The treatment of paramphistomiasis, a neglected tropical disease, has been carried out with different fasciolicidal compounds, all showing weak efficacy. Therefore, the search for alternative paramphistomicidal drugs is warranted. In the present study, the in vitro effects of artemether on adult Paramphistomum microbothrium were evaluated, for the first time, using scanning electron microscopy. After 24 h of incubation with 10 μg ml− 1 artemether, tegumental damage of both anterior and posterior ends of the fluke had occurred in the majority of the specimens examined. Sensory papillae surrounding the oral aperture were ruptured, while those at the acetabular region appeared to be sunken due to tegumental swelling. The tegumental disruption became more pronounced and both oral sucker and acetabulum were severely distorted, on increasing the concentration to 20 μg ml− 1. With higher concentration of 30 μg ml− 1, gross swellings of the body of the fluke, clearly visible to the naked eye, were observed, and damage to both oral sucker and acetabulum was so extreme that little recognizable structure remained.

Six new species of Spirurids are described from terrestrial vertebrates from various countries. They are Camallanus macabukae n.sp. and Procamallanus brevis n.sp. from bull-frogs in S. Africa, C. multilineatus n.sp. from Rana catesbiana in N. America, Tanqua gigantica n.sp. from Python reticulatus and Naja. hannah in E. Indies and S.E. Asia, respectively, Ancyracanthopsis madagascariensis n.sp. from Dryolimnas cuvieri in Madagascar, and Physaloptera singhi n.sp. from the monkey (?) in S. America. Three species inquirendae, Camallanus sp., Streptocara sp. and Physaloptera sp. are also described. Some new morphological features in Habronema mansioni and Physaloptera paradoxa are discussed and the female of Hartertia zuluensis is described for the first time.

1. A new Caryophyllaeid cestode Adenoscolex oreini n.g., n.sp., from fresh-water fish, Oreinus sinuatus, is described.

2. Genus Bothrioscolex Szidat, 1937 is regarded as a synonym of the genus Khawia Hsü, 1935. The existing species of Khawia are listed and are briefly described.

Experimental Echinococcus multilocularis infection and deworming was repeated three or five times in nine dogs at various re-infection schedules. The mean number of worms decreased more than 91% in dogs with repeated infection, compared to first infection controls (n= 6). The copro-antigen assay and the egg count in the faeces suggested that the worm burden gradually decreased each time the dogs were re-infected. To examine whether such worm exclusion was a non-specific response, five dogs were sequentially infected with the parasite four times and subsequently fed freely for 6 months. Even after the 6-month interval, the five dogs that were infected five times with the parasite were still able largely to exclude the adult worms. The results suggested that the ability of worm exclusion in dogs that developed a resistance did not become rapidly extinct. Observation of the condition of faeces and the excretion of hooks in the faeces of repeatedly infected dogs revealed that the exclusion of worms started at the first week after the re-infection, and it continued during the patent period. Serum antibodies specific to the parasite antigen increased gradually until the third infection and significantly decreased during the 6-month interval. There was little enhancement of serum antibodies after the fifth infection in most dogs, although no clear correlation was observed between the antibody response and the worm burden. These findings suggested the possibility of developing a vaccine.

We determined the prevalence and seasonality of infections by Fasciola of goats and bovine species (cattle and water buffalo) in Hubei and Anhui provinces of China. Faecal samples were collected at 2- to 3-month intervals from 200 goats in Hubei province and from 152 bovine species in Anhui province. All faecal samples were examined for the presence of parasites. We determined the nucleotide sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA (rDNA) of 39 Fasciola worms from Anhui province. The prevalence of Fasciola infection in goats ranged between 3.5 and 37.0%, with mean eggs per gram (EPG) ranging between 29.0 and 166.0. Prevalence and EPG exhibited downward trends over time with significant differences. The prevalence of Fasciola infection in cattle ranged between 13.3 and 46.2% (mean EPG, 36.4–100.0), and that of water buffalo ranged between 10.3 and 35.4% (mean EPG, 25.0–89.6), with a higher prevalence of infection and EPG from June to October compared with December to March. Analysis of ITS-1 and ITS-2 sequences revealed that F. hepatica and F. gigantica were present in all bovine species of Anhui province and that F. gigantica mainly infected water buffalo. This is the first demonstration of Fasciola infection in Hubei province and detection of F. hepatica and F. gigantica in Anhui province. The present study of Hubei province shows that mass treatment of livestock with closantel sodium injections in April and August/September controlled Fasciola infection effectively.

The relationship between the frequency of loiasis objective symptoms and microfilaraemic or amicrofilaraemic infection was assessed in 1148 exposed patients also infected, or not, with Mansonella perstans. Filarial infections were detected by direct microscopy, leucoconcentration and serology, with prevalence values of 39.5% Loa loa, 5.6% M. perstans and 3.4% co-infection with both filarial species. Amicrofilaraemic or occult loiasis (OL) predominated among L. loa-infected individuals, with a prevalence of 58.2%. Hypermicrofilaraemia (>8000 microfilariae (mf)/ml) was found in 18.4% of L. loa microfilaraemic patients, with 25.7% of them harbouring more than 30,000 mf/ml. Up to 34% of patients with OL showed evidence of Calabar swelling, compared with 26.3% of microfilaraemic patients (P= 0.03). Overall 5.3% of patients presented with adult worm migration across the eye, representing 16.3% of microfilaraemic individuals and 11.4% of amicrofilaraemic patients (P= 0.13). This symptom was similarly found in patients with more than 30,000 mf/ml (22%), those with microfilaraemia between 8 and 30,000 mf/ml (15.4%) and also in individuals with low or without microfilaraemia (16.1%) (P= 0.7). Five (14.3%) hypermicrofilaraemic patients did not present any L. loa-specific objective symptoms, as well as all the patients with single M. perstans infection. The presence of adult eye worm migration as a strong predictor of high microfilaraemia density would obscure the real burden of L. loa hypermicrofilaraemia in exposed individuals. For epidemiological purposes and control strategies, the mapping of L. loa in endemic areas should also take into account the group of patients with occult loiasis.

The first stage larva of Anafilaroides rostratus develops, after penetration into the foot of certain molluscs, Laevicaulis alte Fer. Mariella dussumieri Gray, Achatina fulica (Fer.) and Helix aspersa Müller. Two moults occur in the foot of these molluscs in 20–56 days depending on the temperature. After each moult the cuticle is shed. The details of development are described. The infective larvae are found in the foot of these molluscs. Natural infection was found in L. alte.

Mice and chickens can act as auxiliary hosts. Probably rats, other rodents and birds can also act in the same capacity.

The study of the development of the parasite in the cats is not complete. On ingestion the infective larvae penetrate the stomach wall and reach the lung where the third and the fourth moults occur. Exact times of the occurrence of the moults have not been definitely established. All moults are however completed by the 46th day; from then until the 58th day, immature helminths are found in the lungs. Fully gravid females are found on the 74th day, and larvae are first seen on the 78th day. The worms continue to produce larvae for more than 255 days after maturity. The duration of the life of the adult is probably considerably longer than one year.

Data are presented on the infection dynamics of the brain-dwelling metacercariae of Diplostomum phoxini (Digenea: Trematoda) parasitizing European minnow (Phoxinus phoxinus) populations in a lowland river (River Endrick) and a highland loch (Loch Maragan) in central Scotland. Prevalence of the parasite approached 100% in all samples taken from both populations over a 12-month period, and within each population the intensity of infection increased with increasing host fork length. However, the two relationships differed, and size-matched minnows from the Endrick exhibited significantly higher intensities than those from Loch Maragan, suggesting that metacercarial acquisition occurred at different rates in the two populations. Data regarding seasonal trends in the acquisition of D. phoxini indicated that fish in both populations become infected with the parasites mainly during the spring and summer, with negligible infection occurring during winter months. Analysis of size-matched fish from individual samples revealed apparent differences in the distribution of D. phoxini within the two host populations. Whereas D. phoxini metacercariae appeared to be overdispersed amongst length-matched fish from Loch Maragan samples, the parasite was distributed normally amongst fish from the Endrick. Possible reasons for the observed differences in the infection characteristics of D. phoxini in the two minnow populations are discussed, with reference to the parasite's transmission dynamics and local environmental conditions.

A single oral dose of 50 mg/kg of oxamniquine administered to mice with mature infections of Schistosoma mansoni gave rise to a hepatic shift and almost total elimination of the male worms. Regression of the reproductive system and a conspicuous reduction in size took place in the residual females which eventually resembled sexually immature adults. A second dose of oxamniquine had no apparent effect on these females within a period of 28 days following this treatment and it is suggested that this change in reproductive status is the result of discontinued male stimulation.

In an environment seriously impaired by human interference (draining the reservoir), ecological relationships in a community of copepods and their impact on the transmission of the tapeworm Proteocephalus neglectus La Rue. 1911 were studied. The impairment of the environment resulted in changes in the species composition of the copepod community and in the increased diversity of the copepod species, as well as in a multiple inversion of the dominant and subdominant relationships of the two most numerous copepod species (Cyclops vicinus and Eudiaptomus zachariasi). The structure of the developmental stages of the copepod community, the seasonal dynamics of the number of copepods and the abundance of P. neglectus procercoids have changed. The predominant species in the copepod community and the most susceptible intermediate host of P. neglectus (C. vicinus) was not infected. The infection of copepods decreased by 95% and that of the definitive hosts (Oncorhynchus mykiss) by 97·5% compared with the index values recorded in the previous year.

This study compares the metacercariae of a ‘pygmaeus’ microphallid discovered in Littorina saxatilis from the coast of Northern Ireland with the metacercariae of Microphallus piriformes and M. pygmaeus from the same species of gastropod mollusc from Arctic Russia. Light and scanning electron microscopy were used to provide morphometric and surface details for descriptions of the organisms concerned. Comparison and statistical analysis of the results established that the species from Northern Ireland was M. piriformes and not M. pygmaeus as had previously been assumed. It dearly indicates the need for critical assessment of the accuracy of literature dealing with the occurrence of ‘M. pygmaeus’ in both intermediate and final hosts.

Although synanthropic rodents such as the indigenous species, Mastomys coucha, and the invasive species, Rattus norvegicus, R. rattus and R. tanezumi, are well-known to be hosts to various micro- and macroparasites, their helminth parasite fauna is poorly studied in South Africa. In an attempt to remedy the situation, the aim of the present study was to investigate the helminth fauna of these sympatric rodent species, which were obtained from the informal settlements of Alexandra, Tembisa, Diepsloot and residential suburbs of Pretoria and Hammanskraal, Gauteng Province, South Africa. Helminths were recovered from the urinary bladder, liver and gastrointestinal tract and were identified morphologically and molecularly. The recovered nematodes were all rodent-specific and included Aspiculuris tetraptera, Eucoleus sp., Heterakis spumosa, Mastophorus muris, Nippostrongylus brasiliensis, Protospirura sp., Strongyloides ratti, Syphacia obvelata, Syphacia muris, Trichuris sp. and Trichosomoides crassicauda. Syphacia obvelata, a commensal nematode of laboratory rodents, was recovered from indigenous M. coucha. Strobilar stages of cestodes recovered included Hymenolepis diminuta, Hymenolepis nana and Inermicapsifer madagascariensis. Recovered metacestodes were strobilocerci of Hydatigera taeniaeformis from all three invasive Rattus species and coenurostrobilocerci of Hydatigera parva from M. coucha. An acanthocephalan, Moniliformis moniliformis, was recovered from R. rattus only. All rodent species examined showed high helminth infection prevalence (≥70%) with equal or higher nematode than cestode prevalence. Mastomys coucha, however, showed significantly lower cestode prevalence than Rattus species where they co-occur. Interspecific transmission of helminths likely occurs between invasive and indigenous rodents, and these rodents harbour several helminths that have zoonotic implications.

Information on the incidence of larval trematodes infecting the fresh water molluscs of Llangorse Lake, South Wales, has been collected over a period of three years.

The percentage infection of the molluscs occurring within the habitat has been assessed and comparisons made with the findings of other workers.

The percentage of active and passive parasite stages composing this infection has been considered.

The schistosome transmitting molluscs, Physopsis africana and Biomphalaria tanganikanus, from the Belgian Congo, carried the metacercaria of Echinoparyphium recurvatum and of Echinostoma revolutum, which have been recorded for the first time from the Southern half of the African Continent. Further research may indicate their wider distribution in this Continent.

Development of the larval stages and heavy encystment of the metacercaria of these echinostomes in the schistosome transmitting molluscs led to death of the snails. The use of other trematode species, particularly echinostomes may offer great prospects in the field control of schistosome transmitting molluscs.

A survey was conducted at a locality in the Eastern Transvaal Lowveld where the prevalence of human infection with the bovine parasite, Schistosoma mattheei, is relatively high. It was found that, when compared to the number of S. haematobium eggs released into the environment, the number of S. mattheei eggs, with enclosed hybrid miracidia, is small. The consequences of backcrossing between the hybrids and S. haematobium was considered; a mathematical model indicated that a high percentage of the S. haematobium population should contain a small proportion of S. mattheei genes. The results indicate that it is highly unlikely that the two species will evolve into a single species, neither does it seem that the virulence of the parental species will be influenced.

Three hundred and twenty-five domestic cats (Felis catus) from six villages of the Hulu Sungai Tengah and Banjar Regency of South Kalimantan (Borneo), Indonesia, were examined for filarial nematodes. Parasites were found in 66 cats, of which 61 (92·4%) had Brugia pahangi, four (6·1%) has B. malayi and one (1·5%) had Dirofilaria repens. Infection rates ranged from 11% to 22% in cats from secondary forest/rice-field habitats, from 15% to 30% in open village/rice-field habitats, to 50% in an open coastal village. In all cases the infection rate of B. malayi in man was greater than in cats from the same collecting area. The number of B. pahangi microfilariae per 20 μl cat blood ranged from 34 at 1000 hours to 571 at 2200 hours. The results of this study suggest that in this region of Indonesia the domestic cat is not an important host for maintaining B. malayi.

In August 1962 Dr. C. Amirthalingham brought to me a dead fish, Polypterus senegalus, on which there were a few worms moving. These were found to be monogenetic trematodes of the gyrodactylid type and were later identified as Macrogyrodactylus polypteri Malmberg, 1956.

On examining a tank where a few Polypterus senegalus—from Jebel Awlia on the White Nile near Khartoum—were kept, it was found to be heavily infested with these worms and each fish was covered with a thick greyish-white fluff on its skin. The trematodes could be seen by the naked eye and were found practically on the whole surface of the fishes.

Metazoan parasites of the sand smelt Atherina boyeri Risso, 1810 in Lake Iznik were studied. A total of 271 specimens of A. boyeri, 208 female and 63 male, mean ( ± SD) total length 8.4 ± 2.2 cm (range 3.1–12.2 cm) and mean total weight 4.7 ± 3.5 g (range 0.1–11.7 g) were examined between June 2008 and May 2009 at monthly intervals. In 33 fish no parasites were found. In the other fish, four parasite species were recorded: Diplostomum sp. (prevalence 39.13%, mean intensity 3.50 ± 3.03); Tylodelphys clavata (prevalence 74.16%, mean intensity 10.41 ± 14.89); Bothriocephalus cf. acheilognathi (prevalence 40.59%, mean intensity 31.83 ± 57.74); and Eustrongylides excisus (prevalence 6.64%, mean intensity 1.16 ± 0.39). The mean abundance of Diplostomum sp., T. clavata and E. excisus was higher during the winter and early spring months. In contrast, the mean abundance of B. cf. acheilognathi was higher in the summer and autumn months. This distribution of the parasites was related to a change in the environment of A. boyeri from the pelagic zone to deeper water at the end of autumn and a change in food supply.

The trematodes of this report were killed in hot water, transferred immediately to Lavdowsky's FAA fixative for 24 hours, and then stored in 70% alcohol plus 2% glycerine. Whole mounts were stained in Mayer's carmalum and mounted in permount. Specimens have been deposited in the U.S. National Museum Helminthological Collection as indicated. All measurements are in microns (ftm).

Between 1993 and 1997, 837 stray dogs from North Taiwan were necropsied and examined for dog heartworm infections. A thick smear from 20 ml of peripheral blood from each dog was also prepared and examined for microfilariae (mf). The overall prevalence of adult worms in the dog population was 57%. The prevalence of mf in 1228 house dogs from different parts of Taiwan was also determined from 20 ml of peripheral blood in the same way. The overall prevalence of mf was 25%, with a value of 30% in the main island of Taiwan, this being 15 times higher than that in the offshore islands (2%). In Taiwan, the prevalence ranged from 4% in Hualien County, East Taiwan, to 41% in Nantou County, Central Taiwan. The mf prevalences on offshore islands were 1% on Liuchiu and 2% on Lanyu. The mf density per 20 ml blood in 82 house dogs was found to be 23 mf per dog, with a range of 3–97 mf per dog. A total of 477 stray dogs were found to be infected with adult worms of Dirofilaria immitis. The mean number of 7 worms per dog was obtained, with a range of 1–55 worms per dog. These results indicate that the prevalence of canine dirofilariasis has increased in Taiwan over the past 10 years. Moreover, the prevalence may be related to the wind speed, temperature, relative humidity, and altitude in the different areas surveyed.