnostic markers. Results revealed that EV-miRNAs may play a significant role in the progression of P. knowlesi infection. Further investigations should explore their potential impact on gene expression regulation as diagnostic biomarkers or targets for therapeutic interventions.

The impact of macroparasites on their hosts is proportional to the number of parasites per host, or parasite abundance. Abundance values are count data, i.e. integers ranging from 0 to some maximum number, depending on the host–parasite system. When using parasite abundance as a predictor in statistical analysis, a common approach is to bin values, i.e. group hosts into infection categories based on abundance, and test for differences in some response variable (e.g. a host trait) among these categories. There are well-documented pitfalls associated with this approach. Here, I use a literature review to show that binning abundance values for analysis has been used in one-third of studies published in parasitological journals over the past 15 years, and half of the studies in ecological and behavioural journals, often without any justification. Binning abundance data into arbitrary categories has been much more common among studies using experimental infections than among those using naturally infected hosts. I then use simulated data to demonstrate that true and significant relationships between parasite abundance and host traits can be missed when abundance values are binned for analysis, and vice versa that when there is no underlying relationship between abundance and host traits, analysis of binned data can create a spurious one. This holds regardless of the prevalence of infection or the level of parasite aggregation in a host sample. These findings argue strongly for the practice of binning abundance data as a predictor variable to be abandoned in favour of more appropriate analytical approaches.

Anaplasmosis is a significant tick-borne disease (TBDs) caused by Anaplasma that affecting ruminant health and production worldwide. This study aimed to identify Anaplasma spp. infection using molecular as a fast diagnostic tool, perform a phylogenetic analysis and evaluate associated risk factors for combating Anaplasma spp. infection in small-scale livestock farms in Thailand. Total 963 blood samples from ruminants were collected from 125 farms across 4 regions of Thailand. Molecular diagnosis of Anaplasma spp. targeted the msp4 gene using conventional polymerase chain reaction (PCR) was performed and reported to the farmers within 14 days. Positive PCR products were purified, sequenced, and analysed the phylogenetic. Associated risk factor evaluations were conducted using R software. The overall prevalence of Anaplasma spp. infection in ruminants was 26.90%. The highest prevalence was observed in bullfighting cattle (47.06%), followed by beef cattle (35.75%), dairy cattle (21.73%), and goats (6.67%), with no infection in buffalo. Regionally, the Northern region had the highest prevalence (49.01%), followed by the Southern (25.88%), Central (22.01%), and Northeastern (13.81%) regions. Anaplasma spp. was commonly detected in Phrae, Chiang Rai, and Tak provinces. Sequencing confirmed A. marginale 99.64% to 99.76% identity to sequences in GenBank. Risk factors associated with A. marginale infection were history of TBDs on farm, animal illnesses, responsible person for treatment, and improper faeces removal practices. This study revealed a moderate to high Anaplasma infection across four regions. These findings underscore the need for enhanced tick control measures on farms, should be strictly implemented and promoted to reduce disease prevalence.

It is often postulated that natural systems are expected to suffer an increasing risk of infectious disease outbreaks as climate change accelerates. In the northern Argentine Sea, the rise of ocean temperature has produced a tropicalization of demersal megafauna since 2013. This rapidly warming hotspot provides an excellent model to test whether fish parasites have increased, declined, or remained stable in the region. Cardiocephaloides physalis a parasite of penguins Spheniscus magellanicus as adult and suspected to parasitize anchovies Engraulis anchoita as larvae is here used to compare their occurrence and abundance between samples composed by 1752 fish of variable age caught at different latitudes during 1993–1995 and 2022 and between 20 juvenile birds and literature data. In the present work, the identity of metacercariae as C. physalis is confirmed genetically, as well as a net decline of population parameters of the parasite to its effective disappearance in anchovies from northern areas and to extremely low levels in fish from southern regions and penguins. After analysing possible causes for such changes in a scenario of rapid regional tropicalization, a direct effect of increasing temperature on parasites arose as the main causal candidate for the observed decline in their populations over the last decades. Beyond the biological and ecological consequences of global change on them, parasites offer excellent systems for measuring and monitoring such effects. The almost local extinction of C. physalis in a marine hotspot of global warming seems to be one of the first examples of such processes.