An early rise in serum IgE levels was observed in five of seven patients with acute primary trichinosis. Parallel increases in the total IgG, IgM and IgA levels, as well as specific IgG and IgM antibody titres to Trichinella spiralis larval antigen, were detected in two. The elevated levels persisted long after the clinical recovery of the patients.

Infection with single miracidial doses of Schistosoma intercalatum from Cameroun in Bulinus forskalii and from Zaïre in B. globosus resulted in an equal number of male and female infections. The cercarial production of both sexes started at the same time. The male infected snails produced a greater number of cercariae, because of the longer duration of infection.

The recovery of schistosomes from infection with male and female cercariae was for S. intercalatum, Zaïre, 38·8 ± 10·6 and 18·7 ± 14·0 respectively.

For S. intercalatum from Cameroun, with single sex cercariae from two different populations of intermediate hosts from Zaïre and Cameroun were 38·3 ± 7·3 (♂); 20·3 ± 9·3 (♀) and 35·0 ± 8·7 (♂); 12·2 ± 4·5 (♀), respectively.

Five cestode, one monogenean, and two nematode species comprised the “normal” intestinal helminth fauna of Raja naevus in British waters. An additional two nematodes, a digenean, an acanthocephalan and a crustacean recorded are considered to be accidental infections. Geographical differences in the species composition and level of infection are noted and discussed. Short descriptions of the tetraphyllidean cestode Echeneibothrium sp. and the nematode Capillaria sp. are given, but the species, although probably both new, are left unnamed. The intensity of cestode infections show two patterns associated with host length and these are discussed in relation to variations in host diet. Speculations are made on the cestode life cycles. Only Echeneibothrium sp. numbers showed any significant variation associated with host sex.

Ethyl-6-ethoxybenzothiazole-2-carbamate (Sch 18099) was evaluated for efficacy against natural helminth infections in ponies, pigs, lambs and chickens.

Sixteen critical trials were conducted in ponies at dosages of 15 to 150 mg/kg. At 15 mg/kg, efficacy against adult and larval Oxyuris equi was 100% and 91% and against small strongyles it was 98%. Efficacy levels were >95% against Strongylus vulgaris and S. edentatus at the 20 mg/kg dosage. In two trials at 100 mg/kg efficacy against Parascaris equorum was 77%. No efficacy was observed against Gastrophilus spp. or Anoplocephala spp.

In swine single oral doses of 10 to 100 mg/kg were not effective. 500 ppm Sch 18099 in the diet for seven days resulted in 100% efficacy against Ascaris suum and Trichuris suis but had no effect on Strongyloides ransomi. Efficacy at 250 ppm against A. suum was 77%.

Efficacy at 200 mg/kg in lambs was >90% for Haemonchus contortus, Trichostrongylus axei, Marshallagia marshalli, Bunostomum trignocephalum, Oesophagostomum columbianum, Trichuris ovis, and Chabertia spp. Efficacy was <80% for Trichostrongylus vitrinus, Nematodirus filicollis, Ostertagia circumcinta and Cooperia curticei. Except for O. circumcinta and C. curticei, drug efficacy was reduced for these worms in lambs treated at 100 mg/kg.

Efficacies of 14˙3–89% against Ascaridia galli were obtained with dietary levels of 125–1000 ppm Sch 18099 fed for 7 days. Efficacy of 100% was recorded against Heterakis gallinarum at the 1000 ppm dietary drug level.

Two new species of the genus Oochoristica Lühe, 1898 from Australian dasyuried marsupials are described and their affinities discussed. The new species are O. antechini sp. nov. from Antechinus macdonnellensis and O. eremophlia sp. nov. from Antechinus rosamondae.

The species of the genera Longistrongylus, Kobusinema and Bigalkenema are redescribed. Kobusinema and Bigalkenema are considered synonyms of Longistrongylus and their species are transferred as new combinations. Bigalkenema neveulemairei (Gutteres, 1947) Jansen, 1958 and Longistrongylus muraschkinzevi (Shulz and Kadenatsii, 1950), Jansen, 1958 are considered species inquirendae. A key to the species of the genus Longistrongylus is given and their hosts and geographical localities are listed.

Schizorchis arfaai sp. n. is described from the wood-mouse in the Caspian area of Iran and its morphological characteristics compared with those of the five previously known species of Schizorchis Hansen, 1948.

Over 90% of Schistosoma haematobium and S. mansoni infections show a dominance of male worms in experimental animals. Male: female ratios as high as 5: 1 are common in S. haematobium (Ghana) infections and 1·5: 1 is a typical ratio in S. mansoni infections. The male parasite seems to be more successful than the female in reaching maturity. To test this theory experiments were set up to compare the infectivity of male and female cercariae.

Several methods are being applied for solubilizing adult Schistosoma mansoni antigens which may allow their immunochemical characterization and purification. Studies on antigens and immunoprecipitins in schistosome infections have been carried out with homogenized extracts of adult worms and/or larval forms of Schistosoma mansoni in saline (Biguet et al., 1962; Kagan and Norman, 1963; Silva and Ferri, 1965), or water (Kent, 1963). Kusel (1972) studied surface proteins in S. mansoni membrane, treating the worms with 0·5% saponin in 3% calcium chloride. Murrel et al. (1974) compared by immunodiffusion a crude culture antigen with extracts obtained by freeze-thawing of adult worms and by treatment in 3M KCl.

The influence of temperature and ultra-violet radiation on the degree of activity, survival and infectivity of schistosome miracidia is profound. Miracidia of Schistosoma mansoni and S. haematobium were affected equally. Only miracidia classified as “active” or “slow” were capable of penetration, a capacity they retained for about 17 hours at 19°C. Miracidia that were “lethargic” as a result of low temperature, old age or ultra-violet radiation lost their infective capacity. The conclusion, however, is that neither the temperatures encountered in the field nor the solar ultra-violet radiation penetrating turbid waters are likely to be harmful to miracidia and thus have no effect on the level of transmission.

The present investigation has shown that combined treatment with dexamethasone and prednisolone or with hydrocortisone and dexamethasone enhances the susceptibility of albino rats to Paragonimus miyazakii, presumably by suppressing the host’s immune responses. In the rats given these combined treatments, the size and egg production of worms were markedly increased. Use of dexamethasone or prednisolone alone had relatively little influence on the growth and maturity of P. miyazakii. In serological analysis and agar double diffusion, considerable differences were recognized between the gamma-globulin fractions and antigen-antibody systems (Precipitin bands) of the treated groups and the untreated group. The mechanism of action of these immunosuppressants in this system remains obscure.