Experimental infection of larval Echinococcus multilocularis in the rodent brain was attempted to establish a murine model for cerebral alveolar echinococcosis. Balb/c mice and jirds were injected intracranially with 10% of a homogenated hydatid cyst mass. Small cystic larvae were observed macroscopically in the cranial cavity 1, 2 and 5 months post-infection in both mice and jirds. Some larval cysts from both rodents contained mature or immature protoscoleces. In mice, the laminated layer was found in the lateral ventricle 2 months post-infection but without protoscoleces. At five months post-infection, larger larval cysts were found in the cranial cavity of a mouse, which also demonstrated partial palsy of the legs. A laminated layer with mature protoscoleces was observed in the third ventricle and the mouse also harboured, in the left lung, a larval cyst containing protoscoleces surrounded by lymphocytes. Jirds were also found to be infected with metacestodes in the cranial cavity, but neither unusual behaviour nor establishment of cysts inside the brain was observed in jirds during the course of infection.

The secondary response of eosinophilia has been studied in mice infected with A. suum. In mice infected orally with 1000 A. suum eggs, larvae disappeared from the body within two weeks after infection. The number of peripheral blood eosinophils decreased to the pre-infection level within eight weeks. A typical secondary response of IgG antibody production to egg antigen was found after reinfection with 1000 eggs. The number of peripheral blood eosinophils increased more rapidly after reinfection than after the primary infection. However, the peak number of eosinophils after reinfection was similar to that after primary infection, and the long-lasting characteristics of eosinophilia after reinfection did not differ from those after primary infection. These results suggest that the secondary response of eosinophilia is characterized by a rapid increase in the number of eosinophils in A. suum-reinfected mice.

Rabbits were vaccinated once, by subcutaneous and intradermal injection, with sonicates of oncospheres (TpO) or conditioned media from in vitro maintained mature metacestodes (TpMcES) of Taenia pisiformis. Extracts were either incorporated into or mixed with unilammelar liposomes (reverse phase evaporative vesicles) or emulsified in Freund's Incomplete Adjuvant (FIA). Control groups received liposomes or FIA without antigen, or antigen preparation without adjuvant. Rabbits were challenged orally two weeks after vaccination with approximately 1500 eggs of T. pisiformis and necropsied eight weeks after challenge. A mean of 155 cysts was recovered from seven control rabbits. A 67% reduction in peritoneal cyst numbers was obtained in TpO–IFA vaccinated rabbits compared to 75% for the TpO–liposome entrapped group. The highest level of protection (86%) was obtained when TpO was mixed with but not entrapped in liposomes. Only 32% and 39% reduction in peritoneal cyst numbers was obtained after immunizing with the TpMcES preparation in liposomes or IFA respectively, however >85% of peritoneal metacestodes were dead (necrotic or calcified) and suggests a different immune response than occurs after vaccination with oncosphere extracts. Specific anti-oncospheral or anti-metacestode ES antibody (IgG) responses at two weeks post vaccination were similar in rabbits immunized with liposome or IFA associated extracts.

The lesions associated with the migration of the larvæ of Ascaris megalocephala through the tissues of the host were studied in rabbits, guinea pigs and mice. In addition to studying the changes in those organs directly invaded by the larvæ in the course of migration, an organ remote from the migratory route but exposed to the action of any toxic products elaborated by the larvæ was also examined. In each case therefore, sections were prepared from (a) liver, (b) lungs and (c) kidneys.

Third-stage and fourth-stage Dirofilaria immitis larvae exhibited positive thermotaxis when placed in a thermal gradient. Negative thermotaxis was not observed. Positive thermotaxis may be important for the successful transmission and for directing third and fourth-stage larval migration toward predilection sites in the Host.

The material on which this article is based was sent to Dr. R. T. Leiper, C.M.G., F.R.S., by Mr. L. R. Hutson, Veterinary Officer, Antigua, to both of whom my thanks are due. Most of the cestodes had already been described by Prof. J. G. Baer and recorded by him in 1940. The rest of the collection consists mainly of nematodes but there are, however, representatives of all three groups of helminths—Trematoda, Cestoda and Acanthocephala as well as the Nematoda. The hosts were all described by the local popular names and I am much indebted to Mr. Kinnear, of the Natural History Museum, London, for identifying them.

The only trematode in the collection is the Strigeid, Apharyngostrigca cornu Goeze, 1800, which had been removed from the large gut of a Yellow crowned night heron, Nycticorax violaceous. It has already been recorded from a number of birds belonging to the Ciconidae and to the Ardeidae but not from this particular host. It is not uncommon in Europe and the United States but has not been reported in the British West Indies before. There are two specimens both attached to the mucous membrane but they were easily removed and seemed to have caused no pathological changes. They are mature and contain eggs and the vitellaria are strongly developed, obscuring most of the other organs.

It was possible to make a more critical study of immunity against A. suum by infecting pathogen-free, colostrum-deprived pigs produced by hysterectomy.

By means of the conglutinating complement absorption test, using a saline extract of worm as antigen, antibodies were first demonstrated in the circulation of three experimentally-infected pigs between the 10th and 13th days of infection, and were detected in the sera of two of them for at least 97 days.

The infections did not become patent, and no acquired immunity was shown by the pigs against a reinfection 97 days later. There was no evidence of an age immunity against migrant larvae.

A rise in serum antibody was observed, within seven days of infection, in six pigs aged between 10 weeks and 11 months, following a test dose of 500,000 eggs. Three suckling pigs, aged three weeks, did not respond serologically within seven days to the same test dose.

In June, 1931, some specimens of field-grown peas infested by eelworms were sent for diagnosis to the Institute of Agricultural Parasitology by Mr. H. W. Thompson, of Cardiff University. The plants were found to be very heavily attacked by Heterodera schachtii in early stages of development.

Taliaferro and Sarles (1939) who studied the cellular reaction in the skin, lung and intestine of normal and immune rats after infection with N.muris, stated that “larvae were found penetrating the skin from a half hour through two hours after they had been placed on the skin. They seemed to penetrate directly…” Yokogawa (1922) observed that this parasite when placed on the skin of rats, penetrated into the tissues very quickly. He did not specify any time for their entrance.

Echinostephilla virgula occupies an isolated position in the Digenea; apparently it does not belong with certainty to any of the existing families and, as the original description is incomplete, it was considered worthy of re-description. This trematode was found frequently at St. Andrews between the months of September, 19–19, and March, 1951, in the intestine of the Turnstone (Arenaria interpres Linn.). There was usually a heavy parasitism, fifty to one hundred worms being found in one host. However, in spite of frequent examinations of birds shot after this period, no further specimens were found.

An experiment was set up to investigate the effect of root diffusates from different varieties of potatoes on natural infestations of cysts in three different soils. A series was included in which no root diffusate at all was used, to obtain an estimate of the degree of spontaneous hatching which occurred. In the absence of diffusate, about 50 per cent, of larvae emerged from the cysts, as compared with 84 per cent, in the case of soils treated with diffusates. Significant differences were detected in the degree of emergence under the action of the different diffusates, that from “Ulster Chieftain” having the greatest effect. Significant differences were also detected between the different soils, larval emergence being lowest in the greensand.

Paradistomoidella cerberi n.g, n.sp. and Paracanthostomum cerberi from Cerberus rhynchops, Xenopharynx pyriformis and Allopharynx mehrai from Ptyas korros, Neopronocephalus orientalis from Geoemyda spinosa, and Duthiersia expansa from Varanus salvator are all reported from the area of Kuala Lumpur, Malaysia. Paradistomoidella cerberi most closely resembles members of Paradistomum and of Paradistomoides but is characterized by relatively short caeca, a cirrus sac containing a bipartite rather than sinuous internal seminal vesicle, and unevenly-sized suckers. Kuala Lumpur is a new locality for Paracanthostomum cerberi, X. pyriformis, A. melvrai, and D. expansa. Ptyas korros is a new host for X. pyriformis and G. spinosa is a new host for N. orientalis.

The results of a vaccination trial in lambs with gamma-irradiated infective larvae of Gaigeria pachyscelis are described. A single percutaneous (P/C) vaccination of lambs with 2000 infective larvae irradiated at 40 Kr induced the development of resistance. The vaccinated lambs successfully resisted a lethal challenge infection of 5000 non-irradiated larvae 3 months later. In the vaccinated lambs, the manifestations of resistance were shown by marked reduction in the worm establishment, development of retarded and functionally sterile worms and absence of clinical signs of hookworm disease after the challenge infection.

Ozolaimus linstowi n. sp. is described from the large intestine of Iguana iguana Linnaeus, 1758 from Mexico. The present species can be easily distinguished from O. megatyphlon and O. cirratus by the presence of a long and slender pharynx not divided into sections, more similar to the remaining two species, O. monhystera and O. ctenosauri. Ozolaimus linstowi n. sp. can be differentiated from O. monhystera by the shorter spicule length and smaller body size of both males and females. Males of O. linstowi n. sp. are morphologically close to those of O. ctenosauri, but females possess a markedly smaller body size and differ in the organization of the oral cuticular armature. Adult males of O. linstowi n. sp. bear some characteristic features of the J3 juvenile morphology in terms of the cuticular organization of the oral and buccal capsule. Phylogenetic analysis of O. linstowi n. sp. using partial small subunit (SSU) and D2–D3 large subunit (LSU) rDNA shows relationships with several Oxyuridae genera.

A mouse-derived strain of Rodentolepis ( = Hymenolepis) nana was transferred to the Mongolian jird Meriones unguiculatus. It was found that M. unguiculatus has low susceptibility to R. nana mouse isolates. Likewise, adaptation of the parasite to jird hosts, in the absence of dexamethasone treatment, was not demonstrable, at least during ten-passage trials. Nevertheless, the parasite was able to establish, grow and develop to gravid adults in M. unguiculatus treated daily with dexamethasone. Prepatent periods in dexamethasone-treated jirds in ten-passage series ranged from 10 to 17 days post-infection (DPI), the average being 12 days, and the patent periods lasted from 18 to 30 DPI, with an average of 25 days. The population pattern of faecal egg output in immunosuppressed jirds suggests that under a daily dexamethasone treatment protocol, the parasite is able to maintain egg production as long as treatment is sustained.

Protease activities in preparations from the plant-parasitic nematodes Heterodera glycines and Meloidogyneincognita and the free-living nematode Panagrellus redivivus were inhibited by exposure to a series of eight catechin polyphenol analogues, (+)-catechin, ( − )-epicatechin (EC), ( − )-gallocatechin (GC), ( − )-epigallocatechin (EGC), ( − )-catechin gallate (CG), ( − )-gallocatechin gallate (GCG), ( − )-epicatechin gallate (ECG) and ( − )-epigallocatechin gallate (EGCG) (1 mm each), and by a preparation from H. glycines cysts. General protease activity detected with the FRET-peptide substrate QXL520-KSAYMRF-K(5-FAM)a and proteasome chymotrypsin-like (CTL) activity detected with succinyl-LLVY-AMC were each inhibited significantly more (P< 0.05) by the gallated form of the polyphenol than by the corresponding non-gallated form. Species differences in response to inhibition across all analogues were revealed with the CTL substrate, but CG was a consistently potent inhibitor across all three species and with each substrate. A heat-stable component (CE) from H. glycines cysts inhibited M. incognita CTL activity by 92.07 ± 0.68%, significantly less (P< 0.05) in H. glycines (52.86 ± 2.77%), and by only 17.24 ± 0.55% (P< 0.05) in P. redivivus preparations. CTL activity was, however, inhibited more than 60% in all preparations by the proteasome-specific inhibitor MG-132. Hatching of M. incognita infective juveniles exposed to 1 mm CG, ECG, GCG or EGCG was reduced by 83.88 ± 4.26%, 69.98 ± 9.14%, 94.93 ± 1.71% and 87.93 ± 2.89%, respectively, while hatching of H. glycines was reduced less than 25% by each analogue. CE had no effect on nematode hatch, but did cause a 60% reduction in mobility of H. glycines infective juveniles exposed overnight to CE in vitro, which was more (P< 0.05) than the reduction of M. incognita infective juvenile mobility (20%).

Cystic liver disease (CLD), presenting with solitary or multiple cysts in the liver, is a common diagnosis today, primarily due to the frequent application of modern radiological methods. There is a wide range of possible causes. CLD of infective origin is usually caused by an echinococcal species. During the past three decades a number of cystic echinococcosis (CE) control programmes have led to a significant decrease in the incidence of human hydatidosis in some endemic areas. The aim of this study was to determine the seroprevalence of E. granulosus infection in Croatian patients with CLD. A total of 540 serum samples from patients with hepatic cysts detected by imaging methods were screened for the presence of E. granulosus IgG antibodies using semiquantitative enzyme-linked immunosorbent assay. The Western blot technique was used as a confirmatory test for the CE diagnosis. The overall E. granulosus seroprevalence rate in patients with CLD was 3.9%. There was no significant difference in seroprevalence rate between male and female patients (P = 0.541). According to age groups, there was a significant difference in seropositivity among age groups (P = 0.002). The highest seroprevalence rate was detected in the youngest age group (up to 18 years), both in males and females (20% and 13%, respectively). This study indicates that CE still represents a public health problem in Croatia. Preventive measures should be used to control Echinococcus infections, including avoidance of contact with infected dogs, egg-contaminated soil or plants; control and treatment of dogs with antihelmintics; hand washing, improved sanitation and health education.

Bunocotyle progenetica is a hemiuroid digenean whose sexual adults become fully developed and lay their eggs inside the rediae in the molluscan host. In this study, the fine structure of the germinal mass, brood cavity and birth canal in the B. progenetica rediae was examined using transmission electron and confocal microscopy. The large germinal mass attached to the body wall has a cellular composition typical for this organ. The characteristic traits of this germinal mass are weakly developed supporting tissue and the presence of deep lacunae opening into the brood cavity. These lacunae presumably participate in feeding the deeply lying embryos and facilitate their release into the brood cavity. The germinal mass is also characterized by intensive degeneration of cellular elements, which may represent a mechanism controlling the offspring number, limited in this species by the size of the redial brood cavity. The brood-cavity lining consists of flattened cells bearing lamellar projections and is connected anteriorly with the epithelium of the birth canal. The brood-cavity musculature, which is well developed in other hemiuroid digeneans, is significantly reduced in B. progenetica, most likely because their cystophorous cercariae remain inside the rediae, removing the need for muscle contractions pushing them through the brood cavity. The birth canal comprises three regions distinguished by the structure of the lining and muscle arrangement. The comparison of rediae of B. progenetica with parthenitae of other digeneans has shown that the organization of the redial reproductive apparatus in this species may have been influenced by life-cycle modification.

A new genus and species of the philometrid nematode Dentirumaiphilippinensis n. gen., n. sp. Philometrinae, Philometridae, are described on the basis of the female specimens found in the loach goby, Rhyacichthys aspro (Valenciennes), from the upper Bianuan River, Municipality of Casiguran, Aurora Province, in the Philippine Archipelago. Dentirumai philippinensis was collected from the body cavity, subcutaneous tissues near the bases of the pectoral and pelvic fins, and surrounding body tissues in the hypaxial musculature of R. aspro. Based on light microscopic and scanning electron microscopic examination, the new nematode species is morphologically close to the genus Rumai Travassos, 1960 except for one major difference, i.e. the presence of a sclerotized ring in the oral aperture armed with distinct numerous minute teeth on its inner surface. This important taxonomic feature makes it possible to erect a new genus, Dentirumai n. gen. to accommodate the newly discovered philometrid species. A key to genera of the Philometrinae is provided.