The paper 'A taxonomic revision of the genus Taenia Linnaeus, 1758 s. str.' (Verster, 1969) gives concise characterisations, together with drawings of rostellar hooks and the terminal genital organs, of the 32 Taenia species and three subspecies which this author found to be valid. Yet, it is hardly possible to quickly identify a questionable species or to readily access information on their hosts, geographical range and synonyms. The present paper compiles these data and additional information on larval characteristics into tables. Measurements and numbers of hooks are shown using a graph. Additional data are included from authors not mentioned by Verster and for seven new species (T. dinniki, T. jaipurensis, T. kotlani, T. madoquae, T. saigoni and T. simbae), two re-validated species (T. krepkogorski, T. retracta) and two subspecies (T. polyacantha arctica and T. saginata asiatica) described since 1969. Reasons for rejecting one new species and one new subspecies are given. A table of definitive hosts and the Taenia species occurring in them is also included, as is one of synonyms from 1850 onwards. A good procedure for the staining and mounting of cestodes is described.

An up-date of Verster's (1969) 'Taxonomic revision of the genus Taenia Linnaeus' (Cestoda) in table format.

A review of dicrocoeliosis of ruminants including recent advances in the diagnosis and treatment.

Anoplocephala perfoliata is the commonest tapeworm parasite of horses and is incriminated as a significant cause of clinical disease (e.g., ileocaecal intussusception, caeco-caecal intussusception and/or caecal perforation), particularly in horses chronically infected with large numbers of worms. The high prevalence (approximately 20-80%) of the parasite in some countries suggests an increased risk of clinical cases. In spite of research, there is still a paucity of information regarding the pathogenesis of the disease, the epidemiology of the parasite in different geographical regions and there are significant limitations with the diagnosis of infection. The present article provides an account of the biology, epidemiology and pathogenic effects of A. perfoliata, the diagnosis of infection and treatment. It highlights some gaps in knowledge of the parasite and the disease it causes, and suggests opportunities for future research and prospects for improved diagnosis, prevention and control.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0031182004007127

Anoplocephala perfoliata of horses : significant scope for further research, improved diagnosis and control

Opisthorchis felineus, an emerging infection in Italy and its implication for the European Union.

Prevalence and intensity of gastrointestinal parasites were studied through a longitudinal survey in 400 horses over a 17-month period in an abattoir in Germany. Three hundred and ten horses (77.5 %) were demonstrated harbouring endoparasites either by direct recovery of parasites from the digestive tract and/or in terms of faecal egg counts (strongyles). The following parasites were found (percentage prevalence, range of counts): Gasterophilus intestinalis larvae (2.25 %, 1–154), Gasterophilus nasalis larvae (0.25 %, 44), Trichostrongylus axei (11.0 %, 1–3,620), Habronema majus (8.0 %; 1–422), Habronema muscae (26.5 %, 1–3,563), Habronema spp. fourth-stage larvae (5.5 %; 1–1,365), Parascaris equorum (total prevalence 11.3 %; adults 8.8 %, 1–178; fourth-stage larvae 2.5 %, 5–2,320), Anoplocephala perfoliata (28.5 %, 1–2,013) and Paranoplocephala mamillana (1.0 %, 1–11). Strongyle eggs (≥10 eggs per gram of faeces) were recorded in 60.8 % of the horses (10–6,450 eggs per gram of faeces). Prevalences of infection with T. axei, P. equorum and strongyles did not show a correlation to specific seasons. In contrast, a significant variation among seasons of collection was shown for the infection rates of Habronema spp. (p < 0.05) and A. perfoliata (p < 0.001). Seasonal prevalence of Habronema spp. infection was significantly (p < 0.01) higher in summer (39.0 %), autumn (34.8 %) and winter (36.5 %) than in spring (18.7 %), and A. perfoliata were significantly (p < 0.001) more often recorded during autumn (36.1 %) and winter (36.5 %) than in spring (17.3 %) and summer (15.9 %). Prevalences of T. axei, Habronema spp., strongyles and A. perfoliata in male and female horses were almost alike, but ascarids were significantly (p = 0.025) more often recorded in male than in female horses.

Prevalence, intensity and seasonality of gastrointestinal parasites in abattoir horses in Germany.

Epizootiological questions were studied on a permanent pasture of a farm situated in one of the dicrocoeliasis areas in the GDR during the 1986 grazing season. Helicella obvia snails and Formica fusca ants were found to be first and second intermediate hosts respectively. A total of 1,121 snails and 70 ants were dissected. The infestation rate with Dicrocoelium dendriticum stages in snails decreased in summer after the high spring peak and increased again in autumn. Paralysed ants were found only at temperatures below 20 degrees C. Parthenogenetic stages in snails were identified morphologically according to the structure of cercariae; the metacercariae isolated from the ants' body cavity were determined in animal experiments.

Seasonal occurrence of Dicrocoelium dendriticum in intermediate hosts

An Anoplocephala perfoliata population isolated from the caecum of a dead horse was analysed morphometrically. Besides the number of segments, length and width of strobila, the width of scolex and the last segment, in adult tapeworms the number of eggs per segment was counted. By the aid of these data the population was divided into 4 categories. The length of fixed tapeworms varied between 5.46 and 41.53 mm. There was an direct relation between length of the strobila and number of segments. Only 42 of 440 investigated tapeworms contained mature eggs in the uterus. The number of eggs varied between 125 and 4482. The beetle mite Scheloribates latipes could be infected successfully, 9 cysticercoids were isolated from their body cavity.

Morphometric analysis of an Anoplocephala perfoliata population

Alimentary tract, liver, kidneys and lungs of 25 otters, died of several causes during 1982-1987 in GDR were included in helminthological investigations. Parasites were detected in 8 animals. One cestode: Taenia martis and 3 trematodes: Isthmiophora melis, Opisthorchis felineus and Pseudamphistomum truncatum are regarded to be certain parasites of this host. Other findings like Ligula intestinalis, Azygia luccii and Piscicola geometra and the fragment of a pseudophyllidean enter the alimentary tract with the food and pass through it.

The parasite fauna of East Germany. 9. The helminth fauna of Lutra lutra

During the pasture period in 1990 the snail species Helicella obvia, collected in a dicrocoeliosis area in the east of Brandenburg, was investigated for Dicrocoelium sporocysts. Simultaneously in adult snails the condition of albumen gland was examined. Investigations showed that Dicrocoelium infection in the snail host impairs their reproduction ability and life expectancy. The term "parasite caused sterilisation" is suggested for changes which lead to infertility in the case of parasite infection.

The modification of Helicella obvia by Dicrocoelium parthenitae

The correctness of the name Discrocoelium dendriticum given to the lanceolate liver luke is discussed in the form of a literature review. Possible reasons are discussed for the peculiar first finding of this parasite in the gut of a swordfish. D. dendriticum is regarded as the valid name of this fluke.

R Schuster

Papers

Seasonal occurrence of Dicrocoelium dendriticum in intermediate hosts

Morphometric analysis of an Anoplocephala perfoliata population

The parasite fauna of East Germany. 9. The helminth fauna of Lutra lutra

The modification of Helicella obvia by Dicrocoelium parthenitae

A historical survey of the nomenclature of the lanceolate liver fluke Dicrocoelium dendriticum