The association between visual hepatic damage, burden of Fasciola gigantica, serum levels of gamma glutamyl transferase (GGT) and glutamate dehydrogenase (GLDH) is described from an abattoir study of 70 cattle in the Philippines. In another abattoir study of 60 cattle, the relationship between burden of F. gigantica and haematological indices was investigated. The degree of visual hepatic damage and burden of F. gigantica were significantly positively related to levels of GGT and GLDH. Red blood cell counts and packed cell volume were significantly inversely related to worm burden, but animals compensated for reduced numbers of red blood cells by increasing red cell haemoglobin content.

Hookworms are known to cause marked changes to the intestinal mucosa, especially in relation to erosion of the villi. However, since the development of enteropathy has not been examined thoroughly through quantitative experiments on infected animals, the results of experiments conducted in hamsters infected with Ancylostoma ceylanicum are reported. Changes to intestinal architecture were first apparent between 12 and 14 days after infection, and then increased in intensity for 3–4 weeks, persisting for as long as worms were present (>63 days). Following infection, the height of villi declined from a mean of 1002 μm in naïve controls to less than 200 μm and as low as 18 μm in one case. The depth of the crypts of Lieberkuhn increased from a baseline value of 166 μm in naïve controls to in excess of 600 μm within 6 weeks of infection. Mitotic figures had a baseline value of 5.5 per villus-crypt unit, and this rose to in excess of 25 in some experiments. Changes were dependent on the intensity of the parasite burden on day 20, but by 30 days after infection changes in all three values were maximal and density-dependent relationships were no longer clearly apparent. Villus height and crypt depth returned to near normal values within a week of the removal of worms, although group means for both remained different from naïve controls for at least 3 weeks after treatment. Cellular division, as reflected in numbers of mitotic figures, stayed elevated for over 5 weeks after removal of worms. The results suggest that enteropathy in hookworm infections stems from a combination of intestinal immune responses and from the grazing activities of the adult worms on the mucosal surface, but is not sufficient per se for expulsion of this parasite.

Parasite heterogeneity is thought to be an important factor influencing the likelihood and the dynamics of infection. Previous studies have demonstrated that simultaneous exposure of hosts to a heterogeneous mixture of parasites might increase infection success. Here this view is extended towards the effect of parasite heterogeneity on subsequent infections. Using a system of the tapeworm Schistocephalus solidus and its copepod intermediate host, heterogeneity of the tapeworm surface carbohydrates is investigated, i.e. structures that are potentially recognized by the invertebrate host's immune system. With lectin labelling, a significant proportion of variation in surface carbohydrates is related to differences in worm sibships (i.e. families). Tapeworm sibships were used for experimental exposure of copepods to either homogeneous combinations of tapeworm larvae, i.e. worms derived from the same sibship or heterogeneous mixtures of larvae, and copepods were subsequently challenged with an unrelated larva to study re-infection. Contrary to expectation, neither an effect of parasite heterogeneity on the current infection, nor on re-infection were found. The effect of parasitic heterogeneity on host immunity is therefore complex, potentially involving increased cross-protection on the one hand, with higher costs of raising a more heterogeneous immune response on the other.

To estimate prevalence of amphistomiasis and its association with bovine Fasciola gigantica infections in Zambia, 709 faeces of cattle presented for slaughter from three major cattle rearing areas of Central, Southern and Western provinces were analysed. The prevalence rate of amphistomes was 51.6%. Egg counts per gram (EPG) of faeces ranged from 0 to 385 with a mean (± SEM) of 11.96±1.07. The origin of the cattle had a significant influence (P<0.001) on the prevalence rate. Fasciola gigantica infections accounted for 46.7% of the cattle examined. The mean EPG count (± SEM) was 6.3±0.66 with a range of 0 to 223. A total of 34.6% were mixed infections while single Fasciola and amphistome infections represented 12.1% and 17.1%, respectively. Significantly more cattle (63.8%) were infected with either single or both trematode infections (P<0.0001) than not. Mixed trematode infections were highest in the Southern province (80.0%) while the lowest were recorded in Central province (16.3%). A positive correlation (r2=0.0428) was present in mixed infections. In order to minimize losses, epidemiology and cross-resistance of amphistomiasis and fascioliasis should be studied in different ecological regions of Zambia to formulate efficient control programmes.

In Great Britain free-living common pheasants Phasianus colchicus are often managed at high densities owing to their popularity as a quarry species. They are prone to infection by a range of parasite species including Heterakis gallinarum, Capillaria spp. and Syngamus trachea. In 1995 the efficacy of an indirect anthelmintic technique for controlling parasitic worm burdens of pheasants was determined in a pilot study on a shooting estate in the south of England. Between 2000 and 2003 a large-scale field experiment was conducted on nine estates in eastern England to determine the effect of the technique on parasite burden and pheasant breeding success. In the absence of anthelmintic treatment worm burdens increased rapidly through March and April, whereas birds given anthelmintic-treated grain had lower worm burdens during the same period. The breeding success of pheasants was significantly higher on plots provided with anthelmintic treatment, although no long-term increases in population densities were observed. The burdens of the most common parasite H. gallinarum were significantly lower in pheasants from treatment plots six weeks after the anthelmintic treatment had ceased, but spring treatment did not influence parasite burden in the following winter.

The value of tongue and meat inspection as diagnostic tools for porcine cysticercosis was assessed in 65 Zambian village pigs by comparing the results with carcass dissections. In addition, the intensity of infections, distribution and viability of cysts in infected pigs were measured. Five pigs (7.7%) were positive on tongue examination, while routine meat inspection showed 12 (18.5%) positives. However, carcass dissections detected cysticerci in 31 (47.7%) pigs. The range in number of cysticerci was 1 to 14,662 per carcass. Cysticerci were distributed throughout the carcass with the highest concentration in the heart, tongue and hind legs. In one animal 13 viable cysts were detected only in the brain. Fourteen pigs had more than 100 viable cysts, six between 2 and 100, and four had single cyst infections. Seven animals harboured only calcified cysts. These findings demonstrate the serious shortcomings of routine detection methods for porcine cysticercosis. While the specificity of tongue palpation and meat inspection was 100%, these tests failed to detect the infection in 83.9% and 61.3% of infected pigs, respectively.

The genus Onchocerca (Nematoda: Filarioidea) consists of parasites of ungulate mammals with the exception of O. volvulus, which is a human parasite. The relationship between O. volvulus, O. ochengi and O. gibsoni remains unresolved. Based on morphology of the microfilariae and infective larvae, vector transmission and geographical distribution, O. ochengi and O. volvulus have been placed as sister species. Nevertheless, the cuticle morphology and chromosomal data (O. volvulus and O. gibsoni have n=4 while O. ochengi is n=5) suggest that O. gibsoni could be more closely related to O. volvulus than O. ochengi. Sequences from the 12S rRNA, 16S rRNA and ND5 mitochondrial genes have been used to reconstruct the phylogeny of five Onchocerca species including O. volvulus. Analyses with maximum likelihood and maximum parsimony showed that O. ochengi is the sister species of O. volvulus, in accordance with the classification based on morphology and geographical location. The separate specific status of the species O. gutturosa and O. lienalis was supported, although their phylogenetic relationship was not well resolved. The analyses indicated that the basal species was O. gibsoni, a South-East Asian and Australasian species, but this result was not statistically significant. The possible involvement of sympatric speciation in the evolution of this group of parasites is discussed.

Transmission of the fox tapeworm Echinococcus multilocularis, the causative agent of human alveolar echinococcosis, is known to depend on various environmental factors which are subject to human influence. Epidemiological data suggest that in most endemic regions anthropogenic landscape changes (e.g. deforestation and agricultural practices) have led to more favourable conditions for the parasite's animal hosts, especially arvicolid rodents, thereby increasing the risk for parasite transmission and human disease. Examples are the conversion of forests or crop fields into meadows and pastures in Europe, China and North America, and overgrazing of natural grassland in central Asia. Other anthropogenic factors include interference with host population densities by wildlife disease control, changing hunting pressure and provision of new habitats, e.g. in urban areas. Domestic dogs may, under certain conditions, get involved in the otherwise largely wildlife-based transmission, and thereby greatly increase the infection pressure to humans. The introduction of neozootic host species may increase transmission, or even initiate the parasite's life-cycle in previously non-endemic regions. Lastly, the parasite itself may be accidentally introduced into non-endemic areas, if suitable host populations are present (e.g. in northern Japan).

Specimens of elasmobranchs, collected in the State of Santa Catarina, Brazil, were parasitized with Poecilacanthoidea trypanorhynch cestodes. Sharks of the species Prionace glauca harboured Callitetrarhynchus gracilis and Floriceps saccatus, and those of the species Sphyrna zygaena were infected with Callitetrarhynchus speciosus. Details of the proglottids of F. saccatus, provided by bright-field, and/or scanning electron microscopy, are described. Adults of F. saccatus are reported for the first time in the Brazilian coast.

Among 67 French patients presenting a toxocaral infection, various demographic, environmental, clinical and laboratory parameters (blood eosinophil count, eosinophil cationic protein (ECP), serum total IgE, specific IgE against common inhalant allergens, specific IgE and IgG4 against Toxocara excretory-secretory antigens) were investigated. Correlation studies and logistic regression analyses were conducted, testing elevated levels of ECP, specific anti-Toxocara IgE or IgG4 as outcome variables An elevated ECP level was significantly associated with both cough and rhinitis, a high level of specific anti-Toxocara IgE with itchy rashes and possible atopic status, and an increase of specific anti-Toxocara IgG4 with rural residence.

The immunological, haematological and enzymatic responses to the inoculation in pigs of 100,000 embryonated eggs of Toxocara canis were studied. Fifteen females were inoculated and three remained as controls. Haematological values were analysed from day 7 p.i. until day 126 p.i. In the inoculated group, white blood cells were raised on day 14 p.i. and eosinophil values on days 7, 14, 21, 35 and 49 p.i. showing significant differences compared with controls (P<0.05). Absolute eosinophil counts (per ml) presented two rises, the first on days 7, 14 and 21 p.i. and the second on days 35 and 49 p.i. Blood biochemistry was maintained within normal values. Serological examination by ELISA to determine antibody levels against Toxocara canis L2/L3 excretory–secretory (ES) antigens showed values higher than the positive cut-off (1:32) from day 7 p.i. and until the end of the study on day 126 p.i., presenting two peaks: one on day 28 p.i. and the second covering days 49 to 56 p.i. Western blots of sera of inoculated animals presented, from day 7 p.i., two polypeptide bands of 55 and 70 kDa MW and, from day 56 p.i., an additional band of 120 kDa MW, all of which persisted until the end of the study. Immunological responses were sustained over time. No direct correlation was observed between the rise in eosinophils and antibody titres. To validate the conclusions, more studies are required on the polypeptide bands.

The first human infection with Gongylonema in Iran is reported in a 35-year-old Iranian woman with complaints of one year duration and treated as a psychotic patient. Two worms, a male, and a female, were retrieved, described, and identified as G. pulchrum based on their morphological characteristics.

Plasma etching and ashing for demonstrating the three-dimensional ultrastructure of the internal organs of helminths is described. Adult worms of the cestode Caryophyllaeides fennica were dehydrated through an ethanol series, critical point dried (Polaron E3000) and sputter coated with 60% gold-palladium (Polaron E5100) and glued to a standard scanning electron microscope (SEM) stub positioned as required for ashing. After initial SEM viewing of worm surfaces for orientation, stubs were placed individually in the reactor chamber of a PT7150 plasma etching and ashing machine. Worms were exposed to a radio frequency (RF) potential in a low pressure (0.2 mbar) oxygen atmosphere at room temperature. The oxidation process was controlled by varying the times of exposure to the RF potential between 2 to 30 min, depending on the depth of surface tissue to be removed to expose target organs or tissues. After each exposure the oxidized layer was blown from the surface with compressed air, the specimen sputter-coated, and viewed by SEM. The procedure was repeated as necessary, to progressively expose successive layers. Fine details of organs, cells within, and cell contents were revealed. Ashing has the advantage of providing three dimensional images of the arrangement of organs that are impossible to visualize by any other procedure, for example facilitating testes counts in cestodes. Both freshly-fixed and long-term stored helminths can be ashed. Ashing times to obtain the desired results were determined by trial so that some duplicate material was needed.

The prevalence and potential zoonotic risk factors of intestinal nematodes of military working dogs, which are used for different military purposes, were assessed. Faecal samples from 352 defined-breed Turkish military dogs were investigated and 107 (30.4%) dogs were found to be infected with one or two nematode species. The following nematodes, with their respective prevalences, were diagnosed in the faecal samples: Toxascaris leonina (21.8%), Toxocara canis (13.3%), Trichuris vulpis (2.9%) and Uncinaria stenocephala (1.2%). Toxocara canis infections were more frequently seen in puppies (0–6 months old). The prevalence of T. canis was significantly higher in male than in female dogs and also higher in dogs which were exercised daily than in those without exercise. The highest prevalence was found in Belgian malinois breed dogs. Toxocara canis infections were not influenced by the floor type of the kennels (i.e. concrete or soil floor). There was no difference in the occurrence of T. canis infection when the last anthelmintic treatment was carried out less or more than 3 months prior to sampling. It is suggested that T. canis infected military dogs would be a threat not only for dog trainers but also for military personnel, notably during national and international operations.

In angiostrongyliasis, chronic parasite-induced granuloma formation can lead to tissue destruction and fibrosis. Here, the histomorphology of granulomatous fibrosis and proteinase production in the lungs of Angiostrongylus cantonensis-infected Sprague-Dawley rats were investigated. The relationship between metalloproteinases and granulomatous fibrosis was investigated following infection of each rat with 60 infective larvae. Granulomata and fibrosis were marked in the lungs of rats on day 180 post-inoculation. Reverse transcriptase polymerase chain reaction of lung mRNA showed an up-expression of proinflammatory cytokine including tumour necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β). According to Western blot analysis, matrix metalloproteinase-2 (MMP-2) proenzyme was presented in the lungs of uninfected and infected rats, and partial conversion of 72 kDa proenzyme to the 64kDa active form occurred in infected rats. In addition, increased protein levels of MMP-9 and MMP-13 were detected in infected lungs, but were undetectable in controls. The results suggest that TNF-α, IL-1β, MMP-2, -9, and -13 may be associated with the granulomatous fibrosis.

Adult male worms of Trichobilharzia sp. recovered from a pied wagtail (Motacilla alba) in the Czech Republic were found to belong to a new species of the genus. The finding of Trichobilharzia sp. in a passeriform bird in Europe represents an important discovery, as only anseriform birds have thus far been reported as final hosts of the European Trichobilharzia species.

The production of parasite transmission stages was investigated in the faeces of 77 farm-bred ring-necked pheasants (Phasianus colchicus). Coccidian oocysts (Eimeria sp.), and nematode eggs (Heterakis sp., and Capillaria-like eggs) were recovered before and after release but all birds were treated prior to release. Treatment with fenbendazole significantly reduced the abundance of transmission-stage excretion for all parasites, and reduced the prevalence in the case of Eimeria sp. and Heterakis sp. Nonetheless, a significant increase in the excretion abundance for all parasites and in the prevalence of Eimeria sp. and Heterakis sp. was found after release. Eggs of Ascaridia sp. were found only after releasing, suggesting infection ocurred in the wild. A negative relationship was found between the pheasant body condition and Heterakis excretion abundance and a higher abundance of Capillaria sp. eggs in female birds. No significant relationship was found between parasite excretion abundance and pheasant survival. Despite this, results suggest that an increase in the excretion of parasite transmission stages follows the release of captive pheasants into the wild. This can in part explain restocking failures, but also means that autochtonous free-living birds may become exposed to new and potentially harmful pathogens. To avoid these risks it is proposed that improved prophylactic measures should be taken.

Hard structures of helminths have often been used for taxonomic identification but are usually not clearly defined when treated with conventional methods such as ammonium picrate-glycerin for monogeneans and glycerin for nematodes. The present study reports a rapid and simple technique to better resolve the hard parts of selected monogeneans and nematodes using 5–10% alkaline sodium dodecyl sulphate (SDS). In comparison with established methods, SDS-treated worms become more transparent. In monogeneans treated with SDS, clear details of the hooks, hook filaments, anchors, bars and the sclerotized copulatory organs could be observed. In SDS-treated nematodes, spicules and ornamentations of the buccal capsules could be clearly seen.

Clinical and serological investigations on 175 cattle were carried out in 1999 at the slaughterhouse of Jijel, northeastern Algeria, to verify if partial ablation of a liver infected with Fasciola hepatica represents a good epidemiological indicator in the case of fasciolosis, as partial excision of the liver is widespread throughout North African countries. This study was also performed to determine if there is a direct relationship between the quantity of liver confiscated for fasciolosis and the serological response of slaughtered animals. A significant relationship between highly infected livers and positive serological titres was noted. However, two groups of results were conflicting: the presence of macroscopically healthy, undamaged livers with a positive serology (8.3% of 120 cattle), or the existence of highly damaged livers with a negative serology (13.0% of 31 cattle). These results indicate that partial removal of the liver in the case of fasciolosis is unreliable, so this method does not represent a good tool to establish epidemiological data on this disease.

The infectivity of Echinostoma friedi (Trematoda: Echinostomatidae) miracidia was studied experimentally in a range of laboratory-reared snails that coexist in the same natural locality, namely Radix peregra, Lymnaea fuscus, L. truncatula (Lymnaeidae), Gyraulus chinensis, Helisoma duryi (Planorbidae) and Physella acuta (Physidae), and snails from different geographical origins acting naturally or experimentally as intermediate hosts of Schistosoma spp., namely Planorbarius metidjensis (from Málaga, Spain), Biomphalaria glabrata (Guadeloupe), B. alexandrina (Egypt) (Planorbidae), Bulinus cernicus (Mauritius), B. globosus (Zambia), B. natalensis (South Africa) and B. truncatus (Niger) (Bulinidae). Six species of snails were found to be susceptible, with the rate of infection ranging from 0 to 36.7%. The highest infection was detected in R. peregra. The low host specificity of E. friedi might have an epidemiological significance as a requisite for a recent establishment in a new geographical area.