Observations have been made on the survival and migration of infective larvae of strongylid nematodes of the horse deposited on outdoor herbage plots. Few larvae ascended the herbage when conditions were very dry and migration was often enhanced by falls of rain. Larvae on the herbage died rapidly during summer but there was a much slower mortality rate during the winter months. An appreciable proportion of larvae placed on the plots in late summer and autumn survived until the spring but, at this time, there was a rapid disappearance of larvae which coincided with the rising temperatures.

Trematode infections cause serious economic losses to livestock worldwide. Global production losses due to fasciolosis alone exceed US$3 billion annually. Many trematode infections are also zoonotic and thus a public health concern. The World Health Organization has estimated that about 56 million people worldwide are infected by at least one zoonotic trematode species, and up to 750 million people are at risk of infection. Fasciolosis caused by the fluke Fasciola gigantica is endemic in Nigeria and is one of the most common causes of liver condemnation in abattoirs. Total cattle losses from Fasciola infection in Nigeria have been estimated to cost £32.5 million. Other trematode infections of cattle, including paramphistomosis, dicrocoeliasis and schistosomiasis, have all been reported in various parts of Nigeria, with varying prevalence. Most publications on trematode infections are limited to Nigerian local and national journals, with very few international reports. This paper therefore summarized the current data on distribution, control and zoonotic trematode infections in Nigeria and other African countries. We also identified research gaps and made recommendations for future research and areas for funding for policy/planning.

Field and laboratory observations confirm that L. truncatula is an amphibious species, living in temporary pools and muddy places which often become dry for part of the year.

During times of drought the snail survives in a state of aestivation. At the laboratory newly hatched snails are able to withstand at least two months' aestivation while older snails have been demonstrated to remain alive for more than a year; considerably longer than suggested by previous workers.

A cross-sectional survey was undertaken to study the prevalence and intensity of infection with Toxocara cati in 100 stray cats, from April to October 2004 in urban areas of Sari, northern Iran. A total of 44 cats (44%) were found to be infected with T. cati. There was a significant difference in the prevalence of infection relative to host age and weight (P = 0.000). There was also a significant difference in the intensity of infection relative to body weight and urban sites (P < 0.05). No significant difference was found between the prevalence of infection relative to host gender, urban sites and season (P>0.05), nor in the intensity of infection between host gender, age and season (P>0.05). The intensity of infection ranged from 1 to 32 worms per cat, with a mean of 7.30 ± 6.82.

The production of cercariae from their snail host is a fundamental component of transmission success in trematodes. The emergence of Echinoparyphium recurvatum (Trematoda: Echinostomatidae) cercariae from Lymnaea peregra was studied under natural sunlight conditions, using naturally infected snails of different sizes (10–17 mm) within a temperature range of 10–29°C. There was a single photoperiodic circadian cycle of emergence with one peak, which correlated with the maximum diffuse sunlight irradiation. At 21°C the daily number of emerging cercariae increased with increasing host snail size, but variations in cercarial emergence did occur between both individual snails and different days. There was only limited evidence of cyclic emergence patterns over a 3-week period, probably due to extensive snail mortality, particularly those in the larger size classes. Very few cercariae emerged in all snail size classes at the lowest temperature studied (10°C), but at increasingly higher temperatures elevated numbers of cercariae emerged, reaching an optimum between 17 and 25°C. Above this range emergence was reduced. At all temperatures more cercariae emerged from larger snails. Analysis of emergence using the Q10 value, a measure of physiological processes over temperature ranges, showed that between 10 and 21°C ( ≈ 15°C) Q10 values exceeded 100 for all snail size classes, indicating a substantially greater emergence than would be expected for normal physiological rates. From 14 to 25°C ( ≈ 20°C) cercarial emergence in most snail size classes showed little change in Q10, although in the smallest size class emergence was still substantially greater than the typical Q10 increase expected over this temperature range. At the highest range of 21–29°C ( ≈ 25°C), Q10 was much reduced. The importance of these results for cercarial emergence under global climate change is discussed.

Among eyeflukes, Tylodelphys Diesing, 1850 includes diverse species able to infect the eyes, but also the brain, pericardial sac and body cavity of their second intermediate host. While the genus shows a cosmopolitan distribution with 29 nominal species in Africa, Asia, Europe and America, a likely lower research effort has produced two records only for all of Australasia. This study provides the first description of a species of Tylodelphys and the first record for a member of the Diplostomidae in New Zealand. Tylodephys sp. metacercaria from the eyes of Gobiomorphus cotidianus McDowall, 1975 is distinguished from its congeners as being larger in all, or nearly all, metrics than Tylodelphys clavata (von Nordmann, 1832), T. conifera (Mehlis, 1846) and T. scheuringi (Hughes, 1929); whereas T. podicipina Kozicka & Niewiadomska, 1960 is larger in body size, ventral sucker and holdfast sizes and T. ophthalmi (Pandey, 1970) has comparatively a very small pharynx and body spination. Tylodelphys sp. exhibits consistent genetic variation for the 28S rDNA, internal transcribed spacer (ITS) and Cox1 genes, and phylogenetic analyses confirm that it represents an independent lineage, closely related to North American species. Morphological and molecular results together support the distinct species status of Tylodephys sp. metacercaria, the formal description and naming of which await discovery of the adult. Furthermore, the validity of T. strigicola Odening, 1962 is restored, T. cerebralis Chakrabarti, 1968 is proposed as major synonym of T. ophthalmi, and species described solely on the basis of metacercariae are considered incertae sedis, except those for which molecular data already exist.

The composition and diversity of the total and intestinal component and infra-communities were determined in eels Anguilla anguilla from three shallow lagoons on the Adriatic coast of Italy to determine whether the helminth communities would differ in composition and structure from those in eels from lagoons on the Tyrrhenian coast. The lagoons differed in respect of their management regimes and the extent of freshwater influx. Both freshwater and marine species of helminths were found in the eels in all three lagoons, but the freshwater component was richer in Valle Figheri. A suite of three digenean eel specialist species occurred in all three lagoons, of which any two members dominated each community. This conferred a high degree of similarity between the communities of the three lagoons. The same three species also dominated helminth communities in eels in lagoons along the Tyrrhenian coast of Italy, and compositional similarity levels were similar within and between western and eastern groups. Species richness was higher in the component communities of the eels of the Adriatic lagoons when compared to the Tyrrhenian ones, but diversity and dominance indices were of a similar order of magnitude and range. Intestinal helminth communities were richer and more diverse in two of the Adriatic lagoons because the proportion of eels with zero or one helminth species was, unusually, in the minority. It was nevertheless concluded that infracommunity structure was similar in eels from both western and eastern lagoons and that the hypothesis that it would differ in Adriatic lagoons could not be supported. The findings provide further evidence of the similarity in composition and structure of helminth communities in eels from coastal lagoons throughout Europe.

Microfilariae of Onchocerca volvulus were found in venous blood samples in 17 of 20 patients with moderate to severe ocular onchocerciasis in a Sudan-savanna focus in Cameroon. They were present in the urine in 7 of the 20 patients. The numbers of microfilariae increased during DEC therapy, both in the blood and urine, and they were not completely eliminated after 2 weeks of therapy.

A survey of nematodes associated with native and introduced species of terrestrial slugs was conducted in the Western Cape Province of South Africa, in order to gather new data regarding diversity and distribution. A total of 521 terrestrial slugs were collected from 35 localities throughout the Western Cape. All slugs were dissected and examined for the presence of internal nematodes. Extracted nematodes were identified using a combination of molecular (18S rRNA gene sequencing) and morphological techniques. Nematodes were found parasitizing slugs at 14 of the 35 sites examined, amounting to 40% of sample sites. Of all slugs, 6% were infected with nematodes. A total of seven species of nematode were identified in the province, including Agfa flexilis, Angiostoma sp., Phasmarhabditis sp. SA1, Phasmarhabditis sp. SA2, Caenorhabditis elegans,Panagrolaimus sp. and Rhabditis sp. Of these species, four were thought to be parasitic to slugs (A. flexilis, Angiostoma sp., Phasmarhabditis sp. SA1 and Phasmarhabditis sp. SA2), as opposed to forming necromenic or phoretic associations. Three new species of slug-parasitic nematode were identified during this study (Angiostoma sp., Phasmarhabditis sp. SA1 and Phasmarhabditis sp. SA2).

Schistosome parasites commonly show specificity to their intermediate mollusc hosts and the degree of specificity can vary between parasite strains and geographical location. Here the role of miracidial behaviour in host specificity of Schistosoma haematobium on the islands of Zanzibar is investigated. In choice-chamber experiments, S. haematobium miracidia moved towards Bulinus globosus snail hosts in preference to empty chambers. In addition, miracidia preferred uninfected over patent B. globosus. This preference should benefit the parasite as patent snails are likely to have mounted an immune response to S. haematobium as well as providing poorer resources than uninfected snails. Miracidia also discriminated between the host B. globosus and the sympatric, non-host species Cleopatra ferruginea. In contrast, S. haematobium did not discriminate against the allopatric Bulinus nasutus. Penetration of the host by miracidia was investigated by screening snails 24 h after exposure using polymerase chain reaction (PCR) with S. haematobium specific DraI repeat primers. There was no difference in the frequency of penetration of B. globosus versus B. nasutus. These responses to different snail species may reflect selection pressure to avoid sympatric non-hosts which represent a transmission dead end. The distribution of B. nasutus on Unguja is outside the endemic zone and so there is less chance of exposure to S. haematobium, hence there will be little selection pressure to avoid this non-host snail.

Human infection by Dirofilaria repens in Serbia has been increasing steadily. The first case was reported in 1971, presented in the form of a single subcutaneous nodule on the back of a young boy. As established by a literature search, eight additional cases were reported until mid-2001. The most frequent site of infection was subcutaneous tissue, with the exception of two cases, in which parasites were found in subconjunctiva and epididymis. Our study, conducted from 2001 to 2008, encompasses 19 new cases. Most of them (63.1%) presented as ocular or periocular infections, in which the parasite was typically found under the conjunctiva. In other cases a parasitic nodule was localized in the temporal region of the head, epididymis, testicle, abdomen, breast or arm. The diagnosis was made by morphological and histological analysis of the extracted intact worms and parasite sections from the tissue. Morphology of the filarial worms was well preserved in more than half of the cases (12/19) and there was never more than one parasite found inside the lesions. Adult worms and immature nematodes were observed in nine and seven cases, respectively. Furthermore, in two cases microfilariae were discovered inside the pseudocoelom, sections of the female reproductive tubes filled with clearly visible larval stages. Dirofilaria repens infection was diagnosed by its morphological features (17/19) or by performing polymerase chain reactions (PCR) using paraffin-embedded tissues (2/19) in the cases where the morphology was insufficient for identification and the parasites had been determined initially as Dirofilaria spp. The amplified 246 bp PCR product showed that the worms were D. repens.

A total of 179 urban rats were sampled in the city of Doha in Qatar across the winter seasons (February–April) of 2002 and 2003. Only two parasites were identified, with overall prevalences of 35.8% and 41.3% for the cestode Hymenolepis diminuta and the flea Xenopsylla astia respectively. The prevalence of H. diminuta was markedly influenced by both year of study and host age, being higher in 2003 and amongst older rats. The abundance of infection of H. diminuta was influenced by the year of study, host age and sex. Worm burdens in adult rats were almost twice as heavy in males compared with females and adults of both sexes harboured heavier infections than juveniles. The prevalence of X. astia was influenced by both year and host age, being higher in juvenile rats in 2002 and in adults in 2003. The abundance of X. astia was significantly higher in 2003 and both male and female rats showed similar abundances, but in 2003 females were more heavily infested. Reasons for this are discussed in relation to the differing foraging strategies shown by male and female rats. The prevalence and abundance profiles for both H. diminuta and X. astia were higher overall in 2003 due to a significant increase in the rat population density, although this did not reflect in any increase in parasite species richness. Rats that were infected with H. diminuta were almost twice as likely to be infected with X. astia than those without the cestode, but when controlled for the effects of year, host age and sex, no quantitative interactions were detected between the two parasite species.

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.

Vitelline gland development and incomplete parthenogenesis in 65-week-old female Schistosoma mansoni from single sex infections is described. Vitelline gland development was restricted to the extreme posterior end of each worm and the developed vitelline lobules showed the normal sequence of development and maturation. The ovary, however, was always in an immature state. Egg production occurred although the eggs were non-viable.

The results suggest that, whilst male stimulation is not necessary to initiate vitelline gland development and egg production, it appears to be essential for the complete maturation of the ovary. The possible importance of ovarian maturation to the production of viable eggs is discussed.

A total of 120 gastro-intestinal tracts and 960 faecal samples were examined to assess the prevalence and seasonal changes in the gastro-intestinal helminth parasites of Red Sokoto (maradi) goats slaughtered at Ibadan between May 1991 and April 1992. Egg types of strongyles, Strongyloides, Trichuris, Skrjabinema, Dicrocoelium and Moniezia were encountered in 93%, 83%, 44%, 0.9%, 2.3% and 31% of the faecal samples respectively. However, only strongyle, Strongyloides and Trichuris eggs occurred in large numbers and were more common during the rainy season than in the dry season. The parasites recorded and their prevalences were Haemonchus contortus (90.0%), H. ovis (5.0%), Strongyloides papillosus (80.8%), Trichostrongylus colubriformis (78.3%), T. axei (69.2%), Trichuris ovis (72.5%), T. globulosa (38.3%), Oesophagostomum columbianum (67.5%), Cooperia curticei (58.3%) Gaigeria pachyscelis (40.8%), Skrjabinema ovis (5.0%), Nematodirus battus (5.8%), Moniezia expansa (29.2%), M. benedeni (10.0%), Paramphistomum spp. (5.0%) and Cysticercus tenuicollis (33.3%). Haemonchus ovis is reported for the first time in Nigeria. Mixed infections were most prevalent. Young goats were more commonly infected and had higher worm counts than adult goats. Only Haemonchus, Trichostrongylus, Strongyloides and Cooperia spp. occurred in large numbers. Irrespective of the age of the goats, higher worm counts were generally encountered during the rainy season than in the dry season. The results are discussed in relation to the control of helminthiasis in grazing animals in Nigeria.

The family Camallanidae is examined and two new subfamilies Procamallaninae and Camallaninae are erected for retaining the existing and new genera; the former subfamily for worms with a continuous buccal capsule and the latter for worms with a bivalve buccal capsule. The genus Camallanus s.l. is examined in detail and a revised definition given. Camallanus s.l. is divided into Camallanus s.s., Zeylanema Yeh, 1960, Piscilania gen. nov., and Serpinema gen. nov.

A total of 153 free-ranging birds from Germany belonging to 15 species were examined for nematodes in their digestive and respiratory tracts. In 51.7% of the birds 14 different nematode species were found: the intestinal ascarids Porrocaecum depressum and P. angusticolle, the strongylid Hovorkonema variegatum, which inhabits the trachea and bronchi, the hairworms Eucoleus dispar and Capillaria tenuissima isolated from the digestive system, the spirurid nematodes Cyrnea leptoptera, C. mansioni, C. seurati, Microtetrameres cloacitectus, Physaloptera alata, P. apivori, Synhimantus hamatus and S. laticeps, which inhabit the proventriculus and gizzard of the raptors, and the spirurid nematode Serratospiculum tendo, which lives in the air sacs. To revise their systematic positions the ribosomal 18S gene regions of the nematode species were analysed and a phylogenetic tree was constructed. The molecular data confirmed the morphological systematics, except the spirurid family Physalopteridae, which grouped together with the Acuariidae.

The helminth community of the wood mouse, Apodemus sylvaticus, in the Sierra Espuña was characterized after a complete analysis of its helminth community component and infracommunity structure relative to host age, sex and year of capture. The helminth community comprised 13 species: one trematode, four cestodes and eight nematodes. The cestode Pseudocatenotaenia matovi and the nematode Syphacia frederici were the most prevalent and abundant helminth species, respectively. Sixty four percent of mice analysed presented helminths with a direct cycle and 42% presented helminths with an indirect cycle. The helminth community presents a low diversity with infracommunities usually made up of only one or two helminth species. Host age and year of capture seem to play a major role in determining species richness and helminth diversity, but not in determining the abundance of helminths. Host sex does not seem to affect the infection rate nor the diversity. Further studies on more samples of wood mice and other small mammal species in this regional park are needed to explore any possible interactions between helminth communities in the host populations.

Schistosoma intercalatum and from Cameroon and Zaire each have their specific snail intermediate host. Hybridization experiments between S. intercalatum from Cameroon and Zaire have resulted in viable miracidia for only two generations. If the two strains are of the same species, cross breeding should be possible for several generations. This paper presents a comparison of the characteristics of the two strains of S. intercalatum in experimental infections in mice.

Worm return, male-female worm ratio, growth rate, number of testes in male adult worms are compared. The quantitative distribution of eggs in the tissues of the mice is recorded. A comparison of the size and shape of the parasite eggs is described as are the changes in the weight of the liver and spleen of the infected mice.

It is considered that the differences observed between the two strains of S. intercalatum do not necessitate a division of the two strains into two separate species.

(1) Trichinella spiralis is widespread in East Africa. It has been found in man, bush pig, leopard, serval cat, spotted hyaena, striped hyaena, jackal, lion and domestic dog. It has never been found in the domestic pig nor in rodents, neither has it been found in carnivores which feed mainly on rodents.

(2) Preliminary attempts to transmit the infection from man, hyaenas, jackal and lion to small laboratory animals such as rats, mice, hamsters and rabbits showed that although the Kenya strain was morphologically typical of T. spiralis, it was of exceptionally low infectivity in these animals.

(3) A strain from the serval cat (Felis serval) was eventually established in the laboratory by passage through the mongoose, Myonax sanguineus, and through monkeys and baboons.