[Study on the strategy of interrupting schistosomiasis transmission in a hilly new endemic area of Taoyuan County].

OBJECTIVE: To develop a strategy for interrupting the transmission of schistosomiasis japonica in a hilly new endemic area. METHODS: Since 1996, chemotherapy with praziquantel (adult 40 mg/kg, child 50 mg/kg, cattle 30 mg/kg, once a year) on human beings in Taoyuan County who had ever contacted with infectious water and cattle which were herded in endemic situation was the major intervention, with focal control of Oncomelania snails in susceptible areas as supplementary one. RESULTS: The positive rate of stool examination for schistosomiasis in human and cattle reduced from 5.69% and 6.76% in 1996 to 0.04% and 0 in 2005 respectively. The positive rate of indirect hemagglutination test (IHA) in human dropped from 7.45% in 1996 to 1.61% in 2004. Though living snails were still found in most habitats, the density of infected snails decreased from 0.0036/0.11m2 in 1997 to 0 in 2005 and no infected snails were found since 2000. CONCLUSION: Due to less movement of human and cattle populations and the hilly area relatively isolated, chemotherapy combined with focal mollusciciding have been highly effective in eliminating the infection sources and interrupting transmission of schistosomiasis.

[Schistosomiasis control effect of measures of replacing cattle with machine for cultivation and forbidding depasturage of livestock on marshlands in marshland and lake regions].

OBJECTIVE: To evaluate the schistosomiasis control effect of the measures of replacing cattle with machine for cultivation and forbidding depasturage of livestock on marshlands in marshland and lake regions. METHODS: The retrospective review and field survey were implemented in the Jiangling and Gongan counties of Hubei Province where were implemented with the measure of replacing cattle with machine for cultivation, and Yuanjiang and Huarong counties of Hunan Province where were implemented with the measure of forbidding the depasturage of livestock on marshlands. The schistosome infection status of human, cattle, and Oncomelania hupensis snails, and schistosome-infested field excreta were surveyed from 2007 to 2013. The effects of the interventions were compared before and after their implementations. RESULTS: The 6 villages of Hubei Province were implemented with the measure of replacing cattle with machine for cultivation, and 7 villages of Hunan Province were implemented with the measure of forbidding the depasturage of livestock on marshlands. From 2007 to 2013, the schistosome infection rates of residents declined from 3.95% to 0.70% (χ2 = 128.376, P < 0.05), with the descend range of 82.53%. The descend ranges of the measures of replacing cattle with machine for cultivation and forbidding the depasturage of livestock on marshlands were 83.081% and 81.62% respectively, and there was no significant difference between the two measures (χ2 = 0.132, P > 0.05). The infection rate of cattle decreased from 3.66% in 2007 to 0.65% in 2013, and the descend range was 82.24% (χ2 = 13.692, P < 0.05). The field excreta was surveyed in the snail breeding place in 2013. The investigated area was 157.435 hm2, and 625 samples of field feces of cattle were collected with the density of field excreta of 3.97/hm2, and the positive rate was 1.12% (7/625). The schistosome infection rate of snails and the density of infected snails decreased successively from 2007, and no infected snails were detected from 2011 to 2013. CONCLUSIONS: The schistosomiasis endemic situation are decreased significantly after the interventions of replacing cattle with machine for cultivation and forbidding the depasturage of livestock on marshlands. Therefore, schistosomiasis control effect of these measures is notable in the marshland and lake regions.

[Effect of comprehensive schistosomiasis control measures with focus on buffalo and sheep removal in Anxiang County].

OBJECTIVE: To understand the effect of comprehensive schistosomiasis control measures with focus on buffalo and sheep removal in Anxiang City, Dongting Lake area. METHODS: The data of buffalo and sheep removal, routine schistosomiasis control measures such as disease detection and treatment, Oncomelania snail survey and control, as well as health education were collected and analyzed in Anxiang County, Hunan Province from 2004 to 2012. RESULTS: The schistosome infection rates of people, domestic animals and snails decreased from 11.23%, 17.06% and 1.07% in 2004 when the comprehensive measures had not been implemented to 0.58%, 0 and 0 in 2012, respectively. The average density of infected snails decreased from 0.003 4 snails/0.1 m2 to 0. CONCLUSION: The comprehensive control measures with focus on buffalo and sheep removal are significantly effective, and can control the transmission of schistosomiasis in marshland and lake regions.

[Role of socio-economy and management in sustainable transmission control of schistosomiasis in Taoyuan County, Hunan Province, China].

OBJECTIVE: To clarify the role of socio-economy and management in the sustainable schistosomiasis-control in Taoyuan County, an endemic area in hilly region, Hunan Province, China. METHODS: From 1996 to 2011, the data of socio-economy, the management of schistosomiasis control organizations, environment, and the changes in schistosomiasis prevalence were collected in Taoyuan County where schistosomiasis transmission had been controlled since 2008. A sampling survey of schistosomiasis prevalence of human and bovine was performed in 2011 to verify the current status of schistosomiasis transmission. All the data were analyzed statistically to evaluate the role of socio-economy and management in the sustainable schistosomiasis control. RESULTS: During the period from 1998 to 2012, the socio-economy including the residents' productive mode and daily life in Taoyuan County improved dramatically, but the recurrence risk of schistosomiasis endemic still existed due to the retuning of out-going workers and the migrating population. Moreover, the introduction of exotic species of plants and animals may increase the risk. The low running cost of schistosomiasis control organization as well as the efficient and adequate resource allocation in the county was in line with the national requirement to strengthen the rural grass-roots public health system. CONCLUSION: The harmonious development of socio-economy and the scientific and efficient health system in Taoyuan County are the key factors for the sustainable transmission control of schistosomiasis.

[Endemic features and control strategies of schistosomiasis in Dongting Lake area, Hunan Province, P. R. China].

This paper describes the epidemic status and current endemic features of schistosomiasis in Dongting Lake area and analyzes the achievements and weakness of various control measures. It also summarizes the characteristics of epidemic situation in the Dongting Lake region, which indicates the long-term and the arduous work in the future for the control of schistosomiasis. In strategy, comprehensive measures should be implemented and routine prevention control work should be remained combing with the control of transmission sources.