Irradiated cercariae, irradiated schistosomula, or hcterologous infections were used to vaccinate sheep against Schistosoma mattheei infection. In the first experiment four doses of I04 S. mattheei cercariae irradiated at 6Kr were administered to sheep by percutaneous infection at 4 week intervals. This induced a 74% reduction in a challenge infection compared to control sheep while only 13% protection was achieved in a third group of sheep immunised with normal cercariae of the heterologous parasite S. mansoni. No significant differences were seen in histopathology of the liver of any of the sheep but the pathological changes were more severe in the large and small intestines of sheep vaccinated with the heterologous parasite. In the second experiment with irradiated cercariae only one or two immunising exposures were used. The degree of protection in the adult worm load (9–11%) was not significant and no significant differences were noticed in the pathology of the vaccinated and control animals. In the third experiment four doses of irradiated organisms were used to vaccinate five groups of sheep: 3Kr or 6Kr cercariae were administered by percutaneous infection; 6Kr skin-transformed scbistosomula were administered by intramuscular injection; the same 6Kr skin-transformed schistosomula were given by intravenous injection and 6Kr syringe transformed schistosomula were administered by intramuscular injection. The degree of protection (determined as the reduction in worm burden) achieved by these different procedures was respectively 72%, 61%, 77%, 56% and 78%. These results indicate the possibility of making a live vaccine against ovine schistosomiasis and show that effective immunisation is not dependent on the presence of a mature worm infection or on cercarial penetration of the skin by the immunising infection.

Immature and mature stages of the sheep amphistome Cotylophoron cotylophorum have been analysed histochemically for their lipids. Excretory ducts of the immature worms were the common sites for the accumulation of neutral lipids (triglycerides) and phospholipids which showed very sparse distribution at the corresponding sites in the adult. Phospholipids and lipoproteins observed in the tegument of the adult could not be seen in the immature form. Intestinal caecae of both forms showed the presence of diffused and granular lipids which were relatively less in the immature. The possible physiological significance of these differences in the lipid contents of the immature and mature forms has been discussed.

A modification of the Kato thick smear technique, the Bell filtration technique, and a digestion method were investigated to determine the relative merits of each for the detection of schistosome eggs in human faecal samples. The modified Kato technique was the method of choice because it was sensitive, simple to perform, and suitable for field use. The Bell filtration technique was equally sensitive in detecting light infections, but was more tedious and more complicated to perform than the thick smear technique.

The effects of levamisole on adults, third stage infective larvae, and microfilariae of Brugia pahangi were studied in in vitro culture and in vivo against developing stages in the vector mosquito and in infected cats. In vitro the drug was effective only at dose levels much higher than can be tolerated by mammals. It was active against the developmental stages of the worm in the vector Aedes aegypti.

The drug was strongly microfilaricidal in cats but less effective against adult worms.

In the paper “Acuariid, capillariid and hymenolcpidid parasites of the dasyurid marsupial Antechimis stuartii Macleay, 1841, from southeastern Australia” by I. Beveridge and I. K. Barker, which appeared in part no. 4 (December) of volume 49, 1975, the descriptions of spiruroid larvae and of Capillaria rickardi sp.n. on page 223 should have appeared before that of Hymenolepis aklei sp.n. on page 220.

Echinobothrium harfordi sp. nov. from the spiral intestine of Raja naevus in British waters is described and illustrated. The species most closely resembles E. affine as both possess two groups of eleven large apical hooks, but can be distinguished by fewer peduncle spines and by characteristics of the eggs. The intensity of infection in individual hosts was generally low, and although the incidence of infection was high in rays less than 35 cm in length, this fell towards zero in larger rays. The ccstode showed a marked affinity for the first two tiers of the spiral intestine.

This study shows that some cercariae of S. haematobium and S. mansoni die during penetration of mouse or hamster skin.

Approximately 30–38% of cercariae of both species die in mouse skin and 14–16% die in hamster skin. The greater number of cercariae which die in the skin of mice seems to account for the higher yield of adult worms recovered in hamsters. Adult worm recoveries from animals infected with S. haematobium were, however, only about half the worm recoveries from hosts infected with S. mansoni.

Bulinus (Physopsts) africanus antigens were shown to be associated with the cercarial glycocalyx of Schistosoma haematobium using immunofluorescence and the Cercarienhüllen Reaktion. It is proposed that this snail antigen may sensitise the definitive host and that resistance to further invasion by cercariae could be induced in this manner.

Three cows were treated with different levels of compound “E” which is known to have strong filaricidal activity. In all three animals the number of microfilariae of Onchocerca gutturosa declined after treatment. At autopsy most of the adult worms found were dead and in those still living embryogenesis appeared to have ceased.

It is concluded that, despite the disadvantages, this system represents a possible way of assessing onchocercicidal activity before undertaking human trials.

Counterimmunoelectrophoresis revealed the presence of precipitin antibody in all of 6 dogs and the 1 cat infected with Dirofilaria immitis and in the serum of 17 of 24 individuals living in a setting of hyperendemic subperiodic bancroftian filariasis. Antigens used in the test were prepared from microfilariae and adult male D. immitis. Some humans and animals had antibodies to both antigens while others had antibodies against microfilariae or adult worms only. The presence of soluble circulating antigen was detected in the sera of two dogs with high microfilaraemias.