Experimental Infections Reveal Acquired Zoonotic Capacity of Human Schistosomiasis Trough Hybridization.

We are currently witnessing the endemization of urogenital schistosomiasis in southern Europe. The incriminated parasite is a hybrid between a human parasite and a livestock parasite. Using an experimental evolutionary protocol, we created hybrid lines from pure strains of both parasite species. We showed that the host spectrum of the human parasite is enlarged to the livestock parasite after genomic introgression. We also evidenced that the tropism of the parasites within the host changes and that some hybrid lines are more virulent than the parental strains. These results engage a paradigm shift from human to zoonotic transmission of urogenital schistosomiasis.

Trichinella spiralis inhibits myoblast differentiation by targeting SQSTM1/p62 with a secreted E3 ubiquitin ligase.

Trichinella spiralis infection is associated with the formation of cysts within host skeletal muscle cells, thereby enabling immune evasion and subsequent growth and development; however, the pathogenic factors involved in this process and their mechanisms remain elusive. Here, we found that Ts-RNF secreted by T. spiralis is required for its growth and development in host cells. Further study revealed that Ts-RNF functions as an E3 ubiquitin ligase that targets the UBA domain of SQSTM1/p62 by forming K63-type ubiquitin chains. This modification interferes with autophagic flux, leading to impaired mitochondrial clearance and abnormal myotube differentiation and fusion. Our results established that T. spiralis increases its escape by interfering with host autophagy via the secretion of an E3 ubiquitin ligase.

Immunosuppressive Ability of Trichinella spiralis Adults Can Ameliorate Type 2 Inflammation in a Murine Allergy Model.

BACKGROUND: There is an increase in the global incidence of allergies. The hygiene hypothesis and the old friend hypothesis reveal that helminths are associated with the prevalence of allergic diseases. The therapeutic potential of Trichinella spiralis is recognized; however, the stage at which it exerts its immunomodulatory effect is unclear. METHODS: We evaluated the differentiation of bone marrow-derived macrophages stimulated with T spiralis excretory-secretory products. Based on an ovalbumin-induced murine model, T spiralis was introduced during 3 allergy phases. Cytokine levels and immune cell subsets in the lung, spleen, and peritoneal cavity were assessed. RESULTS: We found that T spiralis infection reduced lung inflammation, increased anti-inflammatory cytokines, and decreased Th2 cytokines and alarms. Recruitment of eosinophils, CD11b+ dendritic cells, and interstitial macrophages to the lung was significantly suppressed, whereas Treg cells and alternatively activated macrophages increased in T spiralis infection groups vs the ovalbumin group. Notably, when T spiralis was infected prior to ovalbumin challenge, intestinal adults promoted proportions of CD103+ dendritic cells and alveolar macrophages. CONCLUSIONS: T spiralis strongly suppressed type 2 inflammation, and adults maintained lung immune homeostasis.

The gut microbiota contributes to changes in the host immune response induced by Trichinella spiralis.

The gut microbiota plays an important role in parasite-host interactions and the induction of immune defense responses. Trichinella spiralis is an important zoonotic parasite that can directly or indirectly interact with the host in the gut. Changes in the gut microbiota following infection with T. spiralis and the role of the gut microbiota in host immune defense against T. spiralis infection were investigated in our study. 16S rRNA sequencing analysis revealed that infection with T. spiralis can reduce the diversity of the gut microbiota and alter the structure of the gut microbiota during early infection, which was restored when the worm left the gut. Antibiotic treatment (ABX) and fecal bacterial transplantation (FMT) were used to investigate the role of the gut microbiota in the host expulsion response during infection with T. spiralis. We found that ABX mice had a higher burden of parasites, and the burden of parasites decreased after fecal bacterial transplantation. The results of flow cytometry and qPCR revealed that the disturbance of the gut microbiota affects the proportion of CD4+ T cells and the production of IL-4, which weakens Th2 responses and makes expulsion difficult. In addition, as the inflammatory response decreased with the changes of the microbiota, the Th1 response also decreased. The metabolomic results were in good agreement with these findings, as the levels of inflammatory metabolites such as ceramides were reduced in the ABX group. In general, T. spiralis infection can cause changes in the gut microbiota, and the presence or absence of microbes may also weaken intestinal inflammation and the expulsion of T. spiralis by affecting the immune response of the host.

A Trichinella britovi outbreak in the Northern Alps of France: investigation by a local survey network.

We describe a small family outbreak of trichinellosis caused by the consumption of raw ham from a wild boar (Sus scrofa) hunted in the northern Alps of France in February 2022. Out of the six people, aged 3-69 years, who consumed the meat, three were confirmed cases, and three were suspected cases. Eosinophilia detected in four people was the hallmark that drove the diagnosis. Three patients presented with myalgia, two with intense and prolonged chest pain, and one with elevated troponin. One patient presented with dermographism during treatment. Anti-Trichinella IgG were detected in three symptomatic individuals after about ten weeks. One patient had negative serology and no symptoms, but was on long-term corticosteroid therapy. Trichinella britovi larvae (8.3 larvae/g) were detected in the wild boar meat remnants. Trichinellosis is rare in France, but this family outbreak is reminiscent of the circulation of this pathogen in wild animals, highlighting the need to inform hunters about the risk of infection linked to the consumption of raw meat of game animals, and about the need for veterinary inspection of game meat. The consumption of raw meat outside controlled circuits is a practice not devoid of risks, which justifies raising the awareness of hunters, doctors, and medical biologists.

Title: Un foyer de Trichinella britovi dans les Alpes du Nord françaises : investigation par un réseau local de prospection. Abstract: Nous décrivons une épidémie familiale de trichinellose causée par la consommation de jambon cru d'un sanglier (Sus scrofa) chassé dans le nord des Alpes françaises en février 2022. Sur les six personnes âgées de 3 à 69 ans qui ont consommé la viande, trois étaient des cas confirmés, et trois étaient des cas suspects. L'éosinophilie détectée chez quatre personnes a permis d'évoquer le diagnostic. Trois patients présentaient des myalgies, et deux des douleurs thoraciques intenses et prolongées dont un avec une troponine élevée. Un patient a présenté un dermographisme pendant le traitement. Des IgG anti-Trichinella ont été détectées chez trois individus symptomatiques après environ dix semaines. Un des patients avait une sérologie négative et aucun symptôme mais était sous corticothérapie au long cours. Des larves de Trichinella britovi (8,3 larves/g) ont été détectées dans les restes du jambon de sanglier incriminé. La trichinellose est rare en France, mais cette épidémie familiale rappelle la circulation de cet agent pathogène chez les animaux sauvages, qui nécessite d'informer les chasseurs sur les risques d'infections liés à la consommation de viande crue de gibier, et de préconiser un contrôle vétérinaire des viandes de gibier. La consommation de viande crue en dehors des circuits contrôlés est une pratique non dénuée de risques, qui justifie une sensibilisation des chasseurs, médecins et biologistes médicaux.

Aptamer-Based Technologies for Parasite Detection.

Centuries of scientific breakthroughs have brought us closer to understanding and managing the spread of parasitic diseases. Despite ongoing technological advancements in the detection, treatment, and control of parasitic illnesses, their effects on animal and human health remain a major concern worldwide. Aptamers are single-stranded oligonucleotides whose unique three-dimensional structures enable them to interact with high specificity and affinity to a wide range of targets. In recent decades, aptamers have emerged as attractive alternatives to antibodies as therapeutic and diagnostic agents. Due to their superior stability, reusability, and modifiability, aptamers have proven to be effective bioreceptors for the detection of toxins, contaminants, biomarkers, whole cells, pathogens, and others. As such, they have been integrated into a variety of electrochemical, fluorescence, and optical biosensors to effectively detect whole parasites and their proteins. This review offers a summary of the various types of parasite-specific aptamer-based biosensors, their general mechanisms and their performance.

Lentinan -triggered butyrate-producing bacteria drive the expulsion of the intestinal helminth Trichinella spiralis in mice.

Trichinellosis caused by Trichinella spiralis is a serious zoonosis with a worldwide distribution. Lentinan (LNT) is known to modulate the intestinal environment with noted health benefits, yet the effect of LNT against intestinal helminth is unknown. In our study, we first observed that LNT could trigger worm expulsion by promoting mucus layer functions through alteration of gut microbiota. LNT restored the abundance of Bacteroidetes and Proteobacteria altered by T. spiralis infection to the control group level. Interestingly, LNT triggered the production of butyrate. Then, we determined the deworming capacity of probiotics (butyrate-producing bacteria) in mice. Collectively, these findings indicated that LNT could modulate intestinal dysbiosis by T. spiralis, drive the expulsion of intestinal helminth and provided an easily implementable strategy to improve the host defence against T. spiralis infection.

Toxocara cati and Toxoplasma gondii in French Birds of Prey.

Parasites have developed many strategies to ensure their development, multiplication, and dissemination, including the use of reservoir hosts that are often nondomesticated species. Despite drastic reductions in their populations, wild birds remain widespread worldwide and could constitute some of these reservoirs. We focused on the identification of wild bird species harboring parasite stages in their muscles. Breast muscles of 327 birds of 27 different species were collected at three different sites in France. After artificial digestion, isolated nematode larvae were identified by PCR sequencing or restriction fragment length polymorphism (PCR-RFLP). Toxocara cati was identified mainly in birds of prey. The presence of anti-Toxoplasma antibodies was investigated by modified agglutination test on muscle fluids. Anti-Toxoplasma antibodies were detected in 65 out of 166 samples from various bird species. Avifauna, particularly birds of prey, could help on the surveillance of parasite circulation and play a role as sentinel species.

Helminth Therapy for Immune-Mediated Inflammatory Diseases: Current and Future Perspectives.

Inflammatory bowel disease and allergic asthma, as typical immune-mediated inflammatory diseases (IMIDs), are associated with immune imbalance caused by complex interactions among environmental, genetic and bacterial factors. The changing immune imbalance of IMIDs not only causes serious pathological damages but also increases the difficulty of treatment. Helminths or helminth-derived molecules have been increasingly employed to treat IMIDs due to their immunoregulatory ability. Since helminth infection is not an appropriate treatment direction due to the complex immunoregulation and safety concerns, one of the new therapies is to harness the immunoregulation induced by the identified helminth-derived molecules using immune indexes as a guide. This review discusses the pathogenesis of inflammatory bowel disease and allergic asthma, and summarizes the therapeutic effect of helminths and the immunoregulatory mechanisms induced by helminth-derived molecules proposing therapeutic regimens.

Characterizing changes in network connectivity following chronic head trauma in special forces military personnel: a combined resting-fMRI and DTI study.

BACKGROUND: Soldiers are exposed to significant repetitive head trauma, which may disrupt functional and structural brain connectivity patterns. PURPOSE/HYPOTHESIS: Integrate resting-state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI) to characterize changes in connectivity biomarkers within Canadian Special Operations Forces (CANSOF), hypothesizing that alterations in architectural organization of cortical hubs may follow chronic repetitive head trauma. METHODS: Fifteen CANSOFs with a history of chronic exposure to sub-concussive head trauma and concussive injuries (1.9 ± 2.0 concussions (range: [0-6])), as well as an equal age-matched cohort of controls (CTLs) were recruited. BOLD-based rs-fMRI was combined with DTI to reconstruct functional and structural networks using independent component analyses and probabilistic tractography. Connectivity markers were computed based on the distance between functional seeds to assess for possible differences in injury susceptibility of short- and long-range connections. RESULTS/DISCUSSION: Significant hyper- and hypo-connectivity differences in cortical connections were observed suggesting that chronic head trauma may predispose soldiers to changes in the functional organization of brain networks. Significant structural alterations in axonal fibers directly connecting disrupted functional nodes were specific to hyper-connected long-range connections, suggesting a potential relationship between axonal injury and increases in neural recruitment following repetitive head trauma from high-exposure military duties.

The Anti-Inflammatory Immune Response in Early Trichinella spiralis Intestinal Infection Depends on Serine Protease Inhibitor-Mediated Alternative Activation of Macrophages.

Trichinella spiralis is recognized for its ability to regulate host immune responses via excretory/secretory (ES) products. Serine protease inhibitors (serpins) play an important role in ES product-mediated immunoregulatory effects during T. spiralis infection. In this study, the immunoregulatory properties of a serpin derived from T. spiralis (Ts-serpin) were explored in BALB/c mice. The results showed that naturally occurring Ts-serpin was detected in the stichosomes of muscle larvae and adult worms. Moreover, enhancing (by injection of a soluble-expressed recombinant Ts-serpin [rTs-serpin]) or blocking (by passive immunization with anti-rTs-serpin serum) the effects of Ts-serpin changed the levels of cytokines related to inflammation induced by T. spiralis infection in the serum, mesenteric lymph nodes, and peritoneal cavity, which then led to a change in the adult worm burden in early T. spiralis infection. Moreover, the phenotypic changes in peritoneal macrophages were found to be related to Ts-serpin-mediated immunoregulation. Furthermore, a STAT6 activation mechanism independent of IL-4Rα has been found to regulate protein-mediated alternative activation of bone marrow-derived macrophages and mimic the immunoregulatory role of Ts-serpin in T. spiralis infection. Finally, the anti-inflammatory properties of rTs-serpin and bone marrow-derived macrophage alternative activation by rTs-serpin were demonstrated using a trinitrobenzene sulfonic acid-induced inflammatory bowel disease model. In summary, a protein-triggered anti-inflammatory mechanism was found to favor the survival of T. spiralis in the early stage of infection and help to elucidate the immunoregulatory effects of T. spiralis on the host immune response.

Nod-like receptor pyrin domain containing 3 plays a key role in the development of Th2 cell-mediated host defenses against Trichinella spiralis infection.

The inflammasome is a key line of immune defense against invading infectious pathogens. However, knowledge of the role of nod-like receptor pyrin domain containing 3 (NLRP3) in Trichinella spiralis infection which characteristically induces T-helper 2 (Th2) immune responses is sparse. In this study, we investigated the role of NLRP3 in the protection against T. spiralis infection through the Th2 immune response. We show that NLRP3 expression in CD4+ T cells was significantly increased at 7 days post-infection of T. spiralis. Compared to wild-type (WT) CD4+ T cells, the expression of IL-4 mRNA was reduced in NLRP3-/- CD4+ T cells, however, the expression of IFN-γ mRNA was comparable between the two groups. Consistently, ELISA and flow cytometry analysis showed that NLRP3-/- CD4+ T cells secreted lower levels of IL-4 than CD4+ T cells from WT mice, whilst the levels of IFN-γ secreted by NLRP3-/- CD4+ T cells were of similar levels to those secreted by WT CD4+ T cells. In addition, we observed a significant reduction of IL-4 and IL-13 by ELISA in NLRP3 -/- mice at 1, 2 and 4 weeks post-infection. Furthermore, we found that adult worm survival was substantially prolonged and muscle larvae burden was significantly increased in NLRP3 -/- mice. We further show that NLRP3 promotes the host defense against T. spiralis through its participation in the differentiation of Th2 cells. These findings provide novel insights into parasite expulsion and highlight the importance of NLRP3 in the host defense against T. spiralis.

The First Report of Trichinella britovi in Armenia.

BACKGROUND: More than a hundred species of mammals, birds, and reptiles are infected by nematodes of the Trichinella genus worldwide. Although, Trichinella spp. are widely distributed in neighboring countries including Georgia, Azerbaijan, Turkey and Iran, no study was conducted in Armenia since 1980's. METHODS: In 2017-2018, five muscle samples belonging to Armenian lynx, otter, wild boar, fox and wolf were tested for Trichinella spp. and recovered larvae were identified by multiplex PCR technique. RESULTS: Twenty-six larvae/gram and one larva/gram were found in lynx and fox samples respectively. They were identified as T. britovi. CONCLUSION: So far only two species were identified in Armenia, T. spiralis and T. pseudospiralis, and this is the first time that T. britovi is reported in Armenia.

A two-step morphology-PCR strategy for the identification of nematode larvae recovered from muscles after artificial digestion at meat inspection.

To ensure that meat from livestock and game is safe for human consumption, European legislation lays down rules for mandatory testing. Helminth larvae are a category of zoonotic foodborne pathogens that can contaminate meat. Among helminths, the only zoonotic nematode regulated in Europe regarding meat inspection is Trichinella spp.. It is precisely during Trichinella testing that other potentially zoonotic larvae can be found. Due to current lack of tools, their identification is often very complicated. Nematode larvae other than Trichinella, recovered from artificial digestions of pig and wild boar muscles from France and Germany, were subjected to a newly developed two-step identification scheme, which includes both morphological examination and molecular assays. The first step is a general orientation towards a broad taxonomic group; the second step consists of targeted identification based on the results of first step. Different parasites were identified, some of which were not zoonotic such as Metastrongylus spp. and Angiostrongylus vasorum, but others are known to be zoonotic such as Toxocara cati, Ascaris suum, and Uncinaria stenocephala. The strategy is efficient for the identification of nematode larvae recovered from muscles but could also be applied for larvae from other sources.

Human Outbreak of Trichinellosis Caused by Trichinella papuae Nematodes, Central Kampong Thom Province, Cambodia.

In September 2017, a severe trichinellosis outbreak occurred in Cambodia after persons consumed raw wild pig meat; 33 persons were infected and 8 died. We collected and analyzed the medical records for 25 patients. Clinical signs and symptoms included myalgia, facial or peripheral edema, asthenia, and fever. We observed increased levels of creatine phosphokinase and aspartate aminotransferase-, as well as eosinophilia. Histopathologic examination of muscle biopsy specimens showed nonencapsulated Trichinella larvae. A Trichinella excretory/secretory antigen ELISA identified Trichinella IgM and IgG. Biopsy samples were digested and larvae were isolated and counted. PCR for the 5S rDNA intergenic spacer region and a multiplex PCR, followed by sequencing identified the parasite as Trichinella papuae. This species was identified in Papua New Guinea during 1999 and in several outbreaks in humans in Thailand. Thus, we identified T. papuae nematodes in humans in Cambodia.

A common source for a trichinellosis outbreak reported in France and Serbia in 2017.

Trichinellosis is a rare parasitic zoonosis in the European Union. Meat from backyard pigs was the common source for a trichinellosis outbreak caused by Trichinella spiralis, which occurred in France and Serbia in the beginning of 2017. An epidemiological study was conducted in France and Serbia to determine the extent of the outbreak, to identify its source and to implement control measures. Three cases were exposed in Serbia and brought back to France pork delicatessen which they shared with relatives and friends. Around 47 individuals were exposed to the parasitised meat in France and Serbia and 20 cases of trichinellosis were reported (nine in France and 11 in Serbia). Nine of them were female. The diagnosis was delayed, in part because the parasitosis was not known by most physicians, which led to complications in the French cases such as facial paralysis and pulmonary embolism. Health alerts and survey networks are indispensable at a European level to control the disease.

Species identification of Trichinella originated from various host and different geographical location by MALDI-TOF.

The foodborne zoonotic nematode Trichinella spp. can cause human trichinellosis when raw or undercooked contaminated meat is ingested. To date, twelve Trichinella species/genotypes have been described. According to EU regulation any Trichinella larvae detected during mandatory routine examinations need to be identified at a species level by a competent laboratory. Currently, Trichinella species identification is performed using molecular biology tools such as multiplex PCR, PCR-sequencing or PCR-RFLP. These techniques require high level of skills for good interpretation of the results. Due to its rapidness and ease of use a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) protocol was previously developed for the identification of Trichinella species. Using this method, spectra from different Trichinella species and strains were acquired allowing to generate new Main Spectra (MSP). Finally a new MSP database from Trichinella spp. Samples of different countries (France, Germany and Poland), including field samples, was generated. Comparing the different main spectra, Trichinella worms were identified at the species level and differences in the genetic diversities within the different species are discussed. In conclusion, using the previously described method on field samples is a reliable, rapid, easy-to-use and cheap tool for Trichinella species identification. The new Trichinella database could be incremented with new samples. It constitutes a tool, which could be used as an alternative method to replace the actual molecular methods for Trichinella species identification.

Evaluation of immunogenicity and protection of the Mic1-3 knockout Toxoplasma gondii live attenuated strain in the feline host.

Toxoplasmosis is a zoonotic disease caused by the parasite Toxoplasma gondii. Up to a third of the global human population is estimated to carry a T. gondii infection, which can result in severe complications in immunocompromised individuals and pregnant women. Humans and animals can become infected by ingesting either tissue cysts containing T. gondii bradyzoites, from raw or undercooked meat, or sporulated oocysts from environmental sources. T. gondii oocysts are released in the faeces of cats and other felids, which are the parasite's definitive hosts, leading to environmental contamination. Therefore, vaccination of the feline host against T. gondii is an interesting strategy to interrupt the parasitic life cycle and subsequently limit contamination of intermediate hosts. With this goal in mind, we tested in cats, an attenuated live strain of T. gondii deleted for the Mic1 and Mic3 genes (Mic1-3KO) that was previously shown to be an efficient vaccine candidate in mouse and sheep models. Subcutaneous or oral vaccination routes induced a high specific antibody titer in the cat sera, indicating that the Mic1-3KO strain is immunogenic for cats. To assess protection induced by the vaccine candidate strain, we followed oocysts shedding by vaccinated cats, after oral challenge with a T. gondii wild-type strain. Surprisingly, a high antibody titer did not prevent cats from shedding oocysts from the challenge strain, regardless of the vaccination route. Our results show that the Mic1-3KO vaccine candidate is immunogenic in the feline host, is well tolerated and safe, but does not confer protection against oocysts shedding after natural infection with wild type T. gondii. This result highlights the particular relationship between T. gondii and its unique definitive host, which indicates the need for further investigations to improve vaccination strategies to limit environmental and livestock contaminations.

First identification of Cryptosporidium parvum zoonotic subtype IIaA15G2R1 in diarrheal lambs in France.

To date, no information is available about the presence of Cryptosporidium spp. in French sheep, nor their potential role as zoonotic reservoirs. A total of 23 fecal samples were collected from diarrheic lambs (<11 days old) from seven randomly selected farms. Cryptosporidium-oocysts were detected microscopically with Direct Immunofluorescence Assays (DFA) in 23/23 (100%) of fecal samples. PCR-RFLP of the 18S rRNA gene was used to determine species in all samples, and only Cryptosporidium parvum was identified. Isolates were subtyped by sequencing the 60 kDa glycoprotein (gp60) gene. Two zoonotic subtypes within the IIa subtype family were identified, including IIaA15G2R1 (22/23) and IIaA16G3R1 (1/23). This study reports for the first time the identification and genotyping of zoonotic C. parvum subtypes from lambs in France. Sheep could thus play an important role as potential reservoirs for this zoonotic protist.

Molecular characterization of Cryptosporidium isolates from diarrheal dairy calves in France.

Cryptosporidium is an obligate intracellular protist parasite infecting a wide range of vertebrate hosts and causes significant intestinal disease in both animals and humans, as some species are zoonotic. Cattle and especially calves have been identified as one of the most common reservoirs of this protist. However, little is known about the genetics of Cryptosporidium in calves in some regions of France. The aim of this study was to detect and isolate Cryptosporidium spp. in faecal samples from naturally infected pre-weaned calves (≤45 days-old) in France. A total of 35 diarrhoeic pre-weaned calf faecal samples were collected from 26 dairy cattle farms in six departments (French administrative provinces). Cryptosporidium presence was established by microscopically screening samples for oocystes with an immunofluorescent (DFA) staining method. DFA-positive samples were then analysed by PCR-RFLP and 18S rRNA gene sequencing to determine species. Cryptosporidium parvum-positive samples were subtyped via nested PCR analysis of a partial fragment of the 60 kDa glycoprotein (gp60) gene product. Data were then integrated into phylogenetic tree analysis. DFA revealed the presence of Cryptosporidium oocysts in 31 out of 35 (88%) samples. Combined with 18S rRNA gene analysis results, C. parvum was detected in 30 samples. Subtyping analysis in 27/30 samples (90%) of the C. parvum isolates revealed two zoonotic subtype families, IIa (24/27) and IId (3/27). Four subtypes were recognised within the subtype family IIa, including the hypertransmissible IIaA15G2R1 subtype that is the most frequently reported worldwide (21/27), IIaA17G3R1 (1/27), IIaA17G1R1 (1/27), and IIaA19G1R1 (1/27). Two subtypes were recognised within the IId subtype family including IIdA22G1 (2/27) and IIdA27G1 (1/27). These findings illustrate the high occurrence of Cryptosporidium in calves in dairy herds and increase the diversity of molecularly characterised C. parvum isolates with the first description of IIaA17G3R1, IIaA19G1R1, and IId subtypes in France. The presence of zoonotic C. parvum subtype families (IIa, IId) in this study suggests that pre-weaned calves are likely to be a significant reservoir of zoonotic C. parvum, and highlights the importance of animal to human cryptosporidiosis transmission risk. Further molecular studies in calves and small ruminants from other French regions are required to better understand the epidemiology of cryptosporidiosis in France.