Ascaris lumbricoides is a helminth commonly infecting humans, particularly in developing countries. It causes a range of clinical symptoms; However, many patients are asymptomatic. This article presents a case study of a young man who experienced diffuse abdominal pain and constipation, eventually being diagnosed with partial bowel obstruction due to Ascaris lumbricoides infection. The article emphasizes the importance of considering helminthic infections like ascariasis as a potential cause of intestinal obstruction, especially in endemic areas. Early diagnosis and intervention, including conservative management and anthelminthic drugs, can lead to a full recovery and avoid unnecessary surgery.

Zebrafish (Danio rerio) is now the second most used animal model in biomedical research. As with other vertebrate models, underlying diseases and infections often impact research. Beyond mortality and morbidity, these conditions can compromise research end points by producing nonprotocol induced variation within experiments. Pseudoloma neurophilia, a microsporidium that targets the central nervous system, is the most frequently diagnosed pathogen in zebrafish facilities. The parasite undergoes direct, horizontal transmission within populations, and is also maternally transmitted with spores in ovarian fluid and occasionally within eggs. This transmission explains the wide distribution among research laboratories as new lines are generally introduced as embryos. The infection is chronic, and fish apparently never recover following the initial infection. However, most fish do not exhibit outward clinical signs. Histologically, the parasite occurs as aggregates of spores throughout the midbrain and spinal cord and extends to nerve roots. It often elicits meninxitis, myositis, and myodegeneration when it infects the muscle. There are currently no described therapies for the parasite, thus the infection is best avoided by screening with PCR-based tests and removal of infected fish from a facility. Examples of research impacts include reduced fecundity, behavioral changes, transcriptome alterations, and autofluorescent lesions.

OBJECTIVE: Parasites in stray cats hold significant zoonotic importance, posing a potential threat to public health. This study, therefore, has practical implications as it aims to investigate the prevalence of cat parasites in Middle Eastern countries.
METHODS: The research process was rigorous and thorough, spanning from 2000 to 2023. Data collection and analysis were conducted utilizing multiple international and national databases, including Google Scholar, Scopus, PubMed, and Irandoc. This meticulous approach ensures the reliability and validity of the findings, providing a solid foundation for further research and preventive measures.
RESULTS: 250 articles were collected and read out of which 170 were comprehensively reviewed. Among these, 85 articles were from Iran, 25 from Türkiye, 20 from Iraq, 11 from Egypt, five from Qatar, three from Cyprus, three from Kuwait, and one each from the UAE, Saudi Arabia, Syria, Lebanon, Jordan, Israel, and Palestine. Toxocara cati emerged as one of the most prevalent nematodes, exhibiting the highest prevalence in Iran, ranging from 8% to 90%, followed by Egypt, with a range of 8.23% to 58.7%. In comparison, the lowest prevalence was recorded in Qatar at 8%. Hydatigera taeniaeformis, a significant cestode, showed the highest prevalence in Qatar, with a range of 73.6% to 75.8%, while the lowest in Kuwait at 0.8%. In Iran, the prevalence ranged from 0.95% to 64.7%. Toxoplasma gondii, a vital protozoan, showcased the highest prevalence in Lebanon at 78.1% and the lowest in the UAE at 0.8%. In Iran, the prevalence ranged between 1.2% and 90%. Additionally, noteworthy patterns regarding the distribution and potential risk factors associated with these parasites were observed. While gender variations were insignificant, environmental conditions such as high humidity and absence of sunlight exposure, along with the age and behavior of cats, emerged as among the most crucial risk factors associated with the prevalence of these parasites.
CONCLUSIONS: The prevalence of parasites among stray cats in Iran and other Middle Eastern countries remains notably high. This emphasizes the urgent need for a series of control and preventive measures. Implementing effective anti-parasitic strategies and emphasizing the development of multiple diagnostic methods are essential.

Polyphenols are phytochemicals commonly found in plant-based diets which have demonstrated immunomodulatory and anti-inflammatory properties. However, the interplay between polyphenols and pathogens at mucosal barrier surfaces has not yet been elucidated in detail. Here, we show that proanthocyanidin (PAC) polyphenols interact with gut parasites to influence immune function and gut microbial-derived metabolites in mice. PAC intake inhibited mastocytosis during infection with the small intestinal roundworm Heligmosomoides polygyrus, and altered the host tissue transcriptome at the site of infection with the large intestinal whipworm Trichuris muris, with a notable enhancement of type-1 inflammatory and interferon-driven gene pathways. In the absence of infection, PAC intake promoted the expansion of Turicibacter within the gut microbiota, increased fecal short chain fatty acids, and enriched phenolic metabolites such as phenyl-γ-valerolactones in the cecum. However, these putatively beneficial effects were reduced in PAC-fed mice infected with T. muris, suggesting concomitant parasite infection can attenuate gut microbial-mediated PAC catabolism. Collectively, our results suggest an inter-relationship between a phytonutrient and infection, whereby PAC may augment parasite-induced inflammation (most prominently with the cecum dwelling T. muris), and infection may abrogate the beneficial effects of health-promoting phytochemicals.

Climate change may exacerbate the impact of invasive parasites from warmer climates through pre-existing temperature adaptations. We investigated temperature impacts on two closely related marine parasitic copepod species that share the blue mussel (Mytilus edulis) as host: Mytilicola orientalis has invaded the system from a warmer climate <20 years ago, whereas its established congener Mytilicola intestinalis has had >90 years to adapt. In laboratory experiments with temperatures 10-26°C, covering current and future temperatures as well as heat waves, the development of both life cycle stages of both species accelerated with increasing temperature. In the parasitic stages, the growth of the established invader increased evenly from 10°C to 22°C, whereas the recent invader barely grew at all at 10°C and grew faster already at 18°C. In contrast, temperature had little effect on the transition success between life cycle stages. However, the highest temperature (26°C) limited the egg development success of the established invader and the host entry success of both species, whereas the infection success of the established invader increased at 18°C and 22°C. In general, our experiments indicate that the main effect of temperature on both species is through development speed and not life cycle stage transition success. Based on regional long-term temperature data and predictions, the numbers of completed life cycles per year will increase for both parasites. The established invader seems better adapted for low current temperatures (around 10°C), whereas the more recent invader barely develops at these temperatures but can cope in high temperatures (around 26°C). Hence, pre-existing temperature adaptations of the recent invader may allow the species to better cope with heat waves.

Pacific pink salmon (Oncorhynchus gorbuscha) were deliberately introduced to rivers surrounding the White Sea and has spread to Norway and several other countries surrounding the North Atlantic Ocean. In August 2021, a female pink salmon displaying pale gills and abnormal behaviour was captured in River Lakselva in Northern Norway and later submitted to the Norwegian Veterinary Institute (NVI) for post-mortem examination. Histological examination of organ samples revealed structures indicative of systemic ichthyophoniasis, caused by Ichthyophonus sp. The parasites appeared to be especially abundant in the heart and skeletal musculature, and local tissue responses were assessed to be absent or very mild. Sequences of the ribosomal 18S rRNA and the mitochondrial cytochrome oxidase 1 (CO1) genes confirmed the diagnosis and identified the pathogen as Ichthyophonus sp. The CO1 sequence further established that the isolate from pink salmon was most similar to sequences of Ichthyophonus sp. from Atlantic salmon, Salmo salar, from the Atlantic Ocean on the east coast of the US and from Atlantic herring, Clupea harengus, from Iceland. We here report the first detection of Ichthyophonus sp. in pink salmon in the North Atlantic Ocean.

Human toxocariasis is a neglected anthropozoonosis with global distribution. Treatment is based on the administration of anthelmintics; however, their effectiveness at the tissue level is low to moderate, necessitating the discovery of new drug candidates. Several groups of synthetic compounds, including coumarin derivatives, have demonstrated bioactivity against fungi, bacteria, and even parasites, such as Dactylogyrus intermedius, Leishmania major, and Plasmodium falciparum. The aim of this study was to evaluate the effect of ten coumarin-derived compounds against Toxocara canis larvae using in vitro, cytotoxicity, and in silico tests for selecting new drug candidates for preclinical tests aimed at evaluating the treatment of visceral toxocariasis. The compounds were tested in vitro in duplicate at a concentration of 1 mg/mL, and compounds with larvicidal activity were serially diluted to obtain concentrations of 0.5 mg/mL; 0.25 mg/mL; 0.125 mg/mL; and 0.05 mg/mL. The tests were performed in a microculture plate containing 100 T. canis larvae in RPMI-1640 medium. One compound (COU 9) was selected for cytotoxicity analysis using J774.A1 murine macrophages and it was found to be non-cytotoxic at any concentration tested. The in silico analysis was performed using computational models; the compound presented adequate results of oral bioavailability. To confirm the non-viability of the larvae, the contents of the microplate wells of COU 9 were inoculated intraperitoneally (IP) into female Swiss mice at 7-8 weeks of age. This confirmed the larvicidal activity of this compound. These results show that COU 9 exhibited larvicidal activity against T. canis larvae, which, after exposure to the compound, were non-viable, and that COU 9 inhibited infection in a murine model. In addition, COU 9 did not exhibit cytotoxicity and presented adequate bioavailability in silico, similar to albendazole, an anthelmintic, which is the first choice for treatment of human toxocariasis, supporting the potential for future investigations and preclinical tests on COU 9.

Myxozoa, a unique group of obligate endoparasites within the phylum Cnidaria, can cause emerging diseases in wild and cultured fish populations. Recently, the myxozoan Myxobolus bejeranoi has been identified as a prevalent pathogen infecting the gills of cultured hybrid tilapia, leading to systemic immune suppression and considerable mortality. Here, we employed a proteomic approach to examine the impact of M. bejeranoi infection on fish gills, focusing on the structure of the granulomata, or cyst, formed around the proliferating parasite to prevent its spread to surrounding tissue. Enrichment analysis showed increased immune response and oxidative stress in infected gill tissue, most markedly in the cyst\'s wall. The intense immune reaction included a consortium of endopeptidase inhibitors, potentially combating the myxozoan arsenal of secreted proteases. Analysis of the cyst\'s proteome and histology staining indicated that keratin intermediate filaments contribute to its structural rigidity. Moreover, we uncovered skin-specific proteins, including a grainyhead-like transcription factor and a teleost-specific S100 calcium-binding protein that may play a role in epithelial morphogenesis and cysts formation. These findings deepen our understanding of the proteomic elements that grant the cyst its distinctive nature at the critical interface between the fish host and myxozoan parasite.

Platybothrium Linton, 1890 is a genus parasitizing sharks of the families Carcharhinidae and Sphyrnidae. No new species has been assigned to the genus in the 20 years since its last treatment. In the present study, a new species is described from the Persian Gulf, which is the second report of a species of Platybothrium in the Indian Ocean. Platybothrium yanae sp. nov. differs from P. auriculatum Yamaguti, 1952, P. cervinum Linton, 1890, P. tantulum Healy, 2003, and P. kirstenae Healy, 2003 in lacking, rather than having, an accessory piece between its hooks. This new species is distinguished from its other congeners by having a particular combination of features including its measurements, morphology, and meristic features, bringing the number of valid species in the genus to 11.

Echinococcus multilocularis, the fox dwarf tapeworm, causes alveolar echinococcosis (AE), a critical and life-threatening condition. A radical surgical approach represents the only curative option. In this case study, we present a 37-year-old man diagnosed with extensive hepatic AE requiring ex-situ extended right-sided liver resection including the caudate lobe and retro-hepatic vena cava. The left liver segments were auto-transplanted with reconstruction of the left hepatic vein and an inferior vena cava graft. In the post-operative course, the patient developed a bile leak, which was successfully managed with endoscopic stent intervention. He was discharged after a three-week hospitalization. Medical treatment with albendazole was initiated preoperatively and continued postoperatively.