Trichinellosis is a worldwide zoonotic disease affecting a wide range of mammals, including humans. It has intestinal and muscular phases. The current work was done to experimentally evaluate the efficacy of zinc oxide nanoparticles (ZnO NPs) and their combination with albendazole on intestinal and muscular stages of Trichinella spiralis (T. spiralis) infection. We had five main groups of mice: Group 1, non-infected control; Group 2, infected control; Group 3, infected and treated with albendazole; Group 4, infected and treated with ZnO NPs; and Group 5, infected and treated with albendazole and ZnO NPs. Each group was divided into two subgroups (A for the intestinal phase and B for the muscular phase). Drug effects were evaluated by parasitological, histopathological, and biochemical studies, including oxidant/antioxidant analysis and vascular endothelial growth factor (VEGF) gene expression in muscle tissue by quantitative real-time PCR. ZnO NPs resulted in a significant reduction of both intestinal and muscular phases of T. spiralis. Their combination with albendazole resulted in the complete eradication of adult worms and the maximum reduction of larval deposition in muscle tissue. Additionally, the treatment showed improvement in T. spiralis-induced pathological changes and oxidative stress status. Moreover, a significant decrease in VEGF gene expression was detected in the treated groups when compared with the infected control. In conclusion, ZnO NPs presented an antihelminthic effect against both adult and larval stages of T. spiralis. In addition, it enhanced antioxidant status and suppressed angiogenesis in muscle.

Because conducting experimental coinfections is intractable in most parasite systems, inferences about the presence and strength of interspecific interactions in parasite communities are often made from analyses of field data. It is unclear whether methods used to test for competition are able to detect competition in field-collected datasets. Data from a study of the intestinal helminth communities of creek chub (Semotilus atromaculatus) were used to explore the potential of commonly available methods to detect negative interactions among parasite species in species-poor, low-intensity communities. Model communities were built in the absence of competition and then modified by four modes of competition. Both parametric and null model approaches were utilized to analyze modelled parasite communities to determine the conditions under which competitive interactions were discerned. Correlations had low Type I error rates but did not reliably detect competition, when present, at a statistically significant level. Results from logistical regressions were similar but showed improved statistical power. Results from null model approaches varied. Envelope analyses had near ideal properties when parasite prevalence was high but had high Type I error rates in low prevalence communities. Co-occurrence analyses demonstrated promising results with certain co-occurrence metrics and randomization algorithms, but also had many more cases of failure to detect competition when present and/or reject competition when it was absent. No analytical approach was clearly superior, and the variability observed in the present investigation mirrors similar efforts, suggesting that clear guidelines for detecting competition in parasite communities with observational data will be elusive.

A new species of the genus Stephanostomum is described for the southeastern Gulf of Mexico based on morphological and nucleotide evidence. Stephanostomum minankisi n. sp. infects the intestine of the dusky flounder Syacium papillosum in the Yucatan Continental Shelf, Mexico (Yucatan Peninsula). Sequences of the 28S ribosomal gene were obtained and compared with available sequences of the other species and genera of the families Acanthocolpidae and Brachycladiidae from GenBank. A phylogenetic analysis was conducted, including 39 sequences, 26 of which represented 21 species and six genera of the family Acanthocolpidae. The new species is characterized by the absence of circumoral spines and spines on the tegument. Nonetheless, scanning electron microscopy consistently revealed the pits of 52 circumoral spines distributed in a double row with 26 spines each, and forebody spined. Other distinctive features of this species are testes in contact (sometimes overlapping), the vitellaria running along the body lateral fields to the mid-level of the cirrus-sac, pars prostatica and ejaculatory duct similar in length, and uroproct present. The phylogenetic tree showed that the three species found as parasites of dusky flounder (the new adult species and two in metacercaria stages) were grouped into two different clades. S. minankisi n. sp. was the sister species of Stephanostomum sp. 1 (Bt = 56) and formed a clade with S. tantabiddii, supported by high bootstrap values (100).

A taxonomic review was performed on cestodes of the genus Neoskrjabinolepis Spassky, 1947 that parasitize different species of Sorex shrews in different regions of the northern Palearctic and in the Nearctic (Alaska, USA). Information on Palearctic Neoskrjabinolepis cestodes published in various articles is summarized. An overview of the geographical distribution of the Neoskrjabinolepis species is also presented. Currently, the genus includes 17 species. In the European part of the Palearctic, four species of the genus are registered; in the Asian part, 13 species; and on the American continent (Seward Peninsula, Alaska, USA), two species. Descriptions, illustrations, and differential diagnoses are given for a new species of Neoskrjabinolepis, i.e. N. paradoxa n. sp., which was found in shrews Sorex unguiculatus Dobson and S. caecutiens Laxmann on Sakhalin Island. A unique feature of the new species is irregularly alternating genital pores in the uterus series in the strobila. Amended new differential features (positioning of the uterus relative to osmoregulatory canals and alternation of genital pores) of genus diagnosis and an identification key for Neoskrjabinolepis spp. are presented.

In this study, we report the first complete mitochondrial genome of the tapeworm Nippotaenia mogurndae in the order Nippotaeniidea Yamaguti, 1939. This mitogenome, which is 14,307 base pairs (bp) long with an A + T content of 72.2%, consists of 12 protein-coding genes, 22 transfer RNA (tRNA) genes, two rRNA genes, and two non-coding regions. Most tRNAs have a conventional cloverleaf structure, but trnS1 and trnR lack dihydrouridine arms of tRNA. The two largest non-coding regions, NCR1 (220 bp) and NCR2 (817 bp), are located between trnY and trnS2 and between nad5 and trnG, respectively. Phylogenetic analyses of mitogenomic data indicate that N. mogurndae is closely related to tapeworms in the order Cyclophyllidea.

Eurytrematosis is a disease caused by flukes of the genus Eurytrema. These parasites infect the pancreatic ducts of a wide variety of species, including cattle, sheep and humans. Diagnosing eurytrematosis through the analysis of faecal samples can be difficult because most of the available techniques are considered of low sensitivity. In this context, a modification of the Dennis, Stone and Swanson technique (Belem Sedimentation Technique, BST) was previously developed to increase the probability of detecting infected animals; nevertheless, the values of eggs per gram obtained using the modified technique are generally low. We proposed a modification of the this technique (MBST), to increase the sensitivity and detection rate of infected animals. The objective of this work was to describe MBST and compare it with BST. Faecal samples of 212 clinically healthy animals (174 from cattle and 38 from sheep) from 20 farms were taken by the intra-rectal route and stored at 4°C. The samples were processed using BST and MBST. Positive samples amounted to 55 (25.9%) using BST and 121 (57.1%) using MBST. In the simples from cattle, 52 (29.8%) and 107 (61.4%) were positive in BST and MBST, respectively. In sheep, three (7.8%) and 14 (36.8%) positive samples were obtained in BST and MBST, respectively.The results obtained using the two methods were significantly different, indicating a lack of agreement between their findings. The results suggest that MBST is a more sensitive method to detect Eurytrema spp. eggs in faeces than BST.

This study aimed to describe the shedding pattern of gastrointestinal parasite eggs by a wild population of desert bighorn sheep (DBS; Ovis canadensis) in northern Mexico. Seventy-five fresh faecal samples were collected from the ground in each season within an hour after being expelled by these animals. The generalized linear mixed model showed that eggs per gram of faeces were highest in winter (577 ± 399) and lowest in summer (260 ± 198). Generalized linear models revealed that Strongyloides spp. predominated during most seasons with a peak in summer (85% of faecal samples analysed) and the absence of this helminth in winter. Nematodirus spp. was another helminth present in three seasons, with the presence of this nematode in 35% of the faecal samples in spring and 0% in summer. Other parasites in DBS faeces included Bunostomun spp., Trichostrongylus spp., Cooperia spp., Mecistocirrus digitatus, Haemonchus contortus, Chabertia ovina and Eimeria ovinoidalis. There were differences among seasons in the percentage of these helminths and coccidia in faecal samples for all these parasites. It was concluded that helminths egg output in DBS in a semi-arid rangeland is lowest in summer and spring and highest in autumn and winter. Furthermore, it was shown that DBS in the study site do not suffer from severe parasite burden. Therefore, this nematode parasite burden is compatible with the conservation and well-being of this particular population.

Interspecific interactions between parasites sharing the same host are often antagonistic; the presence of one species decreases the number of individuals or negatively affects both the distribution and reproduction of the other species. Antagonistic interactions between co-infecting parasites may translate into direct competition or interactive segregation, but elements of both may be present. Potential interactions between two acanthocephalan species, Pomphorhynchus laevis and Acanthocephalus anguillae, were studied in the field in two of their natural fish definitive hosts. There was no evidence for competitive exclusion between P. laevis and A. anguillae. However, a negative interaction was found for the first time in the field between these two species. Based on the analysis of parasite abundance and total biomass using a static regression approach, I found that the abundance and total biomass of parasite was also limited by host characteristics. These results are consistent with previous laboratory studies on competition between P. laevis and A. anguillae.

Although several records now exist of the occurrence of Capillaria (Hepaticola) hepatica (Bancroft, 1893) as a natural infection of the wild rabbit the attempts which have been made to infect this host with eggs obtained from an infection in the rat have not been completely successful. Nishigori (1925) states that although this parasite can infect the rabbit and shew some development it does not reach maturity, while Saito (1925), in the English account of his paper given in The Japan Medical World states that “In the rabbit the larva might develop into maturity and cause pathological changes but do not multiply.”

Nematode spicules vary in shape and size even between closely related species and, therefore, constitute key characters in nematode taxonomy for distinguishing between species. Spicules are seldom measured on fresh specimens, but rather at some time after extraction from culled hosts and after a period of preservation of the worms in chemical fixatives or by freezing. We carried out two experiments to assess the effects of freezing in Hanks’ balanced salt solution, 70% or 80% ethanol and 10% formalin (both of the latter at room temperature and after storage at −80°C) on spicule length of Heligmosomoides bakeri at two time intervals after extraction from mice (Experiment 1, one and four weeks; Experiment 2, one and four months). In Experiment 1, no significant differences were detected, although there was some variation between treatments and over time. In Experiment 2, spicule length varied significantly between treatments and over time, the greatest shrinkage being in 80% ethanol and the least in 10% formalin. However, overall variation in spicule length was very limited, accounting for no more than 5.03% change in length over time and 4.95% between treatments at any of the periods of assessment. Therefore, while whole nematodes can shrivel and shrink in preservatives, making many measurements unreliable, our data indicated that spicule lengths are very little changed by preservation techniques over time, and so spicule length remains as a reliable taxonomic character.

The nematode Mooleptus rabuka is recorded in the digestive tract of catshark Apristurus fedorovi caught at the Imperial Ridge (Pacific Ocean). Important morphological features such as the number of cephalic and caudal papillae, the position of amphids and the shape of the gubernaculum are detailed in this parasite species. According to the phylogenetic analyses based on the 18S ribosomal RNA gene sequences, M. rabuka forms a lineage, Mooleptinae nom. nov., which is close to the gnathostomatid genus Echinocephalus (maximum likelihood analysis), or else forms a polytomy with this genus and the lineages of Anguillicola + Spiroxys and Tanqua + ‘Linstowinema’ sp. (Bayesian inference analysis). Overall, our findings do not support the monophyly of the Gnathostomatidae. We elevate spiroxyines to the family status, Spiroxyidae stat. nov., and temporarily consider the Gnathostomatidae to include the following subfamilies: Ancyracanthinae Yorke & Maplestone, 1926, Gnathostomatinae Railliet, 1895 sensu lato and Mooleptinae nom. nov. The name Mooleptinae nom. nov. is suggested instead of the Metaleptinae Moravec & Nagasawa, 2000, which is based on a preoccupied generic name Metaleptus Machida, Ogawa & Okiyama, 1982.

The ultrastructure of various regions of the male reproductive tract and the prostate gland of Cotylophoron cotylophorum (Trematoda: Digenea) is described. The internal lining of the entire male duct system is syncytial in nature, and regional variation is quite evident. The syncytial epithelium of the vas deferens and seminal vesicle is very thin, flat and lamellate and the lumen is packed with spermatozoa. In the pars musculosa (PM) the syncytium is also flat but lamellae are sparsely distributed and anastomosed at places to form loops. The syncytium of the PM is invested by several layers of circular and longitudinal muscle. The pars prostatica (PP) is lined by an uneven but moderately thick syncytial epithelium with nuclei projecting into the lumen. The syncytium bears numerous very long lamellae. The ejaculatory duct epithelium is devoid of lamellae. It is even and moderately thick throughout. The prostate gland cells are uneven in outline and bear long ducts which open into the lumen of the PP. They show an ultrastructural organization suggestive of protein secretion.

A new genus and species of filarioid worm is described from the peritoneal cavity of fruit bats, Pteropus hawaiiensis from Fiji and the name Chiropterofilaria brevicaudata n. sp. is given to it. The microfilaria is described. This appears to be the first record of a nematode from this host. The new genus is differentiated from its nearest genus Lemdana in that the spicules are only slightly unequal; and in the female worms, the oesophagus usually make several turns around the vagina before joining the intestine. From the same host, a second microfilaria, Microfilaria fijiensis n. sp. is described, the adults of which were not found.

Neoheterakis chapini n.g., n.sp. (Nematoda: Heterakoidea) is described from the caecum of a Congopeacock Afropavo congensis Chapin, 1936. The diagnostic features of the subfamily Spinaspidoderinae are extended to accomodate the new genus.

From time to time attempts have been made to control the spread of sclerostome larvae by treating the manure before use on the pastures or by mechanical means such as ploughing the land to bury the larvae. Various chemicals have been used, including artificial manures and animal waste products. Lucker (1936) buried larvae at varying depths in soils of different quality and measured the percentage that appeared on the surface during periods up to six weeks. Clay soils were almost a complete barrier to vertical migration whereas sandy soils and coarse sand permitted migration, during a period of 3–8 weeks, of appreciable numbers when buried 1–6 inches. He suggests from this evidence that ploughing the land would bury the larvae and therefore reduce the number of infective larvae available to the stock. It would seem to the writer, however, that there is a fallacy in this argument. Ploughing the land would turn the soil over but, even if a plough press were used, many fissures would be left which might form an easier channel for migration to the surface. Infective larvae readily accomplish horizontal migration and the possibility of lateral migration along the overturned turf and up the fissures must not be overlooked. The action of frost and the presence of roots in the overturned sod would possibly be other factors in encouraging vertical migration, not to mention the subsequent preparation of the land required before seeding down again for permanent pasture.

Inbred jirds (Meriones unguiculatus) were divided into three groups; each animal in two of the groups was infected with 30 infective larvae (L3) of Litomosoides carinii. When these infections were patent, the jirds of one of the two infected groups plus those of the third group were injected with 30 L3 L. carinii each. All animals were killed either on day 14 or 24 after the second infection for the recovery, enumeration and measurement of all worms and developing larvae. Challenge larvae were stunted (smaller) and fewer than control larvae. Additionally, fewer challenge larva were recovered on day 14 than on day 24, indicating that migration to the pleural cavity was retarded.

1. A new species, Ganeo bufonis, from a toad, Bufo viridis, in Kashmir, is described. This is the first species of the genus recorded from a toad; it differs from the known species in having both the vitelline glands confined to one side. The uterine coils do not extend into the post-caecal area; the excretory bladder is without any median stem and the metraterm is present.

2. Ganeo tigrinum Mehra and Negi, 1928 is also recorded for the first time from Bufo viridis. Ganeo kumaonensis Pande, 1937 and Ganeo lingnanensis Li, 1938 are both regarded as synonyms of Ganeo tigrinum.

3. A revised generic diagnosis and a key to the species of the genus Ganeo Klein, 1905 are given.

During studies on the ecology of fish helminths, the tapeworm Proteocephalus torulosus (Batsch, 1786) was frequently found in the intestine of the blue bream (Abramis ballerus) from the Oder River (Germany/Poland). In total, 633 fish, ranging between two and 16 years old, were sampled at monthly intervals over a two year period during 1993–1995. Statistically significant differences in the seasonal occurrence of the parasite in its fish host were observed. In 1993, the prevalence remained at a high level, ranging between 61.9 and 100%. During the summer of 1994, this value decreased to 5.5% and remained low for the rest of the year. The pattern of mean intensity of infection was similar to that of the prevalence. In 1993, the mean intensity varied between 8.4 and 31.8 worms per infected fish, with a continual loss of worms being observed in the summer of 1994. Changes in the amount of suspended particulate matter in water have been identified as the main cause of these observed differences in the course of infection of blue bream.

1. Panagrellus silusiae was cultured in various media to determine the possibility of establishing it as a facultative parasite in the mammalian body. It was found to tolerate pH values of its environment between 1.0–8.5.

2. It survived for 24 hours in gastric juice but was rapidly killed by pancreatic juice. In both preparations larval mortality was higher than that of adults.

3. P. silusiae withstood environmental temperatures up to 87°C. At 40°C. death did not occur within 24 hours.

4. P. silusiae could survive without oxygen for at least 24 hours provided that the carbon-dioxide produced by its own respiration was not allowed to accumulate.

Examination of naturally infected felids and viverrids in Malaysia confirmed previously published records which indicated that P. westermani occured only in felid cats. Felis planiceps and F. temnickii were reported as new host records. Analysis of stomach contents revealed no crab remains in either family of cats, but confirmed that felids were strictly carnivorous while viverrids were often omnivorous. In feeding experiments, only viverrids ate the host crabs Potamiscus johorensis and Parathelphusa maculata. The probable transmission of P. westermani to felids via paratenic hosts was discussed.