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.

During the intramolluscan larval development of Schistosoma haematobium (Algerian strain) in Bulinus truncatus, two replication processes of daughter sporocysts occur. Replication by direct sporocystogenesis appears more important than sporocystogenesis post cercariogenesis. These mechanisms assure a periodic renewal of the sporocyst stock in the snail host and seem to be synchronized with the development of cercarial generations. The succession of several generations of cercariae is responsible for the alternation of high and low periods of productivity.

The scheme proposed for the intramolluscan development of S. haematobium is compared with those described for S. mansoni and S. bovis and interpreted in terms of demographic strategies adapted to a better exploitation of the snail host.

During the course of some anthelmintic tests carried out during June, 1949, it was necessary continuously to feed 4 per cent, phenothiazine to pheasant poults in the daily mash, which they ate without any obvious distaste and grew reasonably well. The birds were a mixture of several varieties of Phasianus colchicus, including some Formosan and Korean hybrids. These latter birds have a light coloured plumage and it was soon noticed that the feathers were darkening. The change was obvious less than 86 hours after the first experimental feeding. All the birds were therefore examined and it was found that all were similarly affected though it was less obvious among the melanistics and blacknecks, which have a darker plumage. The leg scales too had taken on a distinct dark green hue, and this became more intense as the tests proceeded; the pigmented feathers assumed a fiat brownish colour, while the filoplumes are distinctly red.

Antibody responses against crude antigens and the two (Em18 and Em16) epitopes of Echinococcus mulfilocularis were analysed by Western blotting using sera from the wild vole, Clethrionomys rufocanus bedfordiae (Crb), which were captured in Hokkaido, Japan and found to have been naturally infected with eggs, and compared with those in patients of AHD and mice experimentally infected with protoscoleces of this parasite. Antibody responses in the wild vole were demonstrated most clearly with anti-Crb-IgG antiserum but more faintly with anti-rat-IgG antiserum and poorly with anti-mouse-IgG or anti-human-IgG antisera or Protein G. Although only two serum samples of the wild vole found naturally infected were analysed, antibody responses against Em18 and Em16 in these voles appeared to be similar to those in AHD patients but differed from those in mice.

Two members of a collection of the South American rodent Viscacia viscacia received by the Zoological Society of London, died early this year, one of them about 10 days after arrival at the Gardens. At the post-mortem examination both were found to have the alimentary canal heavily parasitized with Trichostrongylid nematodes. In the stomach there occurred Graphidioides rudicaudatus and Trichostrongylus retortæformis, whilst in the small intestine there were a few specimens of Trichostrongylus retortæformis and large numbers of the worm which forms the subject of the present paper. To naked eye examination of the intestinal wall the worms appeared as small bright red spots about the size of a pin's head and it could be seen that each was spirally coiled.

Adult Strongylus vulgaris, collected from the caecum of infected horses and embedded in paraplast using standard methods, were sectioned for immunohistochemistry (IHC) studies. Antibodies were raised in rabbit against the excretory–secretory product (ESP) and against two constituent protein bands (28–30 kDa). The use of sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE), enzyme-linked immunosorbent assay (ELISA) and immunoblotting indicated the immunogenicity of ESP and of the subunits (28–30 kDa). In ELISA, both rabbit hyperimmune sera recognized the ESP and (28–30 kDa) bands consistently and strongly. Both hyperimmune sera recognized most ESP subunits (80, 60, 54, 42, 35, 30, 20 and 15 kDa) in immunoblots. IHC, using light microscopy, suggested that the following worm tissues reacted strongly and positively with both antisera: amphids, tooth core, intestine, excretory gland and ducts, and hypodermis. Thus, either these are antigen-producing tissues, or antigens sharing common epitopes occur in them. The following tissues reacted weakly: body cuticle, buccal capsule cuticle, oesophagus, and also somatic muscle (non-contractile portion) perhaps due to diffusion of antigen from adjacent tissues. Preimmune serum gave a negative reaction with most worm tissues.

The karyotype of Isthmiophora melis (Trematoda:Echinostomatidae) is described. The chromosome number in the diploid cell is 2n = 20. The absolute (La) and relative (Lr) lengths of the chromosomes, as well as the centromere position (Ic), are determined. The differences in length between the adjacent chromosomes in the ordered series are not great, with the exception of chromosome 1 which occupies 20.58% of the genome length. This chromosome is metacentric, with lightly stained and elongated centromere region with Giemsa staining. Chromosome 7 is submetacentric. Chromosomes 2 to 6 are defined as telo-subtelocentric, while chromosomes 8 to 10 are subtelo-submetacentric. The fundamental number of arms in the I. melis karyotype is NF-22.

Although outbreaks of trichinosis in Great Britain have been sporadic, the present investigation shows the incidence of Trichinella spiralis in man in Southern England to lie between 7.9% and 13.7%, the average incidence being 10.8%. The condition of the larvae, either free or in thin- or thick-walled cysts recovered by the “digest” technique, indicated that the infections were of varying ages, from recent to those of many years standing. In six cases there was definite evidence of the presence of both recent and old infections.

A preliminary parasitological and malacological survey was effected in rural communities of some Local Government Areas (LGA) in Plateau State, Nigeria, to estimate the prevalence of urinary schistosomiasis and identify active transmission foci. Out of 2888 persons examined in six LGAs, 1381 (47.82%) were excreting eggs of Schistosoma haematobium in their urine. Prevalence rates did not vary significantly (P > 0.05) between the LGAs: Pankshin (62.4%), Shendam (40.2%), Qua'an-Pan (22.9%), Langtang South (45.4%), Langtang North (58.8%) and Wase (50.0%). Infection rates were significantly different (P < 0.001) between the sexes. Many water bodies in the study communities were colonized by infected Bulinus snails. Snail infection rates varied significantly (P < 0.001) between the dry and wet seasons. A positive correlation was observed between snail infection rates and the prevalence of S. haematobium.

Observations on infection and the development of F. gigantica (W. African strain) in the susceptible L. natalensis and in the less susceptible mature L. rufescens (from Pakistan) and the histological study of the two species of snails at various stages of development of the contained parasite, revealed that,

The miracidia appeared to take a longer time to start penetrating the less susceptible host.

There was no significant tissue reaction even in L. rufescens to the development of the sporocysts. The development of the sporocysts which were embedded in denser tissues of the snails was apparently retarded in both the species of snail.

Seven specimens of this new species were collected from the intestine of a freshwater turtle, Trionyx triungnis (═T. nilotica) in the Sudan.

These are lanceolate worms which gradually taper to rounded ends, with a length of 2⋅5–2⋅9 mm. and a width of 0⋅6–0⋅9 mm. The cuticle is invested with scales, dense in the anterior half of the worm, but becoming more and more sparse towards the caudal end. The oral sucker is large, measuring 0⋅23–0⋅27 mm. in diameter and is about one and a half times the diameter of the ventral sucker which measures 0⋅14–0⋅17 mm. in diameter. Both suckers lie in the anterior half of the body. The mouth is subterminal and leads to a pharynx which is stout, 0⋅7–0⋅8 mm. by 0⋅11–0⋅12 mm., and leads to a long oesophagus of 0⋅25–0⋅32 mm. in length. The caeca terminate at the posterior border of the posterior testis or slightly anterior to it.

Hadjelia truncata, Hadjelia inermis and Viguiera euryoptera are newly recorded from India.

Quasithelazia tenuis is described in detail and the genus Quasithelazia Maplestone is considered to be a synonym of the genus Schistorophus Railliet, 1916.

Microtetrameres inermis is newly recorded from India and is described from two new hosts, Temenuchus pagodarum and Brachypternus bengalensis.

Physaloptera alata is described from the type-host, Accipiter nisus.

Syphaciella indica is described in detail and compared with the original description.

The nematode Protospirura numidica criceticola infects the stomach of Neotropical cricetid rodents when they ingest infected arthropods. In North America, prevalence values fluctuated, showing marked peaks in desert habitats, while remaining low in humid environments. The infection pattern has not been studied in South American rodents. In this work, yearly infection by P. n. criceticola was analysed in the South American cricetid Akodon azarae seasonally captured from July 1998 to July 2000 and in March 2001 on poultry farms of a humid region of Argentina. Seasonal occurrence of third- and fourth-stage larvae and adults was recorded. Seasonal population and community parameters of the parasite were calculated. The occurrence of larval stages was confirmed for the four seasons. Prevalence fluctuated between 0 and 36% and did not show a seasonal pattern. It was not related to the abundance of A. azarae (rs = 0.37) or to rainfall. In this humid region of Argentina, where food resources are diverse throughout the year, the omnivorous A. azarae may have a variable diet so that infection can occur in the four seasons. Prevalence values were not very high, in accordance with observations in humid habitats of North America. The infection was also characterized by low intensity, abundance and dominance. Only 3.8% of the rodents were parasitized with three or more specimens of the parasite, and that was only in autumn. It is suggested that rodents can not overwinter successfully with a heavy biomass of stomach parasites.

Taeniid infections in intermediate hosts manifest themselves as extraintestinal larval stages which, in early development, lack species-specific characteristics. The inability to distinguish infections of zoonotic importance such as Echinococcus multilocularis from other taeniid infections that have mainly veterinary significance stimulated the development of species-specific molecular diagnostics. In this study, the prevalence of taeniid infections in potential intermediate hosts was evaluated using both morphological diagnosis and a newly described multiplex polymerase chain reaction (PCR) for species determination. Small mammals (N= 719) were trapped in three different types of habitats in north-east Zealand, Denmark. The sensitivity of the multiplex PCR (90.5%) exceeded that of morphological examination (57.9%) for identifying 95 taeniid infections. The use of the multiplex PCR resulted in higher prevalence rates due to improved detection of immature liver infections with Hydatigera taeniaeformis and Versteria mustelae, but did not affect the observed prevalence rates of peritoneal metacestodes of Taenia polyacantha. The prevalence of taeniid infections showed a significant difference according to habitat type, potentially identifying a ‘sylvatic’ transmission and an ‘urban’ transmission, with marked variation among different taeniid species. Versteria mustelae and T. polyacantha were more prevalent in rural forests, while infections with H. taeniaeformis were dominant in urban parks/forests and in residential and farm gardens. The multiplex PCR facilitated a better utilization of wildlife samples by yielding a higher number of definitive diagnoses of ambiguous taeniid infections in liver lesions, allowing for more accurate epidemiological data and, hence, a more accurate risk assessment.

In this study we examined trematode and nematode lung helminths commonly found in two species of host ranid frogs for competitive interactions. We examined 147 adult (breeding and non-breeding) and juvenile northern leopard frogs, and 84 breeding male wood frogs in Bishops Mills, Ontario for Haematoloechus spp. (Trematoda) and Rhabdias sp. (Nematoda) infections. A strong negative association between phyla of helminth was observed in breeding and juvenile northern leopard frogs, and also in breeding wood frogs, but not in non-breeding adult northern leopard frogs. Few hosts carried both types of worm concurrently. Thirteen northern leopard frogs carried dual infections, while 77 carried only one phylum of helminth. Twenty-seven wood frogs carried dual infections, while 54 carried only one phylum of helminth. We also observed spatial segregation of the two phyla in host lungs. Our study informs future research on the dynamics of interactions among lung helminths in these two host species.

The aim of this survey was to study two Hymenolepididae species in urban rodents, Rattus rattus and Rattus norvegicus, and to analyse factors that favour their presence in the environment and pose a sanitary risk. Hymenolepis diminuta and Rodentolepis nana were found in R. rattus and R. norvegicus in different proportions. Values of prevalence, mean abundance and mean intensity were recorded, and new morphometric characters were described, adding to previously known information. No significant differences were found. However, the results revealed that there is a tendency for these parasites to develop in areas with deficient socio-structural conditions and in water bodies. This study thereby shows that certain areas on the periphery of the Gran La Plata favour the existence of rodents, which act as sentinels of zoonotic diseases, and stresses the need to take action to minimize them in order to avoid putting human and animal health at risk.

The occurrence of benzimidazole (BZ) and levamisole resistance was investigated in 18 randomly selected dairy goat herds located in southwestern France and characterized by extensive management. On each of the 18 farms, 45 adult goats were randomly allocated into three groups of 15 animals each: an untreated control group, a group that was orally administered fenbendazole (10 mg kg-1 body weight) and a group that received orally a levamisole drench (12 mg kg-1 body weight). Individual faecal egg counts and pooled larval cultures were done 10 days after anthelmintic treatment. Naive lambs were infected with larvae obtained from control and fenbendazole treated groups and were necropsied 35 days after infection for worm recovery. Faecal egg count reductions (FERC) were calculated for fenbendazole and levamisole and, when less than 95 per 100, were considered as indicative of anthelmintic resistance. An in vitro egg hatch test (EHT) was conducted with thiabendazole on eggs isolated from pooled faeces of fenbendazole treated goats in nine farms. Faecal egg count reductions indicated the occurrence of benzimidazole resistance in 15 out of 18 farms. Among these farms, nine had EHT values above 0.1 μg thiabendazole ml-1 confirming the benzimidazole resistance status. Levamisole resistance was detected in two farms through FECR. Based on necropsy results, the prevalence of benzimidazole resistance was higher in Trichostrongylus colubriformis, medium in Haemonchus contortus and lower in Teladorsagia circumcincta. In nine farms the benzimidazole resistance was monospecific whereas multispecific resistance was found in the six remaining farms. A negative relationship was found between FECR for fenbendazole and the average number of anthelmintic treatments given per year on the farm. Despite extensive management including a low number of treatments, the prevalence of benzimidazole resistance was very high suggesting that the repeated and sometimes exclusive use of benzimidazole drugs, even at low frequency, is probably the main cause in developing nematode resistance in dairy goat herds. The importance of other factors such as under-dosing or buying animals already carrying resistant nematodes are discussed.

The golden snub-nosed monkey (Rhinopithecus roxellana) is an endangered species endemic to China. Relatively little is known about the taxonomic status of soil-transmitted helminths (STH) in these monkeys. Trichuris spp. (syn. Trichocephalus) are among the most important STHs, causing significant socio-economic losses and public health concerns. To date, five Trichuris species have been reported in golden monkeys, including a novel species, T. rhinopiptheroxella, based on morphology. In the present study, molecular and morphological analysis was conducted on adult Trichuris worms obtained from a dead golden snub-nosed monkey, to better understand their taxonomic status. Morphology indicated that the adult Trichuris worms were similar to T. rhinopiptheroxella. To further ascertain their phylogenetic position, the complete mitochondrial (mt) genome of these worms was sequenced and characterized. The mt genome of T. rhinopiptheroxella is 14,186 bp, encoding 37 genes. Phylogenetic analysis based on the concatenated amino acids of 12 protein-coding genes (with the exception of atp8) indicated that T. rhinopiptheroxella was genetically distinct and exhibited 27.5–27.8% genetic distance between T. rhinopiptheroxella and other Trichuris spp. Our results support T. rhinopiptheroxella as a valid Trichuris species and suggest that mt DNA could serve as a marker for future studies on the classification, evolution and molecular epidemiology of Trichuris spp. from golden snub-nosed monkeys.

The Amazon region may present a high diversity of endoparasites with a high degree of endemism. In this sense, this study describes the endoparasite fauna in freshwater fish from the Upper Juruá, in the Western Amazon. The study was carried out around the municipalities of Cruzeiro do Sul, state of Acre, and Guajará, state of Amazonas, Brazil. Fish were caught between periods of droughts and floods, using passive and active sampling methods. In the laboratory, specimens were biometrically analysed and necropsied. As a result, a total of 23,740 endoparasites were recorded, belonging to 62 species, with 91 new host reports and 91 new occurrences for the Western Amazon. Nematoda and Digenea were the most diverse and abundant groups, and the increase in host fish richness and diversity influenced the diversity and richness of endoparasites in the environments. In this sense, the present study expands the number of new reports, and contributes data on the distribution and richness of endoparasites for South America.

We suggest helminthological investigations of cod as a supplement to traditional biological and hydrographical methods for elucidation of ecological changes in the Baltic Sea. It is under discussion if oxygen deficit or seal abundance should explain the present critical situation of Baltic cod. A comparative investigation of endoparasitic helminths in Baltic cod (Gadus morhua), captured in the same marine habitat with an interval of 35 years (1983/2018) recorded 11 species of helminths comprising trematodes (Hemiurus luehei, Podocotyle atomon, Lepidapedon elongatum), nematodes (Contracaecum osculatum, Hysterothylacium aduncum, Capillaria gracilis, Cucullanus cirratus), cestodes (Bothriocephalus sp.) and acanthocephalans (Echinorhynchus gadi, Pomphorhynchus laevis, Corynosoma semerme). Significant prevalence and intensity increases were recorded for third-stage larvae of the nematode C. osculatum (liver location) and larvae of C. semerme (encapsulated in viscera). Both parasite species use grey seal as their final host, indicating the recent expansion of the Baltic seal population. A lower E. gadi intensity and an increased prevalence of L. elongatum of small cod (31–40 cm body length) suggest a lowered intake of amphipods (intermediate host) and elevated ingestion of polychaetes, respectively, but no significant changes were seen for other helminths.