First Molecular Characterization of Echinococcus multilocularis in Turkey.

This study aimed to find out the occurrence of Echinococcus multilocularis in foxes in Erzurum province, the highest endemic region for human alveolar echinococcosis in Turkey. The sedimentation and counting technique was used to reveal adult Echinococcus spp. in the intestines of foxes. One out of the 10 foxes was infected with E. multilocularis. The adult worms were analyzed morphologically and molecularly and were confirmed to be E. multilocularis by species-specific PCR. Pairwise comparisons between the 12S rRNA sequences of the E. multilocularis isolate from Erzurum and other E. multilocularis isolates showed 100% similarity of the Erzurum isolate with European isolates. With this study, the presence of E. multilocularis in a fox in Erzurum was confirmed by PCR, and molecular identification of E. multilocularis is reported for the first time in Turkey.

Taxonomy, phylogeny and molecular epidemiology of Echinococcus multilocularis: From fundamental knowledge to health ecology.

Alveolar echinococcosis, caused by the tapeworm Echinococcus multilocularis, is one of the most severe parasitic diseases in humans and represents one of the 17 neglected diseases prioritised by the World Health Organisation (WHO) in 2012. Considering the major medical and veterinary importance of this parasite, the phylogeny of the genus Echinococcus is of considerable importance; yet, despite numerous efforts with both mitochondrial and nuclear data, it has remained unresolved. The genus is clearly complex, and this is one of the reasons for the incomplete understanding of its taxonomy. Although taxonomic studies have recognised E. multilocularis as a separate entity from the Echinococcus granulosus complex and other members of the genus, it would be premature to draw firm conclusions about the taxonomy of the genus before the phylogeny of the whole genus is fully resolved. The recent sequencing of E. multilocularis and E. granulosus genomes opens new possibilities for performing in-depth phylogenetic analyses. In addition, whole genome data provide the possibility of inferring phylogenies based on a large number of functional genes, i.e. genes that trace the evolutionary history of adaptation in E. multilocularis and other members of the genus. Moreover, genomic data open new avenues for studying the molecular epidemiology of E. multilocularis: genotyping studies with larger panels of genetic markers allow the genetic diversity and spatial dynamics of parasites to be evaluated with greater precision. There is an urgent need for international coordination of genotyping of E. multilocularis isolates from animals and human patients. This could be fundamental for a better understanding of the transmission of alveolar echinococcosis and for designing efficient healthcare strategies.

Multi-locus microsatellite analysis supports the hypothesis of an autochthonous focus of Echinococcus multilocularis in northern Italy.

Echinococcus multilocularis is characterised by a wide geographical distribution, encompassing three continents (North America, Asia and Europe) yet very low genetic variability is documented. Recently, this parasite has been detected in red foxes (Vulpes vulpes) circulating in an Alpine region of Italy, close to Austria. This finding raised the question as to whether an autochthonous cycle exists in Italy or whether the infected foxes originated from the neighbouring regions of Austria. Studies have shown that multi-locus microsatellite analysis can identify genomic regions carrying mutations that result in a local adaptation. We used a tandem repeated multi-locus microsatellite (EmsB) to evaluate the genetic differences amongst adult worms of E. multilocularis collected in Italy, worms from neighbouring Austria and from other European and extra-European countries. Fluorescent PCR was performed on a panel of E. multilocularis samples to assess intra-specific polymorphism. The analysis revealed four closed genotypes for Italian samples of E. multilocularis which were unique compared with the other 25 genotypes from Europe and the five genotypes from Alaska. An analysis in the Alpine watershed, comparing Italian adult worms with those from neighbouring areas in Austria, showed a unique cluster for Italian samples. This result supports the hypothesis of the presence of an autochthonous cycle of E. multilocularis in Italy. EmsB can be useful for 'tracking' the source of infection of this zoonotic parasite and developing appropriate measures for preventing or reducing the risk of human alveolar echinococcosis.

Equinococosis alveolar humana. Presentación de un caso / Human alveolar echinococcosis. A case report

Introducción: La equinococosis está causada por diversasespecies de Echinococcus, parásitos céstodos de la familiade las tenias. La especie más frecuentemente observadaes el Echinococcus granulosus, agente causal del quistehidatídico. Otras especies de Echinococcus se observan conpoca frecuencia en nuestro medio. Caso clínico: Presentamosel caso de un varón de 83 años con equinococosis alveolarhumana. Discusión: La equinococosis alveolar humanaes una enfermedad rara, causada por el E. multilocularis. Enpacientes que no reciben tratamiento o que son tratados deforma inadecuada, la mortalidad es muy alta. En Europa, esendémica en Bélgica, Luxemburgo, Holanda, Francia, Alemania,Suiza, Austria, Polonia y la república checa. En lasúltimas dos décadas, como consecuencia del aumento de lapoblación de zorros, se ha observado la propagación de esteparásito a áreas no endémicas. Por ello, el personal médicodebería conocer esta grave enfermedad y saber cómo diagnosticarlay tratarla (AU)

Introduction: Echinococcosis is caused by severalspecies of Echinococcus, cestode parasites in the familyTaeniidaea. The most widely observed specie is E. granulosus,the causative agent of the cystic hydatid disease. Otherspecies of Echinococcus are seldom encountered in ourenvironment. Case report: The case of an 83-year-old malewith human alveolar echinococcosis is presented. Discussion:Human alveolar echinococcosis is a rare zoonotic diseasecaused by E. multilocularis. It has a high mortality ratein untreated or inadequately treated patients. In Europe, it isendemic in Belgium, Luxembourg, Holland, France, Germany,Switzerland, Austria, Poland and the Czech Republic.As a consequence of the increase in fox population, thespread of this parasite has been observed in non-endemicareas over the last two decades. Therefore, medical personnelshould be familiar with this serious disease, and knowhow to diagnose and treat it (AU)

Species identification of human echinococcosis using histopathology and genotyping in northwestern China.

Human cystic echinococcosis, caused by infection with the larval stage of Echinococcus granulosus, and alveolar echinococcosis, caused by the larval form of E. multilocularis, are known to be important public health problems in western China. Echinococcus shiquicus is a new species of Echinococcus recently described in wildlife hosts from the eastern Tibetan plateau and its infectivity and/or pathogenicity in humans remain unknown. In the current study, parasite tissues from various organs were collected post-operatively from 68 echinococcosis patients from Sichuan and Qinghai provinces in eastern China. The tissues were examined by histopathology and genotyped using DNA sequencing and PCR-RFLP. Histopathologically, 38 human isolates were confirmed as E. granulosus and 30 as E. multilocularis. Mitochondrial cob gene sequencing and PCR-RFLP with rrnL as the target gene confirmed 33 of 53 of the isolates to have the G1 genotype of sheep/dog strain of E. granulosus as the only source of infection, while the remaining 20 isolates were identified as E. multilocularis. No infections were found to be caused by E. shiquicus. Additionally, 5 of 20 alveolar echinococcosis patients were confirmed to have intracranial metastases from primary hepatic alveolar echinococcosis lesions. All these cases originated from four provinces or autonomous regions but most were distributed in Sichuan and Qinghai provinces, where high prevalence rates of human alveolar echinococcosis and cystic echinococcosis were previously documented.

[Parasite-host relationships and treatment]. / Le parasite et ses relations avec ses hôtes.

Alveolar echinococcosis (AE) is a parasitic disease caused by intrahepatic growth of the larval stage of the cestode Echinococcus multilocularis. The main definitive host in Europe is the fox. The adult worms live in the fox intestine and their oncospheres are disseminated by faeces. Wolves, dogs and cats may also serve as definitive hosts. Small rodents--especially voles in Europe and small lagomorphs in Asia--are the natural intermediate hosts. The tumour-like larva is composed of multiple vesicles which produce protoscoleces, the fertile stage of the E. multilocularis metacestode. Carnivores are infected by preying on infected rodents. Like rodents, humans are intermediate hosts and are infected either by eating uncooked vegetables and berries contaminated by faeces of infected carnivores, or by touching such animals. Humans are naturally resistant to metacestode development. Genetic characteristics are involved in susceptibility/resistance to E. multilocularis metacestodes. In humans and other intermediate animal hosts, immune suppression enhances parasite growth, which is normally controlled by cytotoxic mechanisms and delayed-type hypersensitivity. Tolerance of E. multilocularis is due in part to parasite characteristics (especially carbohydrate antigens of the laminated layer) and in part to the "anti-inflammatory/tolerogenic" cytokines IL-10 and TGF-beta. Treatment with interferon-a restores a cytokine balance favorable to the host and might be a new therapeutic option for AE patients. Vaccination is a scientifically sound but economically and politically Utopian means of preventing the disease. Prevention thus relies on simple lifestyle measures: cooking potentially contaminated food, regular treatment of domestic animals with praziquantel, and precautions when touching potentially infected definitive hosts (foxes and dogs).