Showing papers on "Biomphalaria alexandrina published in 1978"

Effect of some herbicides on the toxicity of certain molluscacides against Biomphalaria alexandrina snails.

Abstract: Studies dealing with the effect of some herbicides on the molluscicidal action of certain molluscicides against B. alexandrina have been carried out. In the first part of the study the toxicity of 3 molluscicides (Copper sulphate, Niclosamide and Frescon) and 3 herbicides (Gramaxone, Preforan and Treflan) was tested individually. Results indicated that the molluscicides were more potent than the herbicides. In the second part, snails were exposed for 24 hr to one of the tested herbicides using LC0 or (Sub. lethal conc) then the toxicity of molluscicides was determined among the same snails. Data indicated that pre-exposure to herbicides caused a synergistic action with copper sulphate, while with Niclosamide and Frescon marked antagonistic effect was observed. In the third part molluscicides and herbicides were mixed in different ratios (1:2, 1:1 and 2:1) and the toxicity of the mixtures was tested. A synergistic effect was observed in the case of copper sulphate plus various herbicides especially with Treflan at 1:2 ratio. With Niclosamide and Frescon slight antagonistic effect was detected.

Prevalence of schistosomiasis among fishermen of Lake Maryut.

Abstract: A survey was carried out to investigate the presence of Bilharziasis among the fishermen of the lake Maryut. Schistosoma mansoni is more prevalent, than S. haematobium among fishermen of lake Maryut. Biomphalaria alexandrina, snails were prevalent around the lake specially in places of low salinity, where fresh water discharges exist. Bulinus truncatus snails were not found during the time of the present survey and more frequent surveys are needed. There is an inverse relation between the number of snails and the salinity of the water. Since the salinity of the water is decreasing by time as a result of the increased discharge of agricultural and domestic waste into the lake, Bilharziasis infection may increase among the fishermen. This situation needs more attention from public health authorities in the area.