Few digeneans of the family Fellodistomidae are known from the Russian Arctic seas. The taxonomic status of these species, their life cycles and host range raised recurrent questions, some of which remain unanswered. To revise the species composition and life cycles of fellodistomids in the White Sea, we searched for them in several known and suspected hosts: wolffish, flatfishes (definitive), gastropods of the family Buccinidae (second intermediate) and protobranch bivalves (first intermediate). Species identification was based both on morphology and 28S ribosomal RNA gene sequences. We found Fellodistomum agnotum in the White Sea for the first time. Buccinum undatum was proved to be intermediate host of both F. agnotum and Fellodistomum fellis, and metacercariae of F. fellis were registered from two more buccinid species: Buccinum scalariforme and Neptunea despecta. We also found metacercariae of F. agnotum and F. fellis producing eggs in the second intermediate host. Two fellodistomids were found in protobranch bivalves: sporocysts and cercariae of Steringophorus furciger in Nuculana pernula, and sporocysts with large furcocercous cercariae in Ennucula tenuis. The latter were identified as F. agnotum by molecular analysis; thus, the entire life cycle of this species was reconstructed.

The epidemiology of toxocariasis in humans in Mexico has been poorly explored. There is a lack of information about toxocariasis in Tepehuanos, an indigenous ethnic group in Durango State in northern Mexico. Therefore, the presence of anti-Toxocara immunoglobulin (Ig) G antibodies was determined in 126 rural Tepehuanos using an enzyme-linked immunoassay. Socio-demographic, clinical and behavioural data of the participants were also obtained. Of the 126 Tepehuanos assessed (mean age 32.46 ± 17.36 years), 33 (26.2%) had anti-Toxocara IgG antibodies. Multivariate analysis showed that Toxocara seropositivity was associated with unemployment (students and housewives) (odds ratio (OR) = 3.1; 95% confidence interval (CI) 1.25–7.47). Other socio-demographic and behavioural characteristics, including age, educational level, contact with animals or soil, consumption of unwashed raw fruits and vegetables or untreated water, were not associated with Toxocara seropositivity. Clinical data were similar in seropositive and seronegative Tepehuanos. These results indicate that Toxocara exposure is common among Tepehuanos but Toxocara does not appear to impact on the health of the population. This is the first report of toxocaral infection in Tepehuanos, and of an association of toxocariasis in adults with unemployment. Further research is needed to elucidate the routes of transmission of Toxocara in Tepehuanos, including the role of hygiene practices, canine and feline contacts, paratenic hosts and soil contamination with infective Toxocara eggs.

The transmission of zoonoses by wildlife, including elephants, is a growing global concern. In this study, we screened for helminth infections among Asian wild elephants (Elephas maximus) of the Salakpra Wildlife Sanctuary, Kanchanaburi, Thailand. Elephant faecal samples (45) were collected from the sanctuary grounds during January through November 2013 and assayed individually using the tetranucleotide microsatellite technique. Microscopic examination indicated a high prevalence of strongylids (93.0%) and low prevalences of trichurids (2.3%) and ascarids (2.3%). To identify the strongylid species, small subunit (SSU) rDNA sequences were amplified from copro-DNA and compared with sequences in GenBank. The generated SSU-rDNA sequences comprised five distinct haplotypes that were closely related to Oesophagostomum aculeatum. A phylogenetic analysis that incorporated related nematodes yielded a tree separated into two main clades, one containing our samples and human and domestic animal hookworms and the other consisting of Strongyloides. The present results indicate that O. aculeatum in local elephants is a potential source of helminthiasis in human and domestic animals in this wild-elephant irrupted area.

The association between visual hepatic damage, burden of Fasciola gigantica, serum levels of gamma glutamyl transferase (GGT) and glutamate dehydrogenase (GLDH) is described from an abattoir study of 70 cattle in the Philippines. In another abattoir study of 60 cattle, the relationship between burden of F. gigantica and haematological indices was investigated. The degree of visual hepatic damage and burden of F. gigantica were significantly positively related to levels of GGT and GLDH. Red blood cell counts and packed cell volume were significantly inversely related to worm burden, but animals compensated for reduced numbers of red blood cells by increasing red cell haemoglobin content.

Investigations into the effect of internal parasitism on the digestive economy of sheep have been carried out at the Grassland Research Station, with particular reference to the effect of sub-clinical wormburdens on live-weight increase and digestive efficiency in these animals.

Proteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyneincognita, and the free-living Panagrellus redivivus, were surveyed for substrate preferences using a battery of seven FRET-modified peptide substrates, all derived from members of the large FMRF-amide like peptide (FLP) family in nematodes. Overall protease activity in P. redivivus was four- to fivefold greater than in either of the parasites, a result that might reflect developmental differences. Digestion of the M. incognita FLP KHEFVRFa (substrate Abz-KHEFVRF-Y(3-NO2)a) by M. incognita extract was sevenfold greater than with H. glycines extract and twofold greater than P. redivivus, suggesting species-specific preferences. Additional species differences were revealed upon screening 12 different protease inhibitors. Two substrates were used in the screen, Abz-KHEFVRF-Y(3-NO2)a and Abz-KPSFVRF-Y(3-NO2)a), which was digested equally by all three species. The effects of various inhibitor, substrate and extract source combinations on substrate digestion suggest that M. incognita differs significantly from P. redivivus and H. glycines in its complement of cysteine proteases, particularly cathepsin L-type protease.

A topographical distribution of Ostertagia spp. lesions in the abomasum of sheep has been observed under certain field conditions which is the reverse of that described by Sommerville (1953, 1954) and also seen by this author to be characteristic of a primary Ostertagia spp. infection.

This “reverse distribution” has been demonstrated experimentally under conditions in which a heavy primary Ostertagia infection has been acquired (in the field or artificially) and naturally eliminated; the “reverse distribution” is then characteristically acquired by a challenge infection.

Mice, CBA/HT6T6 and C57BL/10, were vaccinated with 1 × 350 or 1 × 500 Schistosoma mansoni cercariae or schistosomula attenuated with 20 or 56 krad 60Co irradiation and challenged with 200 cercariae. Protective resistance against homologous strain challenge was compared using the Winches Farm Field Station (WFFS) and Naval Medical Research Institute (NMRI) strains of S. mansoni. Maximal resistance to challenge was obtained in both strains of mice with cercariae or schistosomula of either WFFS or NMRI strain attenuated with 20 krad. Protection using organisms attenuated with 56 krad was significantly lower. Since previous studies with the two parasite strains have shown that the biological effects of irradiation are similar, the difference in the immunogenicity of the 56 krad-irradiated NMRI strain in this study from earlier studies must be due either to different local conditions for irradiation or to adaptation of the NMRI strain to a new laboratory environment. This finding may have important implications for vaccination studies and investigations of the mechanisms of immunity where radiation-attenuated parasites are used.

The indirect fluorescent antibody technique has been applied to detect antibody levels in jirds (meriones unguiculatus) infected with Brugia malayi. Sonicated antigens were prepared from microfilariae and adult worms. Sonicated microfilariae were found to be satisfactory for this purpose. Cyanogen bromide-activated sepharose coated with soluble antigens prepared from microfilariae and adult worms was also used to detect antibodies to Brugia infections. The present observation show that these techniques can be usefully applied for detection of filarial infections. Antibody titres in infected jirds generally ranged from 1: 16 –1:256 and were not affected by treatment with diethylcarbamazine.

The ability of Hymenolepis nana oncosphere extract to induce eosinophil chemotactic response was examined in vitro and in vivo. The extract showed a chemotactic activity specific for eosinophils but not for neutrophils. Partially purified eosinophil chemotactic factors (ECFs) from the oncosphere extract showed apparent molecular mass from 5.5 to 9.6kDa and 30 to 40kDa. These were resistant to heating and proteinase K digestion but sensitive to periodate oxidation. Peritoneal injection of the crude extract or partially purified ECFs to mice resulted in a preferential eosinophil infiltration. The chemotactic activity for eosinophils was not separable from the adhesion molecule expression or oxygen radical-inducing activity by means of chromatography or chemical treatments. Furthermore, histological examination demonstrated a marked tissue eosinophilia around H. nana larvae in the intestinal lamina propria of both humoral and cell-mediated immunodeficiency mice. The present findings suggest that H. nana oncosphere-derived molecules facilitate in vivo the intestinal eosinophilia during the infection.

The Sheathbill is a distinctive bird breeding on the islands of the Scotia Arc and the Graham Land peninsula, and regularly occurring north to the Falkland Islands, the Magellanic Islands and the Atlantic coast of Argentina (Jones, 1963). Rather surprisingly no cestodes have previously been recorded or described from this bird.

The following account describes Nototaenia fileri gen. et sp. nov. and Lateriporus ausiralis n.sp. from two of 13 adult Sheathbills collected on Signy Island in July and October 1965 by Mr Charles Howie of the British Antarctic Survey, preserved in deep-freeze, and later entrusted to us for examination.

New host and geographical records and new morphological data are reported on three monogeneans: Encotyllabe spari YAMAGUTI, 1934, Choricotyle hysteroncha (FUJII, 1944) and Pseudotagia cupida (HARGIS, 1956).

It has been suggested (Hammond, 1967) that Acanthocephalus ranae absorbs a large proportion of its nutrients through the surface of the trunk, while lipids may be excreted through the surface of the proboscis. The performance of these functions by the proboscis and trunk may well be affected by the mode of attachment of the parasite, and by its behaviour within the host.

The working of the proboscis apparatus of Acanthocephalus ranae has been described (Hammond, 1966a), but its operation in attaching parasite to host has been outlined only briefly (Hammond, 1965).

Infectivity and cercarial production of Indoplanorbis exustus related to variation of miracidial dose (1, 4, 10 or 20) with Schistosoma nasale and S. spindale from Sri Lanka were studied. The intermediate host-parasite relationships of the two schistosome species showed marked differences under the conditions of observation recorded in this study. Prepatent death rates (PDR) were on average higher for S. spindale (30%) than for S. nasale (10%). The size of the miracidial dose to which snails had been exposed had no effect on PDR. The infection rates (IR) were on average higher for S. nasale (41%) compared with S. spindale (27%). Highest IR occurred after exposure to 4 miracidia in S. nasale infections (79%) and after exposure to 10 miracidia in S. spindale infections (6O%). The highest daily average cercarial production per snail was recorded for S. nasale at a level of 4 miracidia (1311), and for S. spindale at a level of 10 miracidia (1615). At low level (1 or 4 miracidia) of exposure, I. exustus showed a better compatibility with S. nasale than with S. spindale. An opposite tendency was observed at higher levels (10 or 20 miracidia) of exposure. Unsuccessful infections of Lymnaea luteola with either S. nasale or S. spindale indicate that this species is not involved in transmission.

In the British Isles potatoes are subject to many pests and diseases of animal, fungal and virus origin. In the first class there are two different kinds of eelworms or nematodes which attack the plant, one affecting the roots and the other the tubers. The former is the cystforming species Heterodera rostochiensis and the latter was for many years considered to be a specialized race of the stem eelworm, Anguillulina dipsaci. As a result, however, of work carried out by Thorne (1945) in the U.S.A., it is now known to be a distinct species, Ditylenchus destructor. Though resembling A. dipsaci closely in size, general shape and structure, D. destructor differs from it in one or two points of microscopic detail which are constant and can be seen in suitably mounted specimens when examined under high magnification. The most important of these is the presence of 6 fine longitudinal lines or incisures on each side of the body in the area known as the lateral field as compared with 4 such lines in the case of A. dipsaci (fig. 1).

Guineapigs infected with a lethal dose of Ascaris eggs died between the fifth and tenth day of infection. The M.L.D. was found to be 20,000 eggs. The clinical symptoms and the macroscopic lesions in the liver and lung are described. Infected guineapigs developed an active acquired immunity and repeated infection conferred a high degree of resistance on animals which were subsequently reinfected. Resistance was manifested by the survival of the host following a lethal dose of eggs, and by an inhibition of larval migration. (Less haemorrhage was found in the lung, and fewer larvae were recovered from the lungs and tracheae, after reinfection than following one infection).

The M.I.D. against a reinfective lethal dose 18 days after infection was 500 eggs. The smallest immunizing dose required to give resistance to a challenge 51 days later was 10,000 eggs. This suggests that the resistance manifested at three weeks is greater than that shown after seven weeks, i.e. there is a waning of the immunity.

Small numbers of the nematode species: Spiculopteragia asymmetrica, Apteragia quadrispiculata, Nematodirus filicollis, Capillaria bovis, Cooperia pectinata and Oesophagostomum venulosum, were recovered from the gastro-intestinal tracts of wild Fallow deer killed in Essex. In addition, the larval cyst of the cestode Taenia hydatigena was found in the liver of one animal.

Mr. T Petre of the Volta Basin Research Project of the University of Ghana kindly entrusted the writer with some nematodes collected from the freshwater fishes of Ghana. As far as can be found from published literature there is no previous record of nematodes from the freshwater fishes of Ghana. In fact, the helminth parasites of the freshwater fishes of this country are inadequately known and only monogeneans, digenetic trematodes and a single acanthocephalan have so far been reported. This collection represents 3 different species of nematodes from various hosts, one of which is new to science and is named after Mr. Petre to whom I am most grateful

Antibodies were demonstrated in the sera of rabbits experimentally infected by mouth with the eggs of A. suum.

An alcoholic extract of freeze-dried ovaries, oviducts and uteri of adult female Ascaris worms was used as an antigen in the complement fixation test, and a polysaccharide fraction and a saline extract of whole worms were used as antigens in the conglutinating complement absorption test.

In all rabbits the pattern and nature of the antibody response was similar using the three different antigens. When the saline extract antigen was used in the C.C.A.T., antibodies were detected earlier, and titres were recorded higher, than when other systems were used. The degree of response was proportional to the size of the infective dose. Circulating antibody first appeared between the third and eighth days of infection. The highest concentration of serum antibody was reached between the eighth and twenty-first days, and in those animals which received large doses the maximum response occurred about the third week. By repeated twice-weekly infection antibody was demonstrated in the serum for 114 days.

The effect of irradiation on the survival, behaviour and immunogenicity of the infective (3rd stage) larvae of O. columbianum was studied. The findings reported are:

1. Irradiation with up to 160,000 r does not significantly alter the survival of the larvae when stored at 4°C and at room temperature (26–32°C) for a period of 42 days.

2. Irradiation at 15.000 r to 40,000 r results in progressively fewer adults developing but more nodules being formed in the intestinal wall. Irradiation at 80,000 r results in the larvae failing to develop and establish in the host.