Genus Trichinella Research Articles

Trichinella britovi outbreak in Piedmont, North-West Italy, 2019–2020: Clinical and epidemiological insights in the one health perspective

BackgroundTrichinellosis, a foodborne zoonosis due to nematodes of the genus Trichinella, occurs in the form of outbreaks following meat consumption. North Italy has been rarely involved. We report here the most significant wildlife derived trichinellosis outbreak ever registered in the Piedmont region. MethodWe retrospectively included 96 outpatients referred to our institution (December 20th, 2019–January 15th, 2020) 2020 after consuming raw sausages prepared from a single wild boar hunted in the Susa Valley, 59 km away from Torino, in November 2019. ResultsWe confirmed 35 cases and found additional 10 probable/suspected cases. Our cohort found that 47% of patients were symptomatic, with a median time from symptoms to presentation at clinic and serology testing of 14 days. Peripheral blood eosinophilia >500/μl and CK alterations were common. Further qualitative and quantitative analysis at the International Trichinella Reference Center c/o ISS, Rome identified T. britovi as the causative agent. ConclusionsNo autochthonous human case has ever been detected in Torino province, and a single wild boar has tested positive for Trichinella since active surveillance was implemented in 2013. This outbreak should raise attention on the preventive role of veterinary surveillance and the need to optimize sampling procedures and targeted health education.

Antiparasitic Action of Lactobacillus casei ATCC 393 and Lactobacillus paracasei CNCM Strains in CD-1 Mice Experimentally Infected with Trichinella britovi.

Nematodes of the genus Trichinella are among the most widespread parasites of domestic and wild omnivores and predatory animals. The present study aimed to evaluate the antiparasitic effect of Lactobacillus casei ATCC 393 (original) and L. paracasei CNCM in CD-1 mice experimentally infected with Trichinella britovi. Four groups of 20 mice (10 females and 10 males/group) were used, with two control (C) groups and two experimental (E) groups, in which each animal received a daily oral dose of 100 µL of 105 CFU/mL probiotics in Ringer’s solution. On day 7, all mice (except the negative control group) were infected orally with Trichinella (100 larvae/animal) as well as the two probiotics. On day 9 post-infection (p.i.), 10 mice/group were euthanized, and the presence of adult parasites in the intestinal content and wall was tested. On day 32 p.i., 10 mice/group were euthanized, then trichinoscopy and artificial digestion were performed to assess the muscle infection with T. britovi. On day 9 p.i., the experimental group pretreated with L. casei ATCC 393 (6.3 ± 3.03) showed a significantly lower number of adult parasites in the intestinal wall compared with the positive control group (24.6 ± 4.78). Additionally, a significantly lower adult parasite count in the intestinal wall was registered in female mice pretreated with L. paracasei CNCM (7.4 ± 4.71) compared to female mice from the positive control (29.0 ± 5.17). No statistically relevant results were obtained concerning the male mice or the data obtained at 32 days p.i., irrespective of mice gender.

Validation of the Magnetic Stirrer Method for the Detection of Trichinella Larvae in Muscle Samples Based on Proficiency Tests Results.

Trichinellosis is a zoonotic disease caused by the nematodes of the genus Trichinella. Infection takes place through the consumption of infected meat containing live larvae. The only way to prevent the disease is to break its epizootic chain. To ensure effective control of Trichinella spp., a range of preventive and control measures have been undertaken. These efforts have been focused on controlling Trichinella in domestic pigs, the main source of the disease. Artificial digestion is also the reference point for other methods for Trichinella risk control. Descriptive data validation of the digestion assay was presented in 1998 based on results published by scientific laboratories. Herein, we supplement those data by characterizing the method’s performance in inter-laboratory comparisons. The source of data was the results of Proficiency Testing conducted in 2015–2019. Samples were contaminated by 0, 1, 3, and 5 larvae. In total, 7580 samples were examined by the laboratories. Based on Proficiency Testing results, the main parameters characterizing the method performance in field conditions were established as follows: specificity, 97.3%; sensitivity, 86.5%; accuracy, 89.2%; uncertainty, 0.3; limit of detection (LOD), 1 larva; and limit of quantification (LOQ), 3 larvae.

Seroprevalence and Risk Factors of Trichinella spiralis Infection in Blood Donors from Western Romania.

Background and Objectives: Trichinellosis, a serious and sometimes fatal human disease, is a foodborne zoonotic disease with worldwide distribution caused by parasitic nematodes of the genus Trichinella. Humans are infected with Trichinella larvae through the ingestion of meat that has not been properly cooked. Romania reported most of the confirmed cases of trichinellosis among the EU countries. The aim of this cross-sectional study was to evaluate, for the first time, the seroprevalence and risk factors of Trichinella infection in blood donors from Western Romania. Materials and Methods: Serum samples of 1347 consecutive blood donors were investigated using an immunoenzymaticassay (ELISA) for the determination of specific IgG class antibodies against T.spiralis. A questionnaire interview was used to obtain information regarding the potential risk factors associated with T. spiralis infection. Mantel–Haenszel chi-squared test or the Fisher exact two-tailed test, as appropriate, were used for comparison between T. spiralis positive and T. spiralis negative blood donors. Student’s t-test was used to evaluate differences between means in studied groups and body mass index was calculated by dividing weight in kilograms by height in meters squared. Statistical analysis was performed using Epi Info Version 7.2 and Stata 16.1. Results: T. spiralis IgG antibodies were detected in 2.00% (27) of 1347 consecutive blood donors. Eating raw and/or undercooked meat, from pigs or wild boars, was found to be the main risk factor (p < 0.001). Strong alcoholic drink consumption was highly associated with T. spiralis infection (p = 0.009). Trichinella seroprevalence was higher among rural residents and males. Subjects identified as Trichinella seropositive were not previously diagnosed and have not been treated for Trichinella infection with any specific therapy. Conclusions: The demonstration of T. spiralis antibodies in healthy blood donors suggests that Trichinella infection may be detected in asymptomatic individuals that were not previously diagnosed with this zoonosis.

Two trichinellosis outbreaks in Serbia - challenging diagnosis due to a potential co-infection with Toxocara spp.

In Serbia, in most cases, small family outbreaks of trichinellosis occur due to the consumption of untested infected meat from domestic pigs that are raised and slaughtered in the backyards of small individual farms. The aim of this study is to present data regarding 24 patients involved in two outbreaks that occurred in two neighbouring districts in Serbia during a closely related period of time in August 2014. The source of infection in the first outbreak was undercooked pork, while raw pork sausages caused the second outbreak. Meat samples and sausages were Trichinella spp. positive by artificial digestion. With the aim to obtain a second opinion and validate the serological findings discovered at the Public Health Institute Nis, all samples were sent to the National Reference Laboratory for Trichinellosis, INEP. Serodiagnosis showed that 21 persons were positive (87.5%) and three (12.5%) were negative for anti-Trichinella antibodies, while 15 patients fulfilled the trichinellosis case definition. Western blot analysis (using an epitope unique for the muscle larvae stage of the Trichinella genus) confirmed the diagnosis of trichinellosis in five patients. Six patients also had specific antibodies against Toxocara canis (T. canis). Due to the fact that in endemic foci in Serbia there is the presence of Trichinella spiralis and T. canis and that these two infections could be asymptomatic, we consider that trichinellosis cases were irrefutably proven. The dilemma about the existence of co-infection with T. canis remained open due to the lack of clinical findings.

Trichinella spp. Y EL CICLO SALVAJE EN LA PROVINCIA DE SANTA FE

Trichinellosis in a zoonotic parasitism of worldwide distribution caused by nematodes of the genus Trichinella. Argentina is considered an endemic country for this zoonosis and so far four species have been identified, spiralis, patagoniensis, britovi and pseudospiralis. It can affect both domestic animals such as pigs, dogs, horses, or wild animals such as cougars, armadillos, wild boars, and wild pigs. With the aim of knowing if any species of Trichinella circulates among the wild fauna of the province of Santa Fe, 22 samples of muscle from pigs between wild and wild boars were analyzed by Artificial Digestion, five from aguará guazú (Chrysocyon brachiurus), one of cat wild (Leopardus geoffroyi), one of weasel (Didelphis albiventris) and one of an equine (Equus caballus). All samples were negative.

Results of Proficiency Testing for Trichinella in Poland, 2015-2019.

Trichinellosis is a zoonotic meat-borne disease caused by the nematodes of the genus Trichinella. Meat containing live Trichinella larvae is a source of infection. The examination of meat for Trichinella was introduced in 1869, but the digestion method for this did not appear in Poland until the late 1970s. Nowadays, the meat of all food animals susceptible to Trichinella spp. is examined in the frame of official post mortem control with the digestion method. The majority of laboratories in Poland meet the requirements of the ISO/IEC 17025 Standard (352 field laboratories). Laboratory personnel participate in quality control programs. This paper presents the results of proficiency tests (PTs) organized within 2015–2019 in Poland. Over this period, the laboratories examined 7580 samples (contamination levels: zero, one, three, and five larvae). Each laboratory was provided with a set of samples (one negative and three positive). Over 95% of the samples were considered correct in qualitative assessments, though the results of the quantitative evaluations were slightly lower, with 89% of samples being considered correct. Based on a sample evaluation, 88% of laboratories passed the PT comparison. A slight decrease was observed in the examination of samples spiked with five larvae, and great progress was achieved in samples containing three larvae. Low levels of sample contamination are sought after in laboratories but may make evaluations difficult. For this reason, we must consider increasing the number of larvae added to the samples in the next PTs.

Infection, genetics, and evolution of Trichinella: Historical insights and applications to molecular epidemiology

Genetic variation in pathogen populations provides the means to answer questions in disease ecology and transmission, illuminating interactions between genetic traits, environmental exposures, and disease. Such studies elucidate the phylogeny, evolution, transmission and pathogenesis of viruses, bacteria and parasites. Here, we review how such studies have fostered understanding of the biology and epidemiology of zoonotic nematode parasites in the genus Trichinella spp., which impose considerable economic and health burdens by infecting wildlife, livestock, and people. To use such data to define ongoing chains of local transmission and source traceback, researchers first must understand the extent and distribution of genetic variation resident in regional parasite populations. Thus, genetic variability illuminates a population's past as well as its present. Here we review how such data have helped define population dynamics of Trichinella spp. in wild and domesticated hosts, creating opportunities to harness genetic variation in the quest to prevent, track, and contain future outbreaks.

Reprint of: Comparison between Trichinella patagoniensis and Trichinella spiralis infection in BALB/c mice

In Argentina, trichinellosis is an endemic disease acquired mainly through consumption of raw pork infected with nematodes larvae from the Trichinella genus. For years, the only species involved in outbreaks in humans and pig foci in Argentina was Trichinella spiralis. In 2008 the presence of a new Trichinella taxon from a cougar (Puma concolor) was detected and recorded in the province of Rio Negro, Argentina, and the finding was established as a new species in 2012: Trichinella patagoniensis. To the best of our knowledge, there is no information available on the intestinal phase and antibody response in a susceptible host during T. patagoniensis infection. Therefore, our research has been designed to study experimental infection with T. patagoniensis compared to infection with T. spiralis in BALB/c mice. One hundred and twenty eight BALB/c mice were divided into two groups and individuals in each group were infected per os with 500 larvae of T. patagoniensis or 500 larvae of T. spiralis, respectively. After that, they were euthanized on different days. Adult worm recovery from small intestines and artificial digestion of each carcass was performed. Histopathology of small intestines was performed using hematoxylin-eosin staining. Systemic cytokines and antibody kinetics were evaluated. Intestinal adult worm recovery of T. patagoniensis and T. spiralis took place until day 17 and 25, respectively. Systemic IFN-γ, IL-10, and TNF showed significant variations in T. patagoniensis infected mice. Seroconversion was detected in animals as from 15 days post-infection (pi) for both T. patagoniensis and T. spiralis, reaching the highest OD value at 42 days pi. Similar microscopic lesions were observed in the small intestine from mice infected with the same dose of T. spiralis and T. patagoniensis. Our findings contribute new information regarding the intestinal phase and the antibody kinetics of T. patagoniensis in BALB/c mice.

Development of a rapid and sensitive immunochromatographic strip based on EuNPs-ES fluorescent probe for the detection of early Trichinella spiralis-specific IgG antibody in pigs

Trichinellosis, which is caused by nematodes of the genus Trichinella, is one of the most important zoonotic parasite diseases in the world. A rapid and sensitive immunochromatographic strip (ICS) based on Eu (III) nanoparticles (EuNPs) was developed for the detection of Trichinella spiralis (T. spiralis) infection in pigs. T. spiralis muscle larvae excretory secretory or preadult worm excretory secretory (ML-ES or PAW-ES) antigens were conjugated with EuNPs probes to capture T. spiralis-specific antibodies in pig sera, after which the complex bound to mouse anti-pig IgG deposited on the test line (T-line), producing a fluorescent signal. In the pigs infected with 100, 1000 and 10 000 ML, seroconversion was first detectable for the EuNPs-ML-ES ICS at 30, 25 and 21 days post-infection (dpi) and for the EuNPs-PAW-ES ICS at 25, 21 and 17 dpi. These results show that EuNPs-PAW-ES ICS detects anti-Trichinella IgG in pigs 4–5 days earlier that test using ML-ES antigens. Our ICS have no cross reaction with other parasite infection sera. Furthermore, the detection process could be completed in 10 min. This study indicated that our ICS can be used for the detection of the circulating antibodies in early T. spiralis infection and provide a novel method for on-site detection of T. spiralis infection in pigs.

Comparative Epigenomics Reveals Host Diversity of the Trichinella Epigenomes and Their Effects on Differential Parasitism.

Comparative epigenomics provides new insights on evolutionary biology in relation with complex interactions between species and their environments. In the present study, we focus on deciphering the conservation and divergence of DNA methylomes during Trichinella evolution. Whole-genome bisulfite sequencing and RNA-seq were performed on the two clades of Trichinella species, in addition to whole-genome sequencing. We demonstrate that methylation patterns of sing-copy orthologous genes (SCOs) of the 12 Trichinella species are host-related and can mirror known phylogenetic relationships. Among these SCOs, we identify a panel of genes exhibiting hyper-/hypo-methylated features in gene-bodies or respective promoters that play pivotal roles in transcriptome regulation. These hyper-/hypo-methylated SCOs are also of functional significance across developmental stages, as they are highly enriched species-specific and stage-specific expressed genes both in Ad and ML stages. We further identify a set of parasitism-related functional genes that exhibit host-related differential methylation and expression among those SCOs, including p53-like transcription factor and Cdc37 that are of functional significance for elucidating differential parasitology between the two clades of Trichinella. This comparative epigenome study can help to decipher the environmental effects on differential adaptation and parasitism of the genus Trichinella.

First record of Trichinella in Leopardus guigna (Carnivora, Felidae) and Galictis cuja (Carnivora, Mustelidae): new hosts in Chile.

BackgroundTrichinellosis is a zoonotic disease with a worldwide distribution. It is caused by several species of nematodes in the genus Trichinella. Trichinella spp. are transmitted through predation or carrion consumption and occur in domestic and sylvatic cycles. In humans trichinellosis occurs due to the consumption of raw or undercooked, infected meat and is mainly associated with the household slaughter of pigs or the consumption of game animals without veterinary inspection, a cultural practice that is difficult to resolve. Therefore, knowledge of this parasite’s reservoir is relevant for better implementing public health strategies. The aim of this study was to assess the presence of Trichinella sp. in several carnivore and omnivore vertebrates in central-southern Chile.MethodsWe collected muscle tissue from a total of 53 animals from 15 species and were digested to detect Trichinella larvae which were further identified to species level using molecular techniques.ResultsWe detected Trichinella larvae in Leopardus guigna (Felidae) and Galictis cuja (Mustelidae). We identified the larvae collected from L. guigna as Trichinella spiralis, but we were unable to molecularly characterize the larvae from G. cuja. This is the first record of Trichinella in a native mustelid of South America and the first record of T. spiralis in L. guigna. This study identified two novel hosts; however, further work is needed to identify the role that these and other hosts play in the cycle of Trichinella in Chile.

First report of Trichinella pseudospiralis in a wolf (Canis lupus italicus).

Within the genus Trichinella, Trichinella pseudospiralis is the only recognized non-encapsulated species known to infect mammals and birds. In October 2020, larvae recovered from muscle tissues of a wolf (Canis lupus italicus) originating from Molise Region, Central Italy, were molecularly confirmed as those of Trichinella britovi and T. pseudospiralis. This is the first detection of T. pseudospiralis from a wolf. In Italy, this zoonotic nematode was detected in a red fox (Vulpes vulpes), three birds (Strix aluco, Athene noctua, Milvus milvus) and five wild boars (Sus scrofa), and was also identified as the etiological agent of a human outbreak of trichinellosis in 2015. Since T. pseudospiralis is rarely reported from carnivore mammals in comparison to the encapsulated species frequently detected in these hosts, this finding opens the question of the role of carnivores as reservoirs for this parasite.

RESEARCH INTO THE ROLE OF BIVALVE MOLLUSKS IN THE PREVALENCE OF TRICHINELLA IN MARINE BIOCENOSES

Trichinosis is a dangerous anthropozoonotic disease caused by a nematode of the genus Trichinella. Being polyhostal, Trichinella is recorded in more than 150 species of animals, including marine mammals. While the circulation mechanism in terrestrial animal species is well-studied and has a logical explanation, the ways of infection of marine mammals remain unexplored in many respects up to the present. Among marine mammals, trichinosis is most common in walruses with the prevalence of 1.5% (Bukina L.A., 2015). The main sources of trichinosis infection for benthophagous walruses are probably their most important prey items, amphipods and bivalve mollusks. The purpose of the present paper was to study the role of bivalves in the transmission of infective material to a potential host. In the experimental infection, decapsulated trichinella larvae isolated from the muscle tissue of cage-kept arctic foxes were used. Trichinella larvae were isolated by the method of trichinelloscopy and digestion of muscle tissue in artificial gastric juice. It was found that the filter feeding structure of mussels does not let trichinella pass into the intestine. However, larvae trapped in the mantle cavity are filtered out and removed as pseudofaeces through the excurrent siphon to the environment. At the same time, they remain viable for 113 hours. The most invasive and viable were trichinella isolated from pseudofaeces and wash off from the mantle cavity (mantle complex) within 30 to 70 hours. The bio-assays performed on white outbred mice were positive. Therefore, mussels can be direct or indirect sources of the invasion. Taking into account that walruses can eat more than 3,000 mollusks in one feeding, the probability of infection increases significantly.

The detection of anti-Trichinella antibodies in free-ranging Nebrodi Regional Park black pigs from Sicily, Italy, suggests the circulation of Trichinella britovi in the island.

• Zoonotic nematodes of the genus Trichinella are known to occur in countries bordering the Mediterranean Sea. For example, Trichinella spiralis was reported in pigs and humans at the turn of the Second World War in Sicily and Trichinella britovi in pigs, red foxes and dogs from Corsica and Sardinia since 2004. Following the discovery of T. britovi in Corsica and Sardinia, a question arose as to whether this species was also present in Sicily which is located only 3.14 km from continental Italy. To address this query, we investigated the presence of anti- Trichinella antibodies in the serum of Nebrodi black pigs, a breed that is bred in the wild in the Nebrodi Regional Park, a protected area of the island rich in flora and fauna. Blood samples were collected from 112 Nebrodi black pigs from five farms. Sera were tested by ELISA and ELISA positive sera were confirmed by Western blot (Wb) using excretory/secretory antigens. Eighteen (16.1%) serum samples belonging to 17 fattening pigs and 1 boar tested positive by Wb. Positive sera tested by Wb using crude worm extract antigens (CWE), displayed a banding pattern similar to the CWE-Wb pattern of T. spiralis and T. britovi reference pig sera but different to that of T. pseudospiralis reference pig sera. No larvae were detected in muscles of serologically positive pigs by artificial digestion. The presence of anti- Trichinella antibodies in the absence of larvae in the muscles, suggests that the pigs were infected with T. britovi and not T. spiralis whose larvae survive in the muscles for at least two years. These results suggest that T. britovi is circulating in Nebrodi Regional Park in Sicily. ELISA testing may constitute a suitable tool for large-scale screening of Trichinella spp. infection in free-ranging pigs, when ELISA-positive sera are confirmed by Wb. Free-ranging animals can act as sentinels for the presence of zoonotic nematodes of the genus Trichinella in wildlife. • Free-ranging pig sentinels for Trichinella spp. surveillance in wildlife. • Combined serological tests are informative for Trichinella spp. epidemiology. • Sicily is the third Mediterranean islands with Trichinella infection in wildlife.

Time-resolved transcriptional profiling of Trichinella-infected murine myocytes helps to elucidate host\u2013pathogen interactions in the muscle stage

BackgroundParasites of the genus Trichinella are the pathogenic agents of trichinellosis, which is a widespread and severe foodborne parasitic disease. Trichinella spiralis resides primarily in mammalian skeletal muscle cells. After invading the cells of the host organism, T. spiralis must elude or invalidate the host’s innate and adaptive immune responses to survive. It is necessary to characterize the pathogenesis of trichinellosis to help to prevent the occurrence and further progression of this disease. The aims of this study were to elucidate the mechanisms of nurse cell formation, pathogenesis and immune evasion of T. spiralis, to provide valuable information for further research investigating the basic cell biology of Trichinella-infected muscle cells and the interaction between T. spiralis and its host.MethodsWe performed transcriptome profiling by RNA sequencing to identify global changes at 1, 3, 7, 10 and 15 days post-infection (dpi) in gene expression in the diaphragm after the parasite entered and persisted within the murine myocytes; the mice were infected by intravenous injection of newborn larvae. Gene expression analysis was based on the alignment results. Differentially expressed genes (DEGs) were identified based on their expression levels in various samples, and functional annotation and enrichment analysis were performed.ResultsThe most extensive and dynamic gene expression responses in host diaphragms were observed during early infection (1 dpi). The number of DEGs and genes annotated in the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology databases decreased significantly in the infected mice compared to the uninfected mice at 3 and 7 dpi, suddenly increased sharply at 10 dpi, and then decreased to a lower level at 15 dpi, similar to that observed at 3 and 7 dpi. The massive initial reaction of the murine muscle cells to Trichinella infection steadied in the later stages of infection, with little additional changes detected for the remaining duration of the studied process. Although there were hundreds of DEGs at each time point, only 11 genes were consistently up- or downregulated at all 5 time points.ConclusionsThe gene expression patterns identified in this study can be employed to characterize the coordinated response of T. spiralis-infected myocytes in a time-resolved manner. This comprehensive dataset presents a distinct and sensitive picture of the interaction between host and parasite during intracellular infection, which can help to elucidate how pathogens evade host defenses and coordinate the biological functions of host cells to survive in the mammalian environment.Graphical

Clinical and laboratory profile of trichinellosis from a non-endemic country

Trichinellosis is a zoonotic parasitic infection caused by nematodes of the genus Trichinella. Humans mostly get infected by eating raw/under-cooked pork. In India, it has been reported mostly as sporadic cases especially from North Eastern and Eastern part of country.In this study, we retrospectively analyzed the socio-demographic pattern, clinical presentation, laboratory profile and treatment response in Trichinella-infected patients visiting our tertiary care center which mainly caters to patients from North India. For this retrospective laboratory-based analysis, patients diagnosed on the basis of positive anti-Trichinella IgG antibodies between 1st June 2008, and 31st May 2019 were included.A total of 11 positive trichinellosis cases were detected, of whom majority were children who presented with history of fever, gastrointestinal symptoms, myalgia, eosinophilia along with hepatomegaly and pulmonary manifestations. No CNS involvement was seen in any of the patients although it is commonly associated with Trichinella infection. All patients recovered uneventfully after antihelminthic treatment.

The study of persistence of microorganisms and parasites in food products

Safety of food products is assessed by hygiene standards, which include biological, chemical and physical risk factors. Biological risk factors include viruses, bacteria, mold and yeast fungi, protozoa, helminths and their toxins. Their presence in food products is either completely unacceptable, or should not exceed the acceptable ranges of concentrations in a certain volume of the test products. The original scoring technique was used for a quantitative assessment of biological risks. The persistence of microorganisms and helminthes was evaluated in meat, dairy and vegetable products, culinary products, eggs, canned food, pickles and marinades. Among the studied biological risk factors, the following have very low persistence in food products: adolescari of Fasciola spp.; eggs of Trichocephalus trichiuris, Enterobius vermicularis, Hymenolepis nana, Echinococcus spp., Ascaris lumbricoides, Strongyloides stercoralis larvae, cysts of Lamblia intestinalis, Entamoeba histolytica. Low persistence was demonstrated by Rotavirus, hepatitis A virus, the genus Norovirus, bacteria of the Leptospira spp. and Vibrio spp., Escherichia coli, Toxoplasma gondii and Cryptosporidium parvum. Medium persistence was demonstrated by plerocercoids of Diphyllobothrium spp, cysticercuses of Taeniarhynchus saginatus and Taenia solium, bacteria Shigella spp. and Francisella tularensis. High persistence was shown by larvae of the genus Trichinella, metacercaria Opisthorchidae, bacteria Mycobacterium spp., Proteus spp., Campylobacter spp., Yersinia spp., Brucella spp., Bacillus cereus, Clostridium perfringens, Staphylococcus aureus and Clostridium botulinum. Aphthovirus, Salmonella spp. and Listeria monocytogenes have very high persistence.

Trichinella spiralis in a cougar (Puma concolor) hunted by poachers in Chile.

Trichinellosis is a zoonosis caused by nematodes of the Trichinella genus, of which 10 species have been described. Species identification when larvae is found is only possible using molecular tools. Meat from pigs and game animals not subjected to veterinary inspection are the main sources of human infections. The hunting of native carnivores is prohibited in Chile due to conservation issues and the fact that those animals favor pest control. The illegal hunting of a cougar (Puma concolor) occurred in September 2020. Herein, the molecular identification of Trichinella larvae, by analyzing nuclear (expansion segment V) and mitochondrial (cytochrome C oxidase subunit I) sequences are described. Both the amplification of the expansion segment V region and the phylogenetic analysis of a segment of a fragment of the cytochrome c-oxidase subunit I sequence confirmed that the larvae belonged to T. spiralis. The case described herein represents the first evidence of illegal hunting of a protected mammal infected with Trichinella in Chile, highlighting the 'One Health' perspective to face this disease in the rural-sylvatic interphase.

Trichinella nativa and Trichinella T6 in arctic foxes (Vulpes lagopus) from northern Canada

Parasitic zoonotic nematodes of the genus Trichinella circulate in wildlife and domestic hosts worldwide through the ingestion of infected meat. Due to their role as scavengers and predators in terrestrial and marine arctic ecosystems, Arctic foxes (Vulpes lagopus) are ideal sentinels for the detection of Trichinella spp. In this study, we determined the prevalence, larval intensity, and species of Trichinella from 91 trapped Arctic foxes collected around the northern Canadian communities of Sachs Harbour (Ikaahuk) on Banks Island (n = 23), and Ulukhaktok and Cambridge Bay (Ikaluktutiak) on Victoria Island (n = 68). Using pepsin-HCl digestion, larvae of Trichinella spp. were recovered from the left forelimb muscle (flexor carpi ulnaris) in 19 of the 91 foxes (21% prevalence, 95% CI: 14–30%). For the first time in Arctic foxes in Canada, Trichinella species were identified using multiplex PCR that was followed up with PCR-RFLP to distinguish between T. nativa and T. chanchalensis. All infected foxes harbored T. nativa, and one fox was co-infected with Trichinella T6; the latter is a new host record. Age of the fox was significantly associated with Trichinella spp. infection and the odds of being infected were three times higher in foxes ≥2 years of age (p = 0.026), indicating cumulative exposure with age. While Arctic foxes are seldom harvested for human consumption, they serve as sentinel hosts of Trichinella spp., confirming the presence of the parasite in wildlife in the region.