Anisakis spp. is a notable fish parasite linked to foodborne diseases, representing a significant public health concern in Indonesia. Despite various reports from different regions indicating fluctuating prevalence levels of Anisakis spp. in diverse fish species in Indonesia, the overarching national prevalence remains uncertain. This study aimed to estimate the overall prevalence of Anisakis spp. infection among Indonesian fish. A comprehensive literature search was conducted across six online databases, and articles were screened based on predefined inclusion criteria. A total of 65 studies fit the inclusion criteria with an average quality assessment score of 7.23 ± 1.77. The overall pooled prevalence of Anisakis spp. infection in fish in Indonesia was 32.63% (95% CI, 25.44%-40.73%). Subgroup analyses conducted based on province, sample origin, ecological niche and fish genus revealed no statistically significant differences. Meta-regression indicated no significant changes in infection rates over time (p-value: 0.44). The study also confirmed the absence of publication bias. In conclusion, the overall prevalence of Anisakis spp. infection is relatively high and poses a potential health risk related to fish consumption, warranting further epidemiological research into its impact on human health.

Seafood plays a vital role in human diets worldwide, serving as an important source of high-quality protein, omega-3 fatty acids, and essential vitamins and minerals that promote health and prevent various chronic conditions. The health benefits of seafood consumption are well documented, including a reduced risk of cardiovascular diseases, improved cognitive function, and anti-inflammatory effects. However, the safety of seafood is compromised by multiple hazards that can pose significant health risks. Pathogenic microorganisms, including bacteria, viruses, and parasites, in addition to microbial metabolites, are prominent causes of the foodborne diseases linked to seafood consumption, necessitating reliable detection and monitoring systems. Molecular biology and digital techniques have emerged as essential tools for the rapid and accurate identification of these foodborne pathogens, enhancing seafood safety protocols. Additionally, the presence of chemical contaminants such as heavy metals (e.g., mercury and lead), microplastics, and per- and polyfluoroalkyl substances (PFASs) in seafood is of increasing concern due to their potential to accumulate in the food chain and adversely affect human health. The biogenic amines formed during the microbial degradation of the proteins and allergens present in certain seafood species also contribute to food safety challenges. This review aims to address the nutritional value and health-promoting effects of seafood while exploring the multifaceted risks associated with microbial contamination, chemical pollutants, and naturally occurring substances. Emphasis is placed on enhanced surveillance, seafood traceability, sustainable aquaculture practices, and regulatory harmonization as effective strategies for controlling the risks associated with seafood consumption and thereby contributing to a safer seafood supply chain.

In this study, we investigated the diversity and survival of aestivating snails in dry-season rice paddies, focusing on their role as intermediate hosts for trematodes. A total of 1,159 snails from various families were collected and analysed, revealing nine species, primarily from the Bithyniidae family, with Bithynia siamensis siamensis being the most abundant. Of the nine species collected, the most common species, B. s. siamensis, exhibited a relatively high survival rate of 81.5% throughout the three-month dry period post-harvest, whereas the remaining eight species had survival rates below 24.0% (0-23.1%). Four snail species, B. s. siamensis, Filopaludina martensi martensi, F. sumatrensis polygramma, and F. doliaris, were found infected with larval trematodes, with an overall prevalence of 8.46% (57/674). The larval trematodes identified were categorized into four types: echinostome metacercaria, Thapariella anastomusa metacercaria, unidentified metacercaria, and unidentified rediae. These findings demonstrate that trematode infections can persist in aestivating snails despite the challenging conditions during the dry season, emphasizing the potential of aestivating snails to act as vectors for trematode transmission in agricultural settings. This underscores the need for effective management strategies to mitigate the risks associated with trematode transmission.

Fish-borne zoonotic parasites pose substantial risks to human health and global aquaculture, primarily through raw or undercooked fish consumption. The rapid expansion of aquaculture, increasing global fish trade, and rising human populations have amplified these concerns. Despite widespread awareness of meat-borne zoonoses, fish-borne parasitic infections remain underrecognized, especially in developed countries. Traditional morphological and molecular methods have provided critical foundations for studying these parasites, yet recent genomic advances have revolutionized our understanding of their genetic diversity, biology, and host-pathogen dynamics. This review underscores the significance of integrating genomic approaches with conventional methods to enhance disease surveillance, risk assessment, and control strategies. Harnessing genomic tools will enable the development of effective interventions to mitigate zoonotic parasite impacts, protect human health, and promote sustainable aquaculture. A comprehensive, genomics-driven approach is essential to overcoming the global challenges of fish-borne zoonotic infections.

Fish and seafood are increasingly recognised as safe and nutritiously valuable foods of animal origin, being a source of about 17% of animal protein globally. Novel culinary trends encourage the consumption of raw or thermally lightly processed fishery products. At the same time, consumers prefer wild, fresh and whole fish over farmed or processed fish. However, the consumption of raw or undercooked fish and other marine organisms poses a risk of contracting parasitic infections, potentially representing a public health risk. Among the most common seafoodborne parasites are members of the Anisakidae family, especially the genus Anisakis, which can cause potentially detrimental effects to human health. These parasites are the causative agent of a zoonosis termed anisakidosis that is prevalent in countries with high per capita fish consumption. Although the number of annual clinical cases varies among countries and regions and is generally not high, sensitisation to this parasite in the general population seems to be considerably higher. Therefore, anisakidosis is still significantly underreported and misdiagnosed globally, making it a disease of rising public health concerns. To prevent infection and mitigate potential negative effects on human health, proper preventive measures such as gutting the fish, freezing or thermal processing are needed. Moreover, a holistic approach implementing One Health principles together with educational campaigns towards the general public and primary care physicians can extend the knowledge on the occurrence of these parasites in their natural hosts and the diagnosis and incidence of anisakidosis, with a final goal to minimize risks for human health and reducing costs for health systems.

Anisakis simplex larvae, commonly found in marine fish, cause anisakiasis in humans, resulting in gastric to gastro-allergic symptoms. Despite known health risks, the impact of Anisakidae larvae on fish hosts is less understood. This study aimed to investigate this interaction by assessing the feeding strategy of A. simplex. Anisakis larvae were isolated from North Sea Merluccius merluccius tissues (stomach, body cavity, liver and muscle) and were analysed for carbon (δ13C) and nitrogen (δ15N) isotope values. Significant differences in δ13C values were found among host tissues, with the liver differing from muscle and stomach tissues. In contrast, no differences were noted for the associated parasites. Additionally, δ15N values indicated that the host occupied a significantly higher relative trophic position than its parasite. This suggests a lack of direct nutrient transfer from host to parasite, as the parasite would typically exhibit higher stable isotope values than the tissue they feed on. Therefore, A. simplex's stable isotope values might reflect those of its previous host (crustacean and/or small fish), providing insights into diet and movement of the paratenic M. merluccius host. Further research is needed to confirm these findings across different fish species and to explore A. simplex as a proxy for trophic ecology.

Clonorchis sinensis (C. sinensis) and Echinostoma hortense (E. Hortense) infections represent significant food-borne zoonotic parasitic diseases. C. sinensis stands as the primary parasite underlying cholangitis, cholelithiasis, and even cholangiocarcinoma, whereas E. Hortense parasitizes the duodenum. Unfortunately, the non-specific clinical presentations of these two trematodes frequently mislead clinicians, resulting in overlooks or misdiagnoses, and consequently, inadequate treatment. We diagnosed digestive system trematodes through endoscopic observation and molecular methods. Herein, we present a case where C. sinensis was definitively diagnosed through direct observation under duodenoscopy. For the first time, we captured the entire migratory process of the parasite from the common bile duct into the intestinal lumen. In another case, multiple active trematodes were detected on the duodenal wall under duodenoscopy, subsequently extracted using endoscopic forceps. Based on the morphology of the worms and their eggs, an initial diagnosis of Echinostoma was made. To confirm the species, we designed primers targeting the ribosomal ITS (internal transcribed spacer) and mitochondrial COX-1 (cyclooxygenase-1) genes, followed by PCR amplification and sequencing. The results conclusively matched the sequence of E. Hortense, verifying our final diagnosis. Our proposed approach, integrating endoscopy with molecular characteristics, offers novel strategies for diagnosing trematode infections. This methodology represents a significant advancement in the field, enhancing the accuracy and timeliness of treatment interventions.

The people of Jammu and Kashmir rely heavily on fish as a source of nutritional protein. Fishes also contribute significantly to the local economy of this area. However, several infectious disorders, some of which are brought on by helminth parasites, constitute a persistent threat to fish. The primary goal of the present review is to find out the parasites in common fishes found in Jammu and Kashmir as well as the impact of parasites on fishes and sickness on human health. Like other animals, fishes are susceptible to several diseases, many of which are external in origin while others are internal in origin. Fishes are known to be susceptible to parasites, fungi, bacteria, viruses, and other external agents that can cause disease, and they also commonly experience organic and degenerative problems internally. Fish parasites have significant impact on both fish and human health. These diverse organisms, including protozoa, helminths, and crustaceans, can infest various fish tissues, leading to detrimental effects. Infested fish often experience reduced growth, weakened immune system, behavioral changes, physical damage, and even mortality. Economically, fish parasites can diminish the value of fish in markets and increase production costs in fisheries and aquaculture. Moreover, fish parasites pose potential human health risks. Consumers who ingest raw or undercooked fish containing certain parasites, like Anisakis spp., may develop gastrointestinal discomfort or anisakiasis. Proper cooking and freezing can mitigate this risk. While fish parasites are primarily harmful, they also play ecological roles, contributing to biodiversity and ecosystem stability by controlling fish populations. Understanding the complex interactions between parasites, fish, and their environment is vital for effective fisheries management, aquaculture practices, and public health measures. Striking a balance between controlling parasite infestation and maintaining ecological integrity is crucial for sustaining both fish populations and human well-being.

In the present study, the ultrastructure of the body surface of mature trematodes of Metagonimus suifunensis Shumenko et al., 2017 has been studied for the first time. It has been found that the tegumental spines on the surface of their bodies are very different from those in three other species of large trematodes of the genus Metagonimus: M. yokogawai Katsurada, 1912; M. takahashii Suzuki in Takahashi, 1929; and M. miyatai Saito et al., 1997. Since other morphological characteristics do not allow us to distinguish between these species, the ultrastructure of tegumental spines can be considered the only reliable morphological feature differentiating this trematode from other representatives of the genus. It has also been suggested that the shape of these spines may correlate with the parasite's ability to damage the host's intestinal tissue.

The zoonotic infectious diseases of poverty (zIDPs) are a group of diseases contributing to global poverty, with significant impacts on a substantial population. This study aims to describe the global, regional, and national burden of zIDPs-schistosomiasis, cystic echinococcosis, cysticercosis, and food-borne trematodiases (FBTs)-to support policy making and resource allocation for their control and elimination.

Data of zIDPs from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 were retrieved from 1990 to 2021. The age-standardized prevalence rate (ASPR), age-standardized mortality rate (ASMR), and age-standardized disability-adjusted life-year (DALY) rate were described and the estimated annual percentage changes (EAPCs) were calculated to quantify their burden and temporal trends. Spearman correlation analysis was conducted to examine the relationship between age-standardized rates and Socio-demographic Index (SDI).

In 2021, these zIDPs exhibited a certain level of ASPRs and age-standardized DALY rates, while maintaining relatively low ASMRs. Noticeably, schistosomiasis presented the highest ASPR of 1914.299 (95% UI: 1378.920, 2510.853 per 100,000 population) and an age-standardized DALY rate of 21.895 (95% UI: 12.937, 37.278 per 100,000 population) among the zIDPs. The tapestry of burden-woven predominantly through low and lower-middle SDI regions-stretched across Africa, Latin America, and parts of Asia. From 1990 to 2021, a kaleidoscopic shift was observed globally as ASPRs, ASMRs, and age-standardized DALY rates declined significantly, as reflected by the EAPC values. Negative correlations were observed between the ASPRs, ASMRs, age-standardized DALY rates of schistosomiasis (r value = - 0.610, - 0.622 and - 0.610), cystic echinococcosis (- 0.676 of ASMR, - 0.550 of age-standardized DALYs), cysticercosis (- 0.420, - 0.797 and - 0.591) and the SDI. In contrast, a slight positive correlation was noted between the ASPR, age-standardized DALY rates of FBTs and SDI with r value of 0.221 and 0.213, respectively.

The burden of zIDPs declined across almost all endemic regions from 1990 to 2021, yet still predominated in low and low-middle SDI regions. Substantial challenges exist to achieve the goal of control and elimination of zIDPs, and integrated approaches based on One Health need to be strengthened to improve health outcomes.

Amphimerus, a liver fluke, is the causative agent of amphimeriasis, a foodborne disease acquired thought the consumption of infected raw or undercooked river fish-a practice embedded in traditional culinary customs. Amphimeriasis represents a significant public health issue and has been endemic in Ecuador since 2011, particularly among the Chachi Amerindians and Montubios populations residing in tropical ecoregions. By employing a mixed-methods research design, we conducted a community-based, cross-sectional study. A survey comprising of 63 questions on KAP was administrated in person to community members, health personnel, and academic staff in the two populations. Additionally, 67 semi-structured interviews were performed. Microscopy was achieved on 273 human and 80 dog fecal samples to detect Amphimerus eggs. A total of 86 questionnaires (54 Chachi) and 67 interviews (44 Chachi), out of 300 residents, were completed. Among the respondents, 31.4% were aware of Amphimerus, locally referred to as "liver worm". Although 79.1% reported not consuming raw fish, most admitted eating raw fish with lime juice and salt, a preparation known as "curtido", and 59.3% reported consuming smoked fish. Here, 86.1% of participants considered "liver worm" a serious disease, and 55.8% recognized raw or marinated fish as a potential transmission route. The Chachi showed a preference for smoked fish, whereas the Montubios favoured "curtido". The prevalence of Amphimerus infection was 23% in humans and 16.2% in dogs. Differences in KAP were observed between infected and non-infected individuals. Local health and academic personnel demonstrated insufficient knowledge about amphimeriasis. Some religious individuals refrained from participating, stating that they were "with God". Despite the high prevalence of Amphimerus infection in both humans and dogs, knowledge about the parasite, the disease, and its transmission routes remains limited. Health education initiatives should be designed to modify the population's KAP. It is crucial for national and local health authorities, as well as religious leaders, to be informed and actively involved in the prevention and control of amphimeriasis.

This study aimed to investigate the occurrence of larval trematode infections in bithyniid snails across five provinces in southern Thailand. A total of 1,413 Bithynia siamensis snails were collected between October 2021 and October 2022 using handpicking and scooping methods. Among these, 844 were identified as B. s. siamensis and 569 as B. s. goniomphalos. The snail samples were examined for parasitic infections in the laboratory using shedding and crushing methods. Among the 27 sampling sites, snails from 6 sites were infected with various trematode species (infection rate: 4.95%, 70/1,413). Evaluation of the morphological and internal organ characteristics of the cercariae allowed for the categorization of the trematodes into five species of trematodes (belonging to four families). The identified species included Echinochasmus pelecani (family: Echinostomatidae), Echinostoma revolutum (family: Echinostomatidae), Haematoloechus similis (family: Haematoloechidae), Loxogenoides bicolor (family Lecithodendriidae), and Stictodora tridactyla (family: Heterophyidae), and the infection rates for these species were 3.26% (46/1,413), 0.35% (5/1,413), 0.42% (6/1,413), 0.78% (11/1,413), and 0.14% (2/1,413), respectively. The cercariae from the identified trematode species were studied for DNA analysis. The phylogenetic lineage reveals relationships among the species, confirming the morphological distinctions.

Fisheries and aquaculture are crucial for ensuring food security and are significant sources of income and social advancement in developing nations. Parasitic infections among fish in natural and artificial culture systems are detrimental to their health and growth. Epidemiological studies are a prerequisite to understanding the dynamics of the disease in a fish population. In the present study, we have evaluated the prevalence and seasonal variation of the digenetic trematode parasite Isoparorchis hypselobagri infecting the catfish Wallago attu from the Aligarh region of Uttar Pradesh. To perform epidemiological studies, regular sampling of fish was carried out from March 2018 to February 2023. A total of 1110 fish were examined, of which 293 were infected with I. hypselobagri. The total number of parasites recovered from the fish host W. attu was 1297 and the prevalence and mean intensity were 26.39% and 4.42, respectively. The highest prevalence of infection, with a value of 34.94%, was observed during the winter season, while the summer season exhibited the lowest prevalence of 12.78%. The findings suggest that the prevalence of the parasite is highest during the late monsoon to early winter months and lowest during the summer to early monsoon months. This variation in prevalence may be attributed to environmental conditions, particularly temperature fluctuations. The necessity to assess parasite infection arises because parasitic infection or sickness in fish causes significant damage to the fishing industry, and as a consequence, livelihoods in poor or developing countries are affected.

Elasmobranch populations are in steep decline mainly due to overfishing bycatch, but parasites may accelerate the collapse of vulnerable and/or highly parasitized species. We therefore studied metazoan parasites of Rajidae from the northeast Atlantic: vulnerable Leucoraja fullonica, near-threatened Raja brachyura, Raja clavata, Raja microocellata and Raja undulata, and least-concerned Raja montagui and Leucoraja naevus. Overall prevalence varied from 19% for R. montagui to 100% for L. fullonica. Parasite communities differed between skate species, and prevalence and abundance were higher for L. fullonica, R. microocellata, and R. undulata. We recorded 11 parasite taxa in the study: three nematodes, six cestodes, one monogenean, and one myxosporean. Whatever the skate species, the parasite component community comprised at least two nematode taxa among Phocanema spp., Proleptus sp. and Anisakis simplex. DNA-sequencing revealed that Phocanema azarasi and Phocanema krabbei both occurred in R. microocellata and R. undulata. Phocanema spp. was first recorded in L. fullonica, L. naevus, R. microocellata, R. montagui, and R. undulata, as Proleptus sp. in L. fullonica, and A. simplex in L. fullonica and R. clavata, Rockacestus sp. and Nybelinia sp. in R. undulata, and gill-myxosporeans on L. fullonica, L. naevus, R. microocellata, and R. undulata. The occurrence of 16 new host-parasite associations suggests potential environmental changes. Information provided by trophically transmitted helminths confirmed an opportunistic skate diet based on crustaceans and fish. We discuss results in terms of host fitness loss, bioindicator role of parasites, and anisakiasis risk. We recommend incorporating parasitology in research to improve elasmobranch conservation.

Waterbirds, are one of the popular game animals and are of significant relevance to parasite spread due to their ability to fly and migrate great distances in relatively short periods of time. In Australia, however, the knowledge of parasites infecting native waterbirds is lacking with some of the last reports occurring over 50 years ago. The study aimed to characterise Echinostoma spp. infecting wild native Australian ducks found in the southern regions of the Murray Darling Basin (MDB). Ducks (n = 98) were collected from southern New South Wales within the MDB catchment. Three different species of native ducks were found including Anas superciliosa (n = 37), Anas gracilis (n = 47) and Chenonetta jubata (n = 14), of which 4.3 %, 2.7 % and 7.1 %, respectively, were found to be infected with adult stages Echinostoma spp. Examination of the parasites revealed the presence of two morphotypes. The 18S, 28S and ITS rRNA as well as the mitochondrial nad1 genes were sequenced for representative isolates of the two morphotypes. These sequences were then compared with existing sequences of Echinostoma spp. available in the GenBank. Phylogenetic analysis based on the ITS region indicated that the two morphotypes were genetically distinct. Although there are comparable sequences of Echinostoma spp. in Australia these morphotypes appear to be genetically distinct. Based on their distinct morphology and genetics we suggest that these two morphotypes are previously undescribed in Australia. This study sheds light on the presence of Echinostoma parasites in native Australian waterbirds and highlights the need for further research to better understand the diversity and prevalence of these parasites in the region.

Human fish-borne parasitic diseases may be caused by at least 111 taxa of both freshwater and marine fish parasites. It is estimated that they occur in many hundreds of millions of people all over the world, and many more are at risk, sometimes with serious consequences including the death of the host. Therefore, all efforts must be made to minimize and prevent the infection. In this paper we present an overview detailing the several types of parasites infecting humans, the reasons for the occurrence of the disease, the ways of infection, the preventive measures and difficulties encountered when combating such infections. Finally, we discuss the possibility of eliminating or eradicating fish-borne diseases. It is concluded that elimination is difficult to achieve but it is possible in some places under favourable circumstances, and that eradication will probably never be fully achieved.

The aim of this study was to determine the allergenic activity of components present in crude extracts of Pterobothrium crassicolle plerocerci (CPE) and blastocysts (CBE) obtained from Micropogonias furnieri in a murine model. Two groups of seven animals each received 50 µg of CPE or CBE on days 1, 35 and 120. Serum samples were tested by ELISA and Immunoblotting. Specific IgG and IgE levels were detected by ELISA, showing specific humoral responses for the primary immunization for both immunoglobulins and continuously growing titers for IgE. Positive Passive Cutaneous Anaphylaxis tests in rats sensitized with anti-CBE sera and tested by CBE, showed biologically, the allergenic activity of the extracts. The CPE and CBE showed some different recognition regions but both experimental groups recognized all regions of the extracts when tested for cross reactions, showing that CPE and CBE could share antigenic recognition sites.

Eustrongylides excisus is a fish-borne zoonotic parasite known to infect various fish species, including Northern pike (Esox Lucius). This nematode, belonging to the family Dioctophymatidae, has a complex life cycle involving multiple hosts. This study aimed to investigate the occurrence of Eustrongylides nematodes in Northern pike (E. Lucius) collected from Mijran Dam (Ramsar, Iran). Between June and October 2023, an investigation was conducted on Northern pike from Mijran Dam in Ramsar, Iran, following reports of reddish parasites in their muscle tissues. Sixty fish were examined at the University of Tehran, revealing live parasites in the muscles, which were then analyzed microscopically and preserved for a multidisciplinary study. The skeletal muscle tissues of 85% (51/60) of fish specimens were infected by grossly visible larvae which were microscopically identified as Eustrongylides spp. In histopathological examination, the lesion was composed of encapsulated parasitic granulomatous myositis. Microscopically, the cystic parasitic granulomas compressed the adjacent muscle fibers, leading to their atrophy and Zenker's necrosis. Moreover, epithelioid macrophages, giant cells and mononuclear inflammatory cells were present around the larvae and between the muscle fibers. Finally, a molecular analysis by examining the ITS gene region, revealed that they belong to the species E. excisus. Eustrongylidiasis in northern Iran necessitates further research into the biology, epidemiology, and control of Eustrongylides nematodes, focusing on various hosts. This study is the first to comprehensively characterize E. excisus in Northern pike in Ramsar, Iran, raising concerns about possible zoonotic transmission.

Introduced species have a major impact on freshwater ecosystems, particularly on islands. Numerous fish species have been introduced in Corsica (Mediterranean island, southern France) as part of planned programs or clandestinely. The introduction of non-native freshwater fish species can have a range of impacts on the recipient ecosystem, including through the co-introduction of its pathogens. A sample of introduced perch Perca fluviatilis Linnaeus, 1758 from the artificial reservoir of Padula was examined following a report of parasites by an angler. The analyses revealed the occurrence of Eustrongylides sp. (Nematoda) and Clinostomum complanatum (Digenea), two zoonotic parasites in P. fluviatilis. Both parasites are reported for the first time in France. Eustrongylides sp. and C. complanatum may have been introduced with their fish intermediate hosts or through their final bird hosts. The occurrence of the two parasites raises concerns from both a veterinary and human health perspective as they can use a wide range of amphibians as intermediate hosts and can be acquired in humans through the consumption of raw or undercooked fish.

Echinochasmidae are considered one of the digenean intestinal parasites of carnivorous mammals and humans. Some larvicidal medications, such as praziquantel and albendazole, were employed to interrupt the life cycle of Echinochasmidae, which may cause harmful and serious effects on the domestic fish, ducks, and humans in our ecosystem. Cercariae of Echinochasmus sp. (gymnocephalus type) were harvested by exposing snails to strong artificial illumination. The emerging cercariae were exposed in vitro to different concentrations of praziquantel and albendazole at the same period of incubation 12 h. Using probit analysis in SPSS version 25, the lethal concentrations 50 and 95% were determined. They were 0.036 and 0.82 ppm, respectively, for praziquantel and 5.3 and 9.2 ppm, respectively, for albendazole. The ultrastructural changes using scanning electron microscope on the tegumental surface of the treated cercariae with the two drugs were compared to the untreated cercariae. The untreated cercariae have a pear-shaped body with a long tail. The oral sucker is armed with a spiny collar and decorated with ciliated and unciliated sensory papillae. The cardinal ventral sucker has a thick, muscular wall. The cercarial tail is decorated with parallel longitudinal tegumental processes and spherical, unciliated papillae. In comparisons, cercariae treated with both drugs lost all healthy morphological features, but in varying degrees and effects between the two drugs. Our findings suggest that the use of both drugs can be recommended during the design of control strategies to combat this type of intestinal parasite.

Between 1898 and 1940, eight human cases of diphyllobothriasis were reported in Argentina, always in recently arrived European immigrants. In 1982, the first autochthonous case was detected, and since then, 33 other autochthonous cases have been reported, totaling 42 cases of human diphyllobothriasis in Argentina before the present study. Our aim is to update the information on diphyllobothriasis in Argentina by identifying specimens from new cases using morphometrical and/or molecular methods. We also aim to assess the epidemiological relevance of this food-borne disease in the country. Anamnestic data were obtained from patients or professionals, along with 26 worms identified using morphometrical (21 samples) and molecular techniques (5 samples). All the patients acquired the infection by consuming freshwater salmonids caught in Andean lakes in Northern Patagonia. Morphometrics and DNA markers of worms were compatible with Dibothriocephalus latus. In total, 68 human cases have been detected in Argentina, 60 of which were autochthonous. The human population living North-western Patagonia, whose lakes are inhabited by salmonids, is increasing. Similarly, the number of other definitive hosts for Dibothriocephalus dendriticus (gulls) and for D. latus (dogs) is also increasing. In addition, salmonid fishing and the habit of consuming home-prepared raw fish dishes are becoming widespread. Therefore, it is to be expected that diphyllobothriasis in Argentina will increase further.

The incidence of human diphyllobothriasis is expected to rise amidst the current global popularity of Japanese cuisine, such as sushi, which contains raw fish. We report a case of a 10-year-old boy with a diphyllobothriasis infection acquired via sushi consumption. The patient was otherwise healthy, exhibited no symptoms, and was successfully treated with a single dose of 10 mg/kg praziquantel. In Japan, this parasite is known as "Sanada-mushi" because it resembles a Sanada cord. Prompt recognition of this parasite by evoking the Sanada cord's appearance may facilitate early diagnosis and treatment and increase public awareness to prevent diphyllobothriasis.

Lymnaeid snails are some of the most widespread snails and are the first intermediate host of trematode parasites that affect human and livestock health. A full understanding of the genetic relationship of hosts and parasites is of paramount importance for effective parasite management. The present study assessed the prevalence of trematode larvae in lymnaeid snails and examined the genetic diversity of these snails collected across Thailand. We collected 672 lymnaeid snails from 39 locations in 22 provinces of six regions in Thailand. Subsequently, cercarial infection in the snails was observed by using the shedding method. Lymnaeid snails released 5 types of trematode cercariae, namely, xiphidiocercariae, echinostome cercariae I, echinostome cercariae II, furcocercous cercariae, and strigea cercariae. The phylogenetic analysis based on ITS2 and 28S rDNA sequences revealed 5 cercaria types assigned to four trematode families, of which two belong to the group of human intestinal flukes. Combination of shell morphology and sequence analysis of the mitochondrial COI and 16S rDNA genes, the lymnaeid snails were classified into two species, Radix rubiginosa and Orientogalba viridis. Moreover, the combined dataset of mtDNA genes (COI + 16S rDNA) from R. rubiginosa and O. viridis revealed 32 and 15 different haplotypes, respectively, of which only a few haplotypes were infected with cercariae. The genetic diversity and genetic structure revealed that R. rubiginosa and O. viridis experienced a bottleneck phenomenon, and showed limited gene flow between populations. Population demographic history analyses revealed that R. rubiginosa and O. viridis experienced population reductions followed by recent population expansion. These findings may improve our understanding of parasite-lymnaeid evolutionary relationships, as well as the underlying molecular genetic basis, which is information that can be used for further effective control of the spread of trematode disease.

Nematodes that parasitize salmonids are found in both seawater and freshwater. Unlike seawater species such as those in family Anisakidae, freshwater species have not been well studied. In particular, the influences of these nematodes on the body condition of salmonids remain unclear. We studied the effects of Salmonema cf. ephemeridarum on the body condition of masu salmon Oncorhynchus masou. We found a positive relationship between the number of parasites and fish fork length. In contrast, we found a negative relationship between the body condition (condition factor) of fish and the number of parasites. These results suggest that nematode infection could affect host energy reserves for future growth.

Anisakis infects humans by consuming contaminated undercooked or raw fish, leading to gastric anisakiasis, gastro-allergic anisakiasis, or asymptomatic contamination. Although larvae usually die when penetrating the gastric tissue, cases of intra- and extra-abdominal spread were described. We report the first probable case of pericardial anisakiasis.

A 26-year-old man presented to the emergency department because of progressive lower limb oedema and exertional dyspnoea. Two months prior, he had consumed raw fish without any gastrointestinal symptoms. The echocardiogram reported a circumferential pericardial effusion ('swinging heart') and mildly reduced left ventricular ejection fraction (LVEF). He was diagnosed with myopericarditis after a cardiac magnetic resonance. A fluorodeoxyglucose positron emission tomography scan revealed an intense pericardial metabolism. Blood tests exhibited persistent eosinophilia and mild elevation of Anisakis simplex IgE-as for past infestation. A pericardial drainage was performed, subsequently, serial echocardiograms revealed a spontaneous recovery of his LVEF. No autoimmune, allergic, or onco-haematologic diseases were identified. Based on a history of feeding with potentially contaminated raw fish and on long-lasting eosinophilia, we suspected a pericardial anisakiasis, despite a low but persistent titre of specific IgE. Albendazole was administered for 21 days, along with colchicine and ibuprofen for 2 months; pericardial effusion resolution and eosinophil normalization occurred two weeks after.

We hypothesized that Anisakis larvae may have migrated outside the gastrointestinal tract, penetrating the diaphragm and settling in the pericardium, causing pericarditis and pericardial effusion. Clinicians should know that the pericardium may be another extra-abdominal localization of anisakiasis, beyond pleuro-pulmonary involvement.

Liver and intestinal flukes (LIF) are important groups of foodborne zoonotic trematodes (FZTs) in Southeast Asia, including Vietnam. Their complex life cycles require specific freshwater snail species as the obligatory first intermediate hosts. In 2019, we conducted a longitudinal study in Yen Bai and Thanh Hoa provinces in North and Central Vietnam, respectively, to investigate the diversity of LIF and their infection prevalence in relation to snail host abundance and environmental factors. Using a combination of morphological and molecular identification techniques, we identified 10 LIF species infecting 11 snail host species. We observed significant seasonal variation in the mean abundance of several snail host species, with the majority of snails collected during the spring. We also detected seasonal changes in LIF species composition, with the highest species richness reported in the spring. Clonorchis sinensis and Fasciola gigantica, two medically important human liver flukes in Asia, were found only in the spring in Yen Bai. Our study revealed that not all snail host species have the same probability of becoming infected, and we recorded seasonal variations in the prevalence of LIF infection in different snail species in relation to water parameters.

Digenetic trematodes infecting humans are more than 109 species that belong to 49 genera all over the world. According to their habitat in the definitive hosts, they are classified as 6 blood flukes (Schistosoma japonicum. S. mekongi, S. malayensis, S. mansoni, S. intercalatum, and S. haematobium), 15 liver flukes (Fasciola hepatica, F. gigantica, Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Dicrocoelium dendriticum, D. hospes, Metorchis bilis, M. conjunctus, M. orientalis, Amphimerus sp., A. noverca, A. pseudofelineus, Pseudamphistomum truncatum, and P. aethiopicum), nine lung flukes (Paragonimus westermani, P. heterotremus, P. skrjabini, P. skrjabini miyazakii, P. kellicotti, P. mexicanus, P. africanus, P. uterobilateralis, and P. gondwanensis), 30 heterophyid intestinal flukes (Metagonimus yokogawai, M. takahashii, M. miyatai, M. suifunensis, M. katsuradai, M. pusillus, M. minutus, Heterophyes heterophyes, H. nocens, H. dispar, Haplorchis taichui, H. pumilio, H. yokogawai, H. vanissinus, Centrocestus formosanus, C. armatus, C. cuspidatus, C. kurokawai, Procerovum calderoni, P. varium, Pygidiopsis genata, P. summa, Stictodora fuscata, S. lari, Stellantchasmus falcatus, Heterophyopsis continua, Acanthotrema felis, Apophallus donicus, Ascocotyle longa, and Cryptocotyle lingua), 24 echinostome intestinal flukes (Echinostoma revolutum, E. cinetorchis, E. mekongi, E. paraensei, E. ilocanum, E. lindoense, E. macrorchis, E. angustitestis, E. aegyptica, Isthmiophora hortensis, I. melis, Echinochasmus japonicus, E. perfoliatus, E. lilliputanus, E. caninus, E. jiufoensis, E. fujianensis, Artyfechinostomum malayanum, A. sufrartyfex, A. oraoni, Acanthoparyphium tyosenense, Echinoparymphium recurvatum, Himasthla muehlensi, and Hypoderaeum conoideum), 23 miscellaneous intestinal flukes (Brachylaima cribbi, Caprimolgorchis molenkampi, Phaneropsolus bonnei, P. spinicirrus, Cotylurus japonicus, Fasciolopsis buski, Gastrodiscoides hominis, Fischoederius elongatus, Watsonius watsoni, Gymnophalloides seoi, Gynaecotyla squatarolae, Microphallus brevicaeca, Isoparorchis hypselobagri, Nanophyetus salmincola, N. schikobalowi, Neodiplostomum seoulense, Fibricola cratera, Plagiorchis muris, P. vespertilionis, P. harinasutai, P. javensis, P. philippinensis, and Prohemistomum vivax), one throat fluke (Clinostomum complanatum), and one pancreatic fluke (Eurytrema pancreaticum). The mode of transmission to humans includes contact with cercariae contaminated in water (schistosomes) or ingestion of raw or improperly cooked food, including fish (liver flukes, heterophyid flukes, echinostomes, and throat flukes), snails (echinostomes, brachylaimids, and gymnophallid flukes), amphibia, reptiles (neodiplostomes), aquatic vegetables (fasciolids and amphistomes), and insect larvae or adults (lecithodendriids, plagiorchiids, and pancreatic flukes). Praziquantel has been proven to be highly effective against almost all kinds of trematode infections except Fasciola spp. Epidemiological surveys and detection of human infections are required for a better understanding of the prevalence, intensity of infection, and geographical distribution of each trematode species.

Digenetic trematodes form a major group of human parasites, affecting a large number of humans, especially in endemic foci. Over 100 species have been reported infecting humans, including blood, lung, liver and intestinal parasites. Traditionally, trematode infections have been diagnosed by parasitological methods based on the detection and the identification of eggs in different clinical samples. However, this is complicated due to the morphological similarity between eggs of different trematode species and other factors such as lack of sensitivity or ectopic locations of the parasites. Moreover, the problem is currently aggravated by migratory flows, international travel, international trade of foods and changes in alimentary habits. Although efforts have been made for the development of immunological and molecular techniques, the detection of eggs through parasitological techniques remains as the gold standard for the diagnosis of trematodiases. In the present chapter, we review the current status of knowledge on diagnostic techniques used when examining feces, urine, and sputum and also analyze the most relevant characteristics used to identify eggs with a quick key for the identification of eggs.

In addition to Helicobacter pylori, the acute bacterial causes of infectious gastritis, include phlegmonous gastritis, gastric tuberculosis, and gastric syphilis. Bacterial gastritis often improves with appropriate broad-spectrum antibiotics, emphasizing the need for prompt diagnosis and treatment based on the clinical and endoscopic findings. Among viral gastritis, cytomegalovirus gastritis, primarily occurring in immunocompromised patients, necessitates antiviral intervention, while immunocompetent individuals typically achieve amelioration by administering proton pump inhibitors. In contrast, most gastric infections caused by the Epstein-Barr virus (EBV) are asymptomatic, but an EBV infection is a cause of stomach cancer. EBV-associated gastric cancer exhibits distinct clinical, pathological, genetic, and post-genetic mutation features, making it clinically significant. The colonization of Candida albicans in the stomach is uncommon, and typical antifungal treatment is unnecessary. Candida infections in gastric ulcers can be treated with anti-ulcer treatment alone. Lastly, anisakidosis in the stomach, which occurs when consuming raw seafood, can manifest in various clinical presentations and is typically treated through endoscopic removal of the nematode. This article aims to contribute to the rapid diagnosis and treatment of rare stomach infections beyond Helicobacter pylori in real clinical situations.

In recent years, the consumption of fish products has surged in European countries, being an essential part of a healthy diet. Despite representing a small part of EU production, freshwater fisheries hold considerable significance for lake-dwelling populations and tourists seeking traditional dishes. This increased fish consumption has brought to light potential health risks associated with fish-borne zoonotic helminths (FBZHs), now acknowledged as global food-borne parasites. Fish-borne zoonotic helminths belong to various taxonomic groups, including nematodes (Anisakidae), trematodes (Opisthorchiidae and Heterophyidae), and cestodes (Diphyllobothriidae). More than 50 species of FBZH are known to cause human infections, derived from eating raw or undercooked aquatic foods containing viable parasites. Despite increased attention, FBZHs remain relatively neglected compared to other food-borne pathogens due to factors like chronic disease progression and under-diagnosis. This systematic review concentrates on the prevalence of six freshwater FBZHs (Clinostomum complanatum, Contracaecum rudolphii, Dibothriocephalus latus, Eustrongylides excisus, Opisthorchis felineus, and Pseudamphistomum truncatum) in Italy and neighbouring countries. The study explores the expansion of these parasites, analysing their biological and epidemiological aspects, and the factors that influence their proliferation, such as the increased cormorant population and the lake eutrophication phenomena. In summary, this research highlights the necessity for further research, the development of spatial databases, and the establishment of a unified European policy to effectively manage these multifaceted health concerns. It strongly advocates adopting a One-Health approach to address the growing incidence of parasitic zoonoses within the context of food safety in EU countries.

Since 1980s, no new drugs were described for treatment of heterophyiasis with many side effects of the currently used drug; praziquantel. This work aimed to study the therapeutic effect of clorsulon (sulphoamide) and aqueous extract of Cucurbita pepo in the treatment of experimental heterophyiasis. Mice were infected with encysted metacercaiae of Heterophyes heterophyes obtained from infected fish flesh. Mice were divided into five groups according to the drug used. The treatment started two weeks post-infection. Our results showed reduction of the recovered worm count with high efficacy of clorsulon and a moderate effect of C. pepo which was increased in the second week with much improvement of the intestinal histopathological changes. Scanning electron microscopy of adult H. heterophyes obtained from the intestine of mice treated with praziquantel appeared contracted with multiple small vesicles over the dorsal surface. Clorsulon produced loss of the spines on the lateral sides of the parasite with few vesicles whereas C. pepo seeds showed complete loss of the spines. In conclusion, clorsulon has high efficacy against H. heterophyes infection. Although the extract of C. pepo showed moderate curative effect against this parasite, it can be used in combination with other agents for a better synergistic effect.

Trematodes of the genus Metagonimus Katsurada, 1912 (Digenea: Heterophyidae) are zoonotic parasites that cause infections in humans, with most cases reported in Southeast Asia. Larvae from the second intermediate host, called metacercariae, of one of human-infecting species, M. yokogawai (Katsurada, 1912), have been reported from cyprinoid fish in Europe. In the present study, we provided DNA-based evidence that metacercariae of Metagonimus, which are commonly found in the scales of various cyprinoids in Central Europe (Danube River in Hungary) do not belong to M. yokogawai. Sequence analysis of the ITS region, 28S rDNA, and cox1 genes showed that this species is clearly distinct from all Asian species, including M. yokogawai, which probably does not occur in Europe. Metacercariae from cyprinoids might belong to Metagonimus romanicus (Ciurea, 1915), an insufficiently known species described from Romania.

Freshwater snails are important hosts in the life cycles of many medically important parasites, particularly for digenetic trematodes such as liver flukes and schistosomes. The current study was conducted to determine the infection of freshwater snails with parasites that can potentially be transmitted to humans within the Murrumbidgee catchment area which is an area of widespread intensive aquaculture in Australia. A total of 116 freshwater snails, belonging to three species (Isidorella hainesii, Glyptophysa novaehollandica and Bullastra lessoni), were examined for the presence of parasites in both man-made and natural environments. The analysis of sequence data, including the internal transcribed spacers (ITS) of nuclear ribosomal DNA, small subunit (18S) ribosomal DNA, and large subunit (28S) ribosomal DNA, indicated that the collected parasites belonged to two distinct genera, namely Clinostomum and Echinostoma. It is noteworthy that species of both of these digenean parasites have the potential to be zoonotic. Cercariae of both Clinostomum and Echinostoma were observed in snails collected from aquaculture settings. It is important to highlight that infectious stages of Clinostomum  has been previously detected in edible fish within Australia. This information raises concerns regarding the potential transmission of these parasites to humans through the consumption of contaminated fish. These findings emphasize the importance of monitoring and controlling the presence of Clinostomum and Echinostoma in aquaculture environments to minimise the risk of zoonotic infections and ensure food safety. Further research and surveillance are needed to better understand the prevalence, transmission dynamics, and potential public health implications associated with these parasites in the context of aquaculture in Australia.

Extra-gastrointestinal anisakidosis is rare. We herein report an Anisakis pegreffii infection in a patient with hepatic anisakidosis diagnosed based on its molecular identification. A 71-year-old male patient had a hepatic tumor presenting as a low-density area of 20 mm in diameter in segment 6 of the liver on abdominal ultrasonography, computed tomography, and magnetic resonance imaging. The surgically resected pathological specimen revealed a necrotizing eosinophilic granuloma containing nematode larvae, possibly an Anisakis larva. Molecular and phylogenetic analysis demonstrated Anisakis larvae belonging to A. pegreffii. The present results will help identify and characterize unknown Anisakis species in histological sections.

Parasites are a significant component of biodiversity. They negatively affect fish appearance, growth, and reproduction. In this study, the prevalence of infection, diversity, and mean intensity of parasites were examined in 9 freshwater fish species (45 samples per fish species). Ecto-parasites were examined on the skin, gills, and fins with a hand lens. Wet mounts were prepared using mucosal scrapings from all the external and internal organs of the sampled fish. Microscopy, muscle compression, and the pepsin-HCL artificial digestion technique were also performed. In this study, 26 species of parasites were identified including three taxa belonging to 9 species of protozoan parasites, 11 treamtodes, and 6 monogenean parasites. The identified protozoan parasites were Entamoeba histolitica, Chilodonella sp., Coccidia sp., Costia sp., Cryptobia sp., Ichthyopthiris-multifilis, Microsporidia, Piscinoodinium sp., and Ichthyobodo necator. The identified trematode parasites were Fasciola gigantica, Echinostoma revolutum, Fasciola hepatica, Haplorchis pumilio, Brachylaima cribbi, Echinostoma cinetorchis, Neascus sp., Deropegus sp., Trematode Soldier, Centrocestus formosanus, and Clinostomum marginatum. The identified monogenean parasites were Dactylogyrus limipopoensis, Dactylogyrus anchoratus, Dactylogyrus myersi, Dactylogyrus vastator, Gyrodactylus salaris, and Ancyrocephalus. The diversity of parasites was maximum at the Okara site. The host's organs that were targeted for parasitic infection included the intestine, liver, gills, fins, skin, and kidneys. The majority of the parasites were identified in Labeo rohita followed by Hypophthalmichthys molitrix, Ctenopharyngodon idella, Oreochromis niloticus, Cyprinus carpio, and Wallagu attu. Two species appeared to be resistant species because none of the parasites were observed in Notopterus notopterus or Sperata seenghala. This study also concluded that the prevalence of parasites increased with increasing length, size, and age of fish.

Fish-borne trematodes (FiBT) are an important group of zoonotic parasites negatively affecting human health, mainly in Asia. Most studies on FiBT have applied a cross-sectional design, which provides weaker evidence on potential risk factors for transmission than a cohort study. This cohort study aimed to estimate the incidence and identify associated risk factors for FiBT infection in Vietnam. Between April 2018 and May 2019, two communes in Yen Bai province, a highly endemic area for FiBT, were visited for sampling. Participants with a negative stool result for FiBT at baseline, were invited for follow-up and data collection, at months 4, 9, and 13. Stools were examined using Kato-Katz and formalin-ethyl acetate concentration techniques to detect FiBT eggs, whereas a questionnaire was used for interviewing participants to determine the risk factors for FiBT infection during each follow-up period. The incidence risk and the incidence rate were calculated, and univariate and multivariable models were run to identify the risk factors for FiBT. A total of 194 people, negative for FiBT eggs at the baseline survey, were invited to participate in the study, and 111 people agreed to enroll in the follow-up. The incidence risk at months 4, 9, and 13 was 9.0%, 6.4%, and 5.1%, respectively. We finally used data from 95 participants for the risk factor analysis, excluding 16 people lost for the follow-up. Overall, 20 people became infected with FiBT (IR = 21.1%). The incidence rate of FiBT infection was 21.4/100 person-year. In the univariate analysis, consumption of raw fish was the main risk factor (RR = 4.59, 95%CI = 1.95-10.82), followed by being male (RR = 3.41, 95%CI = 1.56-7.45) and drinking alcohol (RR = 3.25, 95%CI = 1.49-7.11). In the multivariable analysis, only consumption of raw-fish dishes was significantly associated with FiBT infection. The people who consumed raw fish were 3.44 (95%CI = 1.11-10.70) times more at risk of infection with FiBT as compared to individuals who did not consume raw fish. It can be concluded that the FiBT incidence is high in the study area. More awareness campaigns are needed to stop eating raw fish in these areas to reduce FBT infection.

Adenocephalus pacificus is a tapeworm parasitic of marine mammals and the main agent of human diphylobothriosis caused by consumption of raw or undercooked marine fishes, being considered as a reemerging disease. Despite having a broad distribution in marine mammals in both hemispheres, plerocercoid larvae in fish have only been reported in the Pacific Ocean, in Peruvian waters, from where most human cases are known. In Argentine waters larval stages of Diphyllobothriidae have been recorded in Merluccius hubbsi, a main fish resource mostly exported frozen, headed and gutted (H&G) or as fillets; therefore, the possible presence of A. pacificus in edible products, and the extent of the risk of parasitism for humans becomes of health and commercial relevance. With the aim of detecting and identifying potentially zoonotic diphyllobothriids and quantifying infection levels in viscera and fillets of hakes, 43 entire fish, 471 H&G, and 942 fillets obtained from research cruises in 2019 and 2021 from the southern Argentine Sea (44-53°S; 63-68°W) were examined by transillumination and under stereoscopic microscopy. Plerocercoids were recovered at low prevalence and mean abundance in entire fish (13.95 % and 0.35) and H&G fish (2.76 % and 0.03) but no larval worms were found adhered to musculature or peritoneum, furthermore, no larvae were found in the fillets. Larvae were genetically identified, based on sequences of the large subunit ribosomal RNA nuclear gene (lsrDNA) and the cytochrome c oxidase subunit 1 (cox1) mitochondrial gene, as members of A. pacificus, representing the first report of this species in a fish host outside South American Pacific coasts. No spatial nor bathymetric patterns in parasite burdens were observed across sampling sites, but prevalence increased with fish size. The recorded low parasite burdens, the absence of infective stages in fillets and the fact that most products are commercialized deeply frozen, diminish the risk of parasitism for consumers to a minimum. However, the identification of this zoonotic agent and the assessment of its distribution in fish products are a first indispensable step for the design of efficient and suitable measures, such as freezing or cooking meet, to ensure the prevention of human infections.

Anisakidosis is a foodborne zoonotic infection induced by members of the family Anisakidae via the consumption of raw or undercooked fish such as sushi and sashimi. Identifying anisakid larval species is critical for the epidemiology and diagnosis of diseases caused by them. This study aimed at identifying Anisakis larvae collected from marine fish in Egyptian waters based on morphological characteristics and molecular analysis. Thirty marine fish coral trout, Plectropomus areolatus, were collected from Hurghada, Red Sea, Egypt, to investigate larval nematodes of the genus Anisakis. The larvae were detected encapsulated in the peritoneal cavity and muscle of the fish host. This examination revealed that anisakid larvae naturally infected 19 fish specimens with a prevalence of 63.33% and a mean intensity of 4.1 ± 0.40. Most of them (68 larvae: 71.57%) were found in the musculature. Morphological and morphometric analyses using light and scanning electron microscopy revealed a head region with a prominent boring tooth, inconspicuous lips, and a characteristic protruded cylindrical mucron. All larvae in this study possessed the same morphology as Anisakis Larval type I. Molecular analysis based on ITS region using maximum likelihood and Bayesian phylogenetic methods confirmed them as Anisakis typica. This is the first study to identify A. typica larvae from the commercial fish coral trout P. areolatus in Egyptian waters using morphological and molecular methods.

Fish is a great nutritious food and provides quality protein and a variety of vitamins and minerals. This contributes significantly to the economy and food security in Iran. However, there are safety concerns related to the presence of zoonotic parasites.

The objective of this study is, therefore, to review fish-borne zoonotic parasites in Iran.

Keywords such as fish-borne, parasites, zoonotic, Iran, and some names of fish-borne zoonotic parasites were searched in databases including PubMed, Science Direct, Elsevier, SID, Magiran, Irandoc, Google Scholar and the World Health Organization.

The most common fish-borne parasites with zoonotic potential identified in reports in the literature were the protozoa Balantidium spp., Myxobolus spp. and Sarcosystis sp.; the trematodes Heterophyes heterophyes and Clinostomum complanatum; the cestodes Ligula intestinalis and Diphyllobothrium latum; the nematodes Pseudoterranova sp., Anisakis spp., Contracaecum spp., Raphidascaris spp., Eustrongylides spp. and Capillaria sp.; and the acanthocephal Corynosoma spp.

The potential risk factors for the transmission of fish-borne zoonotic parasites to humans are consumption of raw or undercooked infected fish, contact with contaminated water and contact with infected fish. There is a need for epidemiological surveillance of fish for parasites with zoonotic potential and of occurrence of infections in humans to better understand the public health significance and design prevention programs.

Fish and aquatic-derived zoonotic diseases have caused considerable problems in the aquaculture industry and fishery worldwide. In particular, zoonotic diseases can pose widespread threats to humans. With the world's growing population and potential global trade of aquaculture and fish, the risk of environmental contamination and development of fish and aquatic-derived zoonoses in humans are increasing. The important causes of zoonoses include bacteria, parasites, viruses, and fungi. The zoonotic bacterial agents are divided into two main groups: Gram-positive (Mycobacteriaceae, Streptococcaceae, Erysipelothricaceae families) and Gram-negative (Aeromonadaceae, Vibrionaceae, Pseudomondaceae, Enterobacteriaceae, and Hafniaceae families). The premier parasitic agents include cestodes (tapeworm; e.g. Diphyllobothrium spp.), trematodes (fluke; e.g. Opisthorchis spp.), and nematodes (round worm; e.g. Anisakis spp.). In addition, protozoan organisms such as Cryptosporidium spp. are also considered fish-derived zoonotic pathogens. Two groups of fish-associated fungi causing basidiobolomycosis and sporotrichosis also pose a zoonotic risk for humans. The majority of the fish-derived zoonotic diseases are transmitted to humans mainly via the consumption of improperly cooked or raw fish or fish products. Therefore, the incidence of zoonotic diseases can be reduced by properly processing fish and fish products, e.g. by thermal (heat/freezing) treatment. The prevalence of zoonotic agents in fishes varies seasonally and should be regularly monitored to evaluate the prevalence of pathogens in both wild and cultured fish populations. This review focuses on the fish zoonotic agents/diseases and their control and prevention.

Aquaculture, also known as aqua farming, is defined as farming fish, crustaceans, mollusks, aquatic plants, algae, and other marine organisms. It includes cultivating fresh- and saltwater populations under controlled conditions compared to commercial fishing or wild fish harvesting. Worldwide, carp, salmon, tilapia, and catfish are the most common fish species used in fish farming in descending order. Disinfectants prevent and/or treat different infections in aquatic animals. The current review indicates the uses of different disinfectants against some important pathogens in aquaculture, with particular reference to tilapia (Oreochromis niloticus) farming. A single review cannot cover all aspects of disinfection throughout aquaculture, so the procedures and principles of disinfection in tilapia farming/aquaculture have been chosen for illustration purposes.

The study aimed to perform the molecular identification of Anisakis larvae in commercial fish from the coast of the Canary Islands and to provide data on their infection level for the host and the species of this nematode parasite that we could find in several species of commercial interest in the Canary Archipelago. Fish specimens (n = 172) from the Canary coasts were examined for parasites. In total, 495 larvae were identified; PCR was carried out for the entire ITS rDNA and cox2 mtDNA region, obtaining sixteen sequences for the entire ITS rDNA region and fifteen for the cox2 mtDNA, this being the first contribution of nucleotide sequences of Anisakis species of fish caught from the Canary Islands. An overall prevalence of 25% was obtained in the fish analyzed, and five species of Anisakis were identified, these being Anisakis simplex (s.s.), Anisakis pegreffii, Anisakis physeteris, Anisakis nascettii and Anisakis typica and the hybrid Anisakis simplex x Anisakis pegreffii. The results obtained in this study have relevance for public health, since the pathology will depend on the species of Anisakis, so it is important to know the health status of fish in the waters of the Canary Islands to assure a safer consumption and take adequate measures, in addition to the provision of epidemiological data.