In a range of trematode species, specific members of the parthenitae colony infecting the molluscan first intermediate host appear specialized for defence against co-infecting species. The evolution of such division of labour requires that co-infection entails fitness costs. Yet, this premise has very rarely been tested in species showing division of labour. Using Himasthla elongata (Himasthlidae) and Renicola roscovita (Renicolidae) infecting periwinkles Littorina littorea as study system, we show that the size of emerged cercariae is markedly reduced in both parasite species when competing over host resources. Cercarial longevity, on the other hand, is negatively influenced by competition only in R. roscovita. Season, which may impact the nutritional state of the host, also affects cercarial size, but only in H. elongata. Hence, our study underlines that cercarial quality is, indeed, compromised by competition, not only in the inferior R. roscovita (no division of labour) but also in the competitively superior H. elongata (division of labour).

The black rat Rattus rattus and the house mouse Mus musculus are two commensal rodent species that harbour and shed zoonotic pathogens, including helminths. The aim of this survey was to study the helminth community and the patterns of infections in R. rattus and M. musculus from two Mayan communities in Mexico. Gastrointestinal helminths were isolated from 322 M. musculus and 124 R. rattus, including Gongylonema neoplasticum, Hassalstrongylus aduncus, Hassalstrongylus musculi, Hydatigera taeniaeformis metacestode, Hymenolepis diminuta, Nippostrongylus brasiliensis, Oligacanthorhynchidae gen. sp., Syphacia muris, Syphacia obvelata, Rodentolepis microstoma and Trichuris muris. The overall richness of helminths was seven in R. rattus and six in M. musculus. The results of generalized linear models showed that juvenile rodents had lower probabilities of being infected with G. neoplasticum, H. taeniaeformis and H. musculi than adult rodents. A positive association between the prevalence of S. muris and rat abundance was found. The intensity of infection with S. muris was higher in the rainy season than in the dry season; the opposite result was found for H. musculi infection. Male R. rattus harboured more S. muris specimens. The intensity of infection with T. muris was inversely associated with mouse abundance. The presence of the zoonotic H. diminuta, as well as H. taeniaeformis and R. microstoma in rodent populations indicates that there is risk of transmission, and that their entire life cycle occurs in the study area.

The inhibition of acetylcholinesterase secretion by male and female Heligmosomoides polygyrus was tested on worms taken from experimentally infected mice and maintained for 3 days in vitro in levamisole. The dose inhibiting 50% of enzyme secretion (ID 50) of male worms was twice the ID 50 for female worms. A similar difference was observed in vivo between the dose of levamisole removing 50% (LD 50) of male and female worms from the mouse. Acetylcholinesterase secretion by worms and ID 50 were tested in vitro at 3-weekly intervals from 3 to 21 weeks post infection (WPI). Acetylcholinesterase secretion was always significantly higher for male than for female worms. A decrease of ID 50, correlated with the age of the worms was observed: from 1·5 to 0·5 μg/ml for males and from 0·7 to 0·1 μg/ml for females. These results were confirmed in vivo by a higher efficacy of the anthelminthic at 21 than at 4 WPI.

En 1927 Journal of Helminthology a publié une note de Goodey sur Cylindrogaster coprophaga gen. et sp. nov., provenant d'une culture des excréments de rat (Rattus norvegicus). La note donne une description détaillée de la nouvelle espèce, accompagnée d'excéllentes figures.

Four groups of 8 rabbits were infected with a range of doses of N. bath's larvae. The percentage recoveries of worms from groups receiving 100 and 1000 larvae were significantly greater than those from groups receiving 10000 and 50000 larvae. It is suggested that the worm population density is dependent on the degree of host response stimulated by the initial larval dose.

Experience of a chemically abbreviated patent infection of N. batlus gave significant protection to a group of 8 rabbits against establishment of worms from subsequent challenge compared with inexperienced controls.

Rabbits aged 5 months and 11 weeks were as susceptible to the establishment of worms as rabbits aged 7½ weeks; but age resistance vas manifested by the greater proportion of worms which developed to the fifth stage in the worm populations of the youngest group than in the other 2 groups.

Cirkennedya porlockensis gen. et sp. nov. is described from the intestine of Mola mola off Porlock, Somerset, England. The Systematic position of this new genus is discussed. It appears to be the first example of the family Macroderoididae to be reported from a marine teleost host. The status of this family in relation to the Plagiorchiidae is briefly commented upon.

A study was made on the host-finding capacity of Fasciola hepatica miracidia in relation to time, number of miracidia per snail, and several physico-chemical environmental factors. Specimens of Lymnaea truncatula were exposed to radiolabelled miracidia and the subsequent snail-bound radioactivity was used to measure the host-finding capacity of the larvae.

Maximum snail-bound radioactivity was achieved after 45–60 minutes exposure to miracidia in a volume of 80 ml water. The efficiency of the snail-location was unaltered up to a volume of 4.5 liters. A linear proportionality was demonstrated between the number of miracidia and the amount of radioactivity obtained in exposed snails. After 4 hours exposure snails placed in darkness took up the same amount of radioactivity as snails placed in bright illumination. Additional experiments showed that miracidia preferentially scan the lighted zone of a given environment, but if no snails are available in this zone, snails in shade are also effectively located.

The host-finding capacity was unaltered up to a salinity level of 3.79%. At 4.74% and 5.68% the snail-location proceeded at a slower rate, but the final levels reached after 3 hours were comparable to that obtained at low salinity. The over-all host-finding capacity was reduced at a salinity level of 7.58% and at 9.47% the capacity had ceased. The host-finding capacity was unaltered in the pH range 5.4 to 8.4, but it was reduced at pH 8.9. Further studies showed that the host-finding capacity was clearly inhibited in water with a high turbidity level.

The distribution of Ancylostoma caninum larvae in the various regions of the central nervous system of mice of previously uninfected or reinfected groups was studied. Although a dose of 4000 larvae was lethal, the distribution of larvae was not appreciable in the CNS. Many larvae were recovered from the cerebral hemispheres and cerebellum of infected mice whereas no incidence of eye involvement was observed in any mouse. In the reinfected mice groups there was a much lower recovery than in the previously uninfected groups in the latent period of study.

Study of a series of lower vertebrates and 2 primates infected with Schistosoma haematobium has revealed their egg producing or egg passing potentials. Viable eggs were not passed by albino or wild rats (R. rattus), or by hedgehogs (Hemiechinus). In hosts passing eggs the counts were not great but data do suggest host-parasite relationships which permit continuance of the parasite cycle. Egg passage was erratic and tended to follow a normal curve, i.e., few eggs at first, building up to a peak period after which the counts usually diminished. There was no close correlation between the sites of egg deposition along the intestinal tract and the numbers of egg produced. The peak of egg production was irregular in time after first egg detection as well as in duration. There was wide range in the percentages of viable eggs passed by different hosts and by individuals of the same species. Data reveal the possibility of lower vertebrates serving as reservoirs should satisfactory circumstances allow.

Twenty European domestic cats were each infected with 15,000 protoscoleces of Echinococcus multilocularis extracted from metacestodes grown in experimentally infected common voles (Microtus arvalis). Sixteen days after infection, ten cats were treated with a broad-spectrum anthelmintic and acaricide comprising praziquantel and milbemycin oxime. Five days later treated and untreated cats were euthanized and the intestine examined for E. multilocularis. Five of ten untreated cats were infected with E. multilocularis with worm burdens ranging from 235 to 1920 worms per cat. No E. multilocularis were recovered from any of the treated cats. This study has demonstrated that this new combination broad spectrum anthelmintic and acaricide for cats is highly efficacious against E. multilocularis and the relevance of this is discussed.

The effects of interferon (IFN) γ on the course of infection with Strongyloides papillosus in calves were investigated. Calves (N=7 each) were inoculated with recombinant bovine IFNγ or control solution daily from day 0 to day 15 following S. papillosus infection. Treatment with IFNγ induced an increase in faecal egg output in the peak stage of infection. The IFNγ-treated animals harboured more worms, especially more immature worms, in the small intestine than control animals at necropsy on day 17, with no decreases in intestinal mucosal mast cells. Both animal groups had similar small numbers of intestinal worms at necropsy on day 26. All control animals developed peripheral blood eosinophilia on day 7, while five of seven IFNγ-treated animals did not. Serum α1-acid glycoprotein concentrations increased on day 7 in both animal groups, with higher values in control animals than in IFNγ-treated animals. Control animals mounted a predominant IgG1 response to S. papillosus from day 10, while IFNγ-treated animals did from day 22. These data suggested that IFNγ inhibited some host protective responses to S. papillosus migrating larvae, resulting in an improvement of worm survival after a period when protective responses should be activated during the early stage of infection. The effects of IFNγ on intestinal worm expulsion should be confirmed by further experiments.

Serpentirhabdias mussuranae n. sp. is described from the lungs of the mussurana, Clelia clelia (Daudin, 1803), from vicinities of Lábrea, Amazonas State, Brazil. The species is characterized by the triangular oral opening, the presence of teeth (onchia) in the oesophastome, the excretory glands longer than the oesophagus and the tail abruptly narrowing in its anterior half and gradually tapering in posterior half. Among the Neotropical representatives of the genus, three species are known to possess the onchia in the oesophastome: S. atroxi, S. moi and S. viperidicus. Serpentirhabdias mussuranae n. sp. differs from S. atroxi and S. viperidicus by its triangular shape of the oral opening and the oesophastome in apical view, vs. round in the latter two congeners. Additionally, S. viperidicus has a larger oesophastome, 13–22 micrometers wide and 13–23 micrometers deep. The new species has relatively longer excretory glands than S. moi. The new species is morphologically and genetically close to S. atroxi, S. moi and S. viperidicus, all parasitic in Brazilian snakes, based on the presence of onchia and the comparison of nucleotide sequences of nuclear ribosomal DNA and mitochondrial cox1 gene (differences varied between 3.8% and 7.1%). Data on the life cycle of S. mussuranae n. sp. is provided, and the life cycle is typical of the genus Serpentirhabdias, with the combination of direct development and heterogony. Free-living larval stages and the adults of amphimictic free-living generation are described. The results of molecular phylogenetic analysis based on nuclear ribosomal internal transcribed spacer (ITS) + partial 28S region and partial mitochondrial cox1 gene are provided.

The helminth fauna of the wood mouse, Apodemus sylvaticus, in the Erro River valley (Navarre, Spain) was investigated from a total of 150 mice between February 2001 and July 2002. An overall prevalence of 90.7% was recorded and up to 14 helminth species identified. The most prevalent species was the nematode Heligmosomoidespolygyrus (78.0%), whereas Syphacia stroma was the species with the highest median abundance (19.8). The detection of Calodium hepaticum, Rodentolepis straminea and the larvae of Hydatigera taeniaeformis are significant, since these helminth species could be considered potential human parasites. The helminth infracommunity comprised no more than five species. A significant predominance of monoxenous species was detected. Statistically significant differences were also found between prevalences, helminth abundance, species richness and helminth diversity of sub-populations of the wood mouse determined by host age and season of capture, which agree with most of the studies carried out on this host. This study will shed light on the helminth community of the wood mouse from a region of Spain which has not previously been documented.

Gastrothylax crumenifer haemoglobin was isolated, purified, chromatographed, and its molecular weight determined on a calibrated Sephadex G–100 column as well as by sodium dodecyl sulphate by the former and 16 500 by the latter method. The oxygen affinity of the pigment (P50O2) was found to be 6·1 mm Hg at pH 7·4.

This new species is described from material consisting of four males and six females said to have been recovered from the intestine of Rhinoceros bicornis in Kenya and sent to the writer through the courtesy of Mr. M. C. Round, B.Sc, of Veterinary Research Laboratory, Department of Veterinary Services, Kabete, Kenya.

The immunological responses in hamsters during treatment with mebendazole against Ancylostoma ceylanicum are studied. Indirect haemagglutination (IHA) counterimmunoelectrophoresis (CIEP), passive cutaneous anaphylaxis (PCA), foot pad swelling for immediate (ITH) and delayed (DTH) types of hypersensitivities were employed for measuring the responses. Serum antibody which was 1:32 before treatment increased to the maximim of 1:512 (control 1:128) on the 10th day and it declined subsequently. The CIEP test was positive for 10 days and then became negative. The PCA test was positive throughout the observation period both in the treated and untreated groups. Foot pad swelling for ITH and DTH responses were comparatively more prominent than in the untreated control up to the 20th day and then both decreased simultaneously. The immunological responses remained prominent for a longer period and decreased more slowly in the untreated control group.

Haematuria and proteinuria as detected by chemical reagent strips correlated moderately (r=0·7) with prevalence and intensity of infection with Schistosoma haematobium in an area of Anambra State, Nigeria. Differences attributable to age and sex were also reflected in a similar pattern, all peaks occurring in the 5–14 year age group. The differences observed with varying levels of intensity and haematuria at both 10 and 50 erythrocytes/μl (p<0·001) and proteinuria at 0·3 g/dl (p<0·01) were statistically significant. At a proteinuria level of 1 g/dl, the observed differences were however not statistically significant (p>0·5). The percentage of specimens from children (1–14 years) positive for S. haematobium eggs and with at least traces of haematuria and proteinuria (63·4% and 95%, respectively) was higher than in adults (33·3% and 80·2%, respectively). All individuals with more than 50 eggs/10 ml of urine were correctly identified using both indices either separately or in combination. For egg counts of less than 50 egg/10 ml of urine, false diagnosis occurred in only 5% of all specimens examined. The sensitivity and specificity of haematuria and proteinuria at trace quantities was very high, hut haematuria had a higher predictive value for a positive test (PvPt) and was considered the overall better indicator. A combination of both indices did not significantly increase the PvPt. When trace haematuria and moderate proteinuria were combined, both the sensitivity, specificity and PvPt were all above 90%, giving the best overall values in all the combinations made.

Internal transcribed spacer (ITS) rDNA sequences of three Nematodirus species from naturally infected goats or sheep in two endemic provinces of China were analysed to establish an effective molecular approach to differentiate Nematodirus species in small ruminants. The respective intra-specific genetic variations in ITS1 and ITS2 rDNA regions were 0.3–1.8% and 0–0.4% in N. spathiger, 0–6.5% and 0–5.4% in N. helvetianus, and 0–4.4% and 0–6.1% in N. oiratianus from China. The respective intra-specific variations of ITS1 and ITS2 were 1.8–4.4% and 1.6–6.1% between N. oiratianus isolates from China and Iran, 5.7–7.1% and 6.3–8.3% between N. helvetianus samples from China and America. For N. spathiger, compared with samples from China, sequence differences in ITS1 rDNA were 0.3–2.4% in isolates from America, 0.3–2.9% in New Zealand and 2.1–2.4% in Australia. Genetic variations in ITS2 rDNA of N. spathiger were 0–0.4% between samples from China and America, and 0–0.8% between samples from China and New Zealand. Using mutation sites, polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) and specific PCR techniques were developed to differentiate these three Nematodirus species. The specific PCR assay allowed the accurate identification of N. oiratianus from other common nematodes with a sensitivity of 0.69 pg and further examination of Nematodirus samples demonstrated the reliability of these two molecular methods.

The 14.5 kDa fatty acid binding protein (FABP) was isolated from the crude extract of adult Fasciola gigantica worms. Polyclonal anti-FABP IgG was generated in rabbits immunized with prepared FABP antigen. Sandwich enzyme-linked immunosorbent assay (ELISA) was applied to detect coproantigen in stools and circulating Fasciola antigen (CA) in sera of 126 water buffaloes by using purified and horseradish peroxidase (HRP)-conjugated anti-FABP IgG. Sandwich ELISA sensitivity was 96.97% and 94.95%; while specificity was 94.12% and 82.35% for coproantigen and CA detection, respectively. However, sensitivity and specificity of the Kato–Katz technique was 73.74% and 100%, respectively. The diagnostic efficacy of sandwich ELISA was 96.55% and 93.1% for coproantigen and CA detection, respectively. In contrast, the diagnostic efficacy of the Kato–Katz technique was 77.59%. In conclusion, these results demonstrate that the purified 14.5 kDa FABP provides a more suitable antigen for immunodiagnosis of early and current bubaline fascioliasis by using sandwich ELISA.