The golden jackal (Canis aureus): A new host for Echinococcus multilocularis and Trichinella britovi in Switzerland.

INTRODUCTION: The golden jackal (Canis aureus) is a wild canid new to Switzerland. It is an officially monitored species and all deceased individuals are submitted for post-mortem examination to collect baseline health data. This includes parasitological examinations, with an emphasis on zoonotic, reportable infections, such as those caused by Trichinella spp. or Echinococcus spp. From 2016 to 2021, five golden jackals originating from four Swiss cantons were submitted for full post-mortem examination. In one case only organ samples were available, and therefore parasitological examination was not possible. Parasite stages recovered during necropsy, as well as by routine coproscopical techniques, were morphologically identified. Taeniid eggs and adult tapeworms were processed for molecular species identification. Additionally, tongue and diaphragm were analysed for Trichinella spp. by the artificial digestion technique followed by multiplex-PCR in positive cases. Of the four jackals investigated for parasites, hookworm eggs were detected in one animal, both adult worms and eggs of Echinococcus multilocularis were present in another case, and one animal was free of parasites. Eggs of E. multilocularis as well as eggs of Toxocara canis and sporocysts of Sarcocystis sp. were detected in the intestinal content, and Trichinella britovi larvae were found in the muscle samples of the last case. The health monitoring programme in place for protected carnivores in Switzerland allowed us to add the golden jackal to the list of hosts for the endemic zoonotic parasites E. multilocularis and T. britovi in this country. Hunters, farmers, and other persons who could come in contact with golden jackals should be aware of the associated health risk and handle faeces and carcasses with caution.

INTRODUCTION: Le chacal doré (Canis aureus) est un canidé sauvage nouvellement présent en Suisse. Il s'agit d'une espèce officiellement surveillée et tous les individus morts sont soumis à un examen post-mortem afin de recueillir des données sanitaires de base. Cela inclut un examen parasitologique mettant l'accent sur les infections zoonotiques à déclaration obligatoire, telles que celles causées par Trichinella spp. ou Echinococcus spp. De 2016 à 2021, cinq chacals dorés originaires de quatre cantons suisses ont été soumis à un examen post-mortem complet. Dans un cas, seuls des échantillons d'organes ont été envoyés, l'examen parasitologique n'a pas été possible pour cet animal. Les stades parasitaires trouvés lors de l'examen pathologique et de la coprologie de routine ont été identifiés morphologiquement. Les espèces de ténias (œufs et stades adultes) ont été déterminées par des techniques de biologie moléculaire. En outre, la recherche de Trichinella spp. a été effectuée sur du tissu musculaire lingual et diaphragmatique par la technique de digestion artificielle suivie d'une PCR multiplex dans les cas positifs. Sur les quatre chacals ayant fait l'objet d'une recherche de parasites, des œufs d'ankylostomes ont été détectés chez un animal, des vers adultes et des œufs d'Echinococcus multilocularis étaient présents chez un autre animal, et aucun parasite n'a été trouvé dans un autre cas. Chez le dernier cas, des œufs d'E. multilocularis ainsi que des œufs de Toxocara canis et des sporocystes de Sarcocystis sp. ont été détectés dans le contenu intestinal, et des larves de Trichinella britovi ont été trouvées dans les échantillons de muscle. Le programme de surveillance sanitaire mis en place pour les carnivores protégés en Suisse a donc permis d'ajouter le chacal doré à la liste des hôtes des parasites zoonotiques endémiques E. multilocularis et T. britovi. Les chasseurs, agriculteurs et autres personnes susceptibles d'entrer en contact avec le chacal doré doivent être conscients du risque sanitaire associé et manipuler les fèces et les carcasses avec précaution.

Efficacy of novel albendazole salt formulations against secondary cystic echinococcosis in experimentally infected mice.

In this study, we evaluated the efficacy, expressed as a mean weight decrease of the whole echinococcal cyst mass, of novel benzimidazole salt formulations in a murine Echinococcus granulosus infection model. BALB/c mice were intraperitoneally infected with protoscoleces of E. granulosus (genotype G1). At 9 months post-infection, treatment with albendazole (ABZ), ricobendazole (RBZ) salt formulations, and RBZ enantiomer salts (R)-(+)-RBZ-Na and (S)-(-)-RBZ-Na formulations were initiated. Drugs were orally applied by gavage at 10 mg kg-1 body weight per day during 30 days. Experimental treatments with benzimidazole sodium salts resulted in a significant reduction of the weight of cysts compared to conventional ABZ treatment, except for the (S)-(-)-RBZ-Na enantiomer formulation. Scanning electron microscopy and histological inspection revealed that treatments impacted not only the structural integrity of the parasite tissue in the germinal layer, but also induced alterations in the laminated layer. Overall, these results demonstrate the improved efficacy of benzimidazole salt formulations compared to conventional ABZ treatment in experimental murine cystic echinococcosis.

To see or not to see: non-invasive imaging for improved readout of drug treatment trials in the murine model of secondary alveolar echinococcosis.

Alveolar echinococcosis (AE) is an emerging zoonotic disease caused by the cestode Echinococcus multilocularis. The secondary infection model of AE is based on intraperitoneal injection of disease-causing metacestodes into the peritoneal cavity of mice, which allows investigations on novel drugs or immunotherapeutical treatment options in vivo. So far, such in vivo studies assessed exclusively the parasite weight at the endpoint of a given treatment period. We here developed an ultrasound (US)-based scoring system that allows to follow-up parasite development in the living animal, and provides insights into parasite growth during the treatment phase. By this method a statistically significant difference between untreated and medicated mice with E. multilocularis infection was observed at 2 months post-infection, and the growth curve of the parasite load was described by a linear mixed model. High correlation and similar levels of variation were observed for the standard method based on parasite weight measurement, the novel US-based scoring system, as well volume segmentation by post-mortem magnetic resonance imaging. Thus, US-based scoring in the live animal has the potential to assist the 3R concept by contributing to the refinement and reduction of animal use in experimental echinococcosis.