An approach to the identification of parasite proteins which are immunogenic in natural infections is described, using the infection with the larval stage of Echinococcus multilocularis as a parasite model. Metacestode proteins were separated by SDS-polyacrylamide gel electrophoresis, and transferred electrophoretically to nitrocellulose sheets (Western blotting). Subsequently, immune recognition of the proteins was performed with various host sera and antigen-antibody complexes were detected enzymatically. Using homologous antisera, different patterns of immunogenic bands were revealed by sera of different host species. Cross-reactions with sera from individuals infected with unrelated helminths were analysed. Four proteins of E. multilocularis which failed to show any cross-reaction were identified.

Groups of five 3-kg Kenyan monkeys, Cercopithecus aethiops, were exposed individually to 150,600 or 1500 Schistosoma mansoni cercariae per monkey. Three monkeys died soon after the infections became patent and the survivors were autopsied 4 months after exposure. Mortality and most haematological, parasitological and pathological sequelae of infection were dose-related, but not the white cell response or changes in the levels of serum proteins or fibrinogen. No gross liver fibrosis was seen. Comparison of this study with earlier ones on related cercopithecine monkeys suggests that the vervet closely resembles the baboon in its response to S. mansoni infections. Difficulties in managing and maintaining vervets can be overcome by using colonybred or properly adapted feral animals. Thus, the vervet provides a cheaper, more readily available primate model for experimental S. mansoni studies. A prolonged infection, sufficiently heavy to permit reliable parasitological monitoring without undue mortality, should be provided by 150 S. mansoni cercariae per kg body-weight, using the Kenyan strains of vervet and parasite.

Specimens Hepatojarakus malayae Yeh, 1955 and H. bandicoti Sood & Parshad, 1973 arc illustrated and their measurements tabulated. H. bandicoti is considered a synonym of H. malayae.

Indirect fluorescent antibody techniques and incubation of sectioned and ligatured larvae have been used to locate the source of azocoll-positivc secretions within the oesophagcal glands of third-stage Anisakis simplex larvae. The “excretory” system, previously suggested as a source of invasive enzymes, docs not seem to be involved. The proteolytic enzyme has trypsin-like properties and evidence is presented for its continuous synthesis during in vitro storage.

During a survey in 1980–81, 125 of 478 (26·2%) camels in Saudi Arabia were found infected with onchoccrciasis. The prevalence rates in local and imported camels were 93/272 (34·2%) and 32/206 (15·5%), respectively. The disease was characterized by hard nodules in the connective tissue around the nuchal ligaments and in the subcutis. The nodules consisted of cavities containing live, degenerate or dead Onchocercafasciata, inflammatory cells, fibrosis and calcification. The microfilariac were concentrated in the skin over the head and neck regions and often caused mild non-suppurativc dermatitis.

The intestinal morphology or rats given one, 10 or 100 cysticercoids of Hymenolepis diminuta was examined by scanning electron microscopy. The presence of this tapeworm causes extensive villous atrophy and fusion. The most extreme changes in mucosal architecture were observed adjacent to the mature proglottides of the worm and in these areas the villi were reduced either to flattened plate-like structures or to low irregularly shaped undulations. The presence of one large H. diminuta resulted in more severe pathological damage than caused by several smaller worms. Colonization of the upper region of the ileum by long filamentous bacteria was also observed in rats infected with H. diminuta.

The efficiency of a new anticestode compound, 3,5-dibromo-2'-chloro-4'-isothiocyanato salicylanilide (GUPTA et al. 1980) for mass eradication of hymenolepiasis from rat colonies was assessed in a pilot study. The drug was administered with milk or food. For effective eradication, depending on the size of animals, single or multiple doses of 100 to 500 mg of the drug'kg body-weight, mixed in milk, or 50mg/kg in feed were necessary. Better results were obtained when the compound was given in feed as it ensured effective consumption irrespective of the seasonal variations. The efficacy of the compound was also assessed on cysticcrcoids in intermediate hosts (Tribalium confusum) by feeding them on flour medicated at 5%, l% and 0.1% levels. None of the concentrations killed the larvae or arrested their development.

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entering the value of s/X in a chi-square table.

A detailed study of the surface topography of the echinostomes Echinostoma revolution and Isthmiophora melis has been carried out using SEM. The tegument of the body surface has a cobblestone-like appearance with interspersed pits. The presence of possible secretory granules is noted. Observations of the anterior end reveal that the collar spines are retractable. An unusual structure is described from the ventral gap of the spiny collar of E. revolutum. The origins of this structure and the possible functions of the spiny collar are discussed. The shape and distribution of body spines is described. Differences in cirrus morphology for the two species are described. The taxonomic position of, I. melis and the significance of cirrus morphology as a useful taxonomic character are discussed. Four types of presumed sensory or secretory structures occur—ciliated, domed, button and bilobed papillae. Their distribution is described and possible functions discussed.

The effects of insulin on worm (Hymenolepls diminuta) migration was studied. Insulin injection (20 U/kg, s.c.) significantly increased gastric acid output but did not affect the serotonin content of blood, intestinal lumen or worms. The drug produced, dose-dcpcndcntly, postcriad migration of the worms in rats without pylorusligation but ligation of the pylorus prevented this migration. It is concluded that the hypcrsccrction of gastric acid induced by insulin is responsible for the postcriad migration of H. diminuta in rats.

Mierofilariae of Litomosoides carinii and Dipetalonema viteae absorbed about ten times as much diethylcarbamazine (DEC) as did their adults, but bound much less. The higher uptake of DEC by the microfilariae might be related to the fact that DEC is microfilariae Binding of DEC: with the parasites supports the view that the microfilarcidal action begins with the fixation of the drug to the microfilariae.

The use of an indirect immunofluorescence technique demonstrated that serum from reindeer, Rangifer tarandus tarandus, infected with Elaphostrongylus rangiferi (Nematoda, Metastrongyloidea) contained antibodies directed against antigen(s) on the cuticle of the parasites first-stage larvae (LI). Output of LI from the male reindeer was low in the period June to August, but increased to a higher level during the rutting season (September to October). The titre of specific antibody showed an inverse pattern. In the female reindeer, larval output remained high throughout the sampling period from January to July. During this period antibody titre was low. A relationship between stress (rutting season or calving period), immunity and larval output is suggested.

The multiplicity of soluble esterases in Raillietina tetragona, R. echinobothrida and R. cesticillus was studied by use of slab polyacrylamide gel electrophoresis. Five fractions of esterase activity were observed in R. tetragona, seven in R. echinobothrida and three in R. cesticillus. The various fractions of esterase activity of closely related species of Raillietina showed differential behaviour towards various chemicals. Based on the inhibitory effect of inhibitors p-CMB, EDTA, malathion, silver nitrate and eserine sulphate, the various esterases have been classified into arylesterase, carboxylesterase, acetylesterase and cholinesterase.

The response of the free-living stages of Nippostrongylus brasiliensis, Nematospiroides dubius, Haemonchus contortus, Trichostrongylus colubriformis and Ostertagia ostertagi to a wide variety of antiparasitic agents in vitro was investigated.

All the major broad spectrum veterinary anthelmintics showed good activity against each of these worms with EC30 values varying from about 00002mg/1 for certain benzimidazoles and ivermectin to about 6–5 mg/1 for febantel. Of 22 known narrow spectrum anthelmintics useful only against H. contortus and/or helminths other than trichostrongyles, only 10% showed good activity at concentrations equal to or less than 100mg/1. Further, only one of 15 antiprotozoal agents showed good activity in these tests at the 100mg/1 level.

Third-stage larvae of Trichostrongylus tenuis, the caccal threadworm of red grouse, show strong positive phototactic behaviour which is reinforced by negative geotactic behaviour. The surfaces of various grouse food plants were examined and those of young Calluna vulgaris (common heather) were suitable for ncmatodc migration. Transmission is probably achieved by third-stage larvae of 71 tenuis migrating up young heather plants, rather than by direct ingestion with grit from the ground.

Histological examination of the small intestine of mice infected with Heligmosomoides polygyrus indicates that the final site of the larvae is in the circular muscle layer of the muscularis externa of the anterior small intestine. The larvae become embedded in the muscle between the first and third days after infection and are subsequently sequestered by a localized leucocytic response. There is no evidence of a true cyst. Histological evidence suggests that the larvae actively feed on the tissues of the host during their development.