Some confusion exists as to the correct identity of Ostertagia trifurcata. The relevant literature is reviewed, and it is concluded that the observations of Sarwar (1954, 1956) pertaining to the identity of O. trifurcata are correct; that is that the genital cone possessed papillae. Teladorsagia davtiani is therefore a synonym of O. trifurcata and O. pinnata a valid species.

A method is described by means of which trichostrongylid spicules are separated from the surrounding soft tissues and their examination made easier. NaOH and KOH are the most satisfactory substances for this purpose, though both substances eventually act on the chitin of the spicules themselves, causing distortion. The reaction takes place at a temperature of 37°C. with reasonable speed. Spicules of Ostertagia can also be freed satisfactorily by this method but those of Nematodirus are quickly affected by the alkali, with consequent distortion.

Nonspecific esterase (NSE), acetylcholinesterase (AChE) and pseudocholinesterase (ChE) have been localized by histochemical methods in various tissues of a cestode, Raillietina (Raillietina) johri obtained from the intestine of pigeon.

NSE has been found in the rostellum, suckers, hooks, tegument, subtegumental muscle, excretory canal, cirrus sac, vagina and eggs. Two types of cells have been recognized on the scolex surface—some are NSE positive and others are NSE negative. AChE, besides being localized in nerves, has also been visualized in almost all the structures as in case of NSE except in hooks, excretory canal and eggs. Additionally AChE has been observed in the vas deferens and sperm ductules. ChE has been observed only in nerves, vas deferens, cirrus sac and vagina; the intensity of enzyme activity being low when compared with AChE. Possible involvement of these enzymes in the physiology of the parasite has been discussed.

A controlled study was carried out to determine the effect of some known anti-filarial drugs on the pattern of emergence of Onchoccrca volvulus microfilariae from skin snips into saline. The results show that before treatment, 81·7 to 92·1% of microfilariae emerge in all the groups within 24 hours. The differences between the groups were not significant. After treatment with oral diethylcarbamazine, metrifonate and topical diethylcarbamazine (DEC) the percentage of microfilariae emerging from the snips dropped significantly to 48·4,560 and 60·1 respectively, whereas no significant change occurred following treatment with levamisole (88·1%) and yeast tablets (89·1%). A pair-wise comparison of the post-treatment microfilarial emergence in all the groups showed statistically significant differences when (i) oral DEC is compared to levamisole, topical DEC and yeast, (ii) metrifonate is compared to levamisole and yeast and (iii) topical DEC is compared to yeast. It is suggested that microfilariae which fail to emerge from snips after treatment are those that have been killed or paralysed by the action of the drugs. The study has thus established that drug action in vivo is one of the factors which affects the proportion of microfilariae which emerge from skin snips and provides an additional parameter for measuring the antimicrofilarial potential of drugs in clinical chemotherapeutic trials.

Certain species of the nematode genus Anguillulina which commonly occur in close association with the roots of grasses are known to invade the root cortex and to reproduce therein. Thus Anguillulina pratensis, A. obtusa and A. erythrinae all occur in the roots of Agrostis stolonifera L. in pastures at this Institute. The writer has on a few occasions, also found one or two specimens of the small tapering-tailed species, A. agricola and A. costata, within the root cortex of the same kind of grass but further observations are needed before we can say definitely whether these two species actually parasitize roots and reproduce within the tissues. An occasional specimen of A. intermedia has also been found by the writer once or twice inside root tissues but never in what could be regarded as fresh, sound roots, and in view of Linford's (1937) observations on the ability of this species to feed upon fungal hyphae, it is probably safest to regard it as not a true parasite. The examples found may have entered partly decayed roots in search of fungal hyphae.

In four experiments, mice harbouring an average 50, 76 or over 200 Schistosoma japonicum female worms were not resistant when challenged six to eight weeks after infection. The female worms from these single sex infections were stunted and immature (average length 4–6 mm) and induced no overt pathology in the host. Male worm burdens of 60, 135 or 140 also induced little or no resistance to challenge in the host. The males from these single sex infections were fully grown for their age (average length 9 mm) and burdens of 135 or 140 induced distended hepatic portal veins and marked deposition of pigment in the livers of infected mice.

Development of Neostrongylus linearis larvae was studied in the snail intermediate hosts Oestophora (Oestophora) barbula, Oestophorella buvinieri, Cepaea nemoralis and Helix (Cryptomphalus) aspersa. The molluscs of each species, all adults, were divided into groups of 40 for infection purposes. The infection doses for the first two snail species were 90 and 50 first stage larvae (L1) of N. linearis, respectively. For C. nemoralis two batches were tested: one with 200 L1 kept at 19°C and the other with 250 L1 at a temperature of 21°C. The same was done with Helix (C.) aspersa with 200 L1 at a temperature of 21°C, on the one hand and 300 L1 at 24°C on the other. One or two molluscs of each species were killed in series from the 6th day post-infection (p.i.) until the 44th. Percentage values for total larvae (1, 2 and 3) and L3 were higher with the lower dose for C. nemoralis, whilst the same was true with the higher dose in Helix (C.) aspersa. In both cases, the higher temperature appeared to contribute to cycle acceleration. Using one way analysis of variance, statistically significant differences were detected between the species of molluscs tested concerning percentages of L1 which penetrated, total larvae and L3. According to our results, the decreasing order of susceptibility of these species of molluscs as experimental intermediate hosts of N. linearis is: O. buvinieri, Oestophora (O.) barbula, C. nemoralis and Helix (C.) aspersa. It is the first time that Oestophora (O.) barbula and Oestophorella buvinieri have been named as experimental intermediate hosts of N. linearis.

Angiostrongylus costaricensis is a parasite that infects rodents, including the wild cotton rat Sigmodon hispidus and pygmy rice rats Oligoryzomys spp., among others. However, urban Rattus norvegicus and Mus musculus have not been identified as important hosts of A. costaricensis. In this study, Swiss mice (SW), Wistar R. norvegicus (RN), wild Oligoryzomys nigripes (ON) and a local strain of M. musculus (RGS) were experimentally infected with A. costaricensis. Survival, elimination of L1 (total sum per group, A0), and the number of adult worms recovered divided by the dose of each L3 inoculum (yield ratio, YR) were examined for each group after a 40-day post-infection period. The survival rates, A0 and YR values were: 27%, 207,589 and 0.42 for the SW group; 81%, 8691 and 0.01 for the RN group; and 63.6%, 26,560 and 0.16 for the RGS group, respectively, in each case. The survival rate for the ON group was 100% and the A0 value was 847,050. A YR was not calculated for the ON group since the ON group was maintained up to 565 days post-infection (pi) to examine long-term mortality. At 500 days pi (16 months), 50% of the ON group had died, while one animal (10%) survived 595 days pi (20 months). Taken together, these data indicate that A. costaricensis has undergone a greater degree of adaptation to the wild rodent, O. nigripes, than to R. norvegicus or a local M. musculus strain. In addition, titre curve (A0) modelling of adaptation status proved to be useful in evaluating A. costaricensis–rodent interactions.

New Zealand’s kākāpō parrot, once widespread, is now critically endangered due to habitat loss and introduced mammalian predators. Prior to major population decline, a unique kākāpō cestode, Stringopotaenia psittacea, was found in the 1880s and first described in 1904. Here we report the discovery of eggs of this cestode in kākāpō coprolites of pre-human settlement age from the Honeycomb Hill cave system, north-west Nelson. Analysis of 52 samples, including coprolites of post-human settlement age, from nine sites within six South Island locations across a wide geographic range, yielded only eight infected samples in this single cave system. Results suggest that prior to human settlement, S. psittacea was not widespread within and between kākāpō populations, in marked contrast to other parasite types of the extinct moa spp. Intense management of the last remaining kākāpō has endangered or possibly caused the extinction of this cestode. This is the first confirmed record of S. psittacea since its discovery in 1884.

On the basis of the morphological characterization of Chelatrema neilgherriensis Manjula & Janardanan, 2006 recovered from the freshwater fish Barilius gatensis (Valenciennes, 1844) in the Wayanad region of the Western Ghats, the diagnostic features of the genus Chelatrema Gupta & Kumari, 1973 have been modified. Based on the phylogenetic analysis of C. neilgherriensis and comparative morphology studies relative to members of other families of Gorgoderoidea Looss, 1901, this genus is placed in a new family Chelatrematidae n. fam. The studies revealed the molecular and morphological closeness of Chelatrema with Paracreptatrematina limi Amin & Myer, 1982, and the latter is transferred to this new family. Hence the new family Chelatrematidae n. fam. comprises the genera Chelatrema and Paracreptatrematina.

A new species belonging to the genus Belondira is described from natural areas in Iran. Belondira coomansi n. sp. is characterized by its general size, the dimensions and appearance of its lip region, presence of distinct labial and post-labial sclerotization, the length of the odontostyle and its inconspicuous lumen and aperture, the length of the neck and its pharyngeal expansion, the reduction of the female anterior genital branch to a simple uterine sac, a very short posterior uterus, the anterior position of the vulva, the length and shape of the caudal region with distinctly thick cuticle at its tip, the length of the spicules, and the presence of only one pair of ventromedian supplements. The new species is close to Belondira brevibulba, B. sacchari, B. tenuidens and B. thornei, and it is compared to them. Molecular characterization (D2–D3 expansion segments of the rRNA large subunit) of the new species is also provided, representing only the second species of this genus for which any DNA sequence data are available.

The diversity and importance of Echinococcus species in domesticated animals in Kazakhstan are poorly understood. In this study, 17 cysts of Echinococcus were collected from cattle and a further 17 cysts from sheep. DNA was extracted from the individual cysts and used for polymerase chain reaction amplification of mitochondrial subunit 1 of the cox1 and nadh1 gene. Amplicon sequencing results revealed the presence of Echinococcus granulosus sensu stricto G1 in 15 cattle and 15 sheep, and G3 genotype from two cattle. Echinococcus canadensis (G6/G7 strain) was found in two cysts originating from sheep.

Partial cross protection against a skin-parasitic ciliate has been recorded in rainbow trout previously immunized with an ectoparasitic platyhelminth. The susceptibility to infection by Ichthyophthirius multifiliis differed significantly between naive and Gyrodactylus derjavini immunized rainbow trout. Fish partly immune to the ectoparasitic monogenean G. derjavini became less infected and experienced lower mortality than naive fish when exposed to I. multifiliisinfections. In vitro studies on immobilization of theronts using decomplemented (heat-inactivated) serum from G. derjavini immune or non-immune hosts showed no immobilization. However, untreated serum from both immune and non-immune fish containing intact complement immobilized theronts (titre 128–256). In addition, non-specific priming of the host response with interleukin (IL-1), bacterial lipopolysaccharide (LPS), concanavalin A (Con A) or mannan did confer a partial resistance to I. multifiliis infection. This will suggest that non-specific factors including complement could be partly responsible for the host response against infections with this ciliate.

The question of helminth parasitism in British goats appears to have had little or no attention paid to it. This is somewhat surprising when one considers the fairly large number of goats which must be present in this country and, although no annual statistics as to the number of goats in Britain are available, Holmes Pegler (1929) observes that early in 1925 the Ministry of Agriculture, assisted by the British Goat Society, obtained returns of the number of goats in England and Wales which was set down as, roughly, 60,000. Similarly little definite data is available on the frequency and intensity with which these animals are infected by helminths in different localities. In this paper an attempt is made to supplement the meagre data relative to these conditions.

Trichinellosis is a zoonotic disease that endangers human health and can lead to death. Restricted absorption and poor results of conventional therapies demand new effective natural remedies to treat both enteral and parenteral trichinellosis. This study assessed the antiparasitic and anti-inflammatory effects of Citrus limon and Capsicum frutescens on murine trichinellosis and compared them with those of albendazole and prednisolone, which are conventionally used to treat trichinellosis. Overall, 50 Swiss albino male mice were divided into five groups, with ten mice in each group: negative control, positive control, albendazole combined with prednisolone, C. limon, and C. frutescens. Mice were sacrificed 7 and 35 days after infection, for intestinal and muscular phase analyses. Drug efficacies were parasitologically, biochemically, histopathologically and ultrastructurally assessed. Our results demonstrated the efficacy of C. frutescens and C. limon extracts as antiparasitic agents, showing a substantial decrease in adult and larval counts. Moreover, both extracts had the ability to decrease serum tumour necrosis factor-α levels during the intestinal and muscular phases. In addition to the improved histopathological changes in the small intestine and muscles, the destructive effects on adults and larvae were ultrastructurally evident on transmission electron microscopy. In conclusion, C. frutescens and C. limon extracts are promising remedies for the treatment of experimental trichinellosis, particularly, the C. frutescens extract.

Nematodes of the genus Gongylonema infect a wide range of mammals worldwide but are only sporadically reported in humans. We describe a case of human infection with Gongylonema pulchrum in a 41-year-old man. The patient extracted the nematode from the submucosa under his tongue and correctly self-diagnosed the infection with the help of the Google search engine. In the laboratory, the collected nematode was confirmed as G. pulchrum microscopically by morphological analysis and genetically by amplifying and sequencing the parasite's rDNA. This is the first report of human G. pulchrum infection in Slovenia.

As part of surveillance of snail-borne trematodiasis in Knowsley Safari (KS), Prescot, United Kingdom, a collection was made in July 2021 of various planorbid (n = 173) and lymnaeid (n = 218) snails. These were taken from 15 purposely selected freshwater habitats. In the laboratory emergent trematode cercariae, often from single snails, were identified by morphology with a sub-set, of those most accessible, later characterized by cytochrome oxidase subunit 1 (cox1) DNA barcoding. Two schistosomatid cercariae were of special note in the context of human cercarial dermatitis (HCD), Bilharziella polonica emergent from Planorbarius corneus and Trichobilharzia spp. emergent from Ampullacaena balthica. The former schistosomatid was last reported in the United Kingdom over 50 years ago. From cox1 analyses, the latter likely consisted of two taxa, Trichobilharzia anseri, a first report in the United Kingdom, and a hitherto unnamed genetic lineage having some affiliation with Trichobilharzia longicauda. The chronobiology of emergent cercariae from P. corneus was assessed, with the vertical swimming rate of B. polonica measured. We provide a brief risk appraisal of HCD for public activities typically undertaken within KS educational and recreational programmes.

While multiple DNase activities occur in the excretory/secretory products (ESPs) of the adult Haemonchus contortus, the DNase activities in ESPs of the infective larvae (L3) have not been studied. Thus, the DNase activities in ESPs of H. contortus L3 were investigated and compared to those of adults for developmental stage-specific analysis. The DNase activities had relative molecular masses (Mrs) of 34 and 36 kDa upon zymographic analysis at pH 5.0 and 7.0 when the larvae were incubated for over 48 h. The 34 and 36 kDa DNases of L3 ESPs were also detected in adult ESPs with similar characteristics. However, the 37 and 38.5 kDa DNases of the adult ESPs were not detected in the L3 ESPs. Since the 37 and 38.5 kDa DNase activities were mainly detected in adult ESPs, these activities appear to be specific to the adult stage whereas the other ESP DNase activities appear to be expressed during multiple stages of the parasite's life cycle. While the difference in DNase activities of L3 and adults remains obscure, the role of DNase in larval development should be further clarified and the identification of stage-specific developmental markers will lead to the discovery of specific factors that stimulate larval development.

We describe the larval developmental stages and life cycle of the dracunculid nematode Mexiconema cichlasomae in both the intermediate, Argulus yucatanus (Crustacea: Branchiura), and definitive hosts, Cichlasoma urophthalmus (Perciformes: Cichlidae), from the Celestun tropical coastal lagoon, Yucatan, Mexico. The morphological analyses showed significant differences between the total length of L1 found in M. cichlasomae gravid female and L2–L3 in A. yucatanus. This result indicates that the M. cichlasomae larval development occurs in the intermediate host. We obtained sequences from the small subunit (SSU) ribosomal marker from larval stages of M. cichlasomae in A. yucatanus and adult nematodes in C. urophthalmus. Our morphological and molecular results support conspecificity between M. cichlasomae larvae in A. yucatanus and the adult stages in C. urophthalmus. We briefly discuss the phylogenetic position of M. cichlasomae among the Daniconematidae, and provide evidence of the monophyly of the daniconematids associated with branchiurid intermediate hosts. Based on the phylogenetic results, we support the transfer of the Mexiconema genus to the family Skrjabillanidae and do not support the lowering of family Daniconematidae to subfamily.