The coordination of regional interest in developing river basin

River basin is a special region with the characteristics of entireO, and relation, regionality and dlversity, gradation and network, openness and dissipation etc. It is an important unit that organizes and governs national economy as well as a natural re, on. In river basin, all natural essential factors relate closely each other, and there is remarkable influence between inter-regions. In the process of developing river basin, the multiplex main interest body, the diverse interest demand and the multi-ways of interest realization constitute a complicated interest network, and result in various contradictions and conflicts. Therefore, egective regional interest coordination mechanism should be estabfished to coordinate various regional interest relations. They are the public interest realization mechanism, the fair interest assignment mechanism, the effective interest integration mechanism, the expedited interest expression mechanism and the reasonable interest compensative mechanism.

Dynamics of freshwater snails and Schistosoma infection prevalence in schoolchildren during the construction and operation of a multipurpose dam in central Côte d’Ivoire

Background:The construction and operation of small multipurpose dams in Africa have a history of altering the transmission of water-based diseases,including schistosomiasis.The current study was designed to investigate the abundance and dynamics of schistosomiasis intermediate host snails and Schistosoma infections in humans during the construction and the first years of operation of a small multipurpose dam in Côte d’Ivoire.Methods:The study was carried out in Raffierkro and four neighbouring villages in central Côte d’Ivoire between 2007 and 2012.Snails were collected by two experienced investigators using scoops and forceps for 15 min at each site.Snails were identified at genera and,whenever possible,species level,and subjected to testing for cercarial shedding.Schoolchildren aged 6-15 years were examined once every year for Schistosoma haematobium and S.mansoni infection,using urine filtration and duplication Kato-Katz thick smears,respectively.Additionally,551 adults were examined for Schistosoma infection before(June 2007)and 359 individuals 2 years after dam construction(June 2009).Results:Overall,1700 snails belonging to nine different genera were collected from 19 sampling sites.Bulinus(potential intermediate host snails of S.haematobium)and Pila were the most common genera,whereas Biomphalaria(potential intermediate host snail of S.mansoni),Lymnaea,Physa and Melanoides were found in two villages.During the first-year sampling period,65 snails were collected,of which 13(20%)were schistosomiasis intermediate hosts.In subsequent years,out of 1635 snails collected,1079(66%)were identified as potential intermediate host for schistosomiasis,but none were shedding cercariae.The prevalence of S.mansoni among adults in the study area was low(0.4%in 2007 and 0.3%in 2009),whereas the prevalence of S.haematobium declined from 13.9%to 2.9%in this two-year period.Conclusions:The low prevalence of schistosomiasis in humans and the absence of infected intermediate host snails during the construction and early phase of operation of a small multipurpose dam suggest that there was no or only very little local transmission.However,the considerable increase in the number of intermediate host snails and their dispersion in irrigation canals call for rigorous surveillance,so that adequate public health measures can be taken in case of early signs of an outbreak.