La distomatosis hepática y su asociación con los factores de riesgo en los municipios Mara y Páez del estado Zulia, Venezuela

From a crossbred bovine population of 3860 animals, 877 fecal samples were obtained, product of a simple aleatory sampling carried out during two periods of sampling in different seasons, the dry season (January to March) and the rainy one (September to November) 1996, in order to studying the degree of existent association among risk factors: the presence of the intermediary host (Limnaea cubensis), the disease, sex of the sampled animal, therapeutic control of the parasite in the farms unit and season of the year. 397 positive samples resulted of the 30 production units belonging to four sectors located in the riverbanks of the Guasare, Socuy and Limon rivers, Mara and Paez municipalities. The prevalence for Mara municipality was of 53.15% and 40.93%, and Paez, 45.09% and 43.14%, for the dry and rainy seasons, respectively. A positive association was detected between the presence of the illness and the season of the year, being evidenced highger prevalence in the dry season, in the one which, the sector with more incidence was "El Colorado" (61.17%) with statistical differences (P<0.05) against the other studied sectors. For the rainy season, differences were not detected among the sectors, not being, also, association between the sector and the incidence of the illness. Association was detected between the sex and the prevalence, according to Ji-Square significance test, being presented higher incidence in females that in males, although the range of inequality showed that the illness can affect equally to both sex. The therapeutic controls of the herds, inside their handling, are associated to a smaller prevalence. In herds without control, the rate of sick animals was of 55.48%, while in the herds with control was of 34.65%. In all the studied farms was proven the presence of Limnaea cubensis, being observed 23.30% of the total of snails with larvarius forms of Fasciola hepatica.