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Fasciolosis is a globally widespread trematodiasis with a major economic and veterinary impact. Therefore, this disease is responsible for millions of dollars in losses to the livestock industry, and also constitutes an emerging human health problem in endemic areas. The ubiquitous nature of Fasciola hepatica, the main causative agent, is one of the key factors for the success of fasciolosis. Accordingly, this parasite is able to subsist in a wide variety of ecosystems and hosts, thanks to the development of a plethora of strategies for adaption and immune evasion. Fasciolosis comprises a growing concern due to its high prevalence rates, together with the emergence of strains of the parasite resistant to the treatment of choice (triclabendazole). These facts highlight the importance of developing novel control measures which allow for an effective protection against the disease before F. hepatica settles in a niche inaccessible to the immune system. However, knowledge about the initial phases of the infection, including the migration mechanisms of the parasite and the early innate host response, is still scarce. Recently, our group developed an in vitro host-parasite interaction model that allowed the early events to be unveiled after the first contact between the both actors. This occurs shortly upon ingestion of F. hepatica metacercariae and the emergence of the newly excysted juveniles (FhNEJ) in the host duodenum. Here, we present a transcriptomic analysis of such model using an approach based on RNA sequencing (RNA-Seq), which reveals changes in gene expression related to proteolysis and uptake of metabolites in FhNEJ. Additionally, contact with the parasite triggered changes in host intestinal cells related to pseudogenes expression and host defence mechanisms, including immune response, among others. In sum, these results provide a better understanding of the early stages of fasciolosis at molecular level, and a pool of targets that could be used in future th

SARS-CoV-2, the causal agent of COVID-19, is a new coronavirus that has rapidly spread worldwide and significantly impacted human health by causing a severe acute respiratory syndrome boosted by a pulmonary hyperinflammatory response. Previous data from our lab showed that the newly excysted juveniles of the helminth parasite Fasciola hepatica (FhNEJ) modulate molecular routes within host cells related to vesicle-mediated transport and components of the innate immune response, which could potentially be relevant during viral infections. Therefore, the aim of the present study was to determine whether FhNEJ-derived molecules influence SARS-CoV-2 infection efficiency in Vero cells. Pre-treatment of Vero cells with a tegument-enriched antigenic extract of FhNEJ (FhNEJ-TEG) significantly reduced infection by both vesicular stomatitis virus particles pseudotyped with the SARS-CoV-2 Spike protein (VSV-S2) and live SARS-CoV-2. Pre-treatment of the virus itself with FhNEJ-TEG prior to infection also resulted in reduced infection efficiency similar to that obtained by remdesivir pre-treatment. Remarkably, treatment of Vero cells with FhNEJ-TEG after VSV-S2 entry also resulted in reduced infection efficiency, suggesting that FhNEJ-TEG may also affect post-entry steps of the VSV replication cycle. Altogether, our results could potentially encourage the production of FhNEJ-derived molecules in a safe, synthetic format for their application as therapeutic agents against SARS-CoV-2 and other related respiratory viruses.

Fasciola hepatica is the main causative agent of fasciolosis, a zoonotic parasitic disease of growing public health concern. F. hepatica metacercariae are ingested by the host and excyst in the intestine, thereby releasing the newly excysted juveniles (FhNEJ), which traverse the gut wall and migrate towards the biliary ducts. Since blocking F. hepatica development is challenging after crossing of the intestinal wall, targeting this first step of migration might result in increased therapeutic success. The intestinal extracellular matrix (ECM) is constituted by a network of structural proteins, including laminin (LM) and fibronectin (FN), that provide mechanical support while acting as physical barrier against intestinal pathogens. Here, we employed ELISA and immunofluorescent assays to test for the presence of LM- and FN-binding proteins on a tegument-enriched antigenic fraction of FhNEJ, and further determined their identity by two-dimensional electrophoresis coupled to mass spectrometry. Additionally, we performed enzymatic assays that revealed for the first time the capability of the juvenile-specific cathepsin L3 to degrade LM, and that LM degradation by FhNEJ proteins is further potentiated in the presence of host plasminogen. Finally, a proteomic analysis showed that the interaction with LM triggers protein changes in FhNEJ that may be relevant for parasite growth and adaptation inside the mammalian host. Altogether, our study provides valuable insights into the molecular interplay between FhNEJ and the intestinal ECM, which may lead to the identification of targetable candidates for the development of more effective control strategies against fasciolosis.

The trematode Fasciola hepatica is the most widespread causative agent of fasciolosis, a parasitic disease that mainly affects humans and ruminants worldwide. During F. hepatica infection, newly excysted juveniles (FhNEJ) emerge in the duodenum of the mammalian host and migrate towards their definitive location, the intra-hepatic biliary ducts. Understanding how F. hepatica traverses the intestinal wall and migrates towards the liver is pivotal for the development of more successful strategies against fasciolosis. The central enzyme of the mammalian fibrinolytic system is plasmin, a serine protease whose functions are exploited by a number of parasite species owing to its broad spectrum of substrates, including components of tissue extracellular matrices. The aim of the present work is to understand whether FhNEJ co-opt the functions of their host fibrinolytic system as a mechanism to facilitate trans-intestinal migration.

La fasciolosis producida por Fasciola hepatica es una enfermedad parasitaria que causa grandes pérdidas económicas en la industria ganadera, y una preocupación sanitaria creciente a nivel mundial debido a su carácter zoonótico. Los mecanismos moleculares que rigen la invasión llevada a cabo por el parásito desde el intestino hasta las vías biliares del hospedador siguen planteando grandes incógnitas. Por ello, el objetivo de este trabajo fue establecer un modelo de infección experimental en ratón para identificar las moléculas parasitarias clave durante la migración de los vermes juveniles a través de los tejidos del hospedador. Ratones C57BL/6 se infectaron oralmente con 200 metacercarias de F. hepatica y, posteriormente, los parásitos fueron recuperados a las 24 horas en la cavidad peritoneal (9.38 % tasa de recuperación) y a los 8 días en el parénquima hepático (21.19 % tasa de recuperación). Los extractos parasitarios tegumental y somático y sus respectivos controles se sometieron a proteómica cuantitativa mediante la adquisición secuencial de todos los espectros de masas teóricos o SWATH-MS, de sus siglas en inglés "Sequential Window Acquisition of All Theoretical Mass Spectra". Los resultados proteómicos revelan la presencia de 1180 proteínas en las muestras, de las cuales, 243 proteínas se expresan diferencialmente en los parásitos extraídos en el peritoneo y 543 proteínas en los procedentes del hígado. La anotación ontológica de los términos asociados a estas proteínas apunta principalmente a la relevancia de mecanismos de defensa antioxidante, proteolíticos, de motilidad, metabólicos y de transporte de moléculas en la invasión llevada a cabo por F. hepatica. En conjunto, los avances de este estudio profundizarán en el conocimiento de la interacción parásito-hospedador de la fasciolosis para identificar nuevas dianas moleculares en el desarrollo de vacunas frente a F. hepatica.

Background: Bat flies (Diptera: Hippoboscoidea: Nycteribiidae and Streblidae) are increasingly appreciated as hosts of "bat-associated" viruses. We studied straw-colored fruit bats (Eidolon helvum) and their nycteribiid bat flies (Cyclopodia greefi) in Nigeria to investigate the role of bat flies in vectoring or maintaining viruses. Methods: We captured bats and bat flies across northern Nigeria. We used metagenomics to identify viruses in 40 paired samples (20 flies from 20 bats). We characterized viruses using genomic and phylogenetic methods, and we compared infection frequencies in bats and their bat flies. Results: In 20 bats, we detected two individuals (10%) infected with eidolon helvum parvovirus 1 (BtPAR4) (Parvoviridae; Tetraparvovirus), previously described in Ghana, and 10 bats (50%) with a novel parvovirus in the genus Amdoparvovirus (Parvoviridae). The amdoparvoviruses include Aleutian disease virus of mink and viruses of other carnivores but have not previously been identified in bats or in Africa. In 20 paired bat flies (each fly from 1 bat) all (100%) were infected with a novel virus in the genus Sigmavirus (Rhabdoviridae). The sigmaviruses include vertically transmitted viruses of dipterans. We did not detect BtPAR4 in any bat flies, and we did not detect the novel sigmavirus in any bats. However, we did detect the novel amdoparvovirus in 3 out of 20 bat flies sampled (15%), including in 2 bat flies from bats in which we did not detect this virus. Discussion: Our results show that bats and their bat flies harbor some viruses that are specific to mammals and insects, respectively, and other viruses that may transmit between bats and arthropods. Our results also greatly expand the geographic and host range of the amdoparvoviruses and suggest that some could be transmitted by arthropods. Bat flies may serve as biological vectors, mechanical vectors, or maintenance hosts for "bat-associated" viruses.

Helminth parasitoses are among the most prevalent health issues worldwide. Their control depends largely on unravelling host-parasite interactions, including parasitic exploitation of the host haemostatic system. The present study undertakes a scoping review of the research carried out in this field with the aim of unifying and updating concepts. Multiple keywords combined with Boolean operators were employed to design the literature search strategy. Two online databases were used to identify original peer-reviewed articles written in English and published before 1st January 2020 describing molecular interactions between helminth parasites and the host haemostatic system. Relevant data from the selected sources of evidence were extracted and analysed. Ninety-six publications reporting 259 interactions were selected. Fifty-three proteins belonging to 32 species of helminth parasites were involved in interactions with components of the host haemostatic system. Many of these proteins from both parasite and host were conserved among the different interactions identified. Most of these interactions were related to the inhibition of the coagulation system and the activation of fibrinolysis. This was associated mainly with a potential of parasites to reduce the formation of blood clots in the host and attributed to biological processes, such as parasite nutrition, survival, invasion, evasion and migration or the appearance of pathological mechanisms in the host. A wide range of helminth parasites have developed similar strategies to exploit the haemostatic system of their hosts, which could be regarded as an evolutionary conserved mechanism that could confer benefits to parasites in terms of survival and establishment in their vertebrate hosts.

Bovine anaplasmosis poses serious challenge to profitable livestock production in the tropics. Accurate information on the prevalence, distribution and genetic characteristics of Anaplasma spp. infections of cattle is invaluable for the design of cost-effective control measures. Blood samples from 275 cattle in Nigeria were screened for the DNA of Anaplasma spp. using species-specific primers and nucleotide sequence analysis. The DNA of Anaplasmataceae was detected based on 16S rRNA gene in 135 out of the 275 (49.1%) individuals examined, with 31 (23.0%) and 21(15.6%) being positive for Anaplasma marginale based on msp4 and msp2 genes, respectively. DNA of Anaplasma platys was detected in 62 (45.9%) based on groEL gene and in 27 (20.0%) using the A. platys species-specific primers. Presence of Anaplasma spp. DNA was significantly associated (p = 0.011) with the breed of the animals. Anaplasma nucleotide sequences of one group of the infected samples showed high identities of 99.0 to 100% (16S rRNA gene) and 99.6% (groEL gene) with reference sequences of A. platys, while those of another group matched to A. marginale references (msp2 with 98.9% and msp4 with 99.1%). Furthermore, phylogenetic analysis clustered the nucleotide sequences in this study with A. platys and A. marginale sequences in GenBank, confirming these relationships. For the first time, this study revealed the presence of mixed haplotypes in both A. platys and A. marginale in cattle in Nigeria. More studies are needed to elucidate the epidemiology and veterinary and public health significance of Anaplasma spp. infections in cattle in Nigeria.

Fasciola hepatica is a trematode parasite that infects animals and humans causing fasciolosis, a worldwide-distributed disease responsible for important economic losses and health problems. This disease is of growing public health concern since parasite isolates resistant to the current treatment (triclabendazole) have increasingly been described. F. hepatica infects its vertebrate host after ingestion of the encysted parasite (metacercariae), which are found in the water or attached to plants. Upon ingestion, newly excysted juveniles of F. hepatica (FhNEJ) emerge in the intestinal lumen and cross the intestinal barrier, reach the peritoneum and migrate to the biliary ducts, where adult worms fully develop. Despite the efforts made to develop new therapeutic and preventive tools, to date, protection against F. hepatica obtained in different animal models is far from optimal. Early events of host-FhNEJ interactions are of paramount importance for the infection progress in fasciolosis, especially those occurring at the host-parasite interface. Nevertheless, studies of FhNEJ responses to the changing host environment encountered during migration across host tissues are still scarce. Here, we set-up an ex vivo model coupled with quantitative SWATH-MS proteomics to study early host-parasite interaction events in fasciolosis. After comparing tegument and somatic fractions from control parasites and FhNEJ that managed to cross a mouse intestinal section ex vivo, a set of parasite proteins whose expression was statistically different were found. These included upregulation of cathepsins L3 and L4, proteolytic inhibitor Fh serpin 2, and a number of molecules linked with nutrient uptake and metabolism, including histone H4, H2A and H2B, low density lipoprotein receptor, tetraspanin, fatty acid binding protein a and glutathione-S-transferase. Downregulated proteins in FhNEJ after gut passage were more numerous than the upregulated ones, and included the heath shock proteins HS

Fasciolosis caused by the trematode Fasciola hepatica is a zoonotic neglected disease affecting animals and humans worldwide. Infection occurs upon ingestion of aquatic plants or water contaminated with metacercariae. These release the newly excysted juveniles (FhNEJ) in the host duodenum, where they establish contact with the epithelium and cross the intestinal barrier to reach the peritoneum within 2-3 h after infection. Juveniles crawl up the peritoneum towards the liver, and migrate through the hepatic tissue before reaching their definitive location inside the major biliary ducts, where they mature into adult worms. Fasciolosis is treated with triclabendazole, although resistant isolates of the parasite are increasingly being reported. This, together with the limited efficacy of the assayed vaccines against this infection, poses fasciolosis as a veterinary and human health problem of growing concern. In this context, the study of early host-parasite interactions is of paramount importance for the definition of new targets for the treatment and prevention of fasciolosis. Here, we develop a new in vitro model that replicates the first interaction between FhNEJ and mouse primary small intestinal epithelial cells (MPSIEC). FhNEJ and MPSIEC were co-incubated for 3 h and protein extracts (tegument and soma of FhNEJ and membrane and cytosol of MPSIEC) were subjected to quantitative SWATH-MS proteomics and compared to respective controls (MPSIEC and FhNEJ left alone for 3h in culture medium) to evaluate protein expression changes in both the parasite and the host. Results show that the interaction between FhNEJ and MPSIEC triggers a rapid protein expression change of FhNEJ in response to the host epithelial barrier, including cathepsins L3 and L4 and several immunoregulatory proteins. Regarding MPSIEC, stimulation with FhNEJ results in alterations in the protein profile related to immunomodulation and cell-cell interactions, together with a drastic reduction in the exp

The evolutionary success of parasitism is directly related to the huge number of species that have evolved this way of life. Seven contributions have been published within the Special Issue. These are research papers in which different strategies to unravel host–parasite interactions are carried out

Human dirofilariosis is a clinical entity caused by infection with nematode species of the genus Dirofilaria. The traditional picture depicts the disease as a sporadic event associated with the presence of a single immature worm causing a nodular lesion. With the aim to reassess this paradigm, establishing a more accurate picture of the disease and homogenize criteria, a scoping review was conducted by searching, screening and analysing published clinical cases of human dirofilariosis worldwide during the 21st century. After extracting data from 305 publications containing 576 case reports, results showed that human dirofilariosis is currently caused by five Dirofilaria species (mainly D. repens). Maturation was not uncommon, since 42.95% of the parasites recovered were described as mature worms, most of them females, 26.42% of which contained micofilariae in the uterus. Moreover, six microfilaremic cases have been described. The predominant clinical manifestation was the presence of a worm encapsulated within a nodule, but there is a considerable variety of accompanying symptoms depending on anatomical location and type of dirofilariosis. Parasites/nodules were found in 71 different anatomical locations, being the traditional nomenclature of human dirofilariosis unable to properly cover this complex situation. Delay in seeking medical assistance (patient perception) and the frequency of wrong clinical suspicions (doctor knowledge), strongly influenced clinical management. The initial suspicion in cases of subcutaneous and pulmonary dirofilariosis is predominantly a tumour, while in the ocular dirofilariosis a parasite (but not directly Dirofilaria) is mostly suspected. Surgery is usually applied, regardless of the use of non-invasive techniques during preoperative management and although its use is still limited, molecular approach is the most accurate technique to establish a species-level diagnosis. Accurate epidemiological, parasitological and clinical informati

[Background] Helminth parasites like the trematode Fasciola hepatica, a veterinary parasite with an important zoonotic potential, have adapted to their mammalian hosts during long co-evolution processes by establishing host-parasite relationships that modulate different aspects of the host physiology. In line with this, previous data from our lab showed that F. hepatica newly excysted juveniles (FhNEJ) modulate cellular routes within host cells related to vesiclemediated transport and components of the innate immune response, which could potentially be relevant during the course of viral infections. Therefore, the aim of the present study was to set up an in vitro platform based on the use of viral particles pseudotyped with the envelope protein of highly pathogenic human viruses to screen for the capability of F. hepatica molecules to alter their infective potential., [Methods] We produced viral particles derived from the vesicular-stomatitis virus (VSV) pseudotyped with Spike, the envelope protein of the recently emerged severe acute respiratory syndrome 2 (SARS-CoV-2), to test for the applicability of this in vitro platform, and validated the results using genuine SARS-CoV-2 infections in Vero cells. Results: Our compound screen revealed that a tegument-enriched antigenic fraction of FhNEJ contains proteins with antiviral potential against both Spike-pseudotyped VSV viral particles and live SARS-CoV-2., [Conclusions] First, our results revealed that FhNEJ express molecules that are capable of mediating virus entry and/or replication of SARS-CoV-2 virus and potentially other enveloped viruses with zoonotic potential. Second, our results evidenced that the in vitro platform that we established for virus pseudotyping is valid for the interrogation of antiviral molecules from F. hepatica. Altogether, this platform could lead to the identification of antiviral molecules in helminth parasites and encourage their production in a safe, synthetic format for their application as therapeutics against viruses of growing public health concern.

SARS-CoV-2, the causal agent of COVID-19, is a new coronavirus that has rapidly spread worldwide and significantly impacted human health by causing a severe acute respiratory syndrome boosted by a pulmonary hyperinflammatory response. Previous data from our lab showed that the newly excysted juveniles of the helminth parasite Fasciola hepatica (FhNEJ) modulate molecular routes within host cells related to vesicle-mediated transport and components of the innate immune response, which could potentially be relevant during viral infections. Therefore, the aim of the present study was to determine whether FhNEJ-derived molecules influence SARS-CoV-2 infection efficiency in Vero cells. Pre-treatment of Vero cells with a tegument-enriched antigenic extract of FhNEJ (FhNEJ-TEG) significantly reduced infection by both vesicular stomatitis virus particles pseudotyped with the SARS-CoV-2 Spike protein (VSV-S2) and live SARS-CoV-2. Pre-treatment of the virus itself with FhNEJ-TEG prior to infection also resulted in reduced infection efficiency similar to that obtained by remdesivir pre-treatment. Remarkably, treatment of Vero cells with FhNEJ-TEG after VSV-S2 entry also resulted in reduced infection efficiency, suggesting that FhNEJ-TEG may also affect post-entry steps of the VSV replication cycle. Altogether, our results could potentially encourage the production of FhNEJ-derived molecules in a safe, synthetic format for their application as therapeutic agents against SARS-CoV-2 and other related respiratory viruses.

Unraveling the molecular interactions governing the first contact between parasite and host tissues is of paramount importance to the development of effective control strategies against parasites. In fasciolosis, a foodborne trematodiasis caused mainly by Fasciola hepatica, these early interactions occur between the juvenile worm and the host intestinal wall a few hours after ingestion of metacercariae, the infectious stage of the parasite. However, research on these early events is still scarce and the majority of studies have focused on the adult worm. Here, we review current knowledge on the biology and biochemistry of F. hepatica juveniles and their molecular relationships with the host tissues and identify the research needs and gaps to be covered in the future.

Excretory/secretory products released by helminth parasites have been widely studied for their diagnostic utility, immunomodulatory properties, as well as for their use as vaccines. Due to their location at the host/parasite interface, the characterization of parasite secretions is important to unravel the molecular interactions governing the relationships between helminth parasites and their hosts. In this study, the excretory/secretory products from adult worms of the trematode Fasciola hepatica (FhES) were employed in a combination of two-dimensional electrophoresis, immunoblot and mass spectrometry, to analyze the immune response elicited in sheep during the course of an experimental infection. Ten different immunogenic proteins from FhES recognized by serum samples from infected sheep at 4, 8, and/or 12 weeks post-infection were identified. Among these, different isoforms of cathepsin L and B, peroxiredoxin, calmodulin, or glutathione S-transferase were recognized from the beginning to the end of the experimental infection, suggesting their potential role as immunomodulatory antigens. Furthermore, four FhES proteins (C2H2-type domaincontaining protein, ferritin, superoxide dismutase, and globin-3) were identified for the first time as non-immunogenic proteins. These results may help to further understand host/parasite relationships in fasciolosis, and to identify potential diagnostic molecules and drug target candidates of F. hepatica.

Inspirada en Primavera Silenciosa, surge esta fábula con la intención de acercar las ideas de su autora, Rachel Carson, para despertar la conciencia medioambiental.

In order to evade the response of their hosts, helminth parasites have evolved precise and highly regulated mechanisms, including migration strategies of the larval stages. In regard to porcine ascariosis caused by Ascaris suum, its infective third-stage larvae (AsL3) undergo a complex migratory route through the bloodstream of their host before establishing in the small intestine to reach maturation. Despite the benefits attributed to this migration, blood clots formation could compromise larvae survival. The aim of this work was to study the interaction between the cuticle and excretory/secretory antigens of AsL3 and the host coagulation cascade. Larvae were obtained after incubating and hatching A. suum eggs, after which the antigenic extracts were produced. Their ability to disrupt the coagulation cascade was studied using anticoagulation and chromogenic assays, and techniques based on electrophoresis. The obtained results showed that both antigenic extracts possessed anticoagulant potential, being able to inhibit the intrinsic, extrinsic and/or common pathways of the blood coagulation cascade as well as the activated factor X. Moreover, three A. suum serpin proteins were identified as candidates to inhibit this host coagulation factor. To the best of our knowledge, this study shows, for the first time, the anticoagulant potential of the infective larvae of A. suum, which could be used by the parasite as a mechanism to facilitate its invasion and survival in the host

Food-borne zoonotic trematodiases are classified as neglected diseases by the World Health Organization. Among them, fascioliasis is caused worldwide by Fasciola hepatica and F. gigantica, and represent a huge problem in livestock production and human health in endemic areas. Fasciolopsis buski, restricted to specific regions of Asia, causes fasciolopsiasis. The incidence of these trematodiases is underestimated due to under-reporting and to the lack of sensitive and widely accepted tool for their diagnosis. This, together with a rising trend in reporting of drug resistance and the need for an effective vaccine against these parasites, pose a challenge in the effective control of these diseases. Here, the latest reports on fascioliasis outbreaks between 2000 and 2020 and the most recent advances in their epidemiology, diagnosis, treatment and control are revised. Finally, future needs in the field of fascioliasis and fasciolopsiasis are presented, which could be addressed based on current knowledge and by means of new emerging technologies.

Leptospirosis is a neglected zoonosis with a nearly global distribution. In order to determine the role of bats in the epidemiology of leptospirosis in Nigeria, a total of 231 bats belonging to three families, Pteropodidae (n = 117), Molossidae (n = 107) and Nycteridae (n = 17), roosting in human habitats were screened by PCR and sequencing for the detection of pathogenic Leptospira species. DNA extracted from the kidneys of bats were subjected to conventional PCR targeting the rrs1, rrs2, flaB and secY genes for the detection of pathogenic Leptospira spp. Overall, 27 out of the 231 (11.7%) of the samples screened were positive for Leptospira spp. High prevalence (>80%) of Leptospira spp. DNA was detected in Chaerophon and Nycteris bat species captures in an abandoned well located within a human habitation. Sequences generated in this study were highly identical to Leptospira borgpetersenii and Leptospira interrogans and clustered with sequences of pathogenic species in GenBank. The detection of pathogenic Leptospira spp. was significantly associated (p < .001) with the bat species, feeding habit, roosting site and study location. To the best of our knowledge, this is the first molecular detection and characterization of pathogenic Leptospira spp. in bats from Nigeria. Results show that bats in Nigeria are infected with diverse Leptospira genotypes phylogenetically related to known pathogenic, including zoonotic taxa. Together, these findings reinforce bats’ roles as potential reservoirs of Leptospira spp. and should be considered as a starting point for future comparative studies to improve our understanding of the epidemiology of this bacterial pathogen in Nigeria.

Dog feces may contain zoonotic parasites that contaminate the environment and serve as a potential source of infection to animals and humans. In this study, microscopic and molecular analyses were used to estimate the prevalence and intensity of gastrointestinal (GI) parasites and assess the risk factors for infection in 948 dogs in three climatically distinct zones of Nigeria. Zoonotic helminths including Strongyloides stercoralis, Ancylostoma braziliense, A. caninum and Toxocara canis were detected either as single or multiple infections in 377 (39.8 %) of dogs examined. At multiple logistic regression analyses, association was found between GI parasite infection and deworming practices and dog management. Regarding A. braziliense, A. caninum and T. canis infections, intensity of egg shedding was statistically associated with the age of the dogs and not with their sex or breed. The majority of GI parasite-positive dogs did not receive regular deworming treatment (59 %) and roamed freely (56 %) thereby constituting public health risk. This is the first nationwide survey and analyses of risk factors of GI parasites of dogs using molecular methods as confirmation of their identity. The zoonotic potential of these parasites is exacerbated by the lack of both operational national policies to control the population of free- roaming dogs and to promote responsible dog ownership, and veterinary public health programs for dogs.

[EN] Some migratory seabird populations have declined sharply in recent decades. Monitoring their migratory movements from strategic locations provides a useful tool to understand their phenology and estimate their population sizes. During the autumn 2020 and spring 2021 migration periods, we conducted a total of 183 hours of counts of two auk species, Razorbill Alca torda and Atlantic Puffin Fratercula arctica, from a strategic coastal point (Tarifa Island in the Strait of Gibraltar). We used Generalized Additive Models (GzAM) to estimate the number of birds that could have entered or left the Mediterranean Sea on the days that no counting took place. Auks entered the Mediterranean from early October to early winter, peaking in the second half of November. In spring, Razorbill movements leaving the Mediterranean were concentrated from mid-January to mid-April, while the peak Atlantic Puffin movement occurred from mid-February to May. We estimate that 4,000-5,000 Razorbills and 15,000 Atlantic Puffins made up the populations migrating through the Strait of Gibraltar in the year of the study. These figures are notably lower than those previously reported for auks passing through this migratory bottleneck. Hence, the results of this study, despite coming from a single year of monitoring, may contribute significantly to assessing the numbers of auks that winter in the Mediterranean and could eventually draw attention to possible declines in their numbers. - De la Cruz, A., Rollán, L., Pérez, B., Guerrero, M., Elorriaga, J., Benjumea, R., González, M., Seminario, Y., Arroyo, G.M. & Ramírez, J. (2022). Phenology and wintering population estimates of auks in the Mediterranean Sea based on counts from a strategic coastal location in the Strait of Gibraltar. Ardeola, 69: 303-317., [ES] Las poblaciones de aves marinas migratorias han sufrido un fuerte descenso en las últimas décadas. El seguimiento de sus movimientos migratorios desde lugares estratégicos supone una herramienta de gran utilidad para entender su fenología y estimar el tamaño de sus poblaciones. Durante los periodos migratorios de otoño de 2020 y primavera de 2021, realizamos censos de dos especies de álcidos, alca común Alca torda y frailecillo atlántico Fratercula arctica, desde un punto costero estratégico (la isla de Tarifa en el estrecho de Gibraltar), contabilizando un total de 183 horas de observación. Se utilizaron modelos aditivos generalizados (GzAM) para estimar el número de aves que podrían haber entrado o salido del Mediterráneo en los días en que no se realizó ningún recuento. Los álcidos entraron al Mediterráneo desde principios de octubre hasta principios del invierno, con un pico en la segunda mitad de noviembre. Durante la migración de primavera, las alcas que salieron hacia el Atlántico se concentraron desde mediados de enero hasta mediados de abril, mientras que el pico de movimiento de los frailecillos se produjo desde mediados de febrero hasta mayo. Estimamos que entre 4.000 y 5.000 alcas y 15.000 frailecillos constituyen la población migradora que cruza el estrecho de Gibraltar durante el año de estudio. Estas cifras son notablemente inferiores a las publicadas anteriormente para los álcidos que pasan por este cuello de botella migratorio. Los resultados de este estudio, a pesar de proceder de un solo año de seguimiento, pueden contribuir de forma significativa a la evaluación de la población de álcidos que invernan en el Mediterráneo y eventualmente llamar la atención sobre posibles descensos en sus efectivos.