ABSTRACT
Objective To understand the distribution of the river beach wetlands and Oncomelania snails in the lower reach-es of the Yangtze River,and explore the countermeasures of snail control. Methods The river beach wetlands outside the Yang-tze River levee were investigated and classified according to the hierarchical and classification system of wetlands of China. The snail survey was carried out in the beach wetlands of Runzhou section of lower reaches of the Yangtze River from 2004 to 2013. The change trend of snail areas and the densities was analyzed in the wetlands. Results The river beach of Runzhou section of lower reaches of the Yangtze River belongs to the riverine wetland. There was Oncomelania snail breeding except the permanent wa-ter area. At present,there were natural wetlands of 1 303.0 hm2,human-made wetlands of 1 479.0 hm2 and wetland function chang-es of 1 059.0 hm2 in the river beach of Runzhou section. There was the snail area of 181.4 hm2 in the natural wetland in 2013. The area of snail control by the molluscicide and environmental modification was 4 624.55 hm2 from 2004 to 2013. The decline rates of snail areas and densities were 66.53%and 77.66%respectively. The existing Oncomelania snails were distributed in the natural wetlands. Conclusion The human-made wetland is helpful to snail control. The snail control in the river beach wetlands should attach a great importance to the protection of wetland ecology.
ABSTRACT
Objective To evaluate the effect of comprehensive prevention and control of soil?transmitted nematodiasis in Runzhou District Zhenjiang City Jiangsu Province from 1997 to 2012. Methods The comprehensive prevention and control measures included the helminthicide health education improvement of water supplier and harmless toilets and these mea?sures were implemented continuously. At the same time the infection rates of soil?transmitted nematodes the local economic in?dicators and the coverage rates of tap water and harmless toilets were surveyed. Results The mass chemotherapy was per?formed for 202 100 person?times and the diagnosed chemotherapy was performed for 2 006 person?times in Runzhou District from 1997 to 2012. The awareness rates of health knowledge were 57.18%in 1997 and 95.62%in 2012. The coverage rates of tap water and harmless toilets were 10.14%and 10.21%in 1997 and 100.0%and 90.38%in 2012 respectively. There were negative correlations between the awareness rate of per capita GDP per capita net income coverage rates of tap water cover?age rates of harmless toilets health knowledge and the infection rate of soil?transmitted nematodes respectively rper capita GDP=-0.526 P 0.05 rper capita net income=-0.671 P 0.01 rcoverage rates of tap water=-0.936 P 0.01 rcoverage rates of harmles toilets=-0.922 P 0.01 rawarenes=-0.774 P 0.01 . The statistical analysis showed that the infection rate of soil?transmitted nematodes had a downward trend as an expo?nential curve in Runzhou District from 1997 to 2012 y=42.031 7e?0.357 6x R2=0.803 6 F=57.28 P=0.000 . The infection rate of degradation by an annual rate was 29.18%. The infection rate in farmers was significantly higher than that in students χ2=17.998 P 0.01 . There was no significant difference between men and women in the infection rate of soil?transmitted nema?todes χ2=3.627 P=0.057 . Conclusion The comprehensive prevention and control measures and the development of so?cial economy contribute to the steady decline of soil?transmitted nematode infections.