Zoonotic helminth infections of humans: echinococcosis, cysticercosis and fascioliasis

A coprological survey on helminths of Jackal Canis aureus Linnaeus 1758 in Kashmir Himalaya

A coprological examination was carried out between February 2017 and January 2019 to determine the prevalence of gastrointestinal helminths in jackals of Kashmir Himalaya, India. Fecal floatation and sedimentation technique revealed helminths in 215 scats out of 879 examined scats, with overall helminth prevalence of 24.45%. In the study, five different species of helminths were detected in scats of jackal: Toxocara canis (22.86%), Ancylostoma caninum (20.47%), Dipylidium caninum (17.17%), Trichuris vulpis (19.34%), and taeniid eggs (13.65%). One helminth species was found in (0.11%) of the jackal scats, two were in (1.25%), three were in (4.77%), four were in (16.38%), and five were in (1.92%). Toxocara canis, a nematode with great zoonotic significance, was most common helminth found in scats of jackal during the study. We observed significant seasonal fluctuation (p < 0.05) in the prevalence of gastrointestinal helminths, with summer having high frequency followed by autumn, spring, and winter having lowest prevalence. The study area's jackal population's preponderance of zoonotic helminth species suggests a high risk of zoonotic infection by canine intestinal helminths. This study will aid veterinarians in better plan preventative strategies with regard to wild animal intestinal parasites.

In Vitro Anthelmintic Effect of Ferula assa-foetida Hydroalcoholic Extract Against Flukes of Fasciola hepatica and Dicrocoelium dendriticum

Background: Dicrocoeliasis and fascioliasis are foodborne parasitic diseases of the biliary tract, resulting from Dicrocoelium dendriticum and Fasciola hepatica causing extensive financial losses and serious health problems in ruminants. Due to low-performance medications, drug delivery is a tremendous project to improve interventions available for these diseases. Objectives: This study aimed to determine the anthelmintic properties of Ferula assa-foetida extract against F. hepatica and D. dendriticum using in vitro assay. Methods: The effects of diverse concentrations of F. assa-foetida extract (400 - 1000 µg/mL) for 12-24 hours were examined for the treatment of D. dendriticum and F. hepatica. The anthelmintic efficacies were evaluated using scanning electron microscopy (SEM). The MTT assay was carried out to evaluate the cell viability of all cells in culture media. Results: The SEM images of treated worms by F. assa-foetida extract (200 µg/mL) confirmed excessive damage, which included an entire lack of sensory papillae and destruction of distinguished network structures and tegument vesicles. Variables of duration and concentration presented a considerable effect on both the mortality rate and the anthelmintic properties of F. assa-foetida; accordingly, as the time and concentration increased, the mortality rate became higher. Based on the MTT assay, the toxicity of F. assa-foetida at 800 µg/mL concentration was 8.7%. Therefore, it can be argued that F. assa-foetida had anthelmintic properties. Conclusions: This is the first study that evaluated the impact of F. assa-foetida on liver flukes of D. dendriticum and F. hepatica. Therefore, it paved the way for further studies on the control of those trematodes. It is recommended to document and look into the indigenous understanding of viable medicinal plants to provide evidence for their use.

Cell repertoire and proliferation of germinative cells of the model cestode Mesocestoides corti

The phylum Platyhelminthes shares a unique population of undifferentiated cells responsible for the proliferation capacity needed for cell renewal, growth, tissue repair and regeneration. These cells have been extensively studied in free-living flatworms, whereas in cestodes the presence of a set of undifferentiated cells, known as germinative cells, has been demonstrated in classical morphology studies, but poorly characterized with molecular biology approaches. Furthermore, several genes have been identified as neoblast markers in free-living flatworms that deserve study in cestode models. Here, different cell types of the model cestode Mesocestoides corti were characterized, identifying differentiated and germinative cells. Muscle cells, tegumental cells, calcareous corpuscle precursor cells and excretory system cells were identified, all of which are non-proliferative, differentiated cell types. Besides those, germinative cells were identified as a population of small cells with proliferative capacity in vivo. Primary cell culture experiments in Dulbecco's Modified Eagle Medium (DMEM), Echinococcus hydatid fluid and hepatocyte conditioned media in non-reductive or reductive conditions confirmed that the germinative cells were the only ones with proliferative capacity. Since several genes have been identified as markers of undifferentiated neoblast cells in free-living flatworms, the expression of pumilio and pL10 genes was analysed by qPCR and in situ hybridization, showing that the expression of these genes was stronger in germinative cells but not restricted to this cell type. This study provides the first tools to analyse and further characterise undifferentiated cells in a model cestode.

Understanding pathogen–host interplay by expression profiles of lncRNA and mRNA in the liver of Echinococcus multilocularis-infected mice

Almost all Echinococcus multilocularis (Em) infections occur in the liver of the intermediate host, causing a lethal zoonotic helminthic disease, alveolar echinococcosis (AE). However, the long non-coding RNAs (lncRNAs) expression profiles of the host and the potential regulatory function of lncRNA during Em infection are poorly understood. In this study, the profiles of lncRNAs and mRNAs in the liver of mice at different time points after Em infection were explored by microarray. Thirty-one differentially expressed mRNAs (DEMs) and 68 differentially expressed lncRNAs (DELs) were found continuously dysregulated. These DEMs were notably enriched in “antigen processing and presentation”, “Th1 and Th2 cell differentiation” and “Th17 cell differentiation” pathways. The potential predicted function of DELs revealed that most DELs might influence Th17 cell differentiation and TGF-β/Smad pathway of host by trans-regulating SMAD3, STAT1, and early growth response (EGR) genes. At 30 days post-infection (dpi), up-regulated DEMs were enriched in Toll-like and RIG-I-like receptor signaling pathways, which were validated by qRT-PCR, Western blotting and downstream cytokines detection. Furthermore, flow cytometric analysis and serum levels of the corresponding cytokines confirmed the changes in cell-mediated immunity in host during Em infection that showed Th1 and Th17-type CD4+ T-cells were predominant at the early infection stage whereas Th2-type CD4+ T-cells were significantly higher at the middle/late stage. Collectively, our study revealed the potential regulatory functions of lncRNAs in modulating host Th cell subsets and provide novel clues in understanding the influence of Em infection on host innate and adaptive immune response.

Role of Fasciola hepatica Small RNAs in the Interaction With the Mammalian Host

MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression being involved in many different biological processes and play a key role in developmental timing. Additionally, recent studies have shown that miRNAs released from parasites are capable of regulating the expression of host genes. In the present work, we studied the expression patterns of ncRNAs of various intra-mammalian life-cycle stages of the liver fluke, Fasciola hepatica, as well as those packaged into extracellular vesicles and shed by the adult fluke. The miRNA expression profile of the intra-mammalian stages shows important variations, despite a set of predominant miRNAs that are highly expressed across all stages. No substantial variations in miRNA expression between dormant and activated metacercariae were detected, suggesting that they might not be central players in regulating fluke gene expression during this crucial step in the invasion of the definitive host. We generated a curated pipeline for the prediction of putative target genes that reports only sites conserved between three different prediction approaches. This pipeline was tested against an iso-seq curated database of the 3’ UTR regions of F. hepatica genes to detect miRNA regulation networks within liver fluke. Several functions related to the host immune response or modulation were enriched among the targets of the most highly expressed parasite miRNAs, stressing that they might be key players during the establishment and maintenance of infection. Additionally, we detected fragments derived from the processing of tRNAs, in all developmental stages analyzed, and documented the presence of novel long tRNA fragments enriched in vesicles. We confirmed the presence of at least 5 putative vault RNAs (vtRNAs), that are expressed across different stages and enriched in vesicles. The presence of tRNA fragments and vtRNAs in vesicles raise the possibility that they could be involved in the host-parasite interaction.

Seroprevalence and risk factors of porcine cysticercosis: A cross-sectional study in Indonesia

Background and Aim:

Cysticercosis is a zoonotic disease with a global concern. Estimation of the prevalence and identification of potential risk factors are necessary for the prevention and control of the disease. This study aimed to estimate the seroprevalence of cysticercosis and the correlation of the increased prevalence with several potential risk factors.

Materials and Methods:

The seroprevalence of cysticercosis was conducted using an enzyme-linked immunosorbent assay (ELISA), developed by the Institute of Tropical Medicine Antwerp, to detect Cysticercus cellulosae. This study used serum samples from 62 pigs taken from two regencies on Timor Island. The data analysis was performed using SPSS software 20.0 (IBM Corp., NY, USA) to evaluate ELISA results and the strength of the relationship between risk factors and the prevalence of disease using the odds ratio (OR).

Results:

Serum samples from 18 out of the 62 pigs were found to be positive; the seroprevalence of cysticercosis was 29%. The results showed that an extensive farming system led to a higher prevalence of cysticercosis compared to an intensive farming system, namely, 10 out of 18 (56.6%), and that the possibility of identifying cysticercosis in pigs in an extensive farming system was 5 times greater than that in pigs in an intensive farming system. In addition, the results showed that nine out of 18 households who did not have toilet facilities were found to be seropositive, indicating a significant relationship between the risk factor of toilet availability with cysticercosis in pigs, with an OR of 4.5. In addition, the results showed that there was no significant relationship between the risk factor of the feed source and the prevalence of cysticercosis in pigs.

Conclusion:

It can be concluded that the seroprevalence of cysticercosis was 29% in domestic pigs of Timor Island. The risk factors of an extensive pig farming system andtoilet availabilityin community houses were significantly related to the possibility of cysticercosis on Timor Island.

Screening of Cystic Echinococcosis and Toxocariasis in Urmia Municipal Workers, Northwest Iran

BACKGROUND

Echinococcus granulosus and Toxocara spp., the causative agents of hydatid cyst and toxocariasis in humans and animals, are zoonotic infections with medical and veterinary significance respectively.

AIM

Herein, we aimed to investigate the seroprevalence of toxocariasis and cystic echinococcosis in Urmia municipal workers (gardeners and sweepers) in 2018 using ELISA assay.

OBJECTIVE

There is no precise report on the seroprevalence of toxocariasis and cystic echinococcosis in Urmia municipal workers using ELISA assay. Therefore, this study found an opportunity to investigate this subject.

METHODS

A total of 220 blood samples were obtained from municipal workers with an average age of 41.31 ± 9.42. Commercial anti-Toxocara canis and hydatid cyst ELISA kits were used to assess the seroprevalence rates.

RESULTS

Approximately, 14.5% and 2.3% of individuals were seropositive for toxocariasis and hydatidosis, respectively. Consuming unboiled milk and/or raw/uncooked meat and rural conditions are risk factors for toxocariasis. Regarding hydatidosis, consuming unwashed vegetables was the only statistically significant risk factor. Toxocara infection (p = 0.01), but not hydatid cyst (p = 0.05), is more prevalent among sweepers than municipal gardeners.

CONCLUSION

Due to the occupational condition of municipal workers, they are exposed to many infectious agents; thus, more researches should be done on these populations.

Fasciola hepatica hijacks host macrophage miRNA machinery to modulate early innate immune responses

Fasciola hepatica, a global worm parasite of humans and their livestock, regulates host innate immune responses within hours of infection. Host macrophages, essential to the first-line defence mechanisms, are quickly restricted in their ability to initiate a classic protective pro-inflammatory immune response. We found that macrophages from infected animals are enriched with parasite-derived micro(mi)RNAs. The most abundant of these miRNAs, fhe-miR-125b, is released by the parasite via exosomes and is homologous to a mammalian miRNA, hsa-miR-125b, that is known to regulate the activation of pro-inflammatory M1 macrophages. We show that the parasite fhe-miR-125b loads onto the mammalian Argonaut protein (Ago-2) within macrophages during infection and, therefore, propose that it mimics host miR-125b to negatively regulate the production of inflammatory cytokines. The hijacking of the miRNA machinery controlling innate cell function could be a fundamental mechanism by which worm parasites disarm the early immune responses of their host to ensure successful infection.

Antiparasitic Effects of Selected Isoflavones on Flatworms

Medicinal plants have been successfully used in the ethno medicine for a wide range of diseases since ancient times. The research on natural products has allowed the discovery of biologically relevant compounds inspired by plant secondary metabolites, what contributed to the development of many chemotherapeutic drugs. Flavonoids represent a group of therapeutically very effective plant secondary metabolites and selected molecules were shown to exert also antiparasitic activity. This work summarizes the recent knowledge generated within past three decades about potential parasitocidal activities of several flavonoids with different chemical structures, particularly on medically important flatworms such as Schistosoma spp., Fasciola spp., Echinococcus spp., Raillietina spp., and model cestode Mesocestoides vogae. Here we focus on curcumin, genistein, quercetin and silymarin complex of flavonolignans. All of them possess a whole spectrum of biological activities on eukaryotic cells which have multi-therapeutic effects in various diseases. In vitro they can induce profound alterations in the tegumental architecture and its functions as well as their activity can significantly modulate or damage worm´s metabolism directly by interaction with enzymes or signaling molecules in dose-dependent manner. Moreover, they seem to differentially regulate the RNA activity in numbers of worm´s genes. This review suggests that examined flavonoids and their derivates are promising molecules for antiparasitic drug research. Due to lack of toxicity, isoflavons could be used directly for therapy, or as adjuvant therapy for diseases caused by medically important cestodes and trematodes.

Detection of rodent-borne parasitic pathogens of wild rats in Serdang, Selangor, Malaysia: A potential threat to human health

Rodent species, such as Rattus rattus diardii and Rattus norvegicus are invasive species of wild rats that serve as potential reservoirs of important human's pathogens. Parasitic zoonosis accounts for over 60% of all human infectious diseases worldwide. This situation arises from the recent changes in the global climate and ecosystem composition, which led to the spread of rodents and rodent-borne pathogens globally. The aim of this study was to determine the occurrence of rodent's parasites and their zoonotic potentials in some selected areas in UPM. Rodents were captured using live-traps and euthanised for helminths and protozoan recovery. Intestinal parasites were detected and identified from stool samples using formalin ethyl-acetate concentration technique (FECT), while tissue parasites were identified by histopathological examination of selected tissue sections of the liver, brain, lungs, and muscle. In this study, a total of 89 wild rats were captured. Twelve species of intestinal and tissue parasites were recorded, of which, Taenia taeniaeformis accounts for the highest infection recorded (28%) followed by Hymenolepis nana (19.5%) and Capillaria hepatica (19.1%), while Toxoplasma gondii was the least parasite (6.7%) identified. Furthermore, other parasites species observed include, Cryptosporidium spp. (21.3%), Entamoeba histolytica/Entamoeba dispar and Moniliformis moniliformis (17.9%), Angiostrongylus cantonensis (16.8%), Hymenolepis diminuta (16.1%), Giardia spp. (14.6%), Trichuris spp. (12.3%), and Sarcocystis spp. (6.74). Based on the results obtained in the present study, 17.1% and 15.4% of the rodents captured were confirmed positive for at least one species of intestinal or tissue parasites, respectively. The presence of these zoonotic parasites in the wild rats suggests the potential risk of rodent-borne zoonotic disease transmission to humans. Hence, the need to improved rats control intervention and public health awareness among the populace.

Treatment failure after multiple courses of triclabendazole in a Portuguese patient with fascioliasis

Fascioliasis is a trematode flatworm infection caused by Fasciola hepatica Humans are incidental hosts, and the infection is most often acquired by eating watercress grown in contaminated water in livestock-rearing areas. Triclabendazole is the only highly effective treatment, with a reported cure rate of >90%. Treatment failure may be due to several factors, though resistance is rare in humans and scarcely reported, most probably a reflection of the widespread use of anthelmintics in livestock. There are three papers describing cases of treatment failure, possibly due to resistance, in the Netherlands, Chile and Peru. We document for the first time one case of failure after multiple treatment courses with triclabendazole in Portugal, probably due to resistance to the anthelmintic. Our aim is to alert for the emergence of resistance across continents, with consequent predictable difficulties in the management of the disease and encourage more investigation in the field.

A Scoping Review of the Prevalence of Fascioliasis in Malaysia and Risk Factors for Infection

This review aimed to provide a comprehensive overview of ruminant and human fascioliasis in Malaysia and to identify research gaps in knowledge of the prevalence of fascioliasis in Malaysia and risk factors for the disease using available evidence-based data. We conducted a scoping review based on the framework of Arksey and O'Malley. The preferred reporting items for systematic reviews and meta-analyses were used to guide the review process. The citation search was performed between May and September 2018. Using specific keywords, literature published between 1998 to September 2018 was retrieved from electronic databases. Six articles related to fascioliasis in Malaysia were included in the final review from 1,932 screened articles and reports. Five studies focused on ruminants, including cattle, buffaloes, sheep and goats in the states of Terengganu and Perak. The most frequent ruminant fascioliasis outbreaks involved cattle and goats, with a prevalence of 82%-95% and these outbreaks occurred in Terengganu. Only one study examined the risk of fascioliasis in cattle. In the study, the age and sex of the cattle were important risk-related parameters. The search returned only one documented report of a suspected case of human fascioliasis with an atypical clinical presentation. At present, human fascioliasis in Malaysia remains under-reported and its prevalence remains unknown. The data summarised in this review based on existing evidence identifies research gaps on fascioliasis in ruminants and humans.

First Record of Stephanostomum Sp. Looss, 1899 (Digenea: Acanthocolpidae) Metacercariae Parasitising the Pleasure Oyster Crassostrea Corteziensis (Hertlein) from the Mexican Pacific Coast

The aim of this investigation was to identify the parasites present in the largely understudied pleasure oyster Crassostrea corteziensis in Sinaloa state in the northwestern Mexican Pacific coast. Inspection of twenty-eight oysters collected on "Ceuta" lagoon revealed the presence of the digenean Stephanostomum sp. (Digenea: Acanthocolpidae) cysts. Metacercariae were found encapsulated and embedded in the digestive gland and mantle tissue of oysters. The prevalence of infection revealed that 84.6 % were infected, the abundance was 13.62, with a mean intensity of 16.09 per host. The members of this genus are characterized by a double crown of spines in the cephalic region surrounding the buccal opening of the worm. Significantly, we report the first incidence of the digenean Stephanostomum sp of the family Acanthocolpidae parasitizing Crassostrea corteziensis. Further we report that this bivalve is now considered a new intermediate host, and the northwestern Mexican Pacific coast is a new geographical distribution area for this digenean. The findings contribute to our understanding of the biology, biodiversity and host preference of these parasites, with implications for health risks posed by human consumption of the pleasure oyster.

Development of a nest-PCR for detection of Fasciola hepatica DNA in the intermediate snail host, Radix cucunorica, and the prevalence in northwestern China

Fasciolosis, a foodborne zoonotic disease, caused by Fasciola species which is considered an important problem for human health and livestock husbandry development. Snails are intermediate hosts of F. hepatica, the epidemiological surveillance of snails can evaluate the transmission risk of this disease in human and livestock. In this study, we developed a nest-polymerase chain reaction (nest-PCR) to detect the DNA of F. hepatica in Radix cucunorica, a prevalent intermediate host of this parasite in northwestern China. The nest-PCR was used to amplify a 208 bp fragment of the second internal transcribed spacer (ITS-2) of F. hepatica with two pairs of primers. The method was able to detect up to 0.16 fg genomic DNA in a 25 μL PCR reaction system even effected with high concentrations of snail DNA, and no cross reaction was observed from the genomic DNA of Paramphistomum cervi, Clonorchis sinensis, Orientobilharzia turkestanicum, Metorchis orientalis, Dicrocoelium chinensis. To evaluate the transmission risk of this disease, 409 snail samples collected from different areas of Gansu province were used to detect and analyze the transmission risk of F. hepatica in this area. Of 409 snail samples, the overall prevalence is 43.76%. The prevalence was 92.75% in Gannan Tibetan Autonomous Prefecture, while no snail was positive for F. hepatica in Linxia Hui Autonomous Prefecture. The nest-PCR was firstly used to detect the infection of F. hepatica in snail. It is a novel, useful and convenient method with high sensitivity and specificity. This study is the first report about the epidemiological surveillance of snail infection by F. hepatica in northwestern China, which will help to evaluate the transmission risk of F. hepatica in northwestern China.

Cloning, expression, characterization, and immunological properties of citrate synthase from Echinococcus granulosus

The larval stages of the tapeworm Echinococcus granulosus (Cestoda: Taeniidae) are the causative agent of cystic echinococcosis, one of the most important parasitic zoonoses worldwide. E. granulosus has a complete pathway for the tricarboxylic acid cycle (TCA), in which citrate synthase (CS) is the key enzyme. Here, we cloned and expressed CS from E. granulosus (Eg-CS) and report its molecular characterization. The localization of this protein during different developmental stages and mRNA expression patterns during H₂O₂ treatment were determined. We found that Eg-CS is a highly conserved protein, consisting of 466 amino acids. In western blotting assays, recombinant Eg-CS (rEg-CS) reacted with E. granulosus-positive sheep sera and anti-rEg-CS rabbit sera, indicating that Eg-CS has good antigenicity and immunoreactivity. Localization studies, performed using immunohistochemistry, showed that Eg-CS is ubiquitously expressed in the larva, germinal layer, and adult worm sections of E. granulosus. Eg-CS mRNA expression levels increased following H₂O₂ exposure. In conclusion, citrate synthase might be involved in the metabolic process in E. granulosus. An assessment of the serodiagnostic potential of rEg-CS based on indirect ELISA showed that, although sensitivity (93.55%) and specificity (80.49%) are high, cross-reactivity with other parasites precludes its use as a diagnostic antigen.

Pharmacokinetics, Safety, and Tolerability of Oxfendazole in Healthy Volunteers: a Randomized, Placebo-Controlled First-in-Human Single-Dose Escalation Study

Cysticercosis is a parasitic disease that frequently involves the human central nervous system (CNS), and current treatment options are limited. Oxfendazole, a veterinary medicine belonging to the benzimidazole family of anthelmintic drugs, has demonstrated substantial activity against the tissue stages of Taenia solium and has potential to be developed as an effective therapy for neurocysticercosis. To accelerate the transition of oxfendazole from veterinary to human use, the pharmacokinetics, safety, and tolerability of oxfendazole were evaluated in healthy volunteers in this phase 1 first-in-human (FIH) study. Seventy subjects were randomly assigned to receive a single oral dose of oxfendazole (0.5, 1, 3, 7.5, 15, 30, or 60 mg oxfendazole/kg body weight) or placebo and were followed for 14 days. Blood and urine samples were collected, and the concentrations of oxfendazole were measured using a validated ultraperformance liquid chromatography mass spectrometry method. The pharmacokinetic parameters of oxfendazole were estimated using noncompartmental analysis. Oxfendazole was rapidly absorbed with a mean plasma half-life ranging from 8.5 to 11 h. The renal excretion of oxfendazole was minimal. Oxfendazole exhibited significant nonlinear pharmacokinetics with less than dose-proportional increases in exposure after single oral doses of 0.5 mg/kg to 60 mg/kg. This nonlinearity of oxfendazole is likely due to the dose-dependent decrease in bioavailability that is caused by its low solubility. Oxfendazole was found to be well tolerated in this study at different escalating doses without any serious adverse events (AEs) or deaths. There were no significant differences in the distributions of hematology, biochemistry, or urine parameters between oxfendazole and placebo recipients. (This study has been registered at ClinicalTrials.gov under identifier NCT02234570.).

How to eliminate taeniasis/cysticercosis: porcine vaccination and human chemotherapy (Part 2)

BACKGROUND

The application of effective vaccines against pig cysticercosis and mass chemotherapy against pig cysticercosis and human taeniasis have shown the feasibility of interrupting the parasite's life cycle in endemic areas.

METHODS

A mathematical model that divides the population into susceptible, infected, and vaccinated individuals is formulated. The model is based upon the life cycle of the parasite. Computer numerical simulation experiments to evaluate the impact of pig vaccination under different vaccination schedules, and combined intervention strategies including pig vaccination and anthelmintic treatment against human taeniasis are carried out.

RESULTS

Vaccination against either pig cysticercosis or against human taeniasis will influence the transmission dynamics not only among vaccinees but also the dynamics of the other hosts as well. When the protective efficacy and/or the coverage rate is less than 100%, different mass interventions like vaccinating the pig population twice in combination with chemotherapeutic treatment against human taeniasis, the elimination of the infection in both pigs and humans can also be achieved.

CONCLUSIONS

Our mathematical model has the potential for planning, and designing effective intervention strategies including both mass vaccination and/or chemotherapeutic treatment to eliminate pig cysticercosis, human taeniasis and human neurocysticercosis. The model can be adapted to any given community with mild, moderate endemicity, or even in hyperendemic regions.

A Retrospective Analysis of the Clinical Features of Inpatients With Epilepsy in the Ganzi Tibetan Autonomous Prefecture

Background: There is limited detailed clinical information for patients with epilepsy in Tibet. This study sought to provide data about the clinical features of epilepsy in the Ganzi Tibetan Autonomous Prefecture to improve strategies for epilepsy prevention and management in this region.

Methods: We reviewed the clinical record of patients with epilepsy in the Neurology Department, Ganzi Tibetan Autonomous Prefecture People's Hospital and compared the clinical features and compared it with control, from West China Hospital in Chengdu.

Results: This retrospective study included 165 patients with epilepsy admitted between January 2015 and February 2018. Majority of patients (97%) in this study had active epilepsy; 28.5% had generalized onset seizures and 68.5% had focal onset seizures. Fifty-four patients had received anti-epileptic drug (AED) treatment prior to hospitalization, however, 38 (70.4%) patients took the medication irregularly. The leading etiology of this cohort was head trauma (20.6%), followed by stroke (10.9%), neurocysticercosis (7.9%), brain hydatidosis (6.7%) and tuberculous infection (5.5%). Compared with in-patients in Chengdu, epilepsy in Ganzi was more frequently caused by infection (OR = 4.216, 95% CI, 2.124–8.367), including neurocysticercosis (OR = 29.301, 95% CI, 1.727–497.167) and brain hydatidosis (OR = 24.637, 95% CI, 1.439–421.670).

Conclusions: These data suggest that the control of cerebral infections, especially parasite infection, is essential for the prevention of epilepsy in the Ganzi Tibetan Autonomous Prefecture. Education of local primary doctors and patients about the literacy of epilepsy will enable better management of epilepsy in this population.

Gastrointestinal helminths in farmers and their ruminant livestock from the Coastal Savannah zone of Ghana

To identify the gastrointestinal helminths of veterinary, zoonotic and public health importance in farmers and their ruminant livestock in Ghana, faecal samples were collected from 95 farmers and their livestock (cattle = 328, sheep = 285 and goats = 217) and examined by microscopy and/or molecular techniques. Overall, 21 farmers tested positive for at least one gastrointestinal helminth, 80.9% of which were single infections and 19.0% co-infections. The parasites identified in the farmers consisted of hookworms (n = 13) (9 were Necator americanus and the other 4 could not be amplified by PCR), Trichostrongylus spp. (n = 9), Schistosoma mansoni (n = 1), Schistosoma haematobium (n = 1) and Diphyllobothrium latum (n = 1). In livestock, strongylid nematodes were dominant (56.6%), followed by Paramphistomum spp. (16.9%), Dicrocoelium spp. (7.1%), Thysaniezia spp. (5.8%), Trichuris spp. (3.3%), Moniezia spp. (3.1%), Fasciola spp. (2.8%), Toxocara spp. (1.1%) and Schistosoma spp. (0.2%). Genotyping of Trichostrongylus spp. in the farmer's stools identified six T. colubriformis similar to T. colubriformis detected in cattle, sheep and goats in the study, two Trichostrongylus spp. with 98.3% and 99.2% genetic similarity to T. probolurus respectively and one Trichostrongylus spp. which showed 96.6% similarity to both T. probolurus and T. rugatus. Trichostrongylus axei was also identified in cattle, sheep and goats. This is the first molecular characterisation of Trichostrongylus spp. in Ghana and the species identified in the present study suggests zoonotic transmission from cattle, sheep and goats. Further studies involving larger numbers of farmers and their household members are essential to understand the transmission dynamics and impact of these parasites on farming communities in Ghana.

Global spread of helminth parasites at the human-domestic animal-wildlife interface

Changes in species distributions open novel parasite transmission routes at the human-wildlife interface, yet the strength of biotic and biogeographical factors that prevent or facilitate parasite host shifting are not well understood. We investigated global patterns of helminth parasite (Nematoda, Cestoda, Trematoda) sharing between mammalian wildlife species and domestic mammal hosts (including humans) using >24,000 unique country-level records of host-parasite associations. We used hierarchical modelling and species trait data to determine possible drivers of the level of parasite sharing between wildlife species and either humans or domestic animal hosts. We found the diet of wildlife species to be a strong predictor of levels of helminth parasite sharing with humans and domestic animals, followed by a moderate effect of zoogeographical region and minor effects of species' habitat and climatic niches. Combining model predictions with the distribution and ecological profile data of wildlife species, we projected global risk maps that uncovered strikingly similar patterns of wildlife parasite sharing across geographical areas for the different domestic host species (including humans). These similarities are largely explained by the fact that widespread parasites are commonly recorded infecting several domestic species. If the dietary profile and position in the trophic chain of a wildlife species largely drives its level of helminth parasite sharing with humans/domestic animals, future range shifts of host species that result in novel trophic interactions may likely increase parasite host shifting and have important ramifications for human and animal health.

Helminths of veterinary and zoonotic importance in Nigerian ruminants: a 46-year meta-analysis (1970-2016) of their prevalence and distribution

BACKGROUND

The livestock industry plays a vital role in the economy of Nigeria. It serves as a major source of income and livelihood for majority of Nigerians who are rural settlers and contributes about 5.2% to the National Gross Domestic Product (GDP). Helminths however, cause economic losses due to reductions in milk production, weight gain, fertility and carcass quality. Zoonotic helminths of livestock origin cause health problems in humans.

METHODS

Using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, the prevalence and distribution of helminths of veterinary and zoonotic importance in Nigerian ruminants were determined in a meta-analysis of data published between 1970 and 2016. Data were stratified based on regions, hosts, study periods, sample sizes and study types while helminths were phylogenetically grouped into cestodes, nematodes and trematodes.

RESULTS

Data from 44 studies reported across 19 Nigerian states revealed an overall pooled prevalence estimate (PPE) of 7.48% (95% CI: 7.38-7.57) for helminths of veterinary and zoonotic importance from a total of 320 208 ruminants. We observed a significant variation (P < 0.001) between the PPEs range of 1.90% (95% CI: 1.78-2.02) and 60.98% (95% CI: 58.37-63.55) reported across different strata. High heterogeneity (99.78, 95% CI: 7.38-7.57) was observed. Strongyloides papillosus was the most prevalent (Prev: 32.02%, 95% CI: 31.01-33.11), while, Fasciola gigantica had the widest geographical distribution.

CONCLUSIONS

Helminths of veterinary and zoonotic importance are prevalent in ruminants and well distributed across Nigeria. Our findings show that helminths of ruminants may also be possible causes of morbidity in humans and economic losses in the livestock industry in Nigeria. High heterogeneity was observed within studies and the different strata. Good agricultural practices on farms, standard veterinary meat inspection and adequate hygiene and sanitation in abattoirs, farms and livestock markets need to be implemented in Nigeria in order to reduce the economic, public health and veterinary threats due to these helminths.

The synthesis of steroids by Taenia crassiceps WFU cysticerci and tapeworms is related to the developmental stages of the parasites

Taeniids tapeworms are hermaphroditic helminths that gradually develop testis and ovaries in their reproductive units. The larval stage of the tapeworms named cysticercus is a vesicle that contains the scolex and proliferates asexually in the abdominal cavity of mice. Once in the host, they evaginate, attach to the gut and develop into an adult organism, the tapeworm. We have previously reported reported that T. crassiceps ORF and solium cysticerci transform steroid precursors to androgens and estrogens. Taenia crassiceps WFU cysticerci can also synthesize corticosteroids. The aim of the present work is to investigate the relationship between steroid synthesis ability and the developmental stage of the parasite T. crassiceps WFU. To this purpose, cysticerci were obtained from the abdominal cavity of female mice, manually separated in invaginated (IC) and evaginated parasites (EC) and preincubated for 24 h in DMEM plus antibiotics/antimycotics. Next step consisted in incubation for different periods in the fresh media added with tritiated androstenedione (³H-A₄) or progesterone (³H-P₄) and incubated for different periods. Taenia crassiceps WFU tapeworms were recovered from the intestine of golden hamsters that had been orally infected with cysticerci. The worms were pre-cultured in DMEM plus FBS and antibiotics, and then incubated without FBS for different time periods, in the presence of ³H-A₄ or ³H-P₄. At the end of the experiments the media from cysticerci and tapeworms were analyzed by thin layer chromatography. Results showed that testosterone synthesis was significantly higher in the evaginated cysticerci and increased with time in culture. The invaginated and evaginated cysticerci also synthesized small quantities of 17ß-estradiol (E₂) and estrone. The evaginated cysticerci synthesized twice more ³H-deoxycorticosterone (³H-DOC) than the invaginated parasites, the production increased significantly with time in culture. Taenia crassiceps WFU tapeworms synthesized significant quantities of ³H-testosterone and small amounts of estrone after only 3 h of culture in the presence of ³H-A₄. The tapeworms also transformed ³H-P₄ to ³H-DOC and increased its synthesis after 24 h in culture. In summary, our data show the pathways that T. crassiceps WFU cysticerci use to synthesize sexual steroids in both larval developmental stages and reveals the steroidogenic capacity of the tapeworms.

Treatment of human and livestock helminth infections in a mobile pastoralist setting at Lake Chad: Attitudes to health and analysis of active pharmaceutical ingredients of locally available anthelminthic drugs

Mobile pastoralists face challenges in accessing quality health care and medication for managing human and animal diseases. We determined livestock disease priorities, health seeking behaviour of people bearing helminthiases and - placing particular emphasis on trematode infections - treatment strategies and outcome satisfaction among mobile pastoralists of four ethnic groups in the Lake Chad area using focus group discussions. People suffering from schistosomiasis were interviewed about symptoms, health seeking behaviour and their satisfaction with respect to the provided treatment. Anthelminthic drugs for human and veterinary use obtained from various health care structures were analysed for active pharmaceutical ingredients (API) and quantity, using high pressure liquid chromatography-UV and liquid chromatography combined with tandem mass spectrometry. Most people suffering from schistosomiasis sought treatment at health care centres. Yet, they also consulted informal providers without medical training. Regarding animal health, self-mediated therapy was common to manage suspected livestock fascioliasis. Self-reported treatment satisfaction for human schistosomiasis and trematodiasis treatment outcome in livestock were low. Mobile pastoralists perceived the purchased drugs to be of low quality. Among 33 products locally sold as anthelminthic drugs for human or veterinary use, 27 contained albendazole or mebendazole, varying between 91% and 159% of the labelled amount. Six products were sold loosely with incomplete information and their API could not be identified. No counterfeit anthelminthic drugs were detected. None of the samples contained praziquantel or triclabendazole, the drugs of choice against schistosomiasis and fascioliasis, respectively. The perceived unsatisfactory treatment outcomes in humans and animals infected with trematodes are most likely due to empiric diagnosis and the resulting use of inadequate therapy for human schistosomiasis and the lack of efficacious drugs against livestock fascioliasis.

Novel Therapeutics for Multiple Sclerosis Designed by Parasitic Worms

The evolutionary response to endemic infections with parasitic worms (helminth) was the development of a distinct regulatory immune profile arising from the need to encapsulate the helminths while simultaneously repairing tissue damage. According to the old friend's hypothesis, the diminished exposure to these parasites in the developed world has resulted in a dysregulated immune response that contributes to the increased incidence of immune mediated diseases such as Multiple Sclerosis (MS). Indeed, the global distribution of MS shows an inverse correlation to the prevalence of helminth infection. On this basis, the possibility of treating MS with helminth infection has been explored in animal models and phase 1 and 2 human clinical trials. However, the possibility also exists that the individual immune modulatory molecules secreted by helminth parasites may offer a more defined therapeutic strategy.

Pipeline for the identification and classification of ion channels in parasitic flatworms

Background

Ion channels are well characterised in model organisms, principally because of the availability of functional genomic tools and datasets for these species. This contrasts the situation, for example, for parasites of humans and animals, whose genomic and biological uniqueness means that many genes and their products cannot be annotated. As ion channels are recognised as important drug targets in mammals, the accurate identification and classification of parasite channels could provide major prospects for defining unique targets for designing novel and specific anti-parasite therapies. Here, we established a reliable bioinformatic pipeline for the identification and classification of ion channels encoded in the genome of the cancer-causing liver fluke Opisthorchis viverrini, and extended its application to related flatworms affecting humans.

Methods

We built an ion channel identification + classification pipeline (called MuSICC), employing an optimised support vector machine (SVM) model and using the Kyoto Encyclopaedia of Genes and Genomes (KEGG) classification system. Ion channel proteins were first identified and grouped according to amino acid sequence similarity to classified ion channels and the presence and number of ion channel-like conserved and transmembrane domains. Predicted ion channels were then classified to sub-family using a SVM model, trained using ion channel features.

Results

Following an evaluation of this pipeline (MuSICC), which demonstrated a classification sensitivity of 95.2 % and accuracy of 70.5 % for known ion channels, we applied it to effectively identify and classify ion channels in selected parasitic flatworms.

Conclusions

MuSICC provides a practical and effective tool for the identification and classification of ion channels of parasitic flatworms, and should be applicable to a broad range of organisms that are evolutionarily distant from taxa whose ion channels are functionally characterised.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1428-2) contains supplementary material, which is available to authorized users.

Fasciola hepatica mucin-encoding gene: expression, variability and its potential relevance in host-parasite relationship

Fasciola hepatica is the causative agent of fasciolosis, a zoonosis with significant impact both in human and animal health. Understanding the basic processes of parasite biology, especially those related to interactions with its host, will contribute to control F. hepatica infections and hence liver pathology. Mucins have been described as important mediators for parasite establishment within its host, due to their key roles in immune evasion. In F. hepatica, mucin expression is upregulated in the mammalian invasive newly excysted juvenile (NEJ) stage in comparison with the adult stage. Here, we performed sequencing of mucin cDNAs prepared from NEJ RNA, resulting in six different cDNAs clusters. The differences are due to the presence of a tandem repeated sequence of 66 bp encoded by different exons. Two groups of apomucins one with three and the other with four repeats, with 459 and 393 bp respectively, were identified. These cDNAs have open reading frames encoding Ser-Thr enriched proteins with an N-terminal signal peptide, characteristic of apomucin backbone. We cloned a 4470 bp gene comprising eight exons and seven introns that encodes all the cDNA variants identified in NEJs. By real time polymerase chain reaction and high-resolution melting approaches of individual flukes we infer that fhemuc-1 is a single-copy gene, with at least two different alleles. Our data suggest that both gene polymorphism and alternative splicing might account for apomucin variability in the fhemuc-1 gene that is upregulated in NEJ invasive stage. The relevance of this variation in host-parasite interplay is discussed.

The miRnome of Fasciola hepatica juveniles endorses the existence of a reduced set of highly divergent micro RNAs in parasitic flatworms

The liver fluke Fasciola hepatica is a foodborne zoonotic parasite affecting livestock worldwide, with increasing relevance in human health. The first developmental stage that the host meets after ingestion of the parasite is the newly excysted juvenile, that actively transverses the gut wall and migrates to its final location in the liver. The regulation of the early developmental events in newly excysted juveniles is still poorly understood and a relevant target for control strategies. Here we investigated the putative involvement of small regulatory RNAs in the invasion process. The small RNA population of the newly excysted juvenile fall into two classes, one represented by micro (mi)RNAs and a secondary group of larger (32-33 nucleotides) tRNA-derived sequences. We identified 40 different miRNAs, most of those belonging to ancient miRNAs conserved in protostomes and metazoans, notably with a highly predominant miR-125b variant. Remarkably, several protostomian and metazoan conserved families were not detected in consonance with previous reports of drastic miRnome reduction in parasitic flatworms. Additionally, a set of five novel miRNAs was identified, probably associated with specific gene regulation expression needs in F. hepatica. While sequence conservation in mature miRNA is high across the metazoan tree, we observed that flatworm miRNAs are more divergent, suggesting that mutation rates in parasitic flatworms could be high. Finally, the distinctive presence of tRNA-derived sequences, mostly 5' tRNA halves of selected tRNAs in the small RNA population of newly excysted juveniles, raises the possibility that both miRNA and tRNA fragments participate in the regulation of gene expression in this parasite.

Transient transgenesis of the tapeworm Taenia crassiceps

Human and porcine cysticercosis is caused by the larval stage of the flatworm Taenia solium (Cestoda). Infestation of the human brain, also known as neurocysticercosis, is the most common parasite disease of the central nervous system worldwide. Significant advances in the understanding of the disease have been achieved using the Taenia crassiceps murine model. We describe here a successful transfection protocol of T. crassiceps cysticerci as the first step to approach a number of currently inaccessible biological questions on cysticercosis. T. crassiceps cysticerci (ORF strain) were microinjected with the plasmid pcDNA3.1/NT-GFP-TOPO, encoding the green fluorescent protein (GFP) driven by a cytomegalovirus promoter (CMV). Twelve hours after the microinjection, GFP fluorescence gradually developed in patches associated to bud structures in the bladder wall of cysts. Fluorescence reached a peak at 24-48 h and lasted up to 72 h after the microinjection. Immunohistochemical studies on tissue sections of transfected cysts using an anti-GFP antibody, demonstrated co-localization of the antibody and the GFP fluorescence in the tegumentary cytoplasm and subtegumentary cytons. To validate at the mRNA level the expression of GFP, we carried out RT-PCR using two pairs of nested primers. Results showed expression of GFP-mRNA at 24 h post-transfection. Moreover, western blot assays of crude extracts of transfected cysts, carried out using the anti-GFP specific antibody, showed the expected protein band of 27 kDa, demonstrating that the GFP expression started at 24 after plasmid microinjection and was maintained up to 72 h. These findings will facilitate the development of functional genomics approaches applied to this model of cysticercosis.

Fascioliasis: An Ongoing Zoonotic Trematode Infection

Zoonotic trematode infections are an area of the neglected tropical diseases that have become of major interest to global and public health due to their associated morbidity. Human fascioliasis is a trematode zoonosis of interest in public health. It affects approximately 50 million people worldwide and over 180 million are at risk of infection in both developed and underdeveloped countries. The one health paradigm is an area that seeks to address the problem of zoonotic infections through a comprehensive and sustainable approach. This review attempts to address the major challenges in managing human and animal fascioliasis with valuable insights gained from the one health paradigm to global health and multidisciplinary integration.

A confocal microscopy-based atlas of tissue architecture in the tapeworm Hymenolepis diminuta

Tapeworms are pervasive and globally distributed parasites that infect millions of humans and livestock every year, and are the causative agents of two of the 17 neglected tropical diseases prioritized by the World Health Organization. Studies of tapeworm biology and pathology are often encumbered by the complex life cycles of disease-relevant tapeworm species that infect hosts such as foxes, dogs, cattle, pigs, and humans. Thus, studies of laboratory models can help overcome the practical, ethical, and cost-related difficulties faced by tapeworm parasitologists. The rat intestinal tapeworm Hymenolepis diminuta is easily reared in the laboratory and has the potential to enable modern molecular-based experiments that will greatly contribute to our understanding of multiple aspects of tapeworm biology, such as growth and reproduction. As part of our efforts to develop molecular tools for experiments on H. diminuta, we have characterized a battery of lectins, antibodies, and common stains that label different tapeworm tissues and organ structures. Using confocal microscopy, we have assembled an "atlas" of H. diminuta organ architecture that will be a useful resource for helminthologists. The methodologies we describe will facilitate characterization of loss-of-function perturbations using H. diminuta. This toolkit will enable a greater understanding of fundamental tapeworm biology that may elucidate new therapeutic targets toward the eradication of these parasites.

Auranofin-induced oxidative stress causes redistribution of the glutathione pool in Taenia crassiceps cysticerci

Previously, we have studied the effect of the gold-compound auranofin (AF) on both thioredoxin-glutathione reductasa (TGR) activity and viability of Taenia crassiceps cysticerci. It was demonstrated that micromolar concentrations of AF were high enough to fully inhibit TGR and kill the parasites. In this work, the dynamics of changes in the glutathione pool of T. crassiceps cysticerci following the addition of AF, was analyzed. A dose-dependent decrease in the internal glutathione concentration, concomitant with an increase in ROS production was observed. These changes were simultaneous with the formation of glutathione-protein complexes and the export of glutathione disulfide (GSSG) to the culture medium. Incubation of cysticerci in the presence of both AF and N-acetyl cysteine (NAC) prevents all the above changes, maintaining cysticerci viability. By contrast, the presence of both AF and buthionine sulfoximine (BSO) resulted in a potentiation of the effects of the gold compound, jeopardizing cysticerci viability. These results suggest the lethal effect of AF on T. crassiceps cysticerci, observed at micromolar concentrations, can be explained as a consequence of major changes in the glutathione status, which results in a significant increase in the oxidative stress of the parasites.

Genome analysis of Excretory/Secretory proteins in Taenia solium reveals their Abundance of Antigenic Regions (AAR)

Excretory/Secretory (ES) proteins play an important role in the host-parasite interactions. Experimental identification of ES proteins is time-consuming and expensive. Alternative bioinformatics approaches are cost-effective and can be used to prioritize the experimental analysis of therapeutic targets for parasitic diseases. Here we predicted and functionally annotated the ES proteins in T. solium genome using an integration of bioinformatics tools. Additionally, we developed a novel measurement to evaluate the potential antigenicity of T. solium secretome using sequence length and number of antigenic regions of ES proteins. This measurement was formalized as the Abundance of Antigenic Regions (AAR) value. AAR value for secretome showed a similar value to that obtained for a set of experimentally determined antigenic proteins and was different to the calculated value for the non-ES proteins of T. solium genome. Furthermore, we calculated the AAR values for known helminth secretomes and they were similar to that obtained for T. solium. The results reveal the utility of AAR value as a novel genomic measurement to evaluate the potential antigenicity of secretomes. This comprehensive analysis of T. solium secretome provides functional information for future experimental studies, including the identification of novel ES proteins of therapeutic, diagnosis and immunological interest.

The Fasciola hepatica genome: gene duplication and polymorphism reveals adaptation to the host environment and the capacity for rapid evolution

Background

The liver fluke Fasciola hepatica is a major pathogen of livestock worldwide, causing huge economic losses to agriculture, as well as 2.4 million human infections annually.

Results

Here we provide a draft genome for F. hepatica, which we find to be among the largest known pathogen genomes at 1.3 Gb. This size cannot be explained by genome duplication or expansion of a single repeat element, and remains a paradox given the burden it may impose on egg production necessary to transmit infection. Despite the potential for inbreeding by facultative self-fertilisation, substantial levels of polymorphism were found, which highlights the evolutionary potential for rapid adaptation to changes in host availability, climate change or to drug or vaccine interventions. Non-synonymous polymorphisms were elevated in genes shared with parasitic taxa, which may be particularly relevant for the ability of the parasite to adapt to a broad range of definitive mammalian and intermediate molluscan hosts. Large-scale transcriptional changes, particularly within expanded protease and tubulin families, were found as the parasite migrated from the gut, across the peritoneum and through the liver to mature in the bile ducts. We identify novel members of anti-oxidant and detoxification pathways and defined their differential expression through infection, which may explain the stage-specific efficacy of different anthelmintic drugs.

Conclusions

The genome analysis described here provides new insights into the evolution of this important pathogen, its adaptation to the host environment and external selection pressures. This analysis also provides a platform for research into novel drugs and vaccines.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-015-0632-2) contains supplementary material, which is available to authorized users.

The complete mitochondrial genome of G3 genotype of Echinococcus granulosus (Cestoda: Taeniidae)

As a cryptic species complex, the taxonomy of Echinococcus granulosus has long been controversial. The complete mitochondrial (mt) genome of the E. granulosus G3 genotype was sequenced and characterized. The G3 mt genome was 13,607 bp in length, and contained 2 ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and 12 protein-coding genes, with a gene order identical to those of other reported genotypes. The overall nucleotide composition (coding strand) for the mt genome sequence of G3 was 19.1% A, 47.8% T, 25.0% G, and 8.1% C, with T being the most common base and C the least common.

Oral helminthic infestations

Oral infections caused by helminths (worms) are rarely encountered in clinical practice, and consequently, there is a paucity of information in the medical and dental literature about these conditions. In the present article, we review the English literature related to oral helminthic infestations. The main oral infections caused by helminths include four roundworm (trichinosis, trichuriasis, filariasis, and larva migrans) and three tapeworm infections (cysticercosis, sparganosis, and echinococcosis). Cases are mainly encountered in endemic areas and mainly present a benign clinical picture. The diagnosis of oral helminthic infections is mostly established after histopathological examination, which shows parasitic larvae lined by fibrous tissue and inflammatory cells. Surgical excision is the preferred treatment of isolated oral lesions caused by helminths; however, patients should undergo thorough medical evaluation to exclude the possible involvement of other body systems.

A Neglected Zoonosis in Albania: why Echinococcosis is Becoming a Surgeon's Exclusivity?

Echinococcosis is an endemic zoonosis in the Mediterranean area, with Albania interested actually to a level that is becoming a public health concern. Authors describe preliminary data from the only tertiary (university) medical facility of Albania, positioned in the capital of the country (Tirana), with 333 new cases diagnosed and treated during the period 2005 - 2011. Out of all these 333 new cases an impressive majority of 91% had a surgical treatment right from the first admission, rendering the disease almost a surgical exclusivity. Even more, 80% of all patients from the study group were hospitalized straightforwardly in surgical wards, with options of surgical intervention's percentages outrunning figures from other sources and authors of the same geographical area. Such a situation, together with a very important level of patients' origin from highly urbanized areas such as those of the capital, suggest the necessity of well-organized interventions, among which might be the mandatory notification of all human cases with Echinococcus infection.

The genomes of four tapeworm species reveal adaptations to parasitism

Tapeworms cause debilitating neglected diseases that can be deadly and often require surgery due to ineffective drugs. Here we present the first analysis of tapeworm genome sequences using the human-infective species Echinococcus multilocularis, E. granulosus, Taenia solium and the laboratory model Hymenolepis microstoma as examples. The 115-141 megabase genomes offer insights into the evolution of parasitism. Synteny is maintained with distantly related blood flukes but we find extreme losses of genes and pathways ubiquitous in other animals, including 34 homeobox families and several determinants of stem cell fate. Tapeworms have species-specific expansions of non-canonical heat shock proteins and families of known antigens; specialised detoxification pathways, and metabolism finely tuned to rely on nutrients scavenged from their hosts. We identify new potential drug targets, including those on which existing pharmaceuticals may act. The genomes provide a rich resource to underpin the development of urgently needed treatments and control.

Current status of food-borne trematode infections

Food-borne trematodiases constitute an important group of the most neglected tropical diseases, not only in terms of research funding, but also in the public media. The Trematoda class contains a great number of species that infect humans and are recognized as the causative agents of disease. The biological cycle, geographical distribution, and epidemiology of most of these trematode species have been well characterized. Traditionally, these infections were limited, for the most part, in populations living in low-income countries, particularly in Southeast Asia, and were associated with poverty. However, the geographical limits and the population at risk are currently expanding and changing in relation to factors such as growing international markets, improved transportation systems, and demographic changes. The diagnosis of these diseases is based on parasitological techniques and only a limited number of drugs are currently available for treatment, most of which are unspecific. Therefore, in-depth studies are urgently needed in order to clarify the current epidemiology of these helminth infections and to identify new and specific targets for both effective diagnosis and treatment. In this review, we describe the biology, medical and epidemiological features, and current treatment and diagnostic tools of the main groups of flukes and the corresponding diseases.

Efficacy of single-dose and triple-dose albendazole and mebendazole against soil-transmitted helminths and Taenia spp.: a randomized controlled trial

Background

The control of soil-transmitted helminth (STH) infections currently relies on the large-scale administration of single-dose oral albendazole or mebendazole. However, these treatment regimens have limited efficacy against hookworm and Trichuris trichiura in terms of cure rates (CR), whereas fecal egg reduction rates (ERR) are generally high for all common STH species. We compared the efficacy of single-dose versus triple-dose treatment against hookworm and other STHs in a community-based randomized controlled trial in the People's Republic of China.

Methodology/Principal findings

The hookworm CR and fecal ERR were assessed in 314 individuals aged ≥5 years who submitted two stool samples before and 3–4 weeks after administration of single-dose oral albendazole (400 mg) or mebendazole (500 mg) or triple-dose albendazole (3×400 mg over 3 consecutive days) or mebendazole (3×500 mg over 3 consecutive days). Efficacy against T. trichiura, Ascaris lumbricoides, and Taenia spp. was also assessed.

Albendazole cured significantly more hookworm infections than mebendazole in both treatment regimens (single dose: respective CRs 69% (95% confidence interval [CI]: 55–81%) and 29% (95% CI: 20–45%); triple dose: respective CRs 92% (95% CI: 81–98%) and 54% (95% CI: 46–71%)). ERRs followed the same pattern (single dose: 97% versus 84%; triple dose: 99.7% versus 96%). Triple-dose regimens outperformed single doses against T. trichiura; three doses of mebendazole – the most efficacious treatment tested – cured 71% (95% CI: 57–82%). Both single and triple doses of either drug were highly efficacious against A. lumbricoides (CR: 93–97%; ERR: all >99.9%). Triple dose regimens cured all Taenia spp. infections, whereas single dose applications cured only half of them.

Conclusions/Significance

Single-dose oral albendazole is more efficacious against hookworm than mebendazole. To achieve high CRs against both hookworm and T. trichiura, triple-dose regimens are warranted.

Trial Registration

www.controlled-trials.comISRCTN47375023

Rapid appraisal of human intestinal helminth infections among schoolchildren in Osh oblast, Kyrgyzstan

A population-representative lot quality assurance sampling (LQAS) survey was conducted in 2009 to determine the prevalence of intestinal helminth infections among schoolchildren across Osh oblast, Kyrgyzstan. The diagnostic approach consisted of duplicate Kato-Katz thick smears from a single stool sample and an adhesive tape test. A questionnaire was administered to identify risk factors for infections. A total of 1262 schoolchildren aged 6-15 years were recruited; 41% of them harboured at least one of the eight identified helminth species. The two most prevalent helminths were Ascaris lumbricoides (23.1%) and Enterobius vermicularis (19.3%). Lower prevalences were found for Hymenolepis nana (4.4%), Fasciola hepatica (1.9%) and Dicrocoelium dendriticum (1.8%). Washing raw vegetables was a protective factor with regard to A. lumbricoides infection (odds ratio (OR)=0.69, p=0.022); tap water was borderline protective (OR=0.56, p=0.057). Children of the richest families were at a lower risk of E. vermicularis infection than the poorest ones (OR=0.41, p=0.011). Sharing the bed with more than one person was a risk factor for E. vermicularis infection (OR=2.0, p=0.002). The results call for targeted interventions against intestinal helminths in Osh oblast. In a first stage, annual deworming of schoolchildren and other high-risk groups with albendazole or mebendazole should be implemented, and reliable diagnosis and additional anthelminthic drugs should be made available. Subsequently, transmission control including locally-adapted health education, improved water supply and adequate sanitation should become the central features.

Proteomic survey of the cestode Mesocestoides corti during the first 24 hours of strobilar development

Despite the fact that cestodes represent major etiological agents of both human and domestic animal diseases, little is known about the molecular aspects of cestode development. In this work, Mesocestoides corti, a model cestode species, was studied from the early development of its larval form (tetrathyridium) into adult worms (strobilation) using different proteomic approaches. The protein profiles of M. corti tetrathyridia induced or not induced to undergo strobilation were compared. Proteomic mapping by two-dimensional gel electrophoresis showed the resolution of 248 and 154 spots from tetrathyridia that were subjected or not subjected to strobilation induction, respectively, allowing for the detection of at least nine spots exclusive to each group. Spot analysis by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) or MALDI-TOF MS/MS identified four reference proteins (six spots). LC-MS/MS analyses of protein extracts identified 66 proteins, eight of which were found exclusively in non-induced tetrathyridia, while 13 were found exclusively in strobilation-induced tetrathyridia. Among the proteins exclusively identified in strobilation-induced worms, there was a predominance of proteins with functions relating to chaperone activity and protein synthesis and turnover. Quantitative differential expression analysis between M. corti tetrathyridia prior to and after strobilation induction revealed six proteins upregulated in strobilation-induced worms; these proteins were involved in metabolic pathways, cell proliferation, and cytoskeletal rearrangement. Overall, despite the absence of a sequenced M. corti genome, using sequences from other platyhelminthes, we were able to establish comprehensive protein profiles for tetrathyridia prior to and after strobilation induction and identify several proteins potentially involved in the early events leading to strobilation.

Multiparasitism a neglected reality on global, regional and local scale

This review focuses on the issue of multiparasitism, with a special emphasis on its characteristics, its extent in eastern Asia and its significance for infectious disease control. Multiparasitism is pervasive among socially and economically disadvantaged or marginalised communities, particularly in tropical and subtropical areas. Intestinal parasites are the most numerous group, but an array of parasites is located elsewhere than in the human gastrointestinal tract. Although multiparasitism has been recognised for decades, in-depth studies are rare, and its public health and economic implications have yet to be fully elucidated. The assessment of multiparasitism is hampered by a lack of sensitive broad-spectrum diagnostic tools and the need to collect multiple biological samples for detailed appraisal. Non-specific symptoms and mainly subtle effects complicate the appreciation of its influence on cognitive and physical development, health, economic productivity and general well-being. Multiparasitism has been reported from virtually every eastern Asian country, and studies regarding the extent of multiparasitism and its effects on child health have been implemented in the region. However, new research is needed, as no comprehensive evaluations of multiparasitism in eastern Asia could be identified. Two case studies pertaining to multiparasitism at the local and regional scale are presented. Multiparasitism was rampant in an ethnic minority village in southern People's Republic of China where the challenges associated with its thorough evaluation are illustrated. The results from a cross-sectional survey covering 35 villages highlight the significance of its evaluation for the design of locally adapted and sustainable parasite control and poverty alleviation programmes. We conclude by listing a set of research needs for future investigations.