Organization of the Nuclei in the Tegument of Some Palaeacanthocephala and Archiacanthocephala.

The giant tegument nuclei of the acanthocephalans of the classes Archiacanthocephala and Palaeacanthocephala are fragmented at the final stage of cystacanthus formation in the intermediate host, but remain connected with each other during later life. It can be assumed that the fragments of each giant tegument nucleus are united with each other to form an independent network that ensures the vital activity of the tegument, the volume of which increases many times during the period of intensive growth of the parasite in the definitive host.

First molecular description of Macracanthorhynchus hirudinaceus in wild boars from Italy with pathomorphological and epidemiological insights.

Macracanthorhynchus hirudinaceus is a zoonotic parasite affecting suids worldwide which are the definitive hosts for this helminth species. Macracanthorhynchus hirudinaceus is of significant economic and management concern due to its pathogenicity, causing intestinal obstruction and perforation in the definitive hosts. Current study is the preliminary investigation from Sardinia, Italy, reporting the pathomorphological findings and molecular characterization of M. hirudinaceus in the wild boars (Sus scrofa meridionalis). A total of 59 wild boars were examined showing acanthocephalan infection in 8 (13.6%) animals. In total, 49 parasites were collected with a mean intensity of 6.1. Comparatively higher infection levels were observed for males (16.7%) and young boars (14.3%); however, these epidemiological differences were statistically non-significant. Histopathological examination revealed the presence of a variable number of nodules (∼5 mm) in the intestine of M. hirudinaceus infested animals surrounded by a hyperemic-hemorrhagic halo. Several parasites were recovered from the intestinal lumen attached by the means of characteristic hooks showing necrosis in muscle layers. A moderate number of plump reactive fibroblasts and lesser numbers of fibrocytes were embedded with and at the borders of the inflammatory nodules in a moderate amount of homogeneous intensely eosinophilic fibrillary material rupturing the cell membrane. For molecular characterization, six isolated worms were amplified for the partial mitochondrial cox1 gene showing distinct interindividual variations. This first pathological and molecular description from southern Europe provided new knowledge about the diffusion of M. hirudinaceus in wild boars, furthering the research into the origin and transmission status of M. hirudinaceus in endemic localities.

Macracanthorhynchus hirudinaceus in expanding wild boar (Sus scrofa) populations in Eastern Spain.

Prevalence and temporal evolution of the infection by the acanthocephalan Macracanthorhynchus hirudinaceus is studied in the Valencian Community (Eastern Spain), a region only recently fully colonized by the expanding native Eurasian wild boar (Sus scrofa). For 8 years, a total of 1486 wild boars were sampled in order to look for the parasite. The mean prevalence was 20.7% (95% CI, 18.6-22.8; 307/1486). We observed an increasing trend through time, both in the number of wild boars and affected districts. The prevalence of M. hirudinaceus rose in parallel to the annual capture of wild boars, and its presence has been expanding towards the East. A hotspot of M. hirudinaceus is located to the west of the study area, in Muela de Cortes Game Reserve, where 89.6% of the wild boars were positive for the infection, constituting one of the world's highest known prevalence areas.

An unexpected case of a Japanese wild boar (Sus scrofa leucomystax) infected with the giant thorny-headed worm (Macracanthorhynchus hirudinaceus) on the mainland of Japan (Honshu).

The giant thorny-headed worm Macracanthorhynchus hirudinaceus is a zoonotic acanthocephalan species with a worldwide distribution. Its natural definitive hosts are primarily pigs and wild boars (Sus scrofa), and scarabaeid beetles serve as the intermediate host. To date, there has only been one record of this acanthocephalan in Japan: a Ryukyu wild boar (Sus scrofa riukiuanus) hunted in 1973 on Amami Island, faraway from the Japanese mainland. The present study reports the second case of this acanthocephalan in Japan: a Japanese wild boar (Sus scrofa leucomystax) hunted in May 2017 in Yamaguchi Prefecture, the westernmost part of the Japanese mainland (Honshu). More than a dozen acanthocephalans (123 to 233 mm in length and 5 to 6 mm in width) were found with their proboscides inserted deeply into the intestinal wall, forming grossly visible nodules on the external surface. Isolated worms underwent a molecular genetic characterization of the ribosomal RNA gene (rDNA) and mitochondrial cytochrome c oxidase subunit 1 gene (cox-1). Long rDNA nucleotide sequences (5870 to 5890 bp) spanning the beginning of the 18S rDNA through to the 28S rDNA, including the internal transcribed spacer regions, and 1384-bp cox-1 nucleotide sequences were obtained. In the future, in conjunction with the accumulation of molecular genetic data of multiple M. hirudinaceus isolates from different endemic localities abroad, our data may help to postulate the origin or present transmission status of this extremely rarely encountered acanthocephalan in Japan.

Macracanthorhynchus ingens Infection in an 18-Month-Old Child in Florida: A Case Report and Review of Acanthocephaliasis in Humans.

A case of acanthocephaliasis in an 18-month-old child caused by Macracanthorhynchus ingens is reported from Florida. This represents only the third documented case of this species in a human host. An overview of human cases of acanthocephaliasis in the literature is presented, along with a review of the biology, clinical manifestations and pathology in the human host, morphology, and diagnosis.

Comparative Analysis of Ascaris suum and Macracanthorhynchus hirudinaceus Infections in Free-Ranging and Captive Wild Boars (Sus scrofa) in Hungary.

Ascaris suum and Macracanthorhynchus hirudinaceus cause a large loss of yield in farm animals as well as in free-living and captive wild boar herds, thereby causing economic damage. This study compared A. suum and M. hirudinaceus infections in free-ranging and captive wild boars (Sus scrofa) in Hungary. The authors measured the A. suum and M. hirudinaceus infections of a 248-hectare wild boar garden and an 11,893-hectare free-living wild boar herd in the sample area. In all cases, samples were collected from shot wild boars. In total, 216 wild boars were examined from June 2015 to June 2023 in Hungary. Of the 173 dissected wild boars from the wild, 57 (32.9%) were infected with A. suum, while 30 (69.8%) of the 43 individuals from the captive area were infected. The prevalence of M. hirudinaceus in the free-living area population was 9.25% (16 wild boars), while that of the captive population was 34.89% (15 wild boars). In the case of the examined helminths, the captive herd was 36.9% more infected than the herd living in the open area.

First Histopathological and Molecular Characterization of Giant Thorny-headed Worm, Macracanthorhynchus hirudinaceus (Pallas, 1781) (Acanthocephala: Oligacanthorhynchidae) in Wild Boars, Sus scrofa Linnaeus, 1758 from Eastern Türkiye.

BACKGROUND: Macracanthorhynchus hirudinaceus (Pallas, 1781) is a zoonotic acanthocephalan that parasitizes the small intestine of wild boars. It is a pathogenic that causes economic losses, and poses a public health threat due to increased emergence. PURPOSE: The aims of this study is describes histopathologically the damage caused by M. hirudinaceus in the small intestine of wild boar Sus scrofa Linnaeus, 1758, and molecularly characterize this parasite (sequences, haplotypes, phylogeny) for the first time in Elazig city, Türkiye. RESULTS: A high prevalence of infection was obtained. Upon separating the worms, it was discovered that there were ulcers resembling craters in the center, of the small intestine mucosa, surrounded by edema. The intestine wall where the parasite attached was damaged, with the villi epithelium and lamina propria in the mucosa being destroyed. The genomic DNA was isolated from all M. hirudinaceus samples, and PCR amplified the 489 bp gene fragments were sequenced and confirmed that all 21 sequences were M. hirudinaceus. The haplotype analysis of the sequences revealed the presence of a central star-shaped haplotype, in addition to four other haplotypes. CONCLUSION: After conducting sequence analysis, the genetic differences between the M. hirudinaceus sequences obtained in this study and those reported from Europe and Japan suggest that this parasite is endemic to Türkiye's local wild boar population. Also, four haplotypes were identified, distinguishing it from other haplotypes by 1-5 mutation steps. It is essential to consider the worm's sequences and the formation of haplotypes, since these intrinsic characteristics may impact in the epidemiology and pathology of the worm in the future.

Morphometric, histopathological and molecular findings of Macracanthorhynchus hirudinaceus infection in wild boar (Sus scrofa) from continental Italy.

Although Macracanthorhynchus hirudinaceus is a neglected acanthocephalan of suids occasionally responsible for severe infections in humans, the spread of wild boar (Sus scrofa) populations in Europe could promote the circulation. Herein, we report the first morphometric, histological and molecular characterization of a severe M. hirudinaceus infection in a boar from continental Italy. The boar's intestine displayed granulomatous enteritis due to 24 helminths (14 females, 10 males), identified as adults of M. hirudinaceus by a combined morphometric/molecular approach. The phylogenetic analysis of the cox1 gene revealed a close relationship of the M. hirudinaceus sequence type found herein with those from Hungary and insular Italy. The high haplotype diversity and low nucleotide diversity of M. hirudinaceus specimens would suggest its rapid demographic expansion in the Mediterranean basin. More research is needed to assess the presence of M. hirudinaceus in susceptible beetle species and the role of boars in the epidemiology of infection.

Patent Macracanthorhynchus ingens Infection in a 17-Month-Old Child, Ohio.

Limited data exist on human Macracanthorhynchus infections. We report an asymptomatic 17-month-old who passed eggs and an adult Macracanthorhynchus ingens worm, indicating parasite maturation and reproduction. Macracanthorhynchus ingens may have a greater capacity to mature in humans versus Macracanthorhynchus hirudinaceus.

A Neglected Parasite: Macracanthorhynchus hirudinaceus, First Report in Feral Pigs in a Natural Park of Sicily (Southern Italy).

Sanitary management and population control of feral pigs remains a major problem in public health, particularly in natural parks where hunting is prohibited and the extensive farming of livestock is common. Macracanthorhynchus hirudinaceus is a zoonotic parasite species with a worldwide distribution of which the natural definitive hosts are primarily pigs and wild boars (Sus scrofa). The present study describes the main anatomo-pathological and parasitological findings in the first case of M. hirudinaceus in feral pigs in the Madonie park in Sicily (Southern Italy). Overall, 52 acanthocephalans were collected from the small intestine of four infected feral pigs. The prevalence among the 36 examined animals was 11.1% with a mean Abundance (mA) and mean Intensity (mI) of 1.4 and 13, respectively. Pathological examination revealed grossly visible nodules on the external surface of the intestines, corresponding to the proboscis of M. hirudinaceus attached deeply into the intestinal wall. In these sites, severe inflammatory reactions in the tissue involved and the destruction of normal intestinal architecture, as well as necrosis and ulceration in the mucosa, submucosa, and part of the muscolaris mucosae were described. This is the first official report of this neglected zoonosis in Italy, in particular in a natural park where the extensive farming of domestic pigs is practiced. This could favor the spread of this parasite in domestic animals and the environment, increasing the accidental risk of infection in human residents of these areas.

Pathomorphological Studies on Wild Boars Infected with Metastrongylus Spp., Ascarops Strongylina, and Macracanthorhynchus Hirudinaceus.

INTRODUCTION: Pathomorphological changes in the lungs, stomach, and small intestines of wild boars infected with Metastrongylus spp., Ascarops strongylina, and Macracanthorhynchus hirudinaceus were investigated. MATERIAL AND METHODS: Dissection of 11 wild boars was performed, and parasitised organs were histologically investigated by common techniques. RESULTS: Macroscopic lesions in the lungs infected with Metastrongyus spp. were seen within the apical parts of the large lobes, irregular in form, pale greyish in colour, and compact in consistency. The main pathohistological findings were: the presence of parasite forms, and lymphocytes and neutrophils in the lumen of bronchi and bronchioles, desquamation of the bronchial and bronchiolar epithelium, emphysema, thickening of alveolar septa, hyperaemia, alveolitis, infiltration of the interstitial tissue with giant cell, monocytes and eosinophils, and peribronchial and disseminated lymphoid hyperplasia. The principal observations accompanying infection with A. strongylina were inflammation and focal mucosal damage in the stomach, the latter clearly demarcated from the surrounding tissues. Severe injuries in the place of attachment of M. hirudinaceus to the wall of the small intestine were seen. Intestinal villi, underlying mucosa, and submucosa were destroyed, and an intense inflammatory reaction was present. CONCLUSION: The histopathological lesions showed wide diversity, varying from mild to severe; but none of them were lethal.

Macracanthorhynchus hirudinaceus: the most common helminthic infection of wild boars in southwestern Iran.

A pathological and epidemiological study on Macracanthorhynchus hirudinaceus infection on 25 wild boars Sus scrofa in southwestern Iran was done. Overall 24 helminthes (18 female and 6 male) were collected from the intestine of 13 infected wild boars. Thus, the prevalence of acanthocephalans among the 25 examined boars was 52 %. Pathological evaluation revealed damages caused by the acanthocephalans penetrated in the small intestine tissue. Helminthes caused severe necrosis with ulcer and inflammation in tunica sub mucosa layer. High prevalence of this helminthic infection may cause severe hazard for farmers, residents and also wild life animals.

Presentación del primer caso humano de parasitismo por Macracanthorhynchus hirudinaceus en el Perú y breve revisión

Se reporta un caso humano portador de Macracanthorhynchus hirudinaceus. Se trata de un varón de 45 años de edad, natural de la provincia de Chota, departamento de Cajamarca, Perú; con molestias digestivas. El diagnóstico se hizo por el hallazgo de huevos de Macracanthorhynchus hirudinaceus en las heces. Además se encontró Trichuris trichiura, Ancylostoma duodenale, Trichostrongylus sp, Blastocystis hominis y Entamoeba coli. Esta es la primera comunicación de un caso humano de M. hirudinaceus para el Perú.

A Macracanthorhynchus hirudinaceus human case is reported. He is a male of 45 years old native of Chota province, department of Cajamarca (Perú), with digestive symptoms. The diagnosis was made by eggs in the faecal examination. Beside Macracanthorhynchus hirudinaceus, he carried Trichuris trichiura, Ancylostoma duodenale y Trichostrongylus sp, Blastocystis hominis y Entamoeba coli. This is the first human case by M. hirudinaceus reported in Perú.