Prevalence of Oestrus ovis in small ruminants from the eastern Iberian Peninsula. A long-term study.

Oestrus ovis is an obligate parasite that causes myiasis in domestic ruminants, being commonly found in the Mediterranean area. From 2009 to 2019 a total of 3476 heads of culling sheep and goats from the Mediterranean coast of Spain were examined for the presence of O. ovis. The total prevalence was 56.3%, significantly higher in sheep than in goats (61.2% and 43%, respectively). Differences were found in the mean annual prevalence, with the highest value being registered in 2018 (61.7%) and the lowest in 2012 (50.3%). Autumn, for sheep, and winter, for goats, were the seasons with the highest number of infested specimens. Temperature, but not rainfall, was found to be associated with prevalence (p < 0.05). Most L1 were found in the anatomic region I (septum, meatus, and ventral conchae), while L2 and L3 were mainly located in regions II (nasopharynx, ethmoid labyrinth, and dorsal conchae), and III (sinuses). The overall intensity was 12.8 larvae per head, significantly higher in sheep (13.3) than in goats (3.5). Our results confirm the high prevalence of O. ovis in sheep and goats in this geographic area over the last decade, with the trend increasing in recent years in association with higher mean temperatures.

Morphological variability in Acanthocephaloides irregularis Amin, Oguz, Heckmann, Tepe & Kvach, 2011 (Acanthocephala: Arhythmacanthidae) from the European sea bass, Dicentrarchus labrax (L.) (Moronidae) in Bizerte Lagoon, Tunisia.

Specimens of an arhythmacanthid acanthocephalan were recovered from the European sea bass Dicentrarchus labrax (L.) (Perciformes: Moronidae) in Bizerte Lagoon, northern Tunisia. The specimens collected showed high morphological similarities to Acanthocephaloides irregularis Amin, Oguz, Heckmann, Tepe & Kvach, 2011, recovered from four species of marine fishes in the Gulf of Odessa and Sukhyi Lyman off the Ukrainian Black Sea coast. Light and scanning electron microscopy revealed some morphological differences from the Black Sea specimens in trunk spine distribution, number of proboscis hooks in males (4 instead of 5), and lack of demonstrable trunk collar. These variations suggest that our specimens may only be a morphotype of A. irregularis with new host and locality records. A comparison between our specimens and those of the original description clarifies the possible reasons of this intraspecific morphological variability.

Ovine dicrocoeliosis in Castellón province, eastern Spain: Prevalence, dynamics, and comparative study of different diagnostic techniques.

Dicrocoeliosis is a parasitic disease that mainly affects ruminants during grazing, caused by trematodes of the genus Dicrocoelium, with D. dendriticum being the most common species worldwide. This parasitosis is a chronic and generally subclinical process, with nonspecific signs, which makes its diagnosis challenging. This study aimed to determine the prevalence and seasonal dynamics of D. dendriticum infection in adult sheep from the Valencian Community, eastern Spain, as well as to evaluate the efficacy of flotation and sedimentation techniques when compared with the macroscopic exam of the liver. From February to May 2018, 2019, 2020, 2021, and 2022, a total of 290 adult sheep were examined. The animals were sourced from Castellón province, where a semi-intensive production system predominates. Each animal was euthanized and underwent a macroscopic examination of the liver, as well as a fecal analysis. Among the sampled animals, 117 (40.6%) tested positive for adult trematodes in their liver, while 87 (30%) showed evidence of trematode eggs in the coprological exam, reaching a total of 126 sheep parasitized, with a prevalence of 43.4%. The parasitic burden was established in 90.3 adults per animal when the liver was examined and in 54.5 eggs per gram when the sedimentation coprological exam was performed. No eggs were observed when the flotation technique was employed. A positive correlation was found between the number of adults in the liver and the fecal egg count. No significant differences were detected in the prevalence or parasitic burden throughout the study. Considering the difficulty in controlling the intermediate hosts and the complexity of the life cycle, effective diagnostic methods, combined with the adoption of other preventive measures, is crucial to achieving proper management of this parasitic disease.

Immunological profile of two canine breeds in an endemic region of Leishmania infantum.

Visceral leishmaniosis is the one of the most important protozoal zoonoses in Europe, and it is caused by Leishmania infantum, an intracellular protozoan parasite. The disease is endemic in dogs in the Mediterranean area. The main goal of this work is to correlate the levels of several cytokines linked to immune response against L. infantum infection in two canine breeds. Thirty-one Boxer and twenty-eight Ibizan Hound dogs living in the Valencian Community (East coast of Spain) were analyzed for the presence of anti-Leishmania antibodies in serum by IFAT test. Cytokines IFN-γ, TNF-α, IL-2, IL-6, IL-8, and IL-18 were determined by ELISA commercial tests. The levels of IFN-γ, IL-2, and IL-18 in our study, cytokines linked to a cellular immune response, were higher (p < 0.05) in the Ibizan Hound breed; IL-6 levels were higher, although not significant, and only levels of IL-8 were higher in Boxer than in Ibizan Hound. No expression of TNF-α was found. These results corroborate that Ibizan Hound can develop a protective response against canine leishmaniosis, while Boxer is a susceptible breed. The study of immunological aspects in the different canine breeds may represent a useful tool in the prediction of the disease.

The Role of Nosema ceranae (Microsporidia: Nosematidae) in Honey Bee Colony Losses and Current Insights on Treatment.

Honeybee populations have locally and temporally declined in the last few years because of both biotic and abiotic factors. Among the latter, one of the most important reasons is infection by the microsporidia Nosema ceranae, which is the etiological agent of type C nosemosis. This species was first described in Asian honeybees (Apis cerana). Nowadays, domestic honeybees (Apis mellifera) worldwide are also becoming infected due to globalization. Type C nosemosis can be asymptomatic or can cause important damage to bees, such as changes in temporal polyethism, energy and oxidative stress, immunity loss, and decreased average life expectancy. It causes drastic reductions in workers, numbers of broods, and honey production, finally leading to colony loss. Common treatment is based on fumagillin, an antibiotic with side effects and relatively poor efficiency, which is banned in the European Union. Natural products, probiotics, food supplements, nutraceuticals, and other veterinary drugs are currently under study and might represent alternative treatments. Prophylaxis and management of affected colonies are essential to control the disease. While N. ceranae is one potential cause of bee losses in a colony, other factors must also be considered, especially synergies between microsporidia and the use of insecticides.

Effectiveness of Gutting Blue Whiting (Micromesistius poutassou, Risso, 1827), in Spanish Supermarkets as an Anisakidosis Safety Measure.

Anisakidosis is a parasitic zoonotic disease which can cause gastroallergic reactions in humans. In 2010, the European Food Safety Agency estimated that approximately 20,000 cases of anisakiasis had been reported across the world, with Spain having the highest number of infections in Europe. The blue whiting (Micromesistius poutassou, Risso, 1827) is one of the most widely fished species worldwide and represents around 25% of the white fish eaten in Spain. The Spanish Food Safety Authority requires obligatory evisceration of certain fish species before commercialization, but not for blue whiting. Nevertheless, some supermarkets carry this out themselves to prevent human infections and negative customer reactions deriving from the presence of ascaridoid larvae. To assess the effectiveness of eviscerations at supermarkets, a total of 320 blue whiting specimens were examined. The risk of larval migration from the visceral cavity to the musculature in gutted and ungutted fish was also assessed. Our results showed a total prevalence (25%) of ascaridoids in fish gutted at the supermarket, and a direct relationship was found between the presence of larvae in the muscle and time until evisceration. In ungutted fish, the standard length and weight were higher for infected than for non-infected fish. Also, massive infections had a higher prevalence in these larger specimens, in which the viability of larvae was also high. Larval viability was not found to be affected by a 24-h refrigeration period. Anisakis was the most prevalent genus identified in the fish examined. The results indicate that gutting at the supermarket is not an effective method for the total removal of ascaridoid larvae and that additional safety measures are advisable.

Feline Leishmaniosis: An Emerging Public Health Problem.

Leishmaniosis is the third most important vector-borne disease in humans, preceded by malaria and lymphatic filariasis, and it is considered endemic in tropical and subtropical areas, where higher temperatures favor development of its vector, sandflies. This zoonotic disease is caused by infection of protozoa Leishmania spp. and the most serious mucocutaneous and visceral form is produced by Leishmania infantum, which predominates in the Mediterranean region. The usual hosts for this parasite are dogs and humans, but an increment in cases of L. infantum infection has been observed in cats in the last years. This increase could be due to the use of sandflies repellents in dogs, obligating the parasite to looking for other hosts. The role of cats in the epidemiology of this disease is unknown, although increase of prevalence of feline leishmaniosis has been observed in endemic areas in the last years. Diagnostic techniques and treatments in cats are not standardized, which makes it difficult to establish prevalence and epidemiology of feline leishmaniosis. Furthermore, the clinical signs and immune response against Leishmania in cats are different to those in dogs, with an observed increment of drug resistance. It is necessary to increase our knowledge about L. infantum infection in cats, including clinical signs, transmission, treatments, and the role of cats in the increasing of zoonoses. Finally, new alternative treatments are required for controlling the spread of this disease in all species of mammals.

Accacoelium contortum (Trematoda: Accacoeliidae) a trematode living as a monogenean: morphological and pathological implications.

BACKGROUND: Accacoelium contortum (Rudolphi, 1819) Monticelli, 1893 is a frequent but poorly known trematode found on gills, pharynx and digestive tract of the ocean sunfish Mola mola (L.). Although the morphology of A. contortum agrees with that of a typical endoparasitic trematode, with two relatively small suckers and no large holdfasts, this parasite is normally ectoparasitic. The main objective of this paper is to explore this peculiar host-parasite relationship. METHODS: A total of 106 ocean sunfish were examined for the presence of A. contortum. The oropharyngeal chamber (gills and pharynx) and the digestive tract were analysed. As the previous descriptions of this species seem to be based on contracted specimens, for the morphological study the parasites were killed using two methods: with hot 70% ethanol (with relaxed bodies) and with 70% ethanol at room temperature (with contracted bodies). For histological studies, samples from fresh fish with parasitised left gills, pharynx and digestive tract were fixed in buffered 10% formalin. For molecular studies the 18S, 28S and ITS-2 sequences were provided and compared with the available data in GenBank®. RESULTS: New information on the morphology of A. contortum and on the parasite-related response and pathological alterations in the host are given. New diagnostic traits for some structures are provided: e.g. tegumental papillae of the forebody with apical digitiform swellings and mouth surrounded by a circum-oral crown of simple papillae. The length of the ventral sucker peduncle and the position of the vitellarium were found to be associated with the contraction degree of the specimen. Immature individuals of this species are described for the first time. An intense proliferative inflammatory response of host gill and pharynx epithelium at the host-parasite interface was detected and parasites became partially covered by overgrowths of host tissues. CONCLUSIONS: The induction of prominent histological alterations associated with A. contortum seems to be an adaptation to the external environment, an unusual location for trematodes.