The morphology of the tegument in the redia of Paramphistomum epiclitum (Digenea: Paramphistomidae) resembles that shown by most larval and adult digeneans; an outer surface syncytium is in continuity with the cytoplasm of in-sunken, nucleated cytons. Although tegumental cytons usually contain a single nucleus, some display up to six nuclei. The tegumental syncytium lining the pharynx of P. epiclitum rediae lack underlying cytons. The apical membrane of the tegument is elaborated by folds and microvilli, which presumably facilitate uptake of nutrients and/or exchange of ions involved in osmoregulation. A single type of secretory body, resulting from the fusion of smaller vesicles produced at Golgi complexes in the cytons, occurs throughout the tegument. Uniciliate sensory receptors occur in the surface syncytium particularly around the oral opening.

Early literature on Red Ring disease of coconuts, caused by the nematode Rhadinaphelenchus cocophilus (Cobb, 1919) Goodey, 19C0, has been reviewed by the writer (Fenwick 1957). Little information is available however on the techniques used, and investigation has shown that the extraction of these nematodes from different types of coconut tissue presents problems which are not dealt with in Goodey's (1957) review of nematological technique. It is felt that the techniques developed by the writer for this worm might be of interest to other workers who are concerned with the extraction of very slender active nematodes from hard plant tissues.

Of a total of sixteen Jackdaws examined, four were found to be infected with Trematodes. These yielded a total of five species, two of which are new to the British fauna, namely Urotocus thalonetensis and Tamerlania zarudnyi. The other parasites found were Platynosomum petiolaium, Lyperosomum longicauda and Prosthogonimus ovatus. With the exception of P. ovatus all the species are described in the text.

The presence of circulating immune complexes (CIC) in the sera of dogs infected with Dirofilaria immitis was detected by using a Clq-binding enzyme-linked immunosorbent assay. Specificity of this assay with different concentrations of heat-aggravated canine IgG (ACG) was observed, i.e., the ELISA readings, expressed as ug equivalents ACG/ml, increased with increasing amounts of ACG. The intra-assay variability was below 10%. The CIC levels of infected and uninfected dogs were 177–0± 104–7 ug/ml and 22–8±45–8 ng/ml (mean±SD), respectively. The highest level was observed in 12 dogs with amicrofilaraemic infection. Age distribution of CIC levels in the 23 infected dogs also showed a significant positive correlation. These findings suggested that the CIC are present in the sera of dogs with dirofilariasis and may relate to canine glomerulonephritis.

Experiments were carried out to investigate if sera of animal species other than dog are chemotactically active for infective larvae of Ancyclostoma caninum. Those sera were also found to contain such a factor(s), although the larvae were attracted significantly better by dog serum. How this chemotaxis might be applied to the in vivo situation, when infective A. caninum larvae penetrate the skin of dogs, is discussed.

The normal ultrastructure of the fundic gastric glands of cattle is described and compared with those from calves infected with T. axei. Loss and alterations in structure of zymogen and parietal cells are observed and are related to changes observed by light microscopy. The significance of these changes is discussed.

Our objective was to measure the efficacy of ivermectin (IVM) and benzimidazoles (BZ, i.e. fenbendazole and albendazole) in 15 cattle farms in western France and southern Italy. A total of 11 groups were treated with IVM and 11 with BZ. Efficacy was assessed by calculating the percentage of faecal egg count reduction (%FECR) using the pre- and post-treatment arithmetic means. Anthelmintic resistance was considered to be present when the %FECR was <95% and the lower limit of the 95% confidence interval <90%. For IVM, the percentages of FECR ranged from 73% to 100%. Lack of efficacy to IVM was detected in two farms out of four in France, but was not detected in any of the seven farms in Italy. For BZ, the percentages of FECR ranged from 95% to 100%. No case of BZ resistance was detected in the five farms in France and the six farms in Italy.

Pathological changes associated with the parasitic nematode Philometroides sanguineus (Rudolphi, 1819) are described for the first time from observations of infections in wild crucian carp Carassius carassius (L.) in England. The damage caused by P. sanguineus was influenced strongly by host size, parasite development and the seasonal migrations of female nematodes within host tissues. Male and unfertilized female nematodes located on the swim-bladder wall caused only minor, localized changes. In contrast, the migration of gravid female nematodes into the fins during autumn provoked an acute inflammatory response comprising neutrophils, eosinophils and lymphocytes. This was accompanied by fin distortion, swelling of the dorsal and caudal tissues, degenerative changes and localized oedema. The encapsulation of female nematodes in connective tissue throughout winter limited additional tissue damage. The emergence of gravid nematodes from the fins in spring to facilitate larval dispersal caused necrosis, hyperplasia and loss of skin integrity. This activity was again accompanied by acute inflammatory reactions. Pathological changes were more severe in crucian carp measuring less than 60 mm in length, with no signs of debilitation in larger fish. These observations suggest that any impact of P. sanguineus is strictly seasonal and may be limited to fry. Lesions caused by this parasite, only recently recorded in Britain, may represent an additional pressure upon wild crucian carp populations already threatened by hybridization, competition and habitat loss.

Mr. L. Ogilvie, Mycologist, of the Research Station, Long Ashton, Bristol, recently sent the writer some bulbs of Lilium longiflorum Thunb., var. takesima, requesting an opinion on the eelworms occurring in the brownish tips of some of the scales. These turned out to be chiefly a species of Rhabditis and Diplogaster nudicapitatus Steiner. There was one thoroughly decomposed bulb scale, dark brown in colour and of a soft consistency throughout which, on teasing in water, was found to contain several insect larvae, mites and numerous nematodes including specimens of Diplogaster longicauda and D. striatus. In addition, about 25 adults of each sex of a new genus of nematode were found which, though somewhat resembling Rhabditis in buccal and oesophageal characters, differed from that genus in certain important features the most outstanding of which was the short buccal cavity. On this character the generic name has been based and because the worms were found in a thoroughly decayed organic medium a specific name has been chosen which denotes their probable feeding habits. Mr. Ogilvie has informed the writer that the bulbs were from stocks imported from Japan. Such bulbs arrive in this country in cases packed with Japanese soil but as the bulbs examined had already been planted in English soil it is impossible to determine from the material available whether the newly discovered nematodes were originally inhabitants of Japanese or English soil.

Ascaridia galli (Nematoda: Ascaridiidae) is the most common intestinal roundworm of chickens and other birds with a worldwide distribution. Although A. galli has been extensively studied, knowledge of the genetic variation of this parasite in detail is still insufficient. The present study examined genetic variation in the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene among A. galli isolates (n = 26) from domestic chickens in Hunan Province, China. A portion of the cox1 (pcox1) gene was amplified by polymerase chain reaction separately from adult A. galli individuals and the amplicons were subjected to sequencing from both directions. The length of the sequences of pcox1 is 441 bp. Although the intra-specific sequence variation within A. galli is 0–7.7%, the inter-specific sequence differences among other members of the infraorder Ascaridomorpha were 11.4–18.9%. Phylogenetic analyses based on the maximum likelihood method using the sequences of pcox1 confirmed that all of the Ascaridia isolates were A. galli, and also resolved three distinct clades. Taken together, the findings suggest that A. galli may represent a complex of cryptic species. Our results provide an additional genetic marker for the management of A. galli in chickens and other birds.

A cross-sectional socio-economic study of fascioliasis in livestock was carried out at the Livestock Development Cooperation (SODEPA) slaughterhouse in Etoudi, Yaoundé during the periods covering the beginning and late dry season in the northern and eastern regions of Cameroon. A total of 768 cattle and 267 sheep were inspected for the presence of Fasciola species. The overall infection rate in cattle and sheep was 18% (n = 767) and 27% (n = 267), respectively. For the animals that were Fasciola positive, a total of 267.86 kg of liver in cattle was condemned, resulting in a loss of US$1124, while a total of 57 kg of liver was condemned from the sheep population, amounting to a loss of US$114. A total of US$76,097 was determined as losses incurred from condemnation of liver for both cattle and sheep per annum based on the total number slaughtered each year. The findings indicate that fascioliasis is present in cattle and sheep slaughtered in Cameroon and that it causes great economic losses due to condemnation of liver. The local climatic conditions, husbandry systems and the presence of snails (intermediate hosts) are probably the main factors influencing the incidence of the disease and may account for the epidemiological significance found in this study.

We have investigated, the accuracy of a nematode egg flotation technique, using magnesium sulphate and the Clayton-Lane centrifuge system routinely used in diagnostic laboratories, to estimate the numbers of H. rubidus in porcine faeces. Eggs present in 3 g samples taken at random from a night's faecal collection from one pig were shown to be randomly distributed. The technique was not of reproducible accuracy and various sources of error were investigated.

The co-occurrence of hepatic cystic echinococcosis (CE) and alveolar echinococcosis (AE) is extremely rare. Here, we present the clinical manifestations and treatment outcomes of three cases with co-occurring CE and AE in the liver. Computed tomography (CT), magnetic resonance imaging and 18FFluorodeoxyglucose Positron Emission Tomography-CT were used for preoperative diagnosis. Specimens were taken intraoperatively and sent for pathological studies to confirm the coexistence of CE and AE by laminated membrane, daughter cysts or germinal layer and infiltration structure. Albendazole was prescribed after operation for 12 months. All patients were completely recovered and showed no recurrence at last follow-up. Therefore, surgical intervention and postoperative application of albendazole are recommended for patients with concurrence of hepatic AE and CE.

Helminths in aquatic invertebrate hosts have been overlooked in comparison with vertebrate hosts. Therefore, the known diversity, ecology and distribution of these host–parasite systems are very limited in terms of their taxonomic diversity, habitat and geographic regions. In this study we examined the published literature on helminth parasites of aquatic invertebrates from Latin America and the Caribbean (LAC) to identify the state of the knowledge in the region and to identify patterns of helminth diversity. Results showed that 67% of the literature is from Argentina, Mexico and Brazil. We found records for 772 host–parasite associations. Most records relate to medically or economically important hosts. Molluscs were the most studied host group with 377 helminth records (80% trematodes). The lymnaeids and planorbids were the most studied molluscs across LAC. Arthropods were the second most studied host group with 78 helminth records (trematodes 38%, cestodes 24% and nematodes 20%), with shrimps and crabs being the most studied hosts. Host species with the largest number of helminth taxa were those with a larger sampling effort through time, usually in a small country region. No large geographical-scale studies were identified. In general, the knowledge is still too scarce to allow any zoogeographical or helminth diversity generalization, as most hosts have been studied locally and the studies on invertebrate hosts in LAC are substantially uneven among countries.

Two male worms of Camelostrongylus mentulatus were found in one of 84 murciano-granadina goats in Murcia, south-eastern Spain. This is the first report of C. mentulatus in goats in the Iberian peninsula and the possible origin and transmission of this nematode in Spain are discussed.

In vitro chemotactic responses of infective third-stage larvae (L3) of Brugia pahangi to NaCl, Na2HPO4, KCl, K2HPO4, MgCl2 and CaCl2 were assessed. Compared to deionized water as a control, 200 mm NaCl and 100 mm Na2HPO4 significantly attracted L3 (P < 0.01 and P < 0.01), whereas L3 were likely to avoid 200 mm KCl and 100 mm K2HPO4 (P < 0.05 and P < 0.05). L3 showed no significant tendency to avoid or to be attracted to 200 mm CaCl2 and 200 mm MgCl2. Furthermore, NaCl exhibited a significant chemoattractant activity for L3 at a low concentration of 100 mm.

Anisakis simplex crude extracts (CE) (IPI, ASAC and ALK-ABELLÓ), A. simplex larval antigens purified using a column of IgG anti-A. simplex (PAK) or a column of IgG anti-Ascaris suum (PAS), antigen eluted from columns of IgG anti-A. suum (EAS) and an A. suum adult CE were assayed by the skin prick test. Thirty percent of assayed patients showed a negative reaction in the Anisakis skin prick test. Of 70% positives, two patients had a weal greater than that produced by histamine with the A. simplex extract from ABELLÓ and IPI. The A. suum skin prick test was positive in 35% of patients, with a lower reaction than that observed with the A. simplex extract from IPI in 57% of the sera and a higher reaction in 28% of the sera. All patients with positive reactions with the crude extract also showed positive weals with the two purified antigens, PAK and PAS. All patients, except three, with a reaction to A. suum antigen, were positive to the EAS antigen. In five patients the weal size produced by PAS was greater than that observed with PAK, whereas in another six patients the contrary was observed. Only one of these six patients did not react to EAS antigen, coincident with the patient showing only a slight increase (7%) in the weal size induced by PAK vs. PAS. When the EAS antigen was tested on patients positive to both PAK and PAS, six patients presented a weal size of >30% and only three patients who were positive to PAS did not react to the EAS antigen. These three patients were also negative against the A. suum CE. Purification by affinity chromatography eliminates from the PAS antigen the proteins responsible for producing cross-reactions with Ascaris (present in the EAS antigen).

A new bisexual species of Rotylenchus is described and illustrated based on morphological, morphometric and molecular characterizations. Rotylenchus zhongshanensis sp. nov. is characterized by having a conoid lip region complying with the basic pattern for Hoplolaimidae, but with pharyngeal glands slightly overlapping intestine dorsally and cuticle thickened abnormally in female tail terminus. Females have robust stylet (30.1–33.8 μm). The pharyngeal gland has short dorsal (11.2–16.8 μm) overlap on the intestine. The vulva is located at 48.0–56.5% of body length, and phasmids are pore-like, 4–6 annuli posterior to the anus. For males, phasmids are pore-like, 11–17 annuli posterior to cloaca. The spicules are ventrally arcuate (21.0–28.5 μm) with gubernaculum in 5–8 μm length. The rRNA and mitochondrial COI genes were successfully sequenced from the assembled whole-genome sequences of the new species, and were used for reconstructing the phylogenetic relationships of the new species. A new strain of cyto-endosymbiont Cardinium was also discovered from the genome sequences of R. zhongshanensis sp. nov. The 16S rRNA phylogeny analyses revealed that this new bacterial strain is closed to that from cyst and root-lesion nematodes.

The activities of the enzymes superoxide dismutase (E.C.:1.15.1.1) and catalase (E.C: 1.11.1.6) were studied in purified extracts of four nematodes: Ascaris suum, Toxascaris leonina, Toxocara canis and T. cati adult males and females. No catalase activity was found in any of the extracts. The results reveal that the SOD activities of the four parasites presented species differences and also sexual differences within each species. Polyacrylamide gel electrophoresis pattern analysis confirmed that the mobilities, widths and band intensities varied according to the species and sex of the parasite from which the enzyme was obtained.

A large collection of avian Ascaridia from a wide diversity of hosts and localities is reported upon. It comprised six species, A. galli, A. columbae, A. compar, A. cristata, A. hermaphrodita and A. numidae. Their morphology is examined critically with reference to previous descriptions, especially in the case of A. columbae, A. cristata, A. hermaphrodita and A. compar, and a new variety of A. columbae is described.

The taxonomic significance of spicule morphology and the tubercles on the ventral surface of the male tail in Ascaridia is discussed.