An integrated environmental improvement of marshlands: impact on control and elimination of schistosomiasis in marshland regions along the Yangtze River, China.

BACKGROUND: Schistosomiasis is a global snail-transmitted infectious disease of poverty. Transmission control had been achieved in China in 2015 after the control efforts for over 60 years. Currently, the remaining core regions endemic for Schistosoma japonicum are mainly located in the marshland and lake regions along the Yangtze River basin. METHODS: During the period from 2001 through 2015, an integrated environmental improvement of the marshlands was carried out through the implementation of industrial, agricultural and resources development projects in Yizheng County along the Yangtze River. S. japonicum infection in humans, livestock and snails was estimated by serology, stool examination, hatching technique and microscopy during the 15-year study period to evaluate the effect of the integrated environmental improvement on control and elimination of schistosomiasis. RESULTS: A 0.05% overall rate of S. japonicum infection was observed in snails during the 15-year study period, and no infected snails were detected since 2012. The overall prevalence of S. japonicum infection was 0.09% in humans during the study period, and no human infection was found since 2012. In addition, only 13 bovines were identified with S. japonicum infection in 2003 during the 15-year study period, and since 2004, no infection was found in livestock. CONCLUSION: The results of the present study demonstrate that the implementation of industrial, agricultural and water resources development projects, not only alters snail habitats in marshland regions, and promotes local economic development, which appears a win-to-win strategy to block the transmission of S. japonicum and accelerate socio-economic development along the Yangtze River.

A multidisciplinary, integrated approach for the elimination of schistosomiasis: a longitudinal study in a historically hyper-endemic region in the lower reaches of the Yangtze River, China from 2005 to 2014.

BACKGROUND: Although great success has been achieved, schistosomiasis remains a major public health concern in China, and the remaining core endemic regions are concentrated along the middle and lower reaches of the Yangtze River. In this longitudinal study, we evaluated the effectiveness of a multidisciplinary, integrated approach for schistosomiasis elimination in a historically hyper-endemic region in the lower reaches of the Yangtze River, China over the 10-year period from 2005 through 2014. METHODS: A three-step roadmap for schistosomiasis elimination was designed in the study site, and multidisciplinary, integrated interventions were implemented by the health, agriculture, water resources development, land and resources, and forestry sectors from 2005 to 2014, including chemotherapy for infected individuals, health education, management of the source of Schistosoma japonicum infection, and intermediate host snail control. The annual number of schistosomiasis patients, S. japonicum infection in humans, bovines and Oncomelania hupensis snails, and water infectivity were observed to assess the effectiveness of the multidisciplinary, integrated approach for the elimination of schistosomiasis. RESULTS: There was a tendency towards a gradual decline in both the number of schistosomiasis cases and the prevalence of S. japonicum human infection across the study period from 2005 through 2014. No S. japonicum human infection was detected since 2012, and no acute infection was seen since 2006. During the study period, no infection was found in bovines, and a 0.03% overall infection rate was observed in O. hupensis snails. Since 2009, no infected snails were identified, and the area of both snail habitats and infected snail habitats appeared a reduction over the study period. Following the 3-year multidisciplinary, integrated control, infection control was achieved, and transmission control was achieved after 6-year implementation, with all infected snails and water infectivity eliminated; in addition, the 10-year implementation resulted in interruption of schistosomiasis transmission in the study site in 2014. CONCLUSIONS: The results of the present 10-year longitudinal study demonstrate that the multidisciplinary, integrated approach is effective for the elimination of schistosomiasis as a public health problem in the lower reaches of the Yangtze River, China.

[Integration and demonstration of key techniques in surveillance and forecast of schistosomiasis in Jiangsu Province I Layout and effect of the demonstration sites for schistosomiasis surveillance and forecast].

OBJECTIVE: To explore and integrate the key techniques used in the surveillance and forecast of schistosomiasis in the water regions along the Yangtze River, so as to provide technical support for identifying rapidly the risk of schistosomiasis transmission and implementing control measures targeting the risk. METHODS: According to the distribution of water systems and water regions along the Yangtze River in Jiangsu Province, the demonstration sites for surveillance and forecast of schistosomiasis were set across the province, where the integration and demonstration of the techniques regarding monitoring of Schistosoma japonicum infection in sentinel mice, human and animal activities, release of forecast information, and emergency treatment of water regions at risk of infection were performed. The pattern of human and animal activities was compared with the S. japonicum infection in sentinel mice in the demonstration sites, and the operability of the release of information and emergency treatment of the risk of S. japonicum infection was evaluated. RESULTS: A total of 50 demonstration sites for surveillance and forecast of schistosomiasis were set in fixed anchor points, opening of the navigation lock to the Yangtze River, freight terminal, agritainment places, ferry, large construction places, and places for guaranteeing the Youth Olympic Games in 23 counties (districts) of 5 cities, Jiangsu Province. During the period between May. and September, 2014, the infectivity of water body was monitored by using 5 batches of sentinel mice, with a 99.06% (4,954/5,001) gross recovery rate of mice. S. japonicum infection was detected in a demonstration site, and an infected mouse was found, with a 0.02% (1/4,933) gross positive rate of sentinel mice. The field survey showed 2 088 person-times contacting water, including 91.95% (1,920/2,088) contacting water due to the production such as capturing fish, harvesting and cultivating crops, and repairing and building boats, and 8.05% (168/2 088) contacting water due to the life activity, such as fishing, washing vegetables and playing with water. The people contacted water predominantly in August and September (49.57%). A total of 859 boats containing 1,877 boatmen were observed, 68.22% (586/859) of which were fishing boats containing 1,306 fishermen (69.58%). There were 32 sheep found in 4 demonstration sites, and 3 sheep were seen in the demonstration site with infected sentinel mouse. Four blue forecasts (emergence of water contact) and one orange forecast (S. japonicum-infected sentinel mouse detected) were released across the province, with one forecast map released which showed 5 sites with fishing and one site with sheep grazing, one emergency response system initiated, mollusciciding implemented in 10 hm2 high-risk regions, 120 sheep grazed in fence, and 35 fishermen given health-education materials, schistosomiasis examination and preventive therapy. In addition, no acute schistosomiasis occurred in the demonstration site with S. japonicum-infected sentinel mice. CONCLUSIONS: The integration and demonstration of the techniques regarding monitoring of S. japonicum infection in sentinel mice, human and animal activities, release of forecast information, and emergency treatment of water regions at risk of infection provides an effective approach for the large-scale surveillance and forecast of schistosomiasis.

[Effect of management on imported malaria in Yangzhou City, 2012-2013].

OBJECTIVE: To evaluate the effectiveness of the management on imported malaria in Yangzhou City, so as to provide a reference for formulating the strategy for the prevention and control of imported malaria. METHODS: The data about the detection rate of Plasmodium of fever people in labor-exporting services and overseas returners, the proportion of laboratory confirmed cases in the whole malaria cases, the proportion of the cases with standardized treatment in the whole falciparum malaria cases within 24 hours, and the status of establishment of labor export platform were collected and analyzed in Yangzhou City from 2012 to 2013. RESULTS: There were 82 imported malaria cases in Yangzhou City from 2012 to 2013. The monitoring of labor-exporting services and overseas returners was carried out in the seven counties and districts of Yangzhou City, and the coverage rate was 100%. There were 5 808 persons of export labor service, and among them, 5 575 persons got the medical alert service (95.99%), and 9 525 persons accepted the healthy behavior (95.13%). Totally 410 medical professional persons received the malaria microscopic examination training in 153 malaria microscopy stations or medical institutions, and the training coverage rate was 100%. The average time from attack to the first visit to a doctor of 82 falciparum malaria patients was 2.5 days; the average time from attack to diagnosis confirmation was 2.75 days. All the patients were cured. In the first visit to a doctor, 78 patients were diagnosed with blood tests, and the newly diagnosed blood test rate was 95.12%, and all of them were detected with Plasmodium. Totally 69 falciparum malaria cases were confirmed by the laboratory, and 58 patients were treated with the standard treatment within 24 hours after the first visit (84.16%). CONCLUSIONS: The effect of the imported malaria control and management in Yangzhou City is obvious. However, it is still necessary to strengthen the health education and relevant medical personnel training to prevent and control imported falciparum malaria efficiently.

[Establishment and application of imported falciparum malaria control system in Yangzhou City].

To aim at the characteristics of epidemic situation that the imported falciparum malaria cases increased year by year in Yangzhou City, an imported falciparum malaria control system was established. This control system was based on enhancing the management of returned labor service export persons from falciparum malaria endemic areas, the active medical remind service, the diagnostic capability and health education, and the cooperation of medical personnel and patients, and also avoiding diagnosis delay and misdiagnosis and promoting the treatment in time so as to decrease the serious patients and prevent them from death. After the application of the control system, there were 164 imported falciparum malaria cases from the returned persons of labor service export. The time from the attack of the disease to the diagnosis confirmed decreased from 6.8 days before the application of the system to 2.7 days after the application, and the rate of serious patients was 1.8% and there were no death cases.

[Epidemiological status of human intestinal nematodiasis in Yangzhou City, Jiangsu Province].

OBJECTIVE: To understand the current epidemiological status of human intestinal nematodiasis. METHODS: Fresh feces of subjects were collected and the ova of intestinal nematodes were detected by Kato-Katz technique. Enterobius vermicularis was detected by the cellophane anal swab method. RESULTS: A total of 21 persons were ova positive among the 5666 subjects with 0.37% infection rate, and 51 persons were Enterobius vermicularis positive among 13,713 subjects with 0.37% infection rate. It was deducted that there were about 20,000 people infected with intestinal nematodes in Yangzhou City. CONCLUSION: There are some people infected with intestinal nematodes. Therefore, health education and surveillance of intestinal nematode infections still need to be strengthened

[Engineering management mode of mollusciciding and assessment of its field application].

OBJECTIVE: To establish the engineering management mode of mollusciciding, and assess its snail control effect in field application, so as to provide the effective management interventions for improving the quality of mollusciciding in the field. METHODS: Engineering management of mollusciciding was performed. The snail distribution was surveyed before and after snail control with molluscicides and environmental modification, and the database was established. The snail control effect of the engineering management mode of mollusciciding was assessed. RESULTS: Engineering management mode of mollusciciding was conducted in 96.27% (1 033/1 073) of the total snail habitats in 6 counties (districts) of Yangzhou City from 2006 to 2011. After the implementation of engineering management mode, the mortality of snails increased from 65.07% before implementation to 87.16% (80.65%-89.38%), and significant difference was observed (chi2 = 4 623.297, P = 0). The reductions in occurrence rate of frames with snails and snail density and the corrected mortality of snails were 57.67% (49.27%-66.98%), 76.67% (76.13%-83.66%) and 86.58% (79.89%-88.89%), respectively, which were 1.45, 1.63 times and 1.37 times more than those before implementation. After the implementation of engineering management mode of mollusciciding for 3 years in Yangzhou City, all infected snails were eliminated. After 6 years of implementation, the number of settings with snails, snail areas, occurrence rate of frames with snails, means snail density decreased by 56.27%, 76.40%, 67.99% and 66.67%, respectively. CONCLUSIONS: High-quality molluscicide is the essential factor to ensure the molluscicidal effect, and engineering management mode of mollusciciding is an effective approach to improve the quality of snail control with molluscicides in the field.

[Study on surveillance and early-warning system of schistosomiasis in first phase of east route of South-to-North Water Diversion Project. III. Indexes of surveillance and early-warning and risk assessment].

OBJECTIVE: To establish the index system of surveillance and early-warning on schistosomiasis and to provide the scientific basis for risk assessment and emergency plan in first phase of east route of South-to-North Water Diversion Project. METHODS: The Delphi method and the multidimensional synthetic evaluation were used in the evaluation of indexes of surveillance and early-warning on schistosomiasis in the east route of the project. RESULTS: There were 53 indexes evaluated in the index system, and among them, there were 3 first grade indexes, 10 second grade indexes and 40 third grade indexes. The indexes on Oncomelania snails were the most important. According to the habitation position of snails, the four grades on surveillance and early-warning of schistosomiasis were established in the east route. The grade I of the early-warning meant that snails crossed the first level of the pumping station. The grade II meant that snails crossed N 32 degrees 54'. The grade III meant that snails crossed N 33 degrees 03' or Jinhu pumping station. The grade IV meant that snails crossed N 33 degrees 15' or Hongze Station. Other 4 indexes on schistosome infection in people and livestock were confirmed as indicative indexes. According to the relationship among the indexes, the evaluation methods were determined on the risk of schistosomiasis transmission. CONCLUSIONS: The index system of surveillance and early-warning and the methods of risk assessment of schistosomiasis have been confirmed in first phase of east route of South-to-North Water Diversion Project. The primary index is related to snails and the supplementary is related to schistosome infection in people and livestock in the system.

[Surveillance of Oncomelania hupensis snails in Baoying and Gaoyou sections of Li Canal in east route of South-to-North Water Diversion Project].

OBJECTIVE: To understand the distribution and diffusion of Oncomelania hupensis snails in the Baoying and Gaoyou sections of the Li Canal in the east route of the South-to-North Water Diversion Project. METHODS: The retrospective survey method was used to investigate the distribution and diffusion of snails in the Baoying and Gaoyou sections of the Li Canal, the conventional survey and the methods of salvage of water and attracting snails were used to detect the distribution of snails in river banks and water. RESULTS: The earliest findings of snails in the Gaoyou section of the Li Canal was in 1955, the northernmost distribution of snails was Dilong ferry at the west dam and east slope of the Li Canal. The dynamic surveillance in the Gaoyou section of the Li Canal from 2001 to 2010 showed that the snail status was of low density and low fluctuation of area, and the distribution range was 119 degrees 24' 36" -119 degrees 25' 34", 32 degrees 48' 30" -32 degrees 54' 05". From 2006 to 2010, the snails were not found by the methods of salvage of water and attracting snails in the surveillance in the Baoying and Gaoyou sections of the Li Canal. CONCLUSIONS: So far, there is no evidence showing that the snails spread to northward in the Li Canal, however, it is still necessary to carry out the surveillance of snails and schistosomiasis in the east route of the South-to-North Water Diversion Project.

[Effect of Management Scheme on Control of Imported Falciparum malaria in Yangzhou City, 2010].

After 1-year implementation of Management Scheme on Control of Imported Falciparum Malaria in Yangzhou City, 2010, the coverage rate of health education was 100% in those returning from foreign countries, and the active treatment rate was 100%. All professional staff in medical and disease control institutions received training. 48.1% of the cases received standard treatment within 24 h, and all persons returning from foreign countries who had fever were examined for Falciparum infections. The cure rate was 100%, and the successful diagnosis of malaria in lab was 100%. It is indicated that the management scheme has an obvious effect on the control of imported falciparum malaria. However, health education among personnel of labor-exporting services and training for health staff should be further strengthened.