Double counterimmunoelectrophoresis, with a novel well format, was used as a sensitive technique for the rapid detection of circulating antigen and antibody in mice infected with Trichinella spiralis. In a primary infection, soluble antigen was initially detected in day 13, followed by a second wave on day 41. Circulating antibody was first apparent on day 34, increasing in intensity and number of precipitation bands until day 102. The first peak of circulating antigen is indicative of non-complexed antigen released from the developing larvae in striated muscle cells, whereas the presence of antigen late in infection is indicative of electrophoresislabile immune complexes. On reinfection (day 35 of primary) circulating antigen was present which could be attributed to products of resident primary infection muscle larvae.

Although the normal intermediate hosts of Hymenolepis microstoma are insects, oncospheres invade the intestinal tissue of the definitive hosts, mice, within 30 min after oral egg inoculation.

A series of monoclonal antibodies was prepared against tegumental and internal antigens of Fasciola hepatica by immunizing mice with whole adult-fluke homogenates prior to harvesting the splenic lymphocytes for fusion. Preliminary screening by the Indirect Fluorescent Antibody technique indicated the occurrence of discrete groups of monoclonals differing from one another in tissue-specificity but within which IFA labelling patterns were fairly consistent. Representative hybridomas for 5 of these groups were stabilized and used to produce ascites fluid in mice. By application of an immunogold labelling technique it was possible to map the distribution of antigens for which each monoclonal antibody had affinity throughout the tissues of 4-week and 12-week flukes. Several monoclonals specifically labelled antigenic determinants on the important tegumental antigen T1. However the distribution of gold colloid labelling suggested that epitopes other than that normally exposed to the infected host were recognized; and several monoclonals specifically attached to T1 antigen in the tegument of juvenile worms only. The glycocalyx of the gut and excretory system of flukes shared T1 antigenicity with the tegument. Monoclonal antibodies were produced against an internal immunogen associated with ribosomes and heterochromatin in active protein-producing cells, and against interstitial material of adult flukes. Monoclonals against antigens in parenchymal cell cytoplasm and in mature vitelline cells were recognized but the corresponding hybridomas were not stabilized.

There is a winter dormancy in the hatchability of some species of Heterodera. The dormancy varies in degrees with eelworm species, being slight in the case of beet eelworm and more pronounced in the case of potato-root eelworm and some other species. It is not wholly dependent on immediate environmental conditions but possibly is induced by previous conditions. The dormancy can be shortened by storing infested soil at certain temperatures, but the cessation of dormancy in spring is not necessarily associated with rise in soil temperature.

A single female specimen of Dirofilaria subgenus Nochtiella was recovered from a painless firm lump above the right eyebrow in the frontalis muscle of a European who had recently visited Nigeria.

The effects of high fat diets (HFDs) on the host–parasite relationship of Echinostoma caproni in ICR mice were studied. Two HFDs were used, one consisting of a customized high fat diet (CHFD) with 45% lipid in the form of cottonseed oil, and the second consisting of an egg yolk diet (EYD) from domestic hens' eggs, with 31% lipid. Controls for both diets consisted of mice fed a standard laboratory diet with 5% lipid. Mice were each fed 25 cysts of E. caproni by stomach tube and necropsied 2, 3 and 4 weeks postinfection (PI). The weight of mice on the CHFD declined significantly compared to mice on the control diet, but there was no significant decline in weight of mice fed EYD compared to the controls. Worm recoveries from mice on both HFDs were significantly less than those from control hosts. There was a significant decline in worm dry weight, body area and uterine egg counts in worms on HFD compared to those on the control diet. Worms from hosts on HFD were located more anteriad in the gut than those recovered from mice on the control diet.

Sera from 36 slaughtered camels with proven hydatid disease, from 46 camels found to be free of hydatidosis at post-mortem meat inspection, and from 26 animals with confirmed caprine heartwater, bovine trypanosomiasis and cysticercosis were examined. The indirect haemagglutination was found to be the most sensitive but least specific of the three tests. Ouchterlony's double diffusion (DD) test was specific and fairly sensitive. Although the countercurrent immunoelectrophoresis was as specific as DD, it was the least sensitive of the three serological tests.

All three serological tests were always positive in camels with hydatid cyst infection affecting both the liver and the lung. A combination of indirect haemagglutination and Ouchterlony's double diffusion tests could be useful for diagnosing hydatidosis in camels and probably other animals.

Philometra kobuleji (Nematoda: Philometridae) is described as a new species from the abdominal cavity of a North American freshwater fish, Catostomits commersoni.

During a parasitological survey on stream fishes of Southern Ontario, males and females of a Philometra species were collected from white suckers, Catostomus commersoni (Laédpéde). This parasite differs from all known Philometra species recorded by Hoffman (1967) in North America.

The early accounts of the morphology and life-cycle of Heterodera schachtii, were, like much of the subsequent work on this subject, the result of observations carried out on the strain of H. schachtii parasitic on sugar-beet in Germany.

Three sheep were vaccinated with two doses of 3 Krad-irradiated cryopreserved Schistosoma bovis schistosomula containing 20,000 and 17,000 organisms respectively, injected intramusculary 23 days apart after storage in liquid nitrogen for between 9 and 46 days. A challenge of 5360 S. bovis cercariae was administered percutaneously approximately four weeks after the last vaccine dose to these animals and to three controls. Post-challenge the vaccinated animals gained significantly more weight (27%v.9%), produceed fewer eggs in their facces, showed a smaller reduction in PCV values (–18%v, –27%) and were over-all in better condition than control animals . At perfusion 49·1% fewer adult worms were found in the vaccinated sheep than in controls. The tissue egg burdens were similar in both groups. Histopathologically both groups were similar except that fewer and smaller egg lesions were observed in the livers of vaccinated animals.

Attempts were made to manipulate specific responses of baboons to protect them from infection with Schistosoma mansoni. In Experiment 1, cosinophilia was induced in naive baboons with Trichinella spiralis larvae given intravenously before intraperitoneal injection of globulin fractions from S. mansoni-infected baboon sera and subsequent percutancous exposure to S. mansoni cercariac. In Experiment 2, baboons with 8- or 32-week-old primary S. mansoni infections received T spiralis i.v. before an S. mansoni challenge. In experiments 3 to 5 respectively, naive baboons received intramuscularly before challenge: formalin-fixed S. mansoni schistosomula, with Bordetella pertussis as an adjuvant; a preparation of S. mansoni adult worm teguments; and a preparation of NE-immune complexes obtained from S. mansoni-infected rat sera, with Freunds Complete Adjuvant. Minor, but statistically insignificant, protection was obtained in Experiments 2 (32-week infections) and 3, but was far less than that given by intact, irradiated living vaccines. There are signs on the horizon of non-living vaccines protecting rodents against S. mansoni infection and it would be prudent, as with drugs, to test these in primates before proceeding to man. The results of our experiments, though essentially negative, should help the design of any future vaccine trials in primates.

In a collection of nematodes received from the Institute of Plant Diseases, Buitenzorg, Java, there were three tubes containing eelworms from pepper gardens on the island of Bangka, Dutch East Indies, where disease of black pepper (Piper nigrum L.) caused by the “burrowing” nematode, Anguillulina similis, is particularly severe. In one of these tubes were worms which had been collected by Dr. J. van der Vecht from diseased pepper roots grown in a garden at Mabat Oerit, Bangka. Among these were large numbers of Anguillulina similis, many Cephalobus striatus, one Aphelenchus avenae, a few Dorylaimus sp. and 30 representatives of the worm which forms the subject of this note. On being cleared and mounted in glycerine it was seen that the buccal spear in all cases was extraordinarily long and closely resembled that figured by Cobb (1913) in Xiphinema americanum from which it was concluded that the worms might possibly belong to the genus Xiphinema. A question which exercised the writer for some time was whether, following Micoletzky (1921), the genus Xiphinema Cobb, 1913 should be considered as synonymous with Tylencholaimus de Man, 1876.

The general outlines of the life history of Taenia pisiformis (Bloch 1780) in the dog and the rabbit have long been well known. The following reinvestigation of the early stages of the development of Cysticercus pisiformis in experimental rabbits was undertaken with the primary objective of checking or refuting the “division” of the Cysticercus described by Moniez in his classical monograph on the Cysticerci, published in 1880.

Fasciolosis is a zoonotic parasitic disease that seriously endangers the development of animal husbandry and human health. In order to develop a rapid serological diagnostic method for fasciolosis in ruminants, the CatL1D and CatB4 genes of Fasciola hepatica were amplified by reverse transcription polymerase chain reaction (PCR) and cloned, respectively, and then the CatL-B fusion gene (MeCatL-B) was constructed by gene splicing by overlap extension PCR technique. The recombinant rCatL1D, rCatB4 and rMeCatL-B proteins were then prepared by prokaryotic expression, respectively, and the recombinant protein with high specificity and sensitivity was screened via indirect enzyme-linked immunosorbent assay. Using the selected recombinant protein rCatL1D as a diagnostic antigen, we developed a colloidal gold immunochromatographic assay (CGIA) for detecting F. hepatica-specific antibodies, and 426 serum samples of slaughtered sheep were used to evaluate the sensitivity and specificity of F. hepatica CGIA assay. The results showed that the sensitivity and specificity of rCatL1D protein (100%, 96.67%) were higher than those of rCatB4 (94.29%, 80%) and rMeCatL-B (91.43%, 90%). Compared with the gold standard post-mortem inspection, the specificity and sensitivity of the CGIA method was 100% and 97%, respectively, and the consistency rate between these two methods was 99.3%. These results confirmed that the CGIA method based on rCatL1D protein could be a promising approach for rapid diagnosis of sheep fasciolosis because of its high sensitivity and specificity.

The sensitivity and specificity of double immunodiffusion (DID), indirect haemagglutination test (IHA), immunoelectrophoresis (IEP), counterimmunoelectrophoresis (CIEP) and enzyme-linked immunosorbent assay (ELISA) were evaluated and compared using saline extracted of Taenia solium larval scolex and its Sephadex G-200 fractionated 1st and 2nd peak as antigens. Various immunodiagnostic tests gave different results with different antigens. Highest sensitivity (92·5%) was obtained with ELISA using 1st peak antigen and lowest sensitivity was obtained with DID. However, 88·4% and 84·6% sensitivity was obtained with IHA and CIEP respectively using scolex antigen. CIEP gave better results as compared to IEP. Crude antigen gave high sensitivity but less specificity. It was concluded that CIEP can be used as a field test for the anti-mortem diagnosis and ELISA can be employed for laboratory confirmation of T. solium cysticercosis in pigs using frationated 1st peak antigen.

No significant difference in cercarial production was noted when Biomphalaria glabrata from Brazil were exposed to one or several miracidia of Schistosoma rodhaini from Burundi, even though the dynamics seemed different. The minor differences can be explained by the intramolluscal larval development of this parasite characterized by the production of a high number of daughter sporocysts over a long period.

The importance of larval viability in relation to the success of recovery techniques and to the interpretation of histological and migration studies was tested using mice infected with Toxocara pteropodis, T. canis and T. cati. Little difference was found in total numbers of viable larvae recovered from tissues incubated for 18 hours in 0·85% saline, 2% trypsin or 1% pepsin, but the rates of larval egress did vary. The recovery of dead larvae by digestion techniques was much lower. Larvae migrated in tissues undergoing fixation, which influenced histological findings. Larvae of T. canis did not undergo significant peritoneal migration in acutely-infected mice, but did penetrate their intestinal walls in large numbers within 4 hours of death. The implications of these findings in experimental studies are discussed.

Heterophyes heterophyes is reported for the first time from the snail host Pirenella conica in Greece. H. aequalis and H. dispar are reported for the first time from Greece and from Europe. The results presented, together with the available data on necropsies of dogs and cats, human infections and the biotope preference of the snail, suggest that Greece is an important focus of infection in Europe.

A modified form of the Seinhorst “Mistifie.” is described which allows the quantitative recovery of nematodes from infested material. Experimental results are given showing the high rate of recovery in a short time, the recovery from a known number of nematodes and a not excessive degree of variation between recoveries from a replicated series of mistifier units. These results are discussed and the value of the technique for replicated quantitative work is stressed.

1. In differentiating between species of snails various ratios of shell dimensions are frequently used as biological constants descriptive of the species. Some of the ratios commonly used are: length to breadth (L/B), length to length of body-whorl (L/W), length to length of shell aperture (L/l), and length of shell aperture to its breadth (1/b). Mean and extreme values of these ratios are given for small samples of five species of Limnaea.

2. In L. palustris the least variable of these simple ratios is L/W and the next best is L/l. Statistics are given for the distributions of these two ratios.

3. Data collected by Mozley are used to show that in L. palustris the ratio L/l (at least) is subject to considerable local variation, a fact which detracts from its value as a species constant.