Taenia saginata Infection Misdiagnosed as Acute Cholecystitis in a Tibetan Patient, in China

The present study reports a rare case of Taenia saginata infection, which was initially diagnosed as acute cholecystitis in a Tibetan patient at the Qinghai-Tibetan Plateau pastoral area, China. A 45-year-old female was initially diagnosed with acute cholecystitis at a hospital in China. She had a slight fever, weight loss and constipation and complained of pain in the upper abdomen and left back areas. Increase of monocyte, eosinophil and basophil levels were shown. Taenia sp. eggs were detected in a fecal examination. An adult tapeworm approximately 146 cm in length, whitish-yellow color, was collected from the patient after treatment with traditional Chinese medicine. The adult tapeworm had a scolex and proglottids with genital pores. The scolex was rectangular shape with 4 suckers and rostellum without hooklet. The cox1 gene sequence shared 99.5-99.8% homology with that of T. saginata from other regions in China. The patient was diagnosed finally infected with T. saginata by morphological and molecular charateristics.

Cysticercosis

Cysticercosis, infection by larvae of the pork tapeworm Taenia solium, is the most common helminthic infection of the human central nervous system. It accounts for up to 30% of all seizures and epilepsy in endemic countries, and travel and immigration now lead to its more frequent presentation in industrialized countries. Ingestion of raw or undercooked pork can lead to infection with the T. solium cysticercus, formerly known as ‘Cysticercus cellulosae’, which is an encysted immature tapeworm. Once attached to the person’s small intestine, the head, or scolex, evaginates from the cysticercus, anchors in the intestinal mucosa and develops segments (proglottids) to become an adult tapeworm. Only by ingesting T. solium ova can humans develop cysticercosis. The commonest syndromes are late-onset epilepsy or intracranial hypertension. Diagnosis is based on brain imaging studies (CT or MRI) and supported by highly specific serology.

Identity of Spirometra theileri from a Leopard (Panthera pardus) and Spotted Hyena (Crocuta crocuta) in Tanzania

In the present study, a <i>Spirometra</i> species of Tanzania origin obtained from an African leopard (<i>Panthera</i> <i>pardus</i>) and spotted hyena (<i>Crocuta</i> <i>crocuta</i>) was identified based on molecular analysis of cytochrome <i>c</i> oxidase I (<i>cox1</i>) and NADH dehydrogenase subunit I (<i>nad1</i>) as well as by morphological observations of an adult tapeworm. One strobila and several segments of a <i>Spirometra</i> species were obtained from the intestine of an African male leopard (<i>Panthera</i> <i>pardus</i>) and spotted hyena (<i>Crocuta</i> <i>Crocuta</i>) in the Maswa Game Reserve of Tanzania. The morphological characteristics of <i>S</i>. <i>theileri</i> observed comprised 3 uterine loops on one side and 4 on the other side of the mid-line, a uterine pore situated posterior to the vagina and alternating irregularly either to the right or left of the latter, and vesicular seminis that were much smaller than other <i>Spirometra</i> species. Sequence differences in the <i>cox1</i> and <i>nad1</i> genes between <i>S</i>. <i>theileri</i> (Tanzania origin) and S. erinaceieuropaei were 10.1% (<i>cox1</i>) and 12.0% (<i>nad1</i>), while those of <i>S</i>. <i>decipiens</i> and <i>S</i>. <i>ranarum</i> were 9.6%, 9.8% (<i>cox1</i>) and 13.0%, 12.6% (<i>nad1</i>), respectively. The morphological features of the Tanzania-origin <i>Spirometra</i> specimens coincided with those of <i>S</i>. <i>theileri</i>, and the molecular data was also consistent with that of <i>S</i>. <i>theileri</i>, thereby demonstrating the distribution of <i>S</i>. <i>theileri</i> in Tanzania. This places the leopard (<i>Panthera</i> <i>pardus</i>) and spotted hyena (<i>Crocuta</i> <i>Crocuta</i>) as new definitive hosts of this spirometrid tapeworm.

Molecular identification of cryptic cysticercosis: Taenia ovis krabbei in wild intermediate and domestic definitive hosts

The complex life cycle of taeniids represents an ideal model of a multi-host system. The complexity of these parasites can therefore cover the epidemiological issues of the interface between wild and domestic animals, especially once spatial overlap between wild and domestic definitive and intermediate hosts occurs. Here we use the occurrence of Taenia ovis krabbei in two model areas as an example of this epidemiological complexity. In two contiguous areas in the Italian northern Apennines, two hunted roe deer (Capreolus capreolus) showed numerous cysticerci in the muscles of their whole body and an adult tapeworm was recorded in a semi-stray dog (Canis lupus familiaris). Through molecular typing of the mitochondrial cytochrome c oxidase I (cox1) gene, cysticerci and the adult tapeworm of T. krabbei were identified. Taenia krabbei cysticercosis was recorded for the first time in Italy. Although the role of dogs in the parasite's life cycle emerges, the overlap between wild and domestic definitive hosts and the increase of wild population densities raise concerns about the temporal (old or new) introduction and the spread of this parasite by one of these canid species (wolf (Canis lupus) or dog). Although T. krabbei is not a public health issue, economic concerns emerged for hunters and meat producers, related to the damage of carcasses by cysticerci. Therefore, there is a need to evaluate the spread of T. krabbei in the intermediate and definitive host populations, and to ensure the relevant sanitary education for hunters in order to avoid practices that could favour the spread and maintenance of its life cycle.

Canine echinococcosis: the predominance of immature eggs in adult tapeworms of Echinococcus granulosus in stray dogs from Tunisia

Canine echinococcosis is caused by the adult tapeworm of Echinococcus granulosus. As intermediate hosts, humans and livestock become infected following ingestion of eggs that are passed in the faeces of dogs. Mature eggs develop into hydatid cysts in different organs, leading to hydatid disease, which is a serious public health problem. In the present study, we investigated the proportion of mature eggs of E. granulosus in 140 dogs from three regions of Tunisia. The results showed the predominance of immature E. granulosus eggs in infected dogs and the occurrence of a small proportion of oncospheres. The ability of immature eggs to infect humans and livestock is discussed.

Canine echinococcosis: genetic diversity of Echinococcus granulosus sensu stricto (s.s.) from definitive hosts

Canids, particularly dogs, constitute the major source of cystic echinococcosis (CE) infection to humans, with the majority of cases being caused by Echinococcus granulosus (G1 genotype). Canine echinococcosis is an asymptomatic disease caused by adult tapeworms of E. granulosus sensu lato (s.l.). Information on the population structure and genetic variation of adult E. granulosus is limited. Using sequenced data of the mitochondrial cytochrome c oxidase subunit 1 (cox1) we examined the genetic diversity and population structure of adult tapeworms of E. granulosus (G1 genotype) from canid definitive hosts originating from various geographical regions and compared it to that reported for the larval metacestode stage from sheep and human hosts. Echinococcus granulosus (s.s) was identified from adult tapeworm isolates from Kenya, Libya, Tunisia, Australia, China, Kazakhstan, United Kingdom and Peru, including the first known molecular confirmation from Gaza and the Falkland Islands. Haplotype analysis showed a star-shaped network with a centrally positioned common haplotype previously described for the metacestode stage from sheep and humans, and the neutrality indices indicated population expansion. Low Fst values suggested that populations of adult E. granulosus were not genetically differentiated. Haplotype and nucleotide diversities for E. granulosus isolates from sheep and human origin were twice as high as those reported from canid hosts. This may be related to self-fertilization of E. granulosus and/or to the longevity of the parasite in the respective intermediate and definitive hosts. Improved nuclear single loci are required to investigate the discrepancies in genetic variation seen in this study.

Tamoxifen Treatment in Hamsters Induces Protection during Taeniosis byTaenia solium

Human neurocysticercosis byTaenia soliumis considered an emergent severe brain disorder in developing and developed countries. Discovery of new antiparasitic drugs has been recently aimed to restrain differentiation and establishment of theT. soliumadult tapeworm, for being considered a central node in the disease propagation to both pigs and humans. Tamoxifen is an antiestrogenic drug with cysticidal action onTaenia crassiceps, a close relative ofT. solium. Thus, we evaluated the effect of tamoxifen on thein vitroevagination and thein vivoestablishment ofT. solium.In vitro, tamoxifen inhibited evagination ofT. soliumcysticerci in a dose-time dependent manner.In vivo, administration of tamoxifen to hamsters decreased the intestinal establishment of the parasite by 70%, while recovered tapeworms showed an 80% reduction in length, appearing as scolices without strobilar development. Since tamoxifen did not show any significant effect on the proliferation of antigen-specific immune cells, intestinal inflammation, and expression of Th1/Th2 cytokines in spleen and duodenum, this drug could exert its antiparasite actions by having direct detrimental effects upon the adult tapeworm. These results demonstrate that tamoxifen exhibits a strong cysticidal and antitaeniasic effect onT. soliumthat should be further explored in humans and livestock.