Helminth zoonoses remain a global problem to public health and the economy of many countries. Polymerase chain reaction-based techniques and sequencing have resolved many taxonomic issues and are now essential to understanding the epidemiology of helminth zoonotic infections and the ecology of the causative agents. This is clearly demonstrated from research on Echinococcus (echinococcosis) and Trichinella (trichinosis). Unfortunately, a variety of anthropogenic factors are worsening the problems caused by helminth zoonoses. These include cultural factors, urbanization and climate change. Wildlife plays an increasingly important role in the maintenance of many helminth zoonoses making surveillance and control increasingly difficult. The emergence or re-emergence of helminth zoonoses such as Ancylostoma ceylanicum, Toxocara, Dracunculus and Thelazia exacerbate an already discouraging scenario compounding the control of a group of long neglected diseases.

Taenia solium is the aetiological agent of cysticercosis, a zoonosis that causes severe health and economic losses across Latin America, Africa and Asia. The most serious manifestation of the disease is neurocysticercosis, which occurs when the larval stage (cysticercus) establishes in the central nervous system. Using Taenia crassiceps as an experimental model organism for the study of cysticercosis, we aimed to identify the in vitro conditions necessary to allow parasite development at the short- and long terms. First, cysticerci were incubated for 15 days in different media and parasite densities. The number of buddings and cysticerci diameter were measured to evaluate asexual multiplication and parasite growth, respectively. Vitality was determined by trypan blue staining and morphology analysis. As a result, high cysticerci density and medium containing FBS and the excretion/secretion (E/S) products of feeder cells induced parasite survival, growth and multiplication. Then, the long-term (5 weeks) incubation of the parasites in co-culture with feeder cells was evaluated. Consequently, the mammalian cell lines induced a significant increase in total parasite volume while axenic cultures did not show any statistically significant change over time. In this study, the proper conditions to maintain T. crassiceps in vitro are described for the first time in a simpler and more controlled setting other than experimental infections. In addition, it was shown that cysticerci growth, survival and asexual multiplication depend on a complex network of secreted factors from both parasite and host.

Pigs act as the intermediate hosts of the zoonotic tapeworms Taenia solium and Taenia asiatica, as well as of the non-zoonotic Taenia hydatigena. In Vietnam, human taeniasis and cysticercosis have been reported throughout the country; however, data on porcine cysticercosis are scarce. Our study aimed to estimate the prevalence of Taenia spp. in slaughtered pigs in two districts in Phu Tho, a mountainous province in northern Vietnam from where neurocysticercosis patients commonly originate. The carcasses of 399 pigs from 51 small-scale abattoirs were checked for cysticerci, while tongue, liver, masseter muscles, diaphragm and heart were sliced and examined. Retrieved cysticerci underwent polymerase chain reaction–restriction fragment length polymorphism and sequencing for species confirmation. Blood was also collected to detect antibodies by lentil lectin-purified glycoprotein enzyme-linked immunoelectrotransfer blot (LLGP-EITB) and recombinant T24H antigen (rT24H)-EITB and circulating antigens by B158/B60 Ag-ELISA. In two pigs, T. asiatica cysticerci were found, confirming the presence of the parasite in pigs in Vietnam at a low prevalence (0.5%; 95% exact confidence interval (CI): 0–1.19%). Cysticerci of T. solium were found in none of the pigs, although one serum sample was positive for antibodies in both LLGP-EITB and rT24H-EITB. Furthermore, a high prevalence of T. hydatigena cysticercosis was observed (18.0%; 95% Wilson score CI: 14.6–22.1%). In more than half of the T. hydatigena-positive pigs, circulating antigens were detected by Ag-ELISA, confirming that this test cannot be used to diagnose T. solium cysticercosis in this region. Finally, Spirometra erinaceieuropaei was found in one pig liver. It is the first record of this zoonotic cestode species in pigs in Vietnam. Overall, the findings confirmed the complex epidemiology of Taenia spp. in pigs in Vietnam.

The aim of this study is to determine the species of parasite that infected the population of Brussels during the Medieval and Renaissance periods, and determine if there was notable variation between different households within the city. We compared multiple sediment layers from cesspits beneath three different latrines dating from the 14th–17th centuries. Helminths and protozoa were detected using microscopy and enzyme-linked immunosorbent assay (ELISA). We identified Ascaris sp., Capillaria sp., Dicrocoelium dendriticum, Entamoeba histolytica, Fasciola hepatica, Giardia duodenalis, Taenia sp. and Trichuris sp. in Medieval samples, and continuing presence of Ascaris sp., D. dendriticum, F. hepatica, G. duodenalis and Trichuris sp. into the Renaissance. While some variation existed between households, there was a broadly consistent pattern with the domination of species spread by fecal contamination of food and drink (whipworm, roundworm and protozoa that cause dysentery). These data allow us to explore diet and hygiene, together with routes for the spread of fecal–oral parasites. Key factors explaining our findings are manuring practices with human excrement in market gardens, and flooding of the polluted River Senne during the 14th–17th centuries.

Echinococcus granulosus sensu latu (s.l.) and Taenia hydatigena are common parasites of ruminant intermediate hosts in the Balkans. Transmission is linked mainly to home slaughtering and the feeding of infected organs to dogs. In Kosovo, many old sheep are slaughtered particularly during Eid al-Adha (Feast of Sacrifice). To determine whether this tradition could affect parasite transmission, we compared the probability of 504 dogs to contract taenid infections after deworming during one period before Eid al-Adha and a similar period beginning with this event. Initially, taeniid eggs were detected in 6·2% (CI 4·2–8·6) of the dogs. The prevalence before Eid al-Adha was significantly lower (1·2%, CI 0·4–2·6) as compared with the prevalence after the event (4·3%, CI 2·6–6·3). A comparable trend was apparent at species level for T. hydatigena and E. granulosus. These results indicate that the pronounced increase of taeniid infections, including E. granulosus s.l., after Eid al-Adha is linked to traditional home slaughtering that occurs during this celebration. This particular epidemiological situation provides an opportunity for implementing focussed control activities.

Taeniid eggs contain an infective larval form of the parasite, known as the oncosphere, which has been found to be highly susceptible to attack by the host's immune system and this fact has been exploited in the development of highly effective vaccines. Relatively little is known about the structure of taeniid oncospheres and the localization of host-protective antigens within or on the oncosphere. Here, we briefly review the current state of knowledge of the structure of the oncosphere and present preliminary data on the localization of a host-protective antigen within the oncospheres of Taenia ovis. The precise localization of the antigens, in the context of a detailed knowledge of the ultrastructure of the parasite, may reveal the immune mechanisms by which the taeniid parasites are killed by vaccine-induced immune responses, which, in turn, may provide clues about how vaccines could be developed against other parasitic helminths.

From 1974 to 1989, a total of 24 500 aborigines at 67 villages in ten mountainous districts/towns in Taiwan were examined for the Taiwan Taenia infection and 12% were found to be infected. In order to define the clinical manifestations of taeniasis caused by the Taiwan Taenia, 1661 aborigines in ten mountainous districts were surveyed. The overall clinical rate was 76%. The clinical rate was highest among Atayal aborigines (81%), followed by Bunun (66%) and Yami (61%) aborgines and lowest among Ami aborigines (40%). Among 1153 infected people, 10% had passed gravid segments in the faeces for less than 1 year, 24% for 1–3 years, 17% for 4–5 years. 23% for 6–10 years, 16% for 11–20 years, 7% for 21–30 years, and 3% over 30 years. Twenty-six occurrences of gastrointestinal and neurological symptoms were reported by 1258 infected persons. Passing proglottides in the faeces (95%) was the most frequent sign, followed by pruritis ani (77%), nausea (46%), abdominal pain (45%), dizziness (42%), increased appetite (30%), headache (26%). etc.

Eggs (1000–100 000/animal) of Taiwan Taenia were inoculated per os into 14 Small-Ear-Miniature (SEM), 19 Landrace-Small-Ear-Miniature (L-SEM), and 5 Duroc-Yorkshire-Landrace (DYL) pigs. These animals were sacrificed 7–107 days after infection. Thirty-four pigs were found to be infected with Taiwan Taenia cysticerci and the infection rates of SEM, L-SEM, and DYL were 86%, 89% and 100% respectively. The cysticerci recovery rates of SEM, L-SEM and DYL pigs were 27·2%, 1·7% and 0·27% respectively. Cysticerci were recovered only from the livers and none were found in muscles, viscera or other parts of the carcasses. More cysticerci were located in the liver parenchyma (71%) than on the liver surface (29%). Taiwan Taenia cysticerci were smaller than those of classical T. saginata or T. solium. Moreover, Taiwan Taenia cysticerci had 2 rows of rudimentary hooklets on the scolex. The results of this study indicate that young pigs are good intermediate hosts for Taiwan Taenia and that the SEM pig is a satisfactory host for experimental studies with this tapeworm. These results were similar to other studies with different geographic strains of the T. saginata-like tapeworm in the Far East. These strains appear to be the same and possibly a new species.

A cysticercus of a possibly undescribed species of Taenia which occurs commonly in Taiwan aborigines was used to establish an experimental infection in a human volunteer. Symptomatic effects attributed to the infection included diarrhoea, upper abdominal pain, and increase or loss of appetite over a four-month period. After an expelled proglottid was observed 122 days post-exposure, eggs and proglottids were found continuously until the patient was treated with anthelmintics. Antibody titres measured by enzyme-linked immunosorbent assay and levels of eosinophilia seemed to correlate with symptoms. Haematological analyses revealed an abnormal lipid metabolism during the entire symptomatic period.

Of 756 dog faecal deposits collected from the road side and public places in five Jordanian Governorates 466 (61·6%) harboured parasite ova, oocysts and/or larvae. Of these, 67·7%, 26·8%, 4·1% and 1·4% revealed one, two, three and four different types of parasite ova, oocysts or larvae in the same sample, respectively. Examination of the infected samples revealed that 44·1% contained taeniid ova, 19·8% Dipylidium caninum, 19% Toxocara canis, 8% Sarcocystis spp. oocysts, 5% hookworm larvae, 1·5% Diphyllobothrium latum, 0·1% Capillaria spp. and 0·1% Trichuris vulpis eggs.

Three ELISA assays, based on hyperimmune rabbit serum raised against adult cestode somatic antigen, were applied in this study for the detection of Taenia- and Echinococcus-specific antigens in host faeces. The first assay, using an antiserum against Taenia pisiformis antigen extract, was used in a time-course of T. pisiformis experimental infection in dogs. The assay was shown to be considerably more sensitive than microscopical detection of eggs in faeces. Antigen was present in faeces before patency and antigen levels were independent of T. pisiformis egg output. The second assay, involving a test for human taeniasis based on antibodies against T. solium, was applied in two field studies carried out in China and Guatemala. The test was highly specific, no false positive reactions occurred with human faecal samples and the test was capable of diagnosing individuals who would not have been detected by coproscopy or treatment to recover the tapeworm. A third assay was designed for E. granulosus and demonstrated 87·5% sensitivity and 96·5% specificity with samples from naturally and experimentally infected dogs with Echinococcus or Taenia infections. In both the human Taenia and canine Echinococcus studies antigen could be detected in faecal samples from infected hosts stored in 5% formalin for 6 months. Further refinements to these tests for field application are discussed.

A dipstick dot ELISA for detection of Taenia-specific coproantigens was developed. The test was based on a sandwich ELISA using antibodies raised against adult Taenia solium. Antibodies were adsorbed to nitrocellulose paper previously adhered to acetate plastic to form dipsticks. Once blocked with 5% skimmed milk and dried the antibody-coated dipsticks were stable for several weeks at room temperature. Both micro and dot ELISA formats were genus specific although the dot ELISA was less sensitive than the micro ELISA based on the same antiserum. During field studies, in which the majority of samples were tested in rural villages soon after collection, 3728 samples were tested. All samples were also examined by microscopy using formol ether concentration and individuals questioned to determine whether they were aware of being infected. After the initial diagnostic work individuals were treated with taeniacidal drugs for worm recovery. Use of the coproantigen test significantly increased the number of cases diagnosed. Of the 41 cases diagnosed by the three diagnostic techniques combined 31 were detected by the dipstick assay making it the most sensitive technique employed. The specificity of the dipstick assay was 99·9% with a positive predictive value of 88·%. The combined diagnostic approach did not, however, diagnose all cases. The coproantigen test was fast and easy to use. Further improvements may make the dipstick test suitable for wide-scale use in field studies and diagnostic laboratories.

The cestode family Taeniidae consists of 2 genera, Taenia and Echinococcus, which both have been the focus of intensive taxonomic and epidemiological studies because of their zoonotic importance. However, a comprehensive molecular phylogeny of this family has yet to be reconstructed. In this study, 54 isolates representing 9 Taenia species were characterized using DNA sequences in the mitochondrial cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes. Phylogenetic relationships within the family Taeniidae were inferred by combining cox1 and nad1 sequence data of the present and previous studies. In the phylogenetic analysis, the genus Echinococcus was shown to be monophyletic, but Taenia proved to be paraphyletic due to the position of T. mustelae as a probable sister taxon of Echinococcus. This indicates that T. mustelae should form a genus of its own. Taenia ovis krabbei was placed distant from T. ovis ovis, as a sister taxon of T. multiceps, supporting its recognition as a distinct species, T. krabbei. High intraspecific sequence variation within both T. polyacantha and T. taeniaeformis suggests the existence of cryptic sister species.

Recombinant vaccines have been developed which are highly effective in preventing infection with Taenia ovis in sheep, Taenia saginata in cattle, Taenia solium in pigs and Echinococcus granulosus in livestock animals. T. ovis and T. saginata are economically significant parasites and the commercial success or otherwise of vaccines against them will rely on their economic value. E. granulosus and T. solium are zoonotic parasites that cause cystic hydatid disease and neurocysticercosis, respectively, in humans. Vaccines against these parasites have been developed to assist with the control of transmission of the human diseases rather than for prevention of infections in livestock per se. Regions of high prevalence for cystic hydatid disease and neurocysticercosis occur primarily in the developing world. As a consequence, vaccines against them are of little or no commercially interest – they are Orphan Vaccines. Lack of commercial interest in these vaccines has made public sector support for their development necessary well beyond the research phase trough into completion of commercial scale-up and other more commercially-related assessments. Practical use of the vaccines will require commercial-scale production according to international manufacturing standards. Identifying partners and support in this endeavour is now of prime importance in efforts to achieve the potential of these vaccines as new tools for the control of cystic hydatid disease and neurocysticercosis.

Cysticercosis, caused by infestation with the pork tapeworm Taenia solium, is known to commonly involve the brain, muscles and subcutaneous tissue. Diagnosing cysticercosis can be difficult as its clinical presentation is usually non-specific. When involving subcutaneous tissue, it can present as firm, non-tender, solitary or multiple nodules. We report a case of subcutaneous cysticercosis at the nasion mimicking a nasal dermoid.