Application of the Midi Parasep® SF technique for the detection of L1 larvae of Angiostrongylus cantonensis in faeces of infected rats.

We investigated parasitic zoonoses caused by protozoans and helminths in urban and peri-urban rat populations (Rattus norvegicus and R. rattus) in Spanish cities. Rats were trapped and then dissected to remove adult helminths, and the contents of the large intestine were retrieved for the study of parasitic forms. The Midi Parasep® solvent free (SF) technique was used to concentrate the parasites in the intestinal contents. Some of the rats studied (n = 8) were infected by the rat lungworm, Angiostongylus cantonensis, whose first stage larvae (L1) are shed in rat faeces. After the concentration technique, L1 larvae were found in the sediment of 6 of the 8 positive rats. The two negative sediment samples were due to the presence of either only adult females or, in addition to males, only young females in the lungs of the rats. In view of our results, Midi Parasep® SF turned out to be a simple, rapid, inexpensive, and sensitive method to detect nematode larvae, such as the L1 larvae of A. cantonensis (or A. costaricensis), in natural and experimentally infected rats.

The helminth community of the wood mouse Apodemus sylvaticus from the Erro River valley, Navarre, Spain.

The helminth fauna of the wood mouse, Apodemus sylvaticus, in the Erro River valley (Navarre, Spain) was investigated from a total of 150 mice between February 2001 and July 2002. An overall prevalence of 90.7% was recorded and up to 14 helminth species identified. The most prevalent species was the nematode Heligmosomoides polygyrus (78.0%), whereas Syphacia stroma was the species with the highest median abundance (19.8). The detection of Calodium hepaticum, Rodentolepis straminea and the larvae of Hydatigera taeniaeformis are significant, since these helminth species could be considered potential human parasites. The helminth infracommunity comprised no more than five species. A significant predominance of monoxenous species was detected. Statistically significant differences were also found between prevalences, helminth abundance, species richness and helminth diversity of sub-populations of the wood mouse determined by host age and season of capture, which agree with most of the studies carried out on this host. This study will shed light on the helminth community of the wood mouse from a region of Spain which has not previously been documented.

The helminth community of the wood mouse Apodemus sylvaticus in a Mediterranean ecosystem in regeneration ten years after a wildfire.

This study was carried out 10 years after a wildfire in the Spanish Serra Calderona Natural Park, following a previous analysis comprising the first 5 years after the fire. Its primary aim was to elucidate the impact of this perturbation on the population biology of the wood mouse Apodemus sylvaticus, and the repercussions on its helminth community in this regenerating Mediterranean ecosystem. Second, confirmation of the ability of the parasites to tolerate environmental stressors and the effects on their transmission strategies was sought. Five hundred and sixty-four individuals of A. sylvaticus were studied in a 9-year period, from the second to the tenth post-fire year: 408 mice from the burned area and 156 from the control--non-burned--area. The helminth community for both areas and the effect of intrinsic (host age and sex) and extrinsic (site, period and year of capture) factors on helminth prevalence, abundance and diversity, and species richness were analysed. Our findings show that, after an environmental disaster, the behaviour of helminth species might be related to their pre-catastrophe presence, their biological cycles, the host's immunological condition, the change of host dynamics, the direct effects of the perturbation, and the processes related to the re-establishment of the ecological balance of a devastated ecosystem.