Cystic echinococcosis caused by Echinococcus granulosus sensu lato is one of the most important helminth zoonoses in the world; it affects both humans and livestock. The disease is endemic in Argentina and highly endemic in the province of Neuquén. Considerable genetic and phenotypic variation has been demonstrated in E. granulosus, and ten different genotypes (G1–G10) have been identified using molecular tools. Echinococcus granulosus sensu lato may be considered a species complex, comprised of E. granulosus sensu stricto (G1–G3), E. equinus (G4), E. ortleppi (G5) and E. canadensis (G6–G10). In endemic areas, the characterization of cystic echinococcosis molecular epidemiology is important in order to apply adequate control strategies. A cut-off value for larval large hook total length to distinguish E. granulosus sensu stricto isolates from those produced by other species of the complex was defined for the first time. Overall, 1780 larval hooks of 36 isolates obtained from sheep (n= 11, G1), goats (n= 10, G6), cattle (n= 5, G6) and pigs (n= 10, G7) were analysed. Validation against molecular genotyping as gold standard was carried out using the receiver operating characteristic (ROC) curve analysis. The optimum cut-off value was defined as 26.5 μm. The proposed method showed high sensitivity (97.8%) and specificity (91.1%). Since in most endemic regions the molecular epidemiology of echinococcosis includes the coexistence of the widely distributed E. granulosus sensu stricto G1 strain and other species of the complex, this technique could be useful as a quick and economical tool for epidemiological and surveillance field studies, when fertile cysts are present.

Kazakhstan is highly endemic for echinococcosis. Both Echinococcus granulosus and E. multilocularis are widely distributed in the country. Official records of human cystic echinococcosis over the past 5–10 years suggest a stable incidence of approximately 800–1000 cases per year, which is 5 cases per 100,000 per year. This followed a rapid increase in the incidence following the dissolution of the Soviet Union. Between 2007 and 2013, 5949 cases were reported in the national surveillance data. The prevalence in sheep, based on slaughterhouse studies, suggests that between 30 and 50% of sheep are infected with hydatid cysts, while cattle have a prevalence of approximately 7%. Rural dogs have a high prevalence of infection of between 5 and 10%, with shepherd dogs having prevalences of over 20%. G1 and G6/7 strains of E. granulosus have been isolated from dogs in Kazakhstan. Wolves are also infected, with one prevalence estimate of approximately 20%. The incidence of human alveolar echinococcosis is less clear, although estimates from Kazakhstani expatriates living in Germany and the hospital records of a single referral centre in Almaty suggest 34 or 130 cases per year (or an annual incidence of 0.20 or 0.76 cases per 100,000), respectively, could be occurring in Kazakhstan. Studies suggest that in some rural dog populations the prevalence may be about 5%. The parasite is widely distributed in foxes and small mammals through much of Kazakhstan.

Internal transcribed spacer (ITS) rDNA sequences of three Nematodirus species from naturally infected goats or sheep in two endemic provinces of China were analysed to establish an effective molecular approach to differentiate Nematodirus species in small ruminants. The respective intra-specific genetic variations in ITS1 and ITS2 rDNA regions were 0.3–1.8% and 0–0.4% in N. spathiger, 0–6.5% and 0–5.4% in N. helvetianus, and 0–4.4% and 0–6.1% in N. oiratianus from China. The respective intra-specific variations of ITS1 and ITS2 were 1.8–4.4% and 1.6–6.1% between N. oiratianus isolates from China and Iran, 5.7–7.1% and 6.3–8.3% between N. helvetianus samples from China and America. For N. spathiger, compared with samples from China, sequence differences in ITS1 rDNA were 0.3–2.4% in isolates from America, 0.3–2.9% in New Zealand and 2.1–2.4% in Australia. Genetic variations in ITS2 rDNA of N. spathiger were 0–0.4% between samples from China and America, and 0–0.8% between samples from China and New Zealand. Using mutation sites, polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) and specific PCR techniques were developed to differentiate these three Nematodirus species. The specific PCR assay allowed the accurate identification of N. oiratianus from other common nematodes with a sensitivity of 0.69 pg and further examination of Nematodirus samples demonstrated the reliability of these two molecular methods.

Ligophorus belanaki n. sp. and Ligophorus kederai n. sp. are described from Liza subviridis Valenciennes, 1836 and Valamugil buchanani Bleeker, 1854, respectively. Ligophorus kederai n. sp. has fenestrated ventral anchors, while in L. belanaki n. sp. the ventral anchor is not fenestrated. Ligophorus belanaki n. sp. is similar to L. careyensis, one of its coexisting congeners, in the overall shape and size of hard parts, but differs in having a flat median piece in the structure of the AMP (antero-median protuberance of the ventral bar), copulatory organ with non-ornamented initial part and longer vaginal tube, compared to raised median piece in the AMP, ornamented initial part and comparatively shorter vaginal tube in L. careyensis. Ligophorus kederai n. sp. is similar to L. fenestrum, a coexisting congener, in having fenestrated ventral anchors, but differs in having longer points and narrower base. Ligophorus fenestrum, unlike L. kederai n. sp., also possesses fenestrated dorsal anchors. The principal component analysis (PCA) scatterplots indicate that the two new and eight known Ligophorus species from Malaysian mugilids can be differentiated based on the morphometries of their anchors, ventral bars and copulatory organ separately and when combined together. Numerical taxonomy (NT) analyses based on Jaccard's Index of Similarity and neighbour-joining clustering, is used to facilitate comparison of these two new species with the 50 known Ligophorus based on morphological and metric characters. The two new species are different from each other and the other 50 species in the overall shapes and sizes of hard parts, as indicated by the NT analyses.

Vaccines against gastrointestinal nematodes are one potential option for the control of parasitic gastroenteritis in ruminants. Excretory/secretory (E/S) and hidden antigens are being studied as candidates for vaccines against Haemonchus spp., which is a major parasite in cattle and small ruminants that are raised in warm climates. Protection has been observed after vaccination with some E/S proteases, particularly cysteine proteases and with some glycans that are abundant on the surfaces and in the secretory products of helminths. However, the most promising results are being obtained with glycoprotein antigens extracted from the microvillar surfaces of the Haemonchus contortus intestinal cells. These antigens are called ‘hidden′ because they are not exposed to the host's immune system during infection. Thus far, recombinant forms of these antigens have not been usefully protective. However, because only 5 μg of antigen is required per dose, production of a native antigen vaccine from adult parasites has been found to be practical and commercially viable. Trials indicate that a vaccine made from one particular isolate will cross-protect against geographically distant isolates.

The following account is based on a review lecture given recently at the British Society of Parasitology. We point out that nematode parasites cause very widespread infections of humans, particularly in economically underdeveloped areas where sanitation and hygiene are not adequate. In the absence of adequate clean water and effective vaccines, control and prophylaxis relies on anthelmintic drugs. Widespread use of anthelmintics to control nematode parasites of animals has given rise to the development of resistance and so there is a concern that similar problems will occur in humans if mass drug administration is continued. Recent research on the cholinergic anthelmintic drugs has renewed enthusiasm for the further development of cholinergic anthelmintics. Here we illustrate the use of three parasite nematode models, Ascaris suum, Oesophagostomum dentatum and Brugia malayi, microfluidic techniques and the Xenopus oocyte expression system for testing and examining the effects of cholinergic anthelmintics. We also show how the combination of derquantel, the selective nematode cholinergic antagonist and abamectin produce increased inhibition of the nicotinic acetylcholine receptors on the nematode body muscle. We are optimistic that new compounds and combinations of compounds can limit the effects of drug resistance, allowing anthelmintics to be continued to be used for effective treatment of human and animal helminth parasites.

Cucullanus tucunarensis n. sp. (Cucullanidae) is described parasitizing the peacock bass Cichla piquiti (Cichlidae) from the Tocantins River, Tocantins State, Brazil. The new species is unique and differs from all its congeners by having a tail tip provided with several sclerotized spine-like processes on its ventral side, present in both the male and female. Furthermore, C. tucunarensis n. sp. is compared with other species of the genus recorded in the same zoogeographical region and in the same group of hosts (Perciformes).

Parasitic nematodes of the family Mermithidae were found to be infecting the introduced European earwig Forficula auricularia (Dermaptera: Forficulidae) in Dunedin, South Island, New Zealand. Adult females were later collected from various garden plants while depositing eggs. These mermithid specimens were identified morphologically as Mermis nigrescens Dujardin, 1842. A genetic distance of 0.7% between these specimens and a M. nigrescens isolate from Canada (18S rRNA gene), suggests that they have diverged genetically, but there are currently no available comparable sequences for the European M. nigrescens. Two additional nuclear fragments were also amplified, the 28S rRNA and the ribosomal DNA first internal transcribed spacer (ITS1), providing a basis for future studies. Bearing in mind the morphological similarity with other reported M. nigrescens and the lack of sequence data from other parts of the world, we retain the name M.nigrescens, and suggest that the species may be found to represent a complex of cryptic species when more worldwide data are available. Herein, we present a brief description of the post-parasitic worms and adult females, along with an inferred phylogeny using 18S rRNA gene sequences.

Although Taenia hydatigena is one of the most prevalent taeniid species of livestock, very little molecular genetic information exists for this parasite. Up to 100 sheep isolates of T. hydatigena were collected from 19 abattoirs located in the provinces of Tehran, Alborz and Kerman. A calibrated microscope was used to measure the larval rostellar hook lengths. Following DNA extraction, fragments of cytochrome c oxidase 1 (CO1) and 12S rRNA genes were amplified by the polymerase chain reaction method and the amplicons were subjected to sequencing. The mean total length of large and small hooks was 203.4 μm and 135.9 μm, respectively. Forty CO1 and 39 12S rRNA sequence haplotypes were obtained in the study. The levels of pairwise nucleotide variation between individual haplotypes of CO1 and 12S rRNA genes were determined to be between 0.3–3.4% and 0.2–2.1%, respectively. The overall nucleotide variation among all the CO1 haplotypes was 9.7%, and for all the 12S rRNA haplotypes it was 10.1%. A significant difference was observed between rostellar hook morphometry and both CO1 and 12S rRNA sequence variability. A significantly high level of genetic variation was observed in the present study. The results showed that the 12S rRNA gene is more variable than CO1.

Alveolar and cystic echinococcosis are highly endemic in the Kyrgyz Republic. This report documents the numbers of recorded cases of these two diseases that have been reported in the past 14 years. The number of cases of echinococcosis has increased from approximately 550 to 1044 cases in 2013. This is an increase in incidence from 11.3 to 18.3 cases per 100,000 annually. In 2000 no cases of alveolar echinococcosis (AE) were reported in the Kyrgyz Republic. During this period the disease has emerged, with 148 cases reported in 2013 (2.6 cases per 100,000). Osh Oblast is a highly endemic focus for AE, with 60 cases reported in 2013 (6.0 per 100,000). The Alay Valley in the south of Osh Oblast reported the majority of AE cases for this region. In this valley, in 2013, 42 cases of AE were reported, which is a local incidence of 58 per 100,000.

The parasitic nematode Trichinella spiralis, an aetiological agent of the disease known as trichinellosis, infects wild and domestic animals through contaminated pig meat, which is the major source for Trichinella transmission. Prevention of this disease by interrupting parasite transmission includes vaccine development for livestock; however, major challenges to this strategy are the complexity of the T. spiralis life cycle, diversity of stage-specific antigens, immune-evasion strategies and the modulatory effect of host responses. Different approaches have been taken to induce protective immune responses by T. spiralis immunogens. These include the use of whole extracts or excretory–secretory antigens, as well as recombinant proteins or synthesized epitopes, using murine experimental models for trichinellosis. Here these schemes are reviewed and discussed, and new proposals envisioned to block the zoonotic transmission of this parasite.

Experimental infections of Lymnaea glabra (two populations) with Fasciola hepatica were carried out during seven successive snail generations, to determine if prevalence and intensity of snail infection increased over time through descendants of snails already infected with F. hepatica. Controls were descendants coming from uninfected parents and infected according to the same protocol. No larval forms were found in the bodies of control snails coming from uninfected parents. In contrast, prevalence and intensity of F. hepatica infection in snails originating from infected parents progressively increased from the F2 or F3 to the F6 generation of L. glabra. In another experiment carried out with the F7 generations of L. glabra and a single generation of Galba truncatula (as controls), the prevalence of F. hepatica infection and the total number of cercariae were lower in L. glabra (without significant differences between both populations). If the number of cercariae shed by infected snails was compared to overall cercarial production noted in snails containing cercariae but dying without emission, the percentage was greater in G. truncatula (69% instead of 52–54% in L. glabra). Even if most characteristics of F. hepatica infection were lower in L. glabra, prevalence and intensity of parasite infection increased with snail generation when tested snails came from infected parents. This mode of snail infection with F. hepatica suggests an explanation for cases of fasciolosis occurring in cattle-breeding farms where paramphistomosis is lacking and G. truncatula is absent.

Echinococcosis, caused by the zoonotic cestodes Echinococcus granulosus (sensu lato) and Echinococcus multilocularis, is highly endemic in the Central Asian Republic of Kyrgyzstan, and is being identified increasingly as a public health problem, especially amongst pastoral communities. As domestic dogs are considered to be the main source of human infection, the identification of potential transmission pathways is of relevance when considering implementing an echinococcosis control scheme. The current report describes the results of an analytical study of canine Echinococcus coproantigen enzyme-linked immunosorbent assay (ELISA) prevalence in the Alay valley of southern Kyrgyzstan prior to the commencement of regular praziquantel dosing of dogs. A logistic regression model using a form of Bayes modal estimation was used to identify possible risk factors for coproantigen positivity, and the output was interpreted in a Bayesian context (posterior distributions of the coefficients of interest). The study found that sheepdogs had lower odds of coproantigen positivity, as did dogs in households with donkeys, where owners had knowledge of echinococcosis, and households which engaged in home slaughtering. Surprisingly, there was no evidence of an association between free roaming or previous praziquantel dosing and coproantigen positivity, as has been found in previous studies. Possible reasons for these findings are discussed in the context of the epidemiology of echinococcosis and potential intervention approaches.

Even in the relatively well-characterized faunas of the developed world, it is difficult to discriminate species of metacercariae in the Diplostomidae using morphology, infection site or host use. The taxonomy, diversity and ecology of diplostomids infecting freshwater fishes in the African continent are particularly poorly known, but recent morphometric and genetic studies have revealed four species of diplostomids in the eyes and brains of siluriform fishes. In the present study, diplostomid metacercariae were collected from the eyes of 288 fish comprising two species within the Cyprinidae (Cyprinus carpio, n= 145, and Barbus paludinosus, n= 67), two Cichlidae (Oreochromis leucostictus, n= 56, and Tilapia zillii, n= 18) and one Centrarchidae (Micropterus salmoides, n= 2) caught in Lake Naivasha, Kenya. Morphometric (14 characters and 8 indices in 111 specimens) and molecular (sequences from the barcode region of the cytochrome c oxidase 1 gene in 11 specimens) data were used to discriminate species. All fish species except B. paludinosus were infected with Tylodelphys metacercariae that were initially separated into two types differing mainly in body length. However, this morphological distinction received only intermediate support in quantitative morphological analysis and molecular data indicated that both morphotypes were conspecific. All the specimens therefore are inferred to belong to a single unidentified species of Tylodelphys, which is not conspecific with any other diplostomid for which comparable molecular data are available, including four diplostomid species known from siluriform fish in Nigeria and Tanzania.

The rhadinorhynchid Sclerocollum saudii Al-Jahdali, 2010 was found in the intestine of its type host, Siganusrivulatus Forsskål & Niebuhr, 1775, a siganid fish permanently resident in a lagoon within the mangrove swamps found on the Egyptian coast of the Gulf of Aqaba (between 28°7′N and 28°18′N). Larval forms of this acanthocephalan (acanthors, acanthellae and cystacanths) were only found in Megaluropus agilis Hoek, 1889 (Crustacea: Gammaridae), a benthic amphipod abundant on algae and seagrasses in the lagoon. So, this life cycle of S. saudii was elucidated under semi-natural conditions: embryonated eggs of S. saudii were directly ingested by the amphipod and hatched in its intestine; the released acanthor penetrated the intestinal epithelium in 12–18 h to reach the connective tissue serosa, where it remained for about 3 days, then penetrated the intestinal wall and remained attached to its outer surface for 4 days. It then detached and dropped free in the amphipod haemocoel and transformed into an oval acanthella, growing for 16 days to reach the cystacanth stage. The cystacanth at 46 days post-infection was infective to fish (excysted in its intestine as an active juvenile). Male and female juveniles reached maturity 17 and 23 days post-infection. Recently copulated females first appeared 26 days post-infection and all females seemed to be copulated at 28 days post-infection; partially and fully gravid females first appeared 31 and 35 days post-infection. Mature males and fully gravid females started to die off naturally 31 and 43 days post-infection and were totally expelled from the fish intestine by 42 and 52 days post-infection. The cycle was completed in 89 days and is similar to other known palaeacanthocephalan life cycles, but has its own characteristics.

The study evaluated the effect of storage time and conditions of nutritional pellets (NP) containing Duddingtonia flagrans chlamydospores on its in vitro trapping ability against Haemonchus contortus L3 larvae. The treated batch (200 NP) contained 4 ×  106 chlamydospores of the FTH0-8 strain, whereas the control batch (200 NP) was produced without spores. Both NP batches were exposed to four experimental storage conditions: (T1) shelves (indoors); (T2) refrigeration (4°C); (T3) outdoors under a roof; and (T4) 100% outdoors. Each group comprised 48 NP with spores and 48 NP without spores (control). The ability of D. flagrans spores to trap H. contortus L3 larvae was evaluated for 8 weeks for each storage condition. For that purpose, six randomly selected NP with spores were compared to their respective control NP. Each NP was individually crushed. The crushed material (1 g) was placed on the surface of a 2% water agar plate with 200 H. contortus L3 larvae. Plates were sealed and were incubated at room temperature for 8 days. The whole content of every plate was transferred to a Baermann apparatus to recover the remaining larvae. There was a clear larval reduction in the NP with spores, compared to the respective control NP in the four storage conditions (P< 0.05). The mean reductions ( ± SEM) of the storage conditions were 67 ± 4.9 (T2), 77 ± 6.1 (T1), 81.5 ± 3.8 (T4) and 82.1 ± 2.5 (T3). Larval reductions were similar at all times and were not affected by storage conditions or storage time (R2< 0.2; P>0.05). The long-term shelf-life of the chlamydospores in the NP suggests that this spore dosage technology is a viable option.

The present study assessed whether the genetic variation among different hosts (sheep and cattle) and geographical isolates (n= 28) of Dicrocoelium dendriticum from Iran is present based on mitochondrial (nad1) and ribosomal (ITS-2) DNA markers. Molecular analysis revealed the presence of at least ten and two distinct haplotypes in the NADH dehydrogenase gene (nad1) and internal transcribed spacer 2 (ITS-2), respectively. The nad1 and ITS-2 sequence data were deposited in GenBank under accession numbers, JX050110–134 and JQ966972–3. According to the results of our study, ND-D and ITS-A are established as being the predominant haplotypes of D. dendriticum in Iran. The Iranian isolates showed a higher intraspecific genetic diversity of 0–0.97% for nad1, compared to 0–0.42% for ITS-2. The alignment and comparison of nad1 and ITS-2 sequences revealed eight and one polymorphic sites, respectively. In the nad1 sequences, six were silent and two nucleotide substitutions were responsible for amino acid alterations. A phylogenetic analysis of the sequence data revealed that host associations and geographic location are not likely useful markers for D. dendriticum haplotype classification. Consequently, sequencing results obtained from the nad1 gene as a mitochondrial marker for the first time in this study would provide a valuable tool to analyse further molecular details of D. dendriticum worldwide.

Approximately 440 million people globally are afflicted by hookworm disease, one of the 17 WHO-recognized neglected tropical diseases (NTDs). The iron-deficiency anaemia attributed to this disease contributes to at least 3.2 million disability-adjusted life years (DALYs) according to the Global Burden of Disease Study 2010. The current WHO-recommended control strategies rely primarily on mass drug administration or preventive chemotherapy. However, evidence is starting to accumulate confirming that preventive chemotherapy alone will not be sufficient to reduce the reinfection rates of hookworm, especially in areas of heavy transmission. The global health and research community is currently building a consensus stressing the need for the advancement of research and innovation to bridge the gaps and identify new public health interventions for diseases such as hookworm and other NTDs. This paper presents the strategies used by the Sabin Vaccine Institute Product Development Partnership (Sabin PDP) in their ongoing endeavour for the development of a human hookworm vaccine. Recent updates and the current prospects for success of an effective human hookworm vaccine, as a new technology to be linked to or combined with drug interventions, are presented.

Aspidogastreans are commonly found infecting freshwater and marine molluscs, teleosts fishes and freshwater turtles. The subclass comprises four families – Rugogastridae Schell 1973, Stichocotylidae Faust & Tang 1936, Multicalycidae Gibson & Chinabut 1984 and Aspidogastridae Poche 1907 – and it is characterized by the presence of a ventral adhesive disc divided into rows of alveoli. In the current work, using light and scanning electron microscopy and molecular approaches, a new species of Aspidogastridae of the genus Rohdella Gibson & Chinabut, 1984, is described as a parasite of Colomesus psittacus in Brazil. The new taxon is distinguishable by the presence of oesophageal glands, teguments covered by ciliated papillae, and the position and shape of the hermaphroditic duct. The present work describes the third species of the genus Rohdella, thereby adding new morphological and molecular data regarding Aspidogastridae.

This study surveyed the genetic differences among Angiostrongylus cantonensis (A. cantonensis) using the mitochondrial cytochrome b (cytb) gene. Partial cytb sequences were determined for 91 worms from eight locations in Thailand. Using morphological techniques, the nematodes were found to be A. cantonensis. Phylogenetic analysis found two main clades, which were subdivided into four subclades (clusters). Haplotype network analysis showed that 11 distinct cytb haplotypes were also present in four groups of A. cantonensis. There was no observable relationship between the genetic differentiation of gene flow and geographical distance. This low genetic variation and geographical distribution of A. cantonensis in each location indicates a founder effect, which may have resulted from multiple independent origins, and suggests that haplotypes migrated from endemic areas via human-related activities.