Effect of climate on the epidemiology of bovine hypodermosis in algeria

In order to explore the effect of climate on cattle warble fly infestation, a total of 1.635 animals from 4 departments of Northern Algeria were examined visually and by manual palpation for the presence of warbles. Cattle were examined from March to June 2014, coinciding with the peak of emergence of warbles, and both the prevalence and intensity of infestation were recorded. The departments included in this study were located in the two different climatic areas in Northern Algeria: humid (Bejaia and Tizi Ouzou) and semi-arid (Tissemssilt and Ain Defla). The overall prevalence was 28.75%; the intensity of infestation ranged from 1 to 98 warbles per animal (mean 18.93±11.05). The prevalence and intensity of infestation within the departments with semi-arid climate (38.23%; 21.57±11.98) was significantly higher than in those with humid climate (20.74%; 14.84±7.86). The CHAID algorithm showed the climate as the most influencing factor for warble fly prevalence, followed by the husbandry system and breed. Logistic regression and multivariate ANOVA indicate that in addition to climate, other intrinsic (age, breed) and extrinsic factors (husbandry system, treatment) included in the study also were associated with both, prevalence and intensity of infestation. Our results indicate that in semiarid areas of Northern Algeria environmental conditions are more favorable for the development of free stages (pupae and adult flies) of Hypoderma spp life-cycle than in humid areas

Larval development of Angiostrongylus vasorum in the land snail Helix aspersa

The metastrongyloid nematode Angiostrongylus vasorum affects the heart and pulmonary arteries of dogs and wild animals. Over the recent years, dog angiostrongylosis has gained great attention in the veterinary community for the expansion of its geographic range and for a rise in the number of clinical cases. Global warming, changes in phenology of mollusc intermediate hosts and movements of wild reservoirs have been evocated in the spreading of mollusc-borne parasites, including A. vasorum. The land snail Helix aspersa, a vector of other respiratory metastrongyloids, is endemic in most regions of the World, where it is a pest outside its native Mediterranean range. In the present study, the susceptibility and suitability of H. aspersa as an intermediate host of A. vasorum were investigated along with the characteristics of larval recovery and development following two different ways of inoculation, i.e. experimental (group A) vs natural infection (group B). After infections, the snails were kept at environmental conditions for 2 months. Five snails from groups A and B were randomly selected, digested and examined at 15-day intervals for 2 months. L1s, L2s and L3s were microscopically identified based on key morphological and morphometric characteristics and their identity was genetically confirmed. The results showed that A. vasorum may reach the infective stage in H. aspersa and that uptake of larvae and parasitic burden within the snails depend on the grazing capability of the molluscs. Biological and epidemiological implications are discussed