Determinants of the prevalence of Heligmosomum costellatum (Heligmosomidae: Trichostrongyloidea) in a common vole population in southern Moravia, Czech Republic.

A study of nematode (Heligmosomum costellatum) prevalence in the common vole (Microtus arvalis) population was performed in 2002 and 2003 in an agricultural region of southern Moravia, Czech Republic. The influence of the trapping date, body weight, age, gender and reproduction of the common vole on the prevalence of the larvae of H. costellatum encapsulated in the stomach wall was examined. Of 503 common voles examined, 27.6% were H. costellatum positive. The prevalence of H. costellatum in the common vole population was influenced mainly by the weight, trapping date, year and reproductive state, as well as by the interactions between year and gender and between year and reproductive state. The influence of age was weak. The most infected common vole groups were the older, heavier and already reproducing females captured from April to August and all voles captured in 2002. In general, parasite prevalence seems to be dependent on the population parameters of the host species. However, the H. costellatum prevalence study in a single common vole population was not sufficient to fully describe and explain the nematode-host interactions.

Hymenolepis pseudodiminuta Tenora et al. 1994 from Apodemus speciosus and H. diminuta: a comparison of experimental infections in rats.

The successful maintenance of Hymenolepis pseudodiminuta, isolated from Apodemus speciosus, is described for the first time. In the laboratory, the flour beetle, Tribolium confusum, and F344 rats could serve as intermediate and definitive hosts, respectively. In single worm infections with H. pseudodiminuta, which were carried in two groups of rats, adult worms were recovered from eight and seven out of ten rats, respectively, while Hymenolepis diminuta was found in all of ten rats 6 weeks after inoculation. The worm weight of H. pseudodiminuta in rats was significantly lower than that of H. diminuta. The egg output of H. pseudodiminuta occurred significantly earlier than that of H. diminuta. The number of eggs in the faeces of H. diminuta-infected rats was approximately twofold higher than the number in the faeces of H. pseudodiminuta-infected rats throughout the course of the infection. Mucosal mast cells in rats infected with H. pseudodiminuta were significantly more common than in rats infected with H. diminuta. No detectable IgE antibodies were found in the uninfected and H. diminuta-infected rat groups; however total IgE was detected in H. pseudodiminuta-infected rats but the concentrations were variable between individuals.

Echinococcus multilocularis in domestic cats in France. A potential risk factor for alveolar hydatid disease contamination in humans.

In France, in North of Alps and South of Jura, around the Swiss town of Geneva, the cestode E. multilocularis was found in three out of 81 domestic cats necropsied given by veterinarians. Morphological and morphometric features established the identity of this species. In an endemic area of alveolar hydatid disease, the prevalence of E. multilocularis in the domestic cat confirms that it is a risk factor for human beings and mainly for veterinarians.

Paranoplocephala maseri n. sp. (Cestoda, Anoplocephalidae), a parasite of sagebrush voles Lemmiscus curtatus (Rodentia) in the USA.

Paranoplocephala maseri n. sp. is described from Lemmiscus curtatus (Cope) in the USA. The new species is related to Paranoplocephala omphalodes (Hermann, 1783), P. caucasica (Kirschenblat, 1938), P. kirbyi Voge 1948, P. microti (Hansen, 1947) and P. macrocephala (Douthitt, 1915) sensu Genov et al. (1996). P. maseri n. sp. differs from P. omphalodes in the position of the genital pores, testes and cirrus-sac; from P. caucasica, in which there is an unarmed cirrus, in both the distribution and larger number of testes; from P. kirbyi in the distribution of the testes, the position of the genital pores and egg dimensions; from P. microti in the distribution and smaller number of testes, the smaller egg dimensions and the position of the genital pores; and from P. macrocephala in the position of genital pores and cirrus-sac.

Contents of several inorganic substances in European eel infected and uninfected by Anguillicola crassus (Nematoda).

The content of 5 macroelements and 5 microelements were analyzed using the atomic absorption method in muscle samples of European eels infected and uninfected by Anguillicola crasus. The mean contents of these substances in infected eels were statistically highly significantly lower in Ca, P, Fe, Mn, but only statistically significantly lower in Na, Mg, Zn and Cu as compared to uninfected fishes. These differences are discussed in relation to hematophagus feeding and pathogenity of the parasite.

Comparative study of Trichuris trichiura from non-human primates and from man, and their difference with T. suis.

Whipworms from the macaque and baboon were studied by light and scanning electron microscopy. They were identified as Trichuris trichiura, though a slight variation was observed in the length of spicule as compared with the whipworms collected from man. Moreover, a row of small knob-like structures was observed at the base of the pericloacal papillae of T. trichiura from the monkey by scanning electron microscopy. T. trichiura from non-human primates and man has been reported to be morphologically indistinguishable from T. suis. However, this study showed that males of T. trichiura from both the monkey and man can be differentiated from T. suis from the pig on the basis of the presence of a pair of pericloacal papillae and a cluster of small papillae near the caudal end in the former, which is totally absent in the latter.

Catenotaenia henttoneni sp. n. (Cestoda: Catenotaeniidae), a parasite of voles Clethrionomys glareolus and C. rutilus (Rodentia).

A description of a new tapeworm species, Catenotaenia henttoneni, parasitizing the voles Clethrionomys glareolus and C. rutilus (Arvicolidae) in Finnish Lapland, is given. We show that all Catenotaenia from arvicolid rodents in Europe, usually described as C. cricetorum Kirschenblat, 1949, evidently represent the species C. henttoneni.

Scanning electron microscopic study on Toxascaris transfuga (Rudolphi, 1819) (Nematoda).

The authors present original observations on the species Toxascaris transfuga obtained by means of scanning electron microscopy. Attention was paid to the structure of head end, morphology of papillae of the head and abdominal end, specific morphological traits of cloacae edges and morphology of the egg surface. Presented are morphological criteria which apparently differentiate the species T. transfuga from T. leonina (Linstow, 1902). T. transfuga and T. multipapillata Kreis, 1938 seem to be conspecific.

Parasitism by helminths in the grey-sided vole (Clethrionomys rufocanus) in northern Finland: influence of density, habitat and sex of the host.

We have studied helminths from 532 grey-sided voles (Clethrionomys rufocanus) in two localities in northern Finland, representing different biogeographic zones, during 1978-1983. The helminth communities in the two study areas were similar, characterized by a small number of species (eight) compared to eastern Siberia and Japan, and by the dominance of a single anoplocephalid cestode Andrya kalelai. The prevalence of this helminth varied significantly among habitats, possibly because of differences in the distribution and abundance of the intermediate hosts, oribatid mites. Vole density did not explain the habitat differences in A. kalelai, nor did the prevalence of A. kalelai increase between 2 yr of sustained high density in the host population. A between-year increase in the prevalence of the larval cestode Taenia tenuicollis at Kilpisjärvi was probably due to a simultaneous increase in the abundance of its definitive hosts, mustelids. The prevalence of A. kalelai was always higher in males; no sexual differences were detected in the larval T. tenuicollis.

Scanning electron microscopic studies on males of trichinella species.

Ultrastructure of the cuticle and pseudobursa of adult males of four species of Trichinella has been studied by SEM. T. nativa differs markedly from T. spiralis, T. nelsoni and Trichinella sp. in the form of the pseudobursa. Trichinella sp. differs only slightly from T. spiralis and T. nelsoni. The ultrastructure of the cuticle revealed no characters suitable for the differentiation of the taxons under study.

Scanning electron microscopic study of the vulva of some trichurids (Nematoda).

The structure of vulva of four Trichocephalus species has been studied using scanning electron microscopy (SEM). The shape of vulva and cuticular elements on vulval appendages is described and documented. The cuticular structures on the vulva have a characteristic shape specific for each species. It is suppossed that SEM can be successfully employed in a detailed study of vulval structure, which is an important taxonomic character for the differentiation of females of Trichocephalus species.