We report a foodborne outbreak of the previously undetected Cryptosporidium parvum gp60 subtype IIγA11. In December 2023, notifications of cryptosporidiosis cases increased in Sweden, prompting the initiation of a national outbreak investigation, and a case–control study was performed to identify the source. We identified 60 cases between 15 December 2023 and 1 January 2024. The median age was 44 years (range: 16–81), and 73% were women. Controls were recruited from a national random pool; frequency was matched by age group and sex. Compared to controls, cases were more likely to have consumed items from salad bars in grocery stores (8% vs. 85%; adjusted odds ratios [aOR]: 58; 95% confidence interval [CI]: 22–186). In regards to food items from the salad bars, cases were more likely to have consumed kale mix salad compared to controls (62% vs. 32%; aOR: 3.6; 95%CI: 1.2–12). Trace-back investigations identified kale producers from Sweden, Belgium, and Spain, but no particular grower was identified, and no food samples were available for microbiological analysis. Our investigation indicates that leafy greens such as kale may contain Cryptosporidium spp. and cause outbreaks and it is important to understand how the contamination occurs to prevent future outbreaks and apply adequate preventive measures.

Trypanosoma cruzi, the aetiological agent of Chagas disease, exists as an anthropozoonosis in Louisiana. Raccoons are an important reservoir, as they demonstrate high prevalence and maintain high parasitaemia longer than other mammals. Given the complex nature of parasite transmission networks and importance of raccoons as reservoirs that move between sylvatic and domestic environments, detailing the genetic diversity of T. cruzi in raccoons is crucial to assess risk to human health. Using a next-generation sequencing approach targeting the mini-exon, parasite diversity was assessed in 2 metropolitan areas of Louisiana. Sequences were analysed along with those previously identified in other mammals and vectors to determine if any association exists between ecoregion and parasite diversity. Parasites were identified from discrete typing units (DTUs) TcI, TcII, TcIV, TcV and TcVI. DTUs TcII, TcV and TcVI are previously unreported in raccoons in the United States (US). TcI was the most abundant DTU, comprising nearly 80% of all sequences. All but 1 raccoon harboured multiple haplotypes, some demonstrating mixed infections of different DTUs. Furthermore, there is significant association between DTU distribution and level III ecoregion in Louisiana. Finally, while certain sequences were distributed across multiple tissues, others appeared to have tissue-specific tropism. Taken together, these findings indicate that ongoing surveillance of T. cruzi in the US should be undertaken across ecoregions to fully assess risk to human health. Given potential connections between parasite diversity and clinical outcomes, deep sequencing technologies are crucial and interventions targeting raccoons may prove useful in mitigating human health risk.

Within the family Adeleidae, Adelina spp. belong to a group of arthropod pathogens. These parasites have been reported to have a wide geographic distribution, however, there are no reports of these protists in the Canary Islands, Spain. One of the peculiarities of the life cycle of Adelina spp. is the participation of a predator, because fecundation and sporulation occur inside the body cavity, and so necessitate destruction of the definitive host. The involvement therefore of a ‘dispersion host’, which eats the definitive host and spreads the oocysts through its faeces, is critical for the maintenance of certain Adelina spp. On the island of Gran Canaria, adeleid oocysts have been found in stool samples from four animals, three California kingsnakes (Lampropeltis californiae), and one feral cat. These animals were part of a larger coprological study of vertebrate parasites (117 snakes, 298 cats), where pseudoparasitic elements were also recorded. L. californiae and feral cats are invasive species which are widespread across the island and this novel finding of Adelina spp. oocysts in their faeces suggests that they could also serve as potential sentinel species for arthropod parasites.

The study aimed to compare the diagnostic performance of the Kato-Katz, formalin ether concentration method (FECM) and FLOTAC using Sheather's sugar solution (FS1), saturated sodium chloride (FS2) and zinc sulfate (FS7) for the diagnosis of intestinal parasites among school children, focusing on Schistosoma mansoni. Ninety fecal samples were examined using the above mentioned techniques. The overall infection rate was 87.7%. Concerning protozoa, FLOTAC (FS1 and FS2) and FECM detected nearly equal infection rates (43.3% and 44.4%, respectively) with very good agreement. Kato-Katz diagnosed the highest helminthic infection rate (57.8%) followed by FLOTAC FS7 (44.4%) and FECM showed the lowest helminthic infection rate (27.7%). As for S. mansoni, Kato-Katz showed an infection rate of 38.8% vs FLOTAC (22.2%) and FECM (11.1%). The three techniques detected the same infection rate (11.1%) with egg counts more than 72 eggs/gram of feces. The FLOTAC sensitivity and accuracy for the diagnosis of protozoa were 97% and 99%, respectively. Regarding helminths diagnosis, FLOTAC technique showed higher sensitivity (77%) and accuracy (87%) compared to FECM (48% sensitivity and 70% accuracy). Therefore, FLOTAC can be used synchronously or in replacement to other diagnostic techniques. This can strategically impact future control programmes of intestinal parasitic infections in limited resources settings.

Due to side-effects and inefficiency of the drugs used in malaria treatment, finding alternative medicine with less side-effects has attracted much attention. In this regard, in the present study, nanocomposite synthesized and its effects on the metabolites of P. falciparum were investigated. Subsequent to synthesis of nanocomposites, characterization was carried out using nuclear magnetic resonance (NMR), liquid chromatography-mass spectrometry (LC-MS), scanning electron microscopy, dynamic light scattering and Fourier-transform infrared tests. Solubility and drug release were measured and its toxicity on Vero cell was assessed using the MTT assay. The antiparasitic effect of the nanocomposite on the metabolites of P. falciparum was investigated by 1H NMR spectroscopy. Among synthesized nanocomposites, the average size of 239 nm showed suitable solubility in water as well as slow drug release. The MTT assay showed no toxicity for Vero cell lines. Concentrations of 2.5 μg mL−1 of nanocomposite eliminated 82.6% of the total parasites. The most effected metabolic cycles were glyoxylate and dicarboxylate metabolism. In this study, 1H NMR spectroscopy was used with untargeted metabolomics to study the effect of the nanocomposite on P. falciparum. Playing an essential role in understanding drug-target interactions and characterization of mechanism of action or resistance exhibited by novel antiprotozoal drugs, can be achieved by targeting metabolic using LC-MS.

Marine mammals are long-lived top predators with vagile lifestyles, which often inhabit remote environments. This is especially relevant in the oceanic waters around New Zealand and Australia where cetaceans and pinnipeds are considered as vulnerable and often endangered due to anthropogenic impacts on their habitat. Parasitism is ubiquitous in wildlife, and prevalence of parasitic infections as well as emerging diseases can be valuable bioindicators of the ecology and health of marine mammals. Collecting information about parasite diversity in marine mammals will provide a crucial baseline for assessing their impact on host and ecosystem ecology. New studies on marine mammals in New Zealand and Australian waters have recently added to our knowledge of parasite prevalence, life cycles and taxonomic relationships in the Australasian region, and justify a first host–parasite checklist encompassing all available data. The present checklist comprises 36 species of marine mammals, and 114 species of parasites (helminths, arthropods and protozoans). Mammal species occurring in New Zealand and Australian waters but not included in the checklist represent gaps in our knowledge. The checklist thus serves both as a guide for what information is lacking, as well as a practical resource for scientists working on the ecology and conservation of marine mammals.

The investigation of the glycan repertoire of several organisms has revealed a wide variation in terms of structures and abundance of glycan moieties. Among the parasites, it is possible to observe different sets of glycoconjugates across taxa and developmental stages within a species. The presence of distinct glycoconjugates throughout the life cycle of a parasite could relate to the ability of that organism to adapt and survive in different hosts and environments. Carbohydrates on the surface, and in excretory-secretory products of parasites, play essential roles in host–parasite interactions. Carbohydrate portions of complex molecules of parasites stimulate and modulate host immune responses, mainly through interactions with specific receptors on the surface of dendritic cells, leading to the generation of a pattern of response that may benefit parasite survival. Available data reviewed here also show the frequent aspect of parasite immunomodulation of mammalian responses through specific glycan interactions, which ultimately makes these molecules promising in the fields of diagnostics and vaccinology.

Cystoisospora (Isospora) belli is a coccidian parasite of humans. It can cause serious digestive disorders involving infection of intestines, biliary tract and gallbladder, especially in those with depressed immunity. It has a direct fecal–oral transmission cycle. After ingestion of sporulated oocysts, the parasite multiplies asexually and sexually within host epithelial cells, resulting in unsporulated oocysts that are excreted in feces. The details of asexual and sexual stages are not known and certain inclusions in epithelial cells in biopsy samples have been erroneously identified recently as C. belli. Here, we provide details of developmental stages of C. belli in two patients, in duodenal biopsy of one and biliary epithelium of the other. Immature and mature asexual stages (schizonts/meronts) were seen in epithelial cells. The merozoites were seen singly, in pairs and in groups in single parasitophorous vacuole (pv) in host cytoplasm. Immature and mature meronts were seen together in the same pv; up to eight nuclei were seen in meronts that retained elongated crescent shape; round multinucleated schizonts, seen in other coccidians, were not found. Meronts were up to 25 µm long and contained up to ten merozoites that were 8–11 µm long. The merozoites and meronts contained PAS-positive granules. Microgamonts (male) contained up to 30 nuclei that were arranged at the periphery and had condensed chromatin; 1–3 PAS-positive, eosinophilic, residual bodies were left when microgametes were formed. The microgametes were 4 µm long and PAS-negative. All stages of macrogamonts, including oocysts were PAS-positive. The detailed description of the life cycle stages of C. belli reported here should facilitate in histopathologic diagnosis of this parasite.

There is a scarcity of recent epidemiological data on intestinal parasitic infections in France. We conducted a prospective study aimed at estimating the prevalence of 10 enteric parasites in Marseille, France, using real-time polymerase chain reaction (PCR)-based diagnosis. A total of 643 faeces from 488 patients referred to the Parasitology-Mycology Laboratory of the University Hospital of Marseille over a 6 months period were included. DNA was extracted using a semi-automated method. Parasites of interest were detected using singleplex quantitative PCRs (qPCRs). For positive samples, the Blastocystis subtype was determined by sequence analysis. During the study, the overall prevalence of enteric parasites was 17%. Blastocystis sp. was the most frequent species (10.5%), followed by Dientamoeba fragilis (2.3%) and Giardia intestinalis (2.3%). The prevalence of other parasites was <1% each. The ST3 Blastocystis subtype was predominant (43.6%) and the other subtypes identified were ST1, ST2, ST4 and ST6. This is the first time that a qPCR-based diagnosis has been used to survey the prevalence of 10 enteric parasites in a French University Hospital. This study confirms that fast, specific, sensitive and simultaneous detection in a single stool sample by qPCR clearly outperforms conventional microscopy-based diagnosis. Furthermore, qPCR is particularly well suited to surveying gastroenteritis agents.

To date, there are no recent studies identifying the prevalence of parasites of human and veterinary importance in dogs and cats in Ireland. The interaction between pets and wildlife species in the environment is an important source of parasite exposure to canids and felines, and one likely to be heightened in the stray animal population. This study aimed to establish the prevalence of endoparasites in unowned dogs and cats in County Dublin, Ireland. Feces from stray dogs (n = 627) and cats (n = 289) entering a rehoming centre were collected immediately after defecation. The main parasitic agents detected were ascarids (15.52 and 30.26%), Cystoisospora (3.27 and 3.69%), Giardia spp. (6.02 and 1.84%) and lungworms (0.64 and 2.08%), in dogs and cats respectively. Animals younger than 3 months of age were more likely to be infected with ascarids (P < 0.001) and Cystoisospora spp. (P = 0.008 and P = 0.014) than older animals. All lungworms were morphologically identified and dogs were infected with Angiostrongylus vasorum (0.48%) and Crenosoma vulpis (0.16%) whereas cats were only infected with Aelurostrongylus abstrusus (2.08%). This represents the first prevalence study of stray animals in Ireland. Data collected will inform the treatment and in addition, the future monitoring and control studies of parasite populations.

Entamoeba histolytica is an enteric parasite that infects approximately 50 million people worldwide. Although E. histolytica is a zoonotic parasite that has the potential to infect nonhuman primates, such transmission is poorly understood. Consequently, this study examined whether E. histolytica is present among humans, chimpanzees and baboons living in the Greater Gombe Ecosystem (GGE), Tanzania. The primary aims were to determine patterns of E. histolytica infection in a system with human-nonhuman primate overlap and to test associations between infection status and potential risk factors of disease. Entamoeba spp. occurred in 60.3% of human, 65.6% of chimpanzee and 88.6% of baboon samples. Entamoeba histolytica occurred in 12.1% of human, 34.1% of chimpanzee and 10.9% of baboon samples. Human E. histolytica infection was associated with gastrointestinal symptoms. This was the first study to confirm the presence of E. histolytica in the GGE. The high sample prevalence of E. histolytica in three sympatric primates suggests that zoonotic transmission is possible and stresses the need for further phylogenetic studies. Interventions targeting better sanitation and hygiene practices for humans living in the GGE can help prevent E. histolytica infection in humans, while also protecting the endangered chimpanzees and other primates in this region.

The rise of antimicrobial resistance, coupled with a lack of industrial focus on antimicrobial discovery over preceding decades, has brought the world to a crisis point. With both human and animal health set to decline due to increased disease burdens caused by near untreatable microbial pathogens, there is an urgent need to identify new antimicrobials. Central to this is the elucidation of new, robustly validated, drug targets. Informed by industrial practice and concerns, the use of both biological and chemical tools in validation is key. In parallel, repurposing approved drugs for use as antimicrobials may provide both new treatments and identify new targets, whilst improved understanding of pharmacology will help develop and progress good ‘hits’ with the required rapidity. In recognition of the need to increase research efforts in these areas, in 14–16 September 2017, the British Society for Parasitology (BSP) Autumn Symposium was hosted at Durham University with the title: Microbial Protein Targets: towards understanding and intervention. Staged in collaboration with the Royal Society of Chemistry (RSC) Chemistry Biology Interface Division (CBID), the core aim was to bring together leading researchers working across disciplines to imagine novel approaches towards combating infection and antimicrobial resistance. Sessions were held on: ‘Anti-infective discovery, an overview’; ‘Omic approaches to target validation’; ‘Genetic approaches to target validation’; ‘Drug target structure and drug discovery’; ‘Fragment-based approaches to drug discovery’; and ‘Chemical approaches to target validation’. Here, we introduce a series of review and primary research articles from selected contributors to the Symposium, giving an overview of progress in understanding antimicrobial targets and developing new drugs. The Symposium was organized by Paul Denny (Durham) for the BSP and Patrick Steel (Durham) for RSC CBID.

The objective of this study was to determine whether a combination of crude glycerin (CG) and soyabean oil (SO) could be used to partially replace maize in the diet of Nellore steers while maintaining optimum feed utilisation. Eight castrated Nellore steers fitted with ruminal and duodenal cannulas were used in a double 4×4 Latin square design balanced for residual effects, in a factorial arrangement (A×B), when factor A corresponded to the provision of SO, and factor B to the provision of CG. Steers feed SO and CG showed similar DM intake, DM, organic matter and neutral-detergent fibre digestibility to that of steers fed diets without oil and without glycerine (P>0·05). Both diets with CG additions reduced the acetate:propionate ratio and increased the proportion of iso-butyrate, butyrate, iso-valerate and valerate (P<0·05). Steers fed diets containing SO had less total N excretion (P<0·001) and showed greater retained N expressed as % N intake (P=0·022). SO and CG diet generated a greater ruminal abundance of Prevotella, Succinivibrio, Ruminococcus, Syntrophococcus and Succiniclasticum. Archaea abundance (P=0·002) and total ciliate protozoa were less in steers fed diets containing SO (P=0·011). CG associated with lipids could be an energy source, which is a useful strategy for the partial replacement of maize in cattle diets, could result in reduced total N excretion and ruminal methanogens without affecting intake and digestibility.

Evaluating the occurrence of diseases in aquatic mustelids is a priority in the conservation strategies for the Neotropical river otter and giant otter. Thus, the objective of this study was to determine the frequency of infection caused by Cryptosporidium spp. and Giardia sp. in both host species in northern Brazil. The collection of biological samples was carried out in the states of Amapá, Amazonas, Pará and Rondônia, totalling 337 faecal samples of these species, which were processed using Kinyoun's technique for the identification of Cryptosporidium spp. oocysts, and centrifugal flotation in zinc sulphate solution for visualization of Giardia sp. cysts. All samples were also tested by direct immunofluorescence. The frequency of infection by Cryptosporidium spp. was higher than Giardia sp., in the two otter species. In the analysed samples co-infection by both protozoa was also found in 4.47% (14/313) of Neotropical river otter and 20.83% (5/24) of giant otter samples. Oocysts and cysts of Cryptosporidium and Giardia, respectively, may remain infectious within specific environmental conditions for long periods of time. The current identification of Neotropical and giant otters as hosts of these protozoa increases the possibility of infection in this species and the transmission of those agents to other aquatic and terrestrial organisms, as well as to human populations. The findings of this study represent the first description of Cryptosporidium spp. and Giardia sp. affecting Lontra longicaudis and Pteronura brasiliensis.

The archaeological evidence for parasites in the Roman era is presented in order to demonstrate the species present at that time, and highlight the health consequences for people living under Roman rule. Despite their large multi-seat public latrines with washing facilities, sewer systems, sanitation legislation, fountains and piped drinking water from aqueducts, we see the widespread presence of whipworm (Trichuris trichiura), roundworm (Ascaris lumbricoides) and Entamoeba histolytica that causes dysentery. This would suggest that the public sanitation measures were insufficient to protect the population from parasites spread by fecal contamination. Ectoparasites such as fleas, head lice, body lice, pubic lice and bed bugs were also present, and delousing combs have been found. The evidence fails to demonstrate that the Roman culture of regular bathing in the public baths reduced the prevalence of these parasites. Fish tapeworm was noted to be widely present, and was more common than in Bronze and Iron Age Europe. It is possible that the Roman enthusiasm for fermented, uncooked fish sauce (garum) may have facilitated the spread of this helminth. Roman medical practitioners such as Galen were aware of intestinal worms, explaining their existence and planning treatment using the humoural theory of the period.

Helminthes have the capacity to modulate host immunity, leading to positive interactions with coinfecting microparasites. This phenomenon has been primarily studied during coinfections with a narrow range of geo-helminthes and intracellular microparasites in human populations or under laboratory conditions. Far less is known regarding differences in coinfection dynamics between helminth types, the range of microparasites that might be affected or the overall community-level effects of helminth infections on microparasites in wild systems. Here, we analysed the presence/absence and abundance patterns of enteric parasites in long-tailed macaques (Macaca fascicularis) on the island of Bali, Indonesia, to assess whether naturally occurring helminth infections were associated with increased shedding of the most common intracellular (Cryptosporidium spp., Isospora spp.) and extracellular (Entamoeba spp., Giardia spp.) microparasites. We also comparatively assessed the statistical correlations of different helminth taxa with microparasite shedding to determine if there were consistent relationships between the specific helminth taxa and microparasites. Helminth infections were associated with increased shedding of both intracellular and extracellular microparasites. Platyhelminthes repeatedly displayed strong positive correlations with several microparasites; while nematodes did not. Our results indicate that helminthes can influence microparasite community shedding dynamics under wild conditions, but that trends may be driven by a narrow range of helminthes.

A meta-analysis was conducted to evaluate the effects of protozoa concentration on methane emission from ruminants. A database was built from 59 publications reporting data from 76 in vivo experiments. The experiments included in the database recorded methane production and rumen protozoa concentration measured on the same groups of animals. Quantitative data such as diet chemical composition, rumen fermentation and microbial parameters, and qualitative information such as methane mitigation strategies were also collected. In the database, 31% of the experiments reported a concomitant reduction of both protozoa concentration and methane emission (g/kg dry matter intake). Nearly all of these experiments tested lipids as methane mitigation strategies. By contrast, 21% of the experiments reported a variation in methane emission without changes in protozoa numbers, indicating that methanogenesis is also regulated by other mechanisms not involving protozoa. Experiments that used chemical compounds as an antimethanogenic treatment belonged to this group. The relationship between methane emission and protozoa concentration was studied with a variance−covariance model, with experiment as a fixed effect. The experiments included in the analysis had a within-experiment variation of protozoa concentration higher than 5.3 log10 cells/ml corresponding to the average s.e.m. of the database for this variable. To detect potential interfering factors for the relationship, the influence of several qualitative and quantitative secondary factors was tested. This meta-analysis showed a significant linear relationship between methane emission and protozoa concentration: methane (g/kg dry matter intake)=−30.7+8.14×protozoa (log10 cells/ml) with 28 experiments (91 treatments), residual mean square error=1.94 and adjusted R2=0.90. The proportion of butyrate in the rumen positively influenced the least square means of this relationship.

We identified two ice-binding protein (IBP) sequences, named EFsymbAFP and EFsymbIBP, from a putative bacterial symbiont of the Antarctic psychrophilic ciliate Euplotes focardii. EFsymbAFP is 57.43% identical to the antifreeze protein (AFP) from the Stigmatella aurantiaca strain DW4/3-1, which was isolated from the Victoria Valley lower glacier. EFsymbIBP is 53.38% identical to the IBP from the Flavobacteriaceae bacterium strain 3519-10, isolated from the glacial ice of Lake Vostok. EFsymbAFP and EFsymbIBP are 31.73% identical at the amino acid level and are organized in tandem on the bacterial chromosome. The relatively low sequence identity and the tandem organization, which appears unique to this symbiont, suggest an occurrence of horizontal gene transfer (HGT). Structurally, EFsymbAFP and EFsymbIBP are similar to the AFPs from the snow mould fungus Typhula ishikariensis and from the Arctic yeast Leucosporidium sp. AY30. A phylogenetic analysis showed that EFsymbAFP and EFsymbIBP cluster principally with the IBP sequences from other Antarctic bacteria, supporting the view that these sequences belong to an Antarctic symbiontic bacterium of E. focardii. These results confirm that IBPs have a complex evolutionary history, which includes HGT events, most probably due to the demands of the environment and the need for rapid adaptation.