Isozyme patterns of six enzymes, glucose-6-phosphate dehydrogenase, glucosephosphate isomerase, hexokinase, malate dehydrogenase, 6-phosphate dehydrogenase and phosphoglucomutase were examined in electrophoresed homogenates of adult male worms of Schistosoma japonicum and S. mansoni. In general, enzyme patterns obtained from the parasite homogenates differed from that of host (mouse) blood and muscle, indicating that electrophoretic patterns from parasite extracts are most probably of parasite origin. Adult male and female S. mansoni worms yielded identical patterns. However, all six enzyme patterns showed distinct differences between S. japonicum and S. mansoni. These results suggest that S. japonicum is clearly distinguishable from S. mansoni at the molecular level.

Our knowledge of the range of intermediate hosts of which Syngamus trachea can take advantage is increasing. Recent observations have shown that the centipede, Scolopendra sp., the leatherjacket, Tipula sp., and the spring tail, Sminthurus viridis may all act as vectors. In each case the larvae had migrated from the gut into the surrounding tissues where they had settled down. All these Arthropods have been found naturally infected on a plot of land known to be carrying a heavy burden of gapes.

Dactylogyrid species (Monogenea) communities were studied in roach, Rutilus rutilus, collected from two localities in the basin of Morava river, Czech Republic, during the period from April to November 1997 and March to September 1998 to determine the effect of water temperature on parasite abundance, species richness and diversity. Dactylogyrid species were found to co-occur on the gills of roach with up to six species found on the same host individual. Nine dactylogyrid species were identified with the abundance of each reaching a very low level. Niche size was considered to increase with species abundance even when water temperature was high. There was a strong effect of water temperature on abundance of the common dactylogyrid species (D. crucifer, D. nanus, D. rutili and D. suecicus) as well as of the rare species D. rarissimus. The temporary occurrence of the rare species was found without any temperature effect. Water temperature did not affect the relationship between abundance and niche size. Niche size increased with abundance, even when the water temperature was high, which suggests that negative interspecific interactions are not important within dactylogyrid communities.

This study focused on the spirurid nematode Mastophorus muris in water voles (Arvicola amphibius) trapped in three regions in southern Sweden during spring and fall 2013. The collection of water voles formed part of a larger project (EMIRO) on the cestode Echinococcus multilocularis in rodents. The voles’ stomach contents were examined for the presence of M. muris. Prevalence, mean abundance and mean intensity of infection were calculated. A generalized linear model model was used to examine the effects of sex, functional group, season and region on the number of M. muris individuals in each vole. Forty-seven of 181 (26%) voles were infected with M. muris, with up to 74 worms each. The overall mean intensity (worms per infected vole) was 15 (95% CI 10–21), and abundance (mean number of worms in all voles) was 4 (95% CI 2–6). Model output indicated a significant effect of season and region with respect to abundance of nematode infection, which was independent of sex and functional group of the investigated host.

A new nematode species, Raphidascaris mundeswariensis n. sp. (Raphidascarididae), is described from male and female specimens found in the intestines of the mudskipper Apocryptes bato (Hamilton, 1822) (Gobiidae) from the Mundeswari River of West Bengal, India. This species is distinguished from its congeners by 214–255-μm-long spicules, 14 pairs of preanal papillae of two markedly different sizes, one pair of adanal papillae, six pairs of postanal papillae and the absence of lateral alae. Phylogenetic analyses using partial sequences of the 28S ribosomal RNA gene place the new species in a clade containing Raphidascaris gigi, Raphidascaris lophii, Raphidascaris longispicula and two species of Hysterothylacium. The molecular analyses also corroborate results of previous studies that have found Raphidascaris and Hysterothylacium to be paraphyletic. The finding of R. mundeswariensis in A. bato is the first Raphidascaris species described from a mudskipper anywhere.

Eye flukes are common infections of freshwater fish and their occurrence as metacercarial stages may occur non-randomly resulting in an asymmetrical distribution within the host eyes. However, from previous studies the presentation of bias by these trematodes lacks consistency suggesting that congenital asymmetrical effects are unlikely to be the cause and exogenous factors, such as environmental stress, may be more influential. The present study, undertaken over a 4-year period, investigates the impact of an extreme heatwave and drought on the annual bilateral asymmetry and occurrence of two eye fluke species (Diplostomum sp. in the lens and Tylodelphys sp. in the vitreous humour) from perch (Perca fluviatilis) and roach (Rutilus rutilus). The onset of the extreme climatic event resulted in a significant negative effect on the occurrence of the eye flukes. Bilateral asymmetry, which was present within both trematode species and hosts, appeared to be highly variable between eye fluke and fish species and also year of study. However, during the pre-drought period both host species demonstrated significant asymmetry for Tylodelphys sp. but not for Diplostomum sp. while during the drought this bias was reversed. The potential role of fluctuating asymmetry of fish hosts in structuring the bilateral asymmetry of eye flukes is discussed.

Ligophorus kaohsianghsieni (Gusev, 1962) Gusev, 1985 was collected from the so-iuy mullet Planiliza haematocheilus (Temminck & Schlegel, 1845) from the Black Sea and the Sea of Japan. DNA sequences data for L. kaohsianghsieni, as well as its morphological characters from the Sea of Japan were obtained for the first time. Significant morphometric and genetic diversity between specimens of L. kaohsianghsieni from the Black-Azov Sea region and the Sea of Japan were not found. For the first time, the molecular phylogeny of L. kaohsianghsieni based on three fragments of the nuclear DNA ribosomal cluster (18S, internal transcribed spacer 1 and 28S) was reconstructed. Molecular analysis of Ligophorus species from the Atlantic and Pacific Oceans revealed a significant phylogenetic distance between L. kaohsianghsieni and two others species (Ligophorus pilengas and Ligophorus llewellyni) from the same host (P. haematocheilus) and region. This result indicates the lack of correspondence between the phylogenetic and geographical closeness of the hosts and the relation of their parasites from the genus Ligophorus.

In reviewing the literature on helminthology one finds that a great deal of attention has been given to the study of the physiology of parasites. Investigations of such a nature are valuable, in that they enable one to approach the problem of anthelmintic treatment in a scientific manner. Most of the early work that was carried out on lungworms in general was concerned either with their life histories or with their morphology, and little work has been done on their physiological characteristics.

The proteins of homogenized adult Opisthorchis viverrini were separated by polyacrylamide gel electro-Phoresis and isoelectric focusing in the presence of detergents. By far the most abundant component(s) had a Mr of 18,000 to 19,000, represented about 47% of the total parasite protein, and did not separate in isotypes.

Five Macaca mulatta were each inoculated with 200 larvae of Brugia pahangi. One monkey showed no microfilariae and the other 4 only low and transient microfilaraemias. Another group of 5 monkeys were each given an original 200 larvae and 11 further infections with 50 larvae but no better microfilaraemias were obtained. These monkeys were killed between 176 and 185 days later and no adult worms could be found. A few adult worms were found in two further monkeys killed 60 days after infection.

Brugia pahangi infects mammalian hosts of several orders but the only primate found naturally infected is Nycticebiis coucang (Laing et al., 1960, Ash and Riley, 1970). Edeson et al. (1960) tried to infect Macaca inis, M. nemestrina, M. mulatta and N. coucang but were only able to detect microfilariae in N. coucang. On the other hand, B. malayi (sub-periodic strain) infects primates much more readily (Laing et al., 1960) in nature. Fredericks and Ramachandran (1968) successfully infected 26 of 27 M. mulatta with B. malayi.

A number of helminths from a small bat from a cave in Northern Rhodesia were presented by Dr. P. L. leRoux to the author for study. The collection of consisted of about twenty specimens of one species of trematode, Prosthodendrium cordiforme; the rest were nematodes, namely, two males and three females of Molinostrongylus pseudornatus sp. nov., at least one species of filarial worm, one species of Capillaria and one or two species of trichostrongylid nematodes. Only the first two helminth species mentioned above were studied in detail. The others, for one reason or another, were inadequate for detailed study.

A Few specimens of the Trichostrongyle, described in this paper, were obtained from the intestine of moles caught on the experimental farm of the Institute of Agricultural Parasitology, St. Albans.

Dissolved carbon dioxide was deemed not to be an important factor in the activation of Taenia taeniaeformis oncospheres. Rabbit bile was found to provide the most appropriate whole bile for in vitro activation of oncospheres

Two males and one female Aphelenchoides were taken from the rootlets of radish, Raphanus sativus, in December, 1967, in the suburbs of Lucknow (India). They are described as new and are named Aphelenchoides franklini n.sp.

The four species of the genus Strongylus Müller, 1780, namely, S. equinus, S. edentatus, S. vulgaris and S. asini were examined with the scanning electron microscope (SEM). The buccal cavity of each species was cut transversely and longitudinally and the scanning electron micrographs illustrate the shape of the buccal cavity and the dorsal gutter. The micrographs also show the presence of denticles near the oral rim of the buccal cavity of S. edentatus and the shape of the teeth in the buccal cavity of S. equinus, S. vulgaris and S. asini. The bursa of the four species has three symmetrical lobes, one dorsal and two lateral. The length of the three lobes in relation to each other varies between the species. The genital cone has a single large ventral papilla, a pair of dorsal raylets, a median dorsal cuticular appendage and a variety of cuticular appendages lateral and ventral to the cloaca. The development and arrangement of these components differs between the four species of the genus and can be used as a supportive character for specific identification.

Terrestrial arthropods host a variety of helminth parasites, yet quantifying the intensity of infection in these hosts post-mortem is challenging because carcasses may desiccate quickly. We recovered cysticercoids of Hymenolepis diminuta from desiccated flour beetle (Tribolium confusum) carcasses by modifying a published insect rehydration procedure. Without rehydration, carcasses dissected more than 1 day post-mortem had noticeable degradation of cysticercoids. Mild rehydration (soaking in water only for 2 days, or 0.5–10% KOH for 1 h followed by 1 day in water, or 0.5% KOH for 1 day) left carcasses tough and time-consuming to dissect, but all parasites could be recovered and were similar in body size to fresh cysticercoids. Moderate rehydration (5–10% KOH for 1 day) allowed all parasites to be recovered and facilitated dissection by partially dissolving internal organs of the beetle while causing little degradation of the cysticercoids. Harsh rehydration (5–10% KOH for 1 day followed by 5 days in water) not only dissolved internal beetle tissues but also severely damaged cysticercoids, such that parasite counts were unreliable. The degree of initial carcass desiccation had little effect on results following rehydration. However, regardless of treatment used, intact cercomers were rarely retained on rehydrated cysticercoids. Rehydration was less successful on early developmental stages of the parasite, which were recovered reliably only as they neared the cysticercoid stage. This method has utility for studies of parasite-induced mortality by permitting accurate and reliable parasite counts from dead, desiccated hosts.

The rediae of Fasciola hepatica were counted according to generation in adult and juvenile Lymnaea truncatula following single infection with Fasciola hepatica, double infection with F. hepatica and then Muellerius capillaris, or double infection with M. capillaris and F. hepatica. The rediae found in double infections were essentially first generation and an early cohort from the second generation. The following differences were observed in adult snails which underwent double infection when compared to corresponding single infections: i) dependent rediae were almost completely absent; ii) degenerating independent rediae were found in identical or decreased numbers; iii) living independent rediae of the first generation were decreased in number, while those of the second generation had variable decreased numbers. The results were similar in juvenile snails with double infections, except that the numbers of degenerating independent rediae were higher than those found in corresponding single infections and the numbers of rediae of the second generation were increased. The order of exposure in double infections had no influence on the number and maturation of fasciolid rediae.

Trichinellosis in humans is most often caused by the parasite Trichinella spiralis. The clinical course of the disease is diverse and the symptoms can vary from mild to severe. Symptoms usually disappear within a few months, but encysted larvae in the muscles can cause myalgia and weakness that last for years. However, the existence of chronic trichinellosis as a disease is still debatable. This study presents the results obtained at the National Reference Laboratory for Trichinellosis – INEP, Serbia. The study was conducted to assess the immunoserological, biochemical and symptomatic disease parameters of twelve patients who acquired trichinellosis 13 and 18 years ago, respectively. They were involved in two T. spiralis outbreaks in Serbia, at the village of Kumane and the city of Belgrade (nine and three patients, respectively). Results indicated the presence of specific anti-Trichinella antibodies in 83% of the total number of patients. However, while the humoral immune response to Trichinella lasted for more than a decade reaching almost two decades after the acute infection phase (7/9 and 3/3 respectively, in two outbreaks), persistence of chronic muscular pain, as the most prolonged symptom of trichinellosis, could be found in the majority of patients from the Kumane outbreak (7/9). As a consequence, these patients suffered from limitations in daily living activities for the same period of time. The results presented in this paper are our contribution to the view that trichinellosis as a chronic disease with symptoms exists and may be related to the severity of the disease in the acute phase.

Factors which influence the establishment of tetrathyridia of Mesocestoides corti in mice following inoculation per os were examined. Only a proportion of the tetrathyridia penetrate the gut wall and gain access to the peritoneal cavity and liver, and most of these penetrate through the wall of the small intestine. It appears that tetrathyridia must attach to the intestinal mucosa and commence penetration immediately or they pass into the large intestine and are voided. Establishment was not influenced by strain, sex or age of host. However, the temperature at which tetrathyridia were maintained before inoculation did influence their ability to penetrate the intestinal wall. Additionally it appears that tetrathyridia have to undergo a morphological change before or during, this penetration phase.