In a paper published towards the end of last year the author (Goodey, 1927) described a new free-living species of Aphelenchus, A. winchesi, and dealt with the type species of the genus A. avenæ, discussing its affinities to certain nearly related species. A further paper was promised dealing with the various species of the genus and the present communication is an attempt to fulfil that promise.

Intestinal infection continues to be a problem worldwide and helminths, which currently infect billions of individuals, are primary culprits. The major burden of disease falls on the populations of developing countries, given that over the last four to five decades helminth infections are disappearing in industrialized societies. In developing countries, a major source of immunomodulatory signals in post-natal life are parasites, particularly helminths, which, unlike most bacteria and viruses, selectively stimulate Th2 function. Helminths and their eggs are probably the most potent stimulators of mucosal Th2 responses. Responses elicited by worms can modulate immune reactions to other parasites, bacterial, viral infections and several unrelated diseases. Bacterial and protozoal infections may also protect against atopy and asthma, through the induction of the Th1 regulatory responses. Today, people in developed countries often live in ultra-hygienic environments, avoiding exposure to viruses, bacteria, ectoparasites and endoparasites, particularly helminths. Perhaps failure to acquire worms and experience mucosal Th2 conditioning predisposes to unrelated diseases. In contrast to this hypothesis it has also been suggested that Th2 responses can make the host more susceptible to other important diseases and to contribute to the spread of them.

Parasitic nematodes of the family Mermithidae were found to be infecting the introduced European earwig Forficula auricularia (Dermaptera: Forficulidae) in Dunedin, South Island, New Zealand. Adult females were later collected from various garden plants while depositing eggs. These mermithid specimens were identified morphologically as Mermis nigrescens Dujardin, 1842. A genetic distance of 0.7% between these specimens and a M. nigrescens isolate from Canada (18S rRNA gene), suggests that they have diverged genetically, but there are currently no available comparable sequences for the European M. nigrescens. Two additional nuclear fragments were also amplified, the 28S rRNA and the ribosomal DNA first internal transcribed spacer (ITS1), providing a basis for future studies. Bearing in mind the morphological similarity with other reported M. nigrescens and the lack of sequence data from other parts of the world, we retain the name M.nigrescens, and suggest that the species may be found to represent a complex of cryptic species when more worldwide data are available. Herein, we present a brief description of the post-parasitic worms and adult females, along with an inferred phylogeny using 18S rRNA gene sequences.

A study of several samples of young conical flukes reared from metacercariae obtained by the late Dr. P. L. LeRoux from certain fresh water snails has resulted in the following findings.

It appears that the species which caused the severe intestinal paramphistomiasis amongst sheep described by LeRoux (1930) in South Africa was Paramphistomum microbothrium Fischoeder, not Cotylophoron cotyhphorum (Fischoeder) as was thought at the time and subsequently repeated in all the text books and reviews on paramphistomiasis published afterwards.

The biological behaviour and morphometric data from two allopatric isolates of Echinostoma paraensei (Rio Bonito – RB and Sumidouro – SU) collected from naturally infected Nectomys squamipes from two secluded Atlantic Forest fragments were studied. Mice that had been experimentally infected with ten encysted metacercariae of each isolate were monitored weekly in two trials to analyse worm burden and the kinetics of worm distribution along the intestine. The total number of uterine eggs, wet weights and measurements of the worms and body, acetabulum, testes and ovaries were also analysed. The RB isolate showed a higher worm burden, 7.7±0.8, and a longer life span, 16 weeks, compared to a worm burden of 5.8±1.1 and life span of 9 weeks for the SU isolate. Worms of the RB isolate were clustered in the duodenum and in the bile duct while the SU isolate worms were dispersed along the small intestine of infected mice. Both isolates developed similarly as regards morphometric data and wet weight, although the total number of uterine eggs was greater in RB. The degree of intraspecific variation observed in the worm distribution along the intestine, worm burden and life span raises questions regarding the use of these criteria for species differentiation. These findings suggest that variation in biological parameters found between the E. paraensei isolates could result from geographical isolation and, in particular, the environmental conditions of transmission. Further studies on E. paraensei polulations from different forest fragments will contribute towards an understanding of the speciation of this parasite.

Skin mucous cells and mucus from four salmonids (rainbow trout, brown trout, Conon salmon, Iijoki salmon) with different susceptibilities to infection with Gyrodactylus derjavini and G. salaris were partly characterized by cytochemistry, immunoblotting and immunocytochemistry. Mucous cell densities in various fin types were partly correlated with resistance to infection with G. derjavini but not with G. salaris. Lectin binding assays indicated slight differences in carbohydrate composition of mucus from the four salmonids but serum antigens specific for salmonids were found in mucus from all of them. Antisera against salmon immunoglobulin and rainbow trout complement factor C3 reacted with mucus from all of the salmonids but not with mucus from phylogenetically unrelated fish. Antisera raised against ACTH reacted with mucus components from rainbow trout, brown trout and Conon salmon but not with mucus from Iijoki salmon. These findings are discussed in relation to the host specificity of ectoparasites and susceptibility to infection.

In Finland during 2003–2005, large numbers of nematodes, tentatively identified as Setaria sp., were observed in the peritoneal cavity of reindeer Rangifer tarandus during a peritonitis outbreak associated with poor body condition. The morphology of worms recovered from slaughtered reindeer is described based on light and scanning electron microscopy. Worms were confirmed as belonging to the superfamily Filarioidea by the presence of microfilariae-producing females and the size and the shape of the male spicules. Further classification to the genus Setaria was based on the location of worms in the peritoneal cavity and the morphology of spicules and the peribuccal crown. The present measurements correlate with those in the description of Setaria tundra by Rajewsky (1929) and only minor differences were present compared with descriptions of key parts of identification of S. yehi from the American white-tailed deer Odocoileus virginianus and mule deer O. hemionus. Current morphological findings support our earlier studies employing a polymerase chain reaction and confirm the occurrence S. tundra in reindeer in Finland.

The presence of vitelline cells in male Schistosoma mansoni from both mixed and single sex infections in mice is described.

Ultrastructurally these vitelline cells resemble the mature, Stage 4 cells from normal female worms. As yet no developing vitelline cells (Stages 1 to 3) have been found. The cells do not appear to form complete lobules as in the female.

The tropidurid lizard Tropidurus hispidus has a wide distribution in South America. However, knowledge about its helminth fauna is patchy and has been reported for only a few localities along its range of distribution. This study presents data on helminth fauna composition and parameters of infection for a population of T. hispidus from an area within the Brazilian Caatinga biome (semi-arid physiognomy). We found five nematode species within the gastrointestinal tract of lizards: Parapharyngodonsceleratus (Pharyngodonidae); Physalopteralutzi, Physalopteraretusa and Physalopteroidesvenancioi (Physalopteridae); and Strongylurisoscari (Heterakidae). The overall prevalence was 84.2% and the mean intensity of infection was 8.5 ± 1.1. The body size of adult male lizards influenced positively the intensity of infection. The infracommunities of nematodes presented an intermediate aggregated distribution (discrepancy index; D= 0.519) and a depauperate nematode fauna. The presence of generalist parasite species has contributed to an increase in the overall richness of the component community. This sampled host population presented the highest prevalence of parasites compared with other studies on T. hispidus, but their relatively low richness can be related to the disturbed environment of the study area.

Eosinophilic meningitis or meningoencephalitis caused by Angiostrongylus cantonensis is endemic to the Pacific area of Asia, especially Taiwan, Thailand, and Japan. Although eosinophilia is an important clinical manifestation of A. cantonensis infection, the role of eosinophils in the progress of the infection remains to be elucidated. In this experiment, we show that A. cantonensis-induced eosinophilia and inflammation might lead to the induction of IAP/NF-κB, JAK/STAT1 and MEKK1/JNK signals. The phosphorylation levels of JAK and JNK, STAT1, IAP, NF-κB and MEKK1 protein products were significantly increased after 12 days or 15 days of A. cantonensis infection. However, no significant differences in MAPKs such as Raf, MEK-1, ERK1/2 and p38 expression were found between control and infected mice. The activation potency of JAK/STAT1, IAP/NF-κB and MEKK1/JNK started increasing on day 3, with significant induction on day 12 or day 15 after A. cantonensis infection. Consistent results were noted in the pathological observations, including eosinophilia, leukocyte infiltration, granulomatous reactions, and time responses in the brain tissues of infected mice. These data suggest that the development of brain injury by eosinophilia of A. cantonensis infection is associated with activation of JAK/STAT1 signals by cytokines, and/or activation of MEKK1/JNK by oxidant stress, and/or activation of NF-κB by increasing IAP expression.

The aims of this study were to investigate the prevalence of Moniezia spp. in domestic ruminants in central Vietnam and to develop a polymerase chain reaction (PCR) technique to distinguish M. expansa from M. benedeni. Among 2040 examined domestic animals (540 cattle, 800 goats, 700 sheep) Moniezia was recovered from 5.4% of cattle, 16.4% of sheep and 20.6% of goats. A set of primers for PCR was designed to classify M. expansa and M. benedeni based on the amplification of DNA corresponding to the internal transcribed spacer of 5.8S rRNA. The 457 specimens (75 from cattle, 162 from goats, 150 from sheep, 30 from horses, 30 from chickens and 10 from dogs) were subjected to PCR for classification of Moniezia spp. PCR products with the expected sizes were amplified from bovine, ovine and caprine specimens. No specific PCR products were found for specimens from horses, chickens and dogs. Of the 75 specimens from cattle, nine were classified as M. expansa and 66 were M. benedeni. Among 162 caprine specimens, 138 were M. expansa and 24 were M. benedeni. The distribution of M. expansa and M. benedeni in 150 ovine specimens was 132 and 18, respectively. These results show that M. expansa is dominant in goats and sheep, whereas M. benedeni is more common in cattle; PCR can be used for classification of these two species.

The objective of this cross-sectional study was to determine the prevalence and intensity of soil-transmitted helminths (STHs) in children aged 0–25 months and to identify the associated risk factors for Ascaris lumbricoides infections. The study was conducted in three villages outside Ile-Ife, Osun state, Nigeria in May/June 2005. Stool samples (369) were processed by formol-ether concentration. Ascaris lumbricoides (12.2%) was the dominant infection. Age, father's occupation and dog ownership were identified as the significant risk factors in the minimal adequate model for A. lumbricoides. The odds of being infected with A. lumbricoides increased as the children got older. Children aged 12–17 months and 18–25 months were 8.8 and 12.4 times, respectively, more likely to harbour Ascaris than those aged 7–11 months. The odds of harbouring Ascaris for children whose families owned a dog were 3.5 times that of children whose families did not own a dog. Children whose fathers were businessmen were 0.4 times less likely to be infected with Ascaris than those whose fathers were farmers. The findings from this study suggest that many of these young children, who are at a critical stage of development, are infected with Ascaris and that the prevalence of infection with this parasite increases with age. This study has highlighted the need to incorporate preschool children into deworming programmes in endemic regions and to investigate innovative ways of delivering cost-effective deworming treatment to this high-risk age group.

Population genetics seeks to understand the genetic relationships within and between populations of a species and the processes that generate these patterns. Little is known about the population genetics of parasitic nematodes. This is a notable gap in our knowledge since understanding the population genetic patterns and processes of parasitic nematodes has profound implications for our ability to fully understand this important group of pathogens. For example, it is only possible to begin to understand how a parasite population will respond to an imposed selection pressure (such as an anthelmintic drug, a vaccine, or resistant hosts) when the population genetic structure and patterns of gene flow of that population is known. Equally, the epidemiology of many nematode parasites is well known empirically and theoretically, yet this epidemiological information is of limited use without a good understanding of the genetic structure of those populations (Anderson & May, 1992).

Host responses to primary infections with Heligmosomoides polygyrus were studied in fast responding FVB mice (H-2q). Pathological changes in the intestinal mucosa, mesenteric lymph nodes and spleen were examined. Features of the fast response were typical: low effectiveness of infection and limiting of parasite survival and egg production, with worm expulsion occurring about 60 days post-infection. The intestinal inflammatory response involved infiltration by different cells into the intestinal mucosa and granulomata formation. As is typical for intestinal nematode infection enteropathy, decreased villus:crypt ratio and hyperplasia of goblet and Paneth cells were also present. Reactions of the intestinal mucosa, mesenteric lymph nodes and spleen increased over time post-infection and after worm expulsion. Enteropathy may help worm expulsion by creating an unfavourable environment for H. polygyrus. The implications of these findings and the potential role of intestinal intraepithelial lymphocytes in the pathogenesis of generated lesions are discussed.

Human toxocariasis, a worldwide parasitic disease, is caused by the larval stage of intestinal nematodes of dogs and cats, namely Toxocara canis and Toxocara cati. Human infection occurs by the accidental ingestion of embryonated eggs present in the soil, vegetables or on other contaminated surfaces, as well as via consumption of uncooked paratenic hosts, such as bird meat and giblets. The objective of this study was to evaluate the contamination of soil in public parks and playgrounds in Shiraz using microscopy and molecular methods. A total of 150 soil samples were collected from public parks and playgrounds in various areas of Shiraz, southern Iran. The samples were treated with saturated zinc sulphate solution, and Toxocara spp. eggs were detected by microscopic observation followed by nested polymerase chain reaction (PCR). To differentiate T. canis and T. cati eggs from each other, PCR restriction fragment length polymorphism (RFLP) of the internal transcribed spacer (ITS)-rDNA region by SalI endonuclease enzyme was used. PCR-sequencing was performed to confirm the results of the PCR-RFLP method. Based on the flotation results of the 150 soil samples, six (4%) were found to be positive for Toxocara spp. eggs, whereas nested-PCR showed 24 samples to be positive (16%). Based on the PCR-RFLP method and the sequence of the ITS-rDNA region, a total of 23 out of 24 isolates were confirmed as T. cati and one out of 24 as T. canis. The results showed a higher number of soil samples to be positive for Toxocara by the molecular method than microscopy, and higher T. cati infection in soil samples, which could have an important role in human infection with toxocariasis in this region.

This study aimed to evaluate the helminth parasites of Geophagus proximus from the São José dos Dourados River, a tributary of Paraná River, Ilha Solteira Reservoir, São Paulo State, Brazil. From May 2006 to May 2007, 116 G. proximus specimens were examined and seven different taxa of helminth were collected and identified: proteocephalidean plerocercoids (Cestoda); metacercariae of Austrodiplostomumcompactum, Clinostomum heluans and Clinostomum sp. (Trematoda); and Raphidascaris (Sprentascaris) hypostomi, and larvae of Raphidascaris sp. and Contracaecum sp. (Nematoda). All parasites presented the typical aggregated pattern of distribution, as well as the presence of a high number of larval stages, an absence of influence of the host sex and seasonality upon community parameters, as well as a correlation between species richness and host body weight. Moreover, with the exception of A. compactum metacercariae, all helminths found in this study are reported for the first time in G. proximus.

Sixty-one serum samples selected on the basis of reactivity in the complement fixation (CF) and latex agglutination (LA) test, were further examined for sensitivity and specificity by indirect haemagglutination (IHA), enzyme linked immunosorbent assay (ELISA) and defined antigen substrate spheres (DASS). Twenty sera from healthy Europeans and 48 samples from patients with either schistosomiasis or trichinosis were also tested. Comparable levels of sensitivity were found between the CF and LA positive sera and IHA, ELISA and DASS. Of the CF positive LA negative group of sera, many were positive by DASS but only a few reacted in IHA and ELISA. Some cross reactivity was also observed in the schistosomiasis sera tested by IHA and ELISA.

Haemonchus contortus and Haemonchus placei are among the major parasites of small ruminants and cattle. Although infection with these nematodes is host-specific, with H. placei predominating in cattle and H. contortus in sheep, cross-infections are observed in areas where both parasites are sympatric, and hybrid offspring can occur. Therefore, a fast and precise method is required for differentiating the parasites. Identification based on spicule morphometry is the most common technique for differentiating Haemonchus species. However, because these measurements overlap between species, morphological analysis is insufficient for differentiating between helminth species. In this work, we present a reliable, conventional polymerase chain reaction (PCR)-based method that uses two species-specific primer pairs to differentiate between H. contortus and H. placei specimens and their hybrids. Each primer pair produces one single and distinct amplification band for each species, which enables the detection of hybrid specimens. These primer pairs were validated by testing eight different populations of H. contortus, H. placei and hybrids.

Game bird farming is associated with high parasite levels that reduce farm productivity, reduce survival after releasing, and may pose a health risk for natural populations. The efficacy of albendazole (orally, 20 mg kg− 1) was evaluated in farmed red-legged partridges naturally infected with the nematodes Aonchotheca caudinflata and Heterakis gallinarum. In treated birds body condition improved, nematode egg deposition was reduced and the proportion of gravid A. caudinflata females was reduced, but not the overall worm burdens. Albendazole was found to be 36.8% and 17.1% effective against A. caudinflata and H. gallinarum, respectively. These results indicate that the anthelmintic treatment used normally in Spanish partridge farms is not effective enough to avoid the introduction of parasites into the field after release.

1. B. glabrata exposed to the sublethal concentrations (0·04 ppm, 0·03 ppm and 0·02 ppm) of TPLA died from the effects of the molluscicide over a period of time. Most of the deaths occurred between the 10th and 35th days after treatment, showing that although TPLA is slow acting, its effect is not continuous but restricted to a limited period of time.

2. 0·01 ppm of TPLA was chosen as a sublethal concentration to study the effect of the molluscicide on the development of S. mansoni in B. glabrata.

3. 240 B. glabrata were infected with S. mansoni, and 40 of these were treated with 0·01 ppm of TPLA 4 days before infection. The remaining 200 were divided into 5 groups of 40 each, one group being maintained as a control and the other four treated 2, 10,15 and 20 days postinfection respectively. Other suitable controls for comparison were also maintained.

4. The infection rate in all groups was high, and comparison with the control showed that there was no significant difference in infection rate between the treated groups and the control group at the 5% level. However, the infection rate in the preinfection treated group was lower than in the control group and significant at the 10% level.