[Observation of molluscicidal effect of black plastic film combined with carbon amide].

OBJECTIVE: To evaluate the molluscicidal effect of black plastic film combined with carbon amide. METHODS: In Jiangdong Town, Jinhua City, the field with Oncomelania hupensis in the history was selected as experimental area and divided into 3 groups: Group One was administered with black plastic film combined with carbon amide; Group Two was administered with simple black plastic film; and Group Three was a control group. RESULTS: On the 3rd, 7th, 15th, 20th and 30th day after the experiment, the mortality rates of 0. hupensis of Group One were 86.0%, 88.0%, 100%, 100% and 100% respectively, which were significantly higher than those of the control group (all P < 0.05). The differences of mortality rates between Group One and Group Two were statistically significant on the 3rd and 7th day after the experiment (Group One was superior to Group Two). CONCLUSION: The bladk plastic film combined with carbon amide can improve the molluscicidal effect.

[Cost-effectiveness analysis of mechanical and manual soil-buried methods for Oncomelania hupensis control].

OBJECTIVE: To explore a high molluscicidal efficient method in special Oncomelania hupensis snail environments. METHODS: In 2005 and 2006, in large special environments (rubble creek beaches and seepage barren hills with snails), the mechanical soil-buried method (excavator digging to bury deep snails) and manual soil-buried method were used respectively, and the results were compared for the cost-effectiveness. RESULTS: With the mechanical soil-buried method in 2006, the investment was 0.78 yuan/m2, and the compression rate of snail areas was 100%; with the manual soil-buried method in 2005, the investment was 1.34 yuan/m2, and the compression rate of snail areas was 20.26%. The former was much better than the latter. CONCLUSION: In the large special environments with snails, the mechanical soil-buried method is superior to manual soil-buried method.

[Sero-epidemiologic investigation on tick-borne diseases of humans and domestic animals in Zhejiang province].

OBJECTIVE: To investigate the seroprevalence of tick-borne diseases in humans and domestic animals from rural areas of Zhejiang province. METHODS: Anji county, Jindong district and Tiantai county were selected for samples collection according to their geographic locations and historical prevalence of tick-borne diseases. Blood samples of humans and domestic animals were collected in the three sites. An indirect immuno-fluorescent antibody test was used to determine the presence of IgG antibodies of Rickettsiae heilongjiangii, Orientia tsutsugamushi, R. typhi, Anaplasma phagocytosis, Ehrlichia chaffeensis, Bartonella, R. hainan and Coxiella burnetii in these samples. RESULTS: Six hundred and eighty-three blood samples including 579 from humans and 104 from domestic animals (53 from cattles and 51 from sheep) were collected from the three sites. Antibody positive rates of Orientia tsutsugamushi, R. typhi, Ehrlichia chaffeensis and Coxiella burnetii were significantly different between these sites. IgG from all the 8 pathogens were detected in samples from humans. It was found that the sero-prevalence rates of R. typhi, Bartonella and C. burnetii (20.7%, 10.9%, 5.5%) of adults were higher than those of other Rickettsiae under investigation. The seroprevalence of R. typhi increased along with age. IgG from the 7 pathogens were detected in samples from domestic animals except for Anaplasma phagocytosis. The sero-prevalence rates of R. typhi, Bartonella and R. hainan (69.2%, 51.0%, 22.1%) of adults were higher than those of other Rickettsiae investigated. CONCLUSION: Tick-borne diseases did spread widely in humans and domestic animals from different rural areas of Zhejiang province. The sero-prevalence rates of R. typhi, B. henselae, R. hainan and C. burnetii were higher than that from other pathogens.