ABSTRACT
Objective To evaluate the molluscicidal effect of 50% wettable powder of niclosamide ethanolamine salt (WPNES) against Oncomelania hupensis on the soil surface and inside the soil layer by immersion method in winter. Methods O. hupensis snails were placed on the soil surface and 2, 5 cm and 10 cm under the soil layer outdoors in winter, and then immersed in 50% WPNES at concentrations of 1 mg/L and 2 mg/L for 1, 3 d and 7 d, while dechlorinated water served as controls. Snail mortality was observed following immersion with 50% WPNES on the soil surface and inside the soil layer. Results Following immersion with 50% WPNES at concentrations of 2 mg/L and 1 mg/L outdoors in winter, the 3-day corrected snail mortality rates were 98.0% and 76.0% on the soil surface, and the 7-day corrected snail mortality rate was both 100.0%. Following immersion with 50% WPNES at concentrations of 2 mg/L and 1 mg/L outdoors in winter, the 7-day corrected snail mortality rates were 95.5% and 85.6% 2 cm below the soil layer, 66.0% and 6.4% 5 cm below the soil layer. However, the 7-day snail mortality rate swere comparable between the 50% WPNES treatment group (at 2 mg/L and 1 mg/L) and controls 10 cm below the soil layer (both P > 0.05). Conclusion Immersion of 50% WPNES at a concentration of 2 mg/L for 7 days presents a high molluscicidal efficacy against O. hupensis on the soil surface and 5 cm within the soil layers in winter.
ABSTRACT
Objective To understand the current epidemic and immunity status of hepatitis B virus in Ma’anshan City, and to compare the prevention and control effect after the adjustment of hepatitis B vaccine immunization strategy. Methods Multi-stage random sampling method was used to select 10 investigation points in the whole city, a random sample of 3 460 people under 60 years old was included according to urban and rural stratification. questionnaires and blood were collected from the subjects, and domestic enzyme linked immunosorbent assay (ELISA) was used for hepatitis B immunoglobulins detection. Results The total positive rate of hepatitis B virus surface antigen (HBsAg), hepatitis B virus surface antibody (HBsAb) and Hepatitis B virus (HBV) infection was 3.32%, 51.21% and 29.16% respectively. The positive rate of HBsAb in urban area was higher than that in rural area ( 2=28.204, P<0.001). The positive rate of HBsAb was significantly different between the medical and nursing staff and other occupational groups ( 2=22.772, P<0.001). The difference of HBsAb positive rate before and after HepB vaccine content adjustment was statistically significant ( 2=90.331, P<0.001). The rate of HepB decreased with age ( 2trend=1 984.342, P<0.001). Conclusions Since HepB was incorporated into the immunization program, hepatitis B prevention and control in school-age children has achieved remarkable results. More attention should be paid on the low positive rate of HBsAb in students and the low immunization rate of HepB in adults.