In Africa, most schistosomiasis control programmes defined the age 5–19 years as the target population for nationwide control through the school systems, excluding the under fives. A study was therefore undertaken to determine the prevalence and intensity of genitourinary schistosomiasis in children aged 0–5 years (pre-primary) in Adim, a rural and endemic community within the Cross River Basin, Nigeria. Of the 126 children examined, 25 (19.8%) were infected with Schistosoma haematobium, with no significant difference (P > 0.05) in infection rates between boys (21.1%) and girls (18.2%). Both prevalence and intensity of infection increased significantly (P <  0.05) with age. The overall geometric mean egg count was 5.9 eggs/10 ml urine. There was no significant association (P > 0.05) between intensity in boys (6.2 eggs/10 ml urine) and girls (5.6 eggs/10 ml urine). A total of 32.5 and 27.8% of the children had haematuria and proteinuria, respectively; it was not gender specific (P > 0.05). Six species of snail were encountered, with Bulinus globosus being the most abundant and widespread. The results of this study have shown that pre-primary schoolchildren are a source of transmission of schistosomiasis in endemic communities and should be integrated into any control intervention.

The life cycle of a new haploporid digenean, Hapladena gymnocephali sp. nov., infecting the bald glassy perchlet Ambassis gymnocephalus from the Chaliyar and Kadalundi rivers of Kozhikode district, Kerala, India, is elucidated. The new species is described in detail, its systematic position discussed and compared with related species, H. acanthuri Siddiqi & Cable, 1960 and H. spinosa Manter & Pritchard, 1961. Hapladena gymnocephali is distinctly different from the two latter species in the shape and size of body, nature of testis, extent of vitelline field and excretory bladder. Hapladena gymnocephali has a typical haploporid, two-host life cycle: the gymnocephalous, bi-ocellate, distome cercariae released by the snail Gabbia travancorica are ingested by the fish and develop directly into adults without undergoing a metacercarial stage of development. This is the first report of the genus Hapladena from India, and also the first report of the life cycle of the genus.

The relationship between the exposure of organisms to chemicals and subsequent alterations in various biochemical processes (commonly referred to as biomarkers) is of growing importance in environmental and ecotoxicological research. However, parasites which also affect the physiological homeostasis of their hosts, and thus may alter biomarker reactions, are usually ignored in environmental research. To address this deficit, we have used the host–parasite system Gammarus roeseli naturally infected with cystacanths of the acanthocephalan Polymorphus minutus to investigate whether infection of gammarids with parasites alters their heat shock protein response following exposure to palladium (Pd). After 24 days of metal exposure relative levels of heat shock protein hsp70 were analysed in the tissues of parasites and intermediate hosts. Simultaneously, the metal accumulation in gammarids and parasites was determined. As none of the infected gammarids showed hsp70 levels at the end of the Pd exposure (either exposed or not), infected and unparasitized G. roeseli were exposed to heat. Again, only uninfected gammarids showed a temperature-dependent increase in hsp70 levels. Interestingly, although the intermediate hosts showed no hsp70 response, exposure to Pd and heat results in increasing hsp70 in the parasites within in the haemocoel of G. roeseli. Heat experiments with isolated cystacanths also showed increasing hsp70 levels in P. minutus with temperature. Concerning uninfected G. roeseli, exposure to Pd and heat causes a hsp70 response. Pd concentrations were found to be higher in the larval parasites than in the gammarids. This result clearly contradicts previous results, as high metal accumulation was so far only described from adult acanthocephalans. Our findings provide experimental evidence that parasites alter the biomarker responses of their host and that the infection status of test animals is extremely important for ecotoxicological studies.

A total of 549 birds from four orders were examined for nematodes in their respiratory system from 1995 to 2000. Twelve individuals of Falconiformes (n = 503), one of Gruiformes (n = 22) and one of Ciconiformes (n = 1), but no bird of the order Strigiformes (n = 23) were infected with syngamids. The syngamid species included Hovorkonema variegatum, Syngamus trachea and Cyathostoma trifurcatum from the trachea, bronchi and air sacs, with H. variegatum being the most prevalent. Cyathostoma trifurcatum from a black stork Ciconia nigra is a new record for Germany. The marsh harrier Circus aeruginosus and the white-tailed sea eagle Haliaeetus albicilla are new hosts for H. variegatum. Morphological characters such as the dorsal rays of the bursa copulatrix, length of the spicules and the mouth capsule are used to differentiate species of the family Syngamidae. Egg size is different between S. trachea and H. variegatum. In addition to morphological characters, the nucleotide sequence of the SSU ribosomal gene was determined for H. variegatum. Pairwise comparisons with the SSU sequence of S. trachea (AF036606) revealed sequence difference of 2.6%. The nucleotide sequence of the second internal transcribed spacer of ribosomal DNA for different populations of H. variegatum was also determined. Pairwise comparisons revealed two separate strains with a sequence difference of 14.0% to 14.5% suggesting the existence of a cryptic species. Pathological findings associated with H. variegatum were found in 7 of 12 cases and consisted of thickened air sac walls and lesions or granuloma at the site of attachment of the worm, which occasionally involved the underlaying tissues. Lymphoplasmocytic air sacculitis was the most prominent histological lesion found.

A polymerase chain reaction (PCR) technique has been used for the differentiation of T. canis and T. cati eggs isolated from soil and previously identified from microscopical observations. The method, using specific primers for the identification of the two Toxocara species, was assessed in both the field and laboratory. Successful results were obtained when only a single or large numbers of eggs were recovered from 40 g soil samples. The method is sensitive, allows analysis of material independent of the stage of egg development and can be adapted for the recovery of other species of parasites from soil.

Using Western blot techniques, the specificities of crude and purified (PAK and PAS) Anisakis simplex antigens were compared against 24 sera from patients diagnosed with Anisakis sensitization. All patients recognized a 60 kDa protein against the A. simplex crude extract, while 37.5% and 12.5% reacted with proteins of 40 and 25 kDa, respectively, when IgG was tested. In the case of IgE determination, 41.6% of sera were negative, while 12.5% and 20.8% appeared to cross-react against Toxocara canis and Ascaris suum, respectively. When the PAK antigen (A. simplex antigen purified by means of a column of IgG anti-A. simplex) was tested, immune recognition towards the 60, 40 and 25 kDa proteins increased in 83.3%, 16.7% and 4.2%, respectively, when the Ig antibodies were tested. In the case of the PAS antigen (PAK antigen purified by means of a column of IgG anti-A. suum), the reaction against the 40 and 25 kDa proteins increased to 45.8% and 25%, respectively, when Ig antibodies were used. Finally, when the EAS antigen (eluted from the anti-A. suum column after PAK purification) was tested, 83.3% of the assayed sera reacted against the 14 kDa protein, when the Ig antibodies, IgG and IgM immunoglobulins were measured. With the IgE determination, the reactions were observed in 41.7% of patients with proteins between 60 and 35 kDa against the PAS antigen. With the EAS antigen, reactive bands of 184, 84 and 14 kDa appeared. In conclusion, in the purification process of the A. simplex larval crude extract, the proteins implicated in cross-reactions with Ascaris and Toxocara were eliminated, with an important concentration of proteins responsible for the induction of specific responses.

The activity of selenium-dependent glutathione peroxidase (GPX), liver concentration of vitamin E, and plasma and liver selenium levels were used for estimation of the antioxidant status of broiler chickens infected with Ascaridia galli. These biomarkers were recorded in an experiment covering 70 days p.i. At the same time the establishment rate of A. galli in chicken intestines, gain in the host body weight and chicken survival were studied. Broiler chickens (Cobb hybrids) were infected with 1450 embryonated A. galli eggs and treated with Sel-plex. A mathematical model was applied to determine the rate of nematode reduction and the relative rate of gain of host body weight, which are essential kinetic parameters of parasite–host interaction. The activity of GPX increased with both elevated selenium and reduced infection levels. The concentrations of selenium and vitamin E, and the GPX activity in the infected chickens demonstrated a similar pattern of change with time after day 30 p.i. The supplementation of the broilers with dietary selenium in the form of Sel-plex improved their antioxidant status. Increases by 29% in vitamin E concentration, 15% in GPX activity, and 22% in liver selenium concentration, respectively, were recorded in the infected and treated, compared to infected and untreated broilers.

The parasite fauna of young-of-the-year herring Clupea harengus L., off Gullmarsfjord and Brofjorden, west coast of Sweden, was studied between May and October for 4 years, from 1994 to 1997. Fifteen species of parasites were found: two Protozoa – Trichodina sp. and Ceratomyxa auerbachi; one species of uncertain affinity – Ichthyophonus hoferi; two Monogenea – Gyrodactylus harengi and Pseudanthocotyloides heterocotyle; five Digenea – Cryptocotyle lingua metacercariae, Cercaria pythionike metacercariae, Hemiurus luehei, Lecithaster confusus and Pseudobacciger harengulae; three Cestoda plerocercoids – Bothriocephalus sp., an acrobothriid and a tetraphyllid; one Nematoda – Hysterothylacium aduncum larva; and one Copepoda – Caligus elongatus. The number of species found in this study represents more than one-sixth of all parasites reported in herring worldwide and all parasites were acquired locally. The parasite fauna of herring from the west coast of Sweden is compared with that of herring from the Baltic Sea and other areas of the north-east Atlantic. The prevalence and intensity of parasites are presented and discussed. Morphological descriptions are based on both light and scanning electron microscopy and new features are described. Possible applications of this new information about the parasite fauna, in different areas of fisheries and fish biology studies, are discussed.

Galactosomum lacteum (Jägerskiöld, 1896) Looss, 1899 metacercariae, encysted on the optic nerve, on the brain and/or on the muscle and the connective of the pharynx and oesophagus, were found in Spicara maena L., S. flexuosa Rafinesque, 1810, S. smaris L. (Centracanthidae), Gobius cruentatus Gmelin, 1789 (Gobiidae), Symphodus tinca L., S. mediterraneus L. (Labridae), Serranus cabrilla L. (Serranidae), Diplodus sargus L. and D. annularis L. (Sparidae) caught in the Gulf of Cagliari (southern Sardinia, Italy). Excysted specimens were identified by some distinctive morphological features: more or less expanded forebody, depending on whether the specimens were living or fixed; tubular excretory bladder extending to the posterior border of the ovary; two-chambered seminal vesicle; asymmetrical and parenchymatous ventral sucker with lines of spines within its cavity; and unarmed gonotyle. Comparison has been made with the congeneric species metacercaria, G. timondavidi Pearson & Prévot, 1971, also registered in the Mediterranean Sea.

The establishment and distribution of Echinoparyphium recurvatum metacercariae in the second intermediate host, Lymnaea peregra, were investigated at a temperature range of 5–29°C. Preliminary studies on the survival and infectivity of E. recurvatum cercariae showed that both parameters were temperature dependent. No cercarial transmission occurred at 5 or 10°C. Nevertheless, the transmission efficiency (1/H0) indicated that transmission was temperature independent in the temperature range 17–25°C and was much lower than in previous studies using this host–parasite system. These differences were attributed to low cercarial densities used in this study. The effect of temperature on encystment site choice (mantle cavity, kidney, pericardium) by metacercariae showed that the mantle cavity was the prime site of encystment, followed by the pericardium and the kidney. Temperatures at the lower and upper ranges (14 and 29°C), however, caused a significant reduction in encystment in the mantle cavity but not in the pericardium or kidney. The importance of cercarial densities, the physiological mechanisms influencing metacercarial distribution and their implications for parasite transmission to the definitive host are discussed.

Faecal egg outputs and subsequent herbage larval contamination with third stage larvae (L3) of Ostertagia spp. and Oesophagostomum spp. from a herd of naturally infected sika deer Cervus nippon were examined in the same pasture in 2001/2002 in Lithuania. Sika deer were infected with Ostertagia circumcincta, O. kolchida, O. spiculoptera, Oesophagostomum radiatum, O. columbianum and O. venulosum. Faecal egg output in adult deer peaked in the spring during the periparturient period and also in late August, compared with a peak in egg output in calves during September to November. Herbage contamination with L3 of Ostertagia spp. peaked in June but larvae were not present on pastures from the end of September. Hence the highest risk of infection was in early born calves grazed on pastures in July. Infective larvae of Oesophagostomum spp. did not survive during the winter, but the nematodes were reintroduced onto the pastures by adult deer in the spring.

Studies on the seasonal population dynamics of Pallisentis (Neosentis) celatus (Acanthocephala: Quadrigyridae) in the intestine of the rice-field eel Monopterus albus from the paddies and ditches in the Dong-ting Lake basin of China, were carried out with samples taken from June 2002 to May 2003. Prevalences were above 21% in all seasons sampled and with a distinct seasonal trend, which was highest (45.81%) in the spring and decreased by degrees. The mean intensity of infection was above 4.0 worms per fish. The maximum intensity of worms recovered from a single fish was 86 in the autumn of 2002. No significant seasonal differences were found in mean intensities, and differences in the mean abundance between winter and spring, winter and autumn were significant. Over-dispersed distributions of P. (N.) celatus in the host population, due to heterogeneity and feeding habits, were observed in all seasons. The size composition of both sexes of P. (N.) celatus showed males between 2.0 mm and 14.0 mm and females between 2.2 mm and 22.2 mm, with the main recruitment phase in the worm populations occurring in the summer and autumn, especially in the autumn, with the lowest recruitment occurring in the winter. The maturation and copulation of worms were mainly focused in the spring season. The sex ratio of female to male was both high in summer (1.09:1) and autumn (1.08:1). The higher proportion of females and the change in the worm sex ratio in summer can be attributed to the reduced longevity of male worms. As immature male worms exhibit a higher proportion of the worm population than females in all seasons, further studies are needed to determine if such a situation compensates for the shorter life span of males.

Histological investigations in Galba truncatula naturally or experimentally co-infected with Fasciola hepatica and Paramphistomum daubneyi were carried out to study parasite development and the responses of the digestive gland and kidney of snails, as larval forms of these digeneans often use these two sites for their growth within the snail's body. The number of live rediae per snail ranged from 2.4 to 4.2 for the dominating parasite (it developed in the digestive gland) and was less than 2.0 for the other species. When the dominating species was F. hepatica, most snails harboured cercariae-containing rediae; if this parasite was P. daubneyi, procercariae-containing rediae with or without free procercariae were observed in most snails. In contrast, most rediae of the other species were immature. The pathology caused by the dominating species in the digestive gland was greater than that recorded in the kidney, where the other parasite was generally located. The most frequent tissue lesions in the digestive gland were generalized epithelial necrosis and epithelial reconstitution. In the kidney, multifocal epithelial necrosis was frequently observed, particularly when P. daubneyi was the dominating species. The frequencies of lesions in the digestive gland agreed with percentages reported by our team in other snails mono-infected with F. hepatica or P. daubneyi. In contrast, multifocal necrosis in the kidney was clearly greater in the present study and this finding might be explained by assuming that a sufficient number of free larvae within the snail would be necessary for the development of epithelial necrosis in the whole kidney.

A total of 984 snails, comprising nine species, were collected from six areas in the Kafue wetlands between August and October 2003 to assess larval trematode infections. Of these, 135 (13.7%) were positive. Most trematode infections were recorded from Lymnaea natalensis (42.8%), which harboured four of the five morphologically different cercariae found. No trematodes were recovered from Bellamya capillata, Biomphalaria pfeifferi, Melanoides tuberculata, Physa acuta and Cleopatra nswendweensis. One snail (0.2%) of 416 Bulinus snails shed brevifurcate-apharyngeate distome cercariae while three (0.7%) shed amphistomes. Gymnocephalous and longifurcate-pharyngeate distome were the commonest types of cercariae recorded while xiphidiocercaria was the least common. The highest prevalence rates of F. gigantica (68.8%) and amphistomes (50.0%) in cattle (n = 101) were in Chiyasa while those in Kaleya had the lowest (9.1 and 18.2%, respectively). In most habitats, infections were recorded in both cattle and snails. Critical determinants of infection may have been the distance of settlements and/or cattle kraals, the number of animals in nearby homesteads and the presence of susceptible host snails. This study suggests that fascioliasis and amphistomiasis could be major constraints of cattle production in the Kafue wetlands because favourable factors were available to introduce and maintain the infections. It further provides a starting point for some comprehensive studies on snail-related aspects of transmission and snail host ecology in Zambia.

Biogenic amines regulate important behaviours in nematodes and are associated with pharyngeal activity in plant-parasitic nematodes. A robust behavioural assay based upon nematode body movements was developed to expand the study of these and other neuroregulators in plant-parasitic nematodes. Dopamine, octopamine and serotonin each had significant but differing effects on the behaviour of soybean cyst nematode Heterodera glycines and root-knot nematode Meloidogyne incognita juveniles. Body movement frequency was increased twofold in H.glycines by 5 mM dopamine (P = 0.0001), but decreased by 50 mM dopamine in H. glycines (88%) and M. incognita (53%) (P <  0.0001). Movement frequency in both species was increased by 50–70% (P <  0.0001) by 50 mM octopamine, and 5 mM octopamine increased M. incognita movement frequency more than twofold (P <  0.0001). Movement frequency in each species was reduced by more than 90% by 5 mM serotonin (P <  0.0001). While amplitude of body movement in H. glycines was unaffected by any amine, it was significantly reduced in M.incognita by all amines (P <  0.0006). Stylet pulsing frequencies in either species were unaffected by dopamine or octopamine, but 5 mM serotonin stimulated pulsing in H. glycines by nearly 13-fold (P <  0.0001) and in M. incognita by more than 14-fold (P <  0.0001). The invertebrate neuropeptide FLRFamide (N-Phe-Leu-Arg-Phe) increased M. incognita body movement frequency 45% (P = 0.02) at 1 mM but did not affect stylet activity. Finally, H. glycines egg hatch was completely suppressed by 50 mM serotonin, and partially suppressed by 50 mM dopamine (75%; P <  0.0001) and 50 mM octopamine (55%; P <  0.0001).

The present study was carried out to determine the prevalence of gastrointestinal helminthiasis in ruminants in an irrigated area of lower Punjab (Pakistan). For this purpose, 100 faecal samples were collected from sheep, goats, cattle and buffaloes. Parasitological procedures including direct and indirect methods (sedimentation and floatation) and coproculture were used for the identification of helminths. The overall prevalence of helminthiasis was 51% in cattle, 47% in buffaloes, 62% in sheep and 52% in goats, with nematodes being the most common helminths. The prevalence of helminths was higher in young animals compared with adults in cattle (P < 0.0001), buffaloes (P < 0.0001), sheep (P < 0.059) and goats (P = 0.010). The prevalence of different species of helminths also varied in different age groups, with Toxocara vitulorum being higher in calves than adults both in cattle (P = 0.017) and buffaloes (P < 0.0001). Sex-wise prevalence of helminths was higher in males than females for buffaloes (P < 0.0001) and sheep (P = 0.014) in contrast to cattle and goats.

Proteinases released during the in vitro maintenance of asynchronous cultures of the free-living nematode Caenorhabditis elegans were characterized on the basis of subunit composition, fluorogenic substrate specificity, inhibitor sensitivity and pH optima. Cysteine proteinases are present in the excretory–secretory products (ESP) as indicated by the hydrolysis of cathepsin fluorogenic substrates and confirmed by immunoblotting. Serine proteinases were predominant as indicated by substrate gel analysis and inhibitor studies. The presence of metallo-proteinases was also indicated by inhibitor studies. The optimal pH value for cysteine proteinases was 5.5, while serine proteinases were optimal at pH 8.0. As a control, cultures of Escherichia coli, the diet of C. elegans, were extracted separately and gave no evidence of overlap with C. elegans ESP. Cross reactivity between the ESP of C. elegans and antibodies raised against the ESP of the equine parasite Strongylus vulgaris indicated antigenic relatedness of a proteic epitope. This is the first study to characterize the ESP of C. elegans and to display its relatedness with that of S. vulgaris.

In Papua New Guinea, Trichinella papuae, a non-encapsulated species, is circulating among wild and domestic pigs and saltwater crocodiles. Since an important phase of the life cycle of nematodes of the genus Trichinella is the time of survival of infective larvae in decaying muscle tissues of the hosts, the carcass of a pig, experimentally infected with larvae of T. papuae, was exposed to the environmental conditions of Papua New Guinea to establish how long these larvae would survive and remain infective to a new host. Larvae retained their infectivity in the pig carcass up to 9 days after slaughtering, during which time the temperature within the carcass reached 35.0°C on 2 days; the average relative humidity was 79.0%. A low number of larvae survived up to day 14 after the pig was killed, when the carcass temperature reached 38.0°C, but they lost their infectivity to laboratory mice. This result suggests that the larvae of T. papuae can survive in a tropical environment for a time, favouring their transmission to a new host in spite of the lack of a collagen capsule.

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.

A study on the prevalence and intensity of Toxocara canis (Werner, 1782) in dogs was carried out in Ile-Ife, Nigeria. Faecal samples were collected from 269 dogs between January and December 2004, processed by the Kato–Katz technique and then examined for T. canis eggs. The prevalence of T. canis obtained was 33.8%. The intensity of infection, measured as mean egg count per gram of faeces ( ± SEM) was 393.8 ± 83.4. The prevalence and intensity of T. canis in dogs aged 0–6 months were significantly higher (P < 0.05) than older age groups. The prevalence and intensity of T. canis infection were significantly higher in males than in female dogs (P < 0.05). Since T. canis is known to cause visceral larva migrans (VLM) in young children, there is the possibility that the high prevalence of T. canis infection obtained in this study might constitute an important risk factor for transmission to humans. Therefore, there is the need to educate the residents of Ile-Ife on the danger of close association of their children with household pets.