Diagnostic efficacy of indirect haemagglutination assay for detection of Schistosoma japonicum infections among boatmen and fishermen in the Dongting Lake region / 中国血吸虫病防治杂志

OBJECTIVE@#To evaluate the diagnostic efficacy of indirect haemagglutination assay (IHA) for detection of Schistosoma japonicum infections among boatmen and fishermen in Dongting Lake region, so as to provide insights into improving the schistosomiasis surveillance program among boatmen and fishermen.@*METHODS@#The boatmen and fishermen were detected for S. japonicum infections using IHA and Kato-Katz technique or miracidium hatching test nylon gauze simultaneously at schistosomiasis testing sites in the anchor sites for boatmen and fishermen in the Dongting Lake region during the period from 2014 to 2016, and using IHA for serological screening followed by parasitological testing of seropositives during the period from 2017 to 2019. The sensitivity and specificity of IHA were evaluated for detection of S. japonicum infections among boatmen and fishermen, with the 2014-2016 parasitological testing results as a gold standard. In addition, the seroprevalence of S. japonicum infections was compared among boatmen and fishermen with different characteristics and among years.@*RESULTS@#A total of 306 schistosomiasis testing sites were assigned for boatmen and fishermen, and a total of 143 360 person-time boatmen and fishermen were tested for S. japonicum infections in the Dongting Lake region from 2014 to 2019. The sensitivity and specificity of IHA were 69.9%, 97.3% and 96.1% (χ2 = 74.6, P < 0.05), and 70.9%, 74.5% and 71.9% for detection of S. japonicum infections from 2014 to 2016 (χ2 = 29.4, P < 0.05), respectively. The seroprevalence of S. japonicum infections reduced from 30.3% in 2014 to 1.8% in 2019 among boatmen and fishermen, appearing an overall tendency towards a decline (Z = 1 552.4, P < 0.05). In addition, male, individuals at ages of 45 to 60 years, full-time boatmen and fishermen were more likely to be seropositive for S. japonicum infections (all P values < 0.05).@*CONCLUSIONS@#The seroprevalence of S. japonicum infections appeared a tendency towards a decline among boatmen and fishermen in the Dongting Lake region year by year from 2014 to 2019. IHA presented a high efficacy for screening of S. japonicum infections among boatmen and fishermen in the Dongting Lake region.

Progress of schistosomiasis control in Dongting Lake regions / 中国血吸虫病防治杂志

As an ancient parasitic disease, schistosomiasis has been endemic in Dongting Lake areas for more than 2 100 years. In the early 20th century, the first human case of schistosomiasis in China was reported in Dongting Lake areas, which was paid extensive attention. After the founding of the People’s Republic of China, large-scale schistosomiasis control activities were launched promptly in Dongting Lake areas, and great successes have been achieved following the three stages of control efforts, including the snail control-based stage, synchronous chemotherapy for humans and livestock-based control stage and infectious source control-based control stage. In 2015, transmission control of schistosomiasis was achieved in Hunan Province. This paper comprehensively describes the discovery and control of schistosomiasis, analyzes the challenges for the current schistosomiasis control programs and proposes the emphasis for future control activities in Dongting Lake areas, so as to provide insights into the schistosomiasis control program in this area.

Challenges and countermeasures of schistosomiasis control in Hunan Province in the new era / 中国血吸虫病防治杂志

This paper describes the current epidemic characteristics and endemic status of schistosomiasis, analyzes the main challenges of schistosomiasis control and proposes the emphasis and interventions for future schistosomiasis control activities in Hunan Province, so as to provide insights into the elimination of schistosomiasis in Hunan Province.

Implications, spiritual characteristics and practical significance of Chinese schistosomiasis control culture / 中国血吸虫病防治杂志

The culture of schistosomiasis control is specific in the history of Chinese culture. Broadly speaking, the culture of schistosomiasis control is a summary of specific social mood, social consciousness and material culture created by Chinese populations during the progress of schistosomiasis control since the founding of the People’s Republic of China. Narrowly speaking, the culture of schistosomiasis control is the spiritual culture that is jointly created and nurtured by schistosomiasis control workers since the founding of the People’s Republic of China. The spiritual features of Chinese schistosomiasis control culture are characterized by the patriotism and care about the people, the matter-to-fact attitude, the pioneering and enterprising spirit, and the spirit of sacrifice and dedication. The ultimate goal of the research on the culture of schistosomiasis control is to facilitate the achievement of the strategic goal of Healthy China 2030 as scheduled, accelerate the progress towards elimination of schistosomiasis, and to promote the sustainable development of schistosomiasis control in China.

Identification and risk monitoring of potential risk areas of schistosomiasis in Dongting Lake area / 中华疾病控制杂志

Objective To identify and monitor potential risk areas of schistosomiasis in Dongting Lake area. Methods With remote sensing (RS)and geographic information system(GIS) technology, potential risk areas of schistosomiasis in Dongting Lake area were extracted by using spectral characteristics and environmental factors. Based on epidemiological data and land use data, the regional epidemic index and environmental susceptibility index were fused with potential epidemic risk areas in the grid system of Dongting Lake area to form the epidemic risk surveillance map of schistosomiasis in Dongting Lake area from 2006 to 2016. Results From 2006 to 2016, the high risk areas of schistosomiasis epidemic in Dongting Lake area were concentrated in the central and Northern lakeside areas of Changde City (Annual average epidemic index R-=0.330 5, Regional average susceptibility index Y-=2.458 2), the sensitive land types were Lake area (Sensitivity coefficient β=1.236 6), the surrounding area of Datong Lake in Nanxian and Northern Yuanjiang City (R-=0.426 0, Y-=0.836 8), paddy field area (β=0.202 1) and other construction land (β=0.308 0). The extremely high risk areas were concentrated in some lake-facing areas in Jinshi (R-=0.449 1, Y-=3.917 0) and the sensitive land type is woodland(β=1.234 5). The risk of river basin from high to low was respectively the Lishui River, the Yuanjiang River, the Zijiang River and the Xiangjiang River. Conclusions The high-risk and extremely high-risk areas should be the focus of future epidemic control. The snail control and environmental renovation of epidemic-sensitive areas such as sparse woodland, grassland with high coverage, reservoir pits and ponds should be done well in Dongting Lake area.

[Measures and achievements of schistosomiasis control in the Yangtze River Basin].

This paper reviewed the prevention and control of schistosomiasis in the Yangtze River Basin in three stages, centered on the measures and achievements. It pointed out the key work of prevention and control which are infectious source control and effective surveillance at present stage. It will be beneficial to schistosomiasis control in China.

[Evolution and evaluation of schistosomiasis prevention and control institutions in China].

Schistosomiasis is one of a few endemic and infectious diseases, which are controlled by the specific prevention and control institutions in China. Through the review of historical data, this paper describes the construction, continuation and changes of schistosomiasis prevention and control institutions in different historical periods and systems, and analyzes and evaluates its historical function, contribution and status.

Measures and achievements of schistosomiasis control in the Yangtze River Basin / 中国血吸虫病防治杂志

This paper reviewed the prevention and control of schistosomiasis in the Yangtze River Basin in three stages, centered on the measures and achievements. It pointed out the key work of prevention and control which are infectious source control and effective surveillance at present stage. It will be beneficial to schistosomiasis control in China.

Measures and achievements of schistosomiasis control in the Yangtze River Basin / 中国血吸虫病防治杂志

This paper reviewed the prevention and control of schistosomiasis in the Yangtze River Basin in three stages, centered on the measures and achievements. It pointed out the key work of prevention and control which are infectious source control and effective surveillance at present stage. It will be beneficial to schistosomiasis control in China.

Evolution and evaluation of schistosomiasis prevention and control institu-tions in China / 中国血吸虫病防治杂志

Schistosomiasis is one of a few endemic and infectious diseases,which are controlled by the specific prevention and control institutions in China.Through the review of historical data,this paper describes the construction,continuation and changes of schistosomiasis prevention and control institutions in different historical periods and systems,and analyzes and evalu-ates its historical function,contribution and status.

[Strategy and effect of Oncomelania hupensis snail control in inside-embankment areas in Junshan District, Hunan Province from 1998 to 2017].

OBJECTIVE: To explore the strategy and countermeasures of Oncomelania hupensis snail control and evaluate the effect in inside-embankment areas of lake-type schistosomiasis endemic area, for providing the effective method for controlling and interrupting the schistosomiasis transmission. METHODS: The data of schistosomiasis epidemic and its control and prevention were collected in Junshan District, Hunan Province, and the effect of snail control countermeasures were evaluated and the trend of indexes of snails was drafted in the inside-embankment areas of Junshan District, Hunan Province from 1998 to 2007. RESULTS: The area with snails in the inside embankment areas of Junshan District decreased by 98.43%, from 1 496.66 hm2 in 1998 to 23.48 hm2 in 2017. The occurrence rate and average density of of living snails decreased from 20.61% and 0.45 snail/0.1 m2 in 2003 to 2.06% and 0.03 snail/0.1 m2 in 2017. The highest area with schistosome infected snails was found in 2001 and the total area was 79.36 hm2, however, no infected snails were found since 2007. The total fiscal investment for schistosomiasis prevention and control was 398.857 million RMB in Junshan District, including molluscicide (81.770 9 million RMB) and environment reform (213.5 million RMB) respectively. CONCLUSIONS: The comprehensive measures, mainly including the combination of molluscicide and environment reform have gotten a significant effect in snail control and elimination in the inside-embankment areas, but the snail surveillance still need to be strengthened in the historic areas with snails.

[Dynamic simulation analysis of effects of project of ditching for drain on Oncomelania hupensis snail control and flood prevention security in Dongting Lake region].

OBJECTIVE: To evaluate the effects of the project of ditching for drain on Oncomelania hupensis snail control and flood prevention security and explore the optimal engineering design plan in Dongting Lake region. METHODS: A retrospective study was performed on the previous studies about the project of ditching for drain. The reference values of project indices were determined. The outside levee of Nanhu New Distinct of Yueyang City in Dongting Lake region was selected as the study area, and the cross section of marshland perpendicular to the center line of the levee was extracted to research. According to the situations of various water levels, a dynamic simulation was performed on the effect and security of the project of ditching for drain through the software FLAC3D. RESULTS: The retrospective study showed that the project would be effective when the relatively subsoil water level decreased by 0.35 m, and the soil water content decreased correspondingly. The dynamic simulation by FLAC3D showed that the minimum safe distances between transverse ditch 1, vertical ditch and levee toe should be 25 m and 13 m respectively. The digging depth of transverse ditch and vertical ditch should be 1.2 m and 1.0 m respectively. If the width of marshland in drought period was less than 500 m, one transverse ditch was efficient. Otherwise, more transverse ditches should be set with the intervals of 300 m. CONCLUSIONS: The project of ditching for drain is an effective ecological snail elimination method. Optimizing the digging depth of ditches and distances between transverse ditches, vertical ditch and levee toe will ensure the effects and security of the project.

[Oncomelania hupensis snail distribution in working areas of Yangtze River hydrologic agencies located in middle and lower reaches of Yangtze River in 2016].

OBJECTIVE: To understand the Oncomelania hupensis snail distribution in the working areas of Yangtze River hydrologic agencies located in the middle and lower reaches of the Yangtze River in 2016, so as to provide the evidence for assessing the risk of schistosome infection of hydrological workers and establishing the control strategies. METHODS: The suspicious environments with O. hupensis snails in the above working areas were selected as study areas, and the snail situation was surveyed by the system sampling method combined with the environmental sampling method. The survey data were collected and analyzed statistically. RESULTS: Totally 19 working areas from 17 hydrological agencies were selected as the investigation sites, among which, 10 working areas from 9 agencies were found with O. hupensis snail distribution. The constituent ratio of the areas with snails reached to 38.81% of the investigation areas, the occurrence rate of frames with snails was 3.08%, and the average density of living snails was 0.07 /0.1 m2. By comparison, the average density of living snails and occurrence rate of frames with snails in hydrological agencies under the jurisdiction of the Middle Reaches Administrative Bureau were the most serious among three administrative bureaus of the Yangtze River Water Resources Commission. CONCLUSIONS: There are various degrees of O. hupensis breeding in the working areas of hydrological agencies located in the middle and lower reaches of the Yangtze River, and the hydrological workers are facing with the risk of schistosome infection.

Study on spatial-temporal variation of infected snail in bottomland areas after an integrated control strategy at village level in the marshland and lake regions based on geographic information system / 中华流行病学杂志

Objective To evaluate the effect of an integrated control strategy and to quantify the spatial-temporal variation of infected snails in the bottomland areas after the strategy was implemented.Methods Based on the geographic database of infected snail distribution at the village level during 2004-2010 in Anxiang county,Hunan province,spatial autocorrelation analysis and spatial scan statistics were applied to analyze the spatial-temporal characteristics on the distribution of infected snails.Results The number of embankments with infected snails in Anxiang county decreased from 23 in 2004 to 10 in 2010,while the rate of frame with infected snail in embankments decreased from 4.32‰ in 2004 to 0.12‰ in 2010.The spatial distribution of infected snails was nonrandom,only in 2004 and 2005 with Moran's I=0.21 (P＜0.10) and Moran's I=0.13 (P＜0.10) respectively.Data from the local spatial auto-correlation analysis showed that the number of villages with H-H types of auto-correlation model had been gradually decreasing.The results of SaTScan statistics appeared the same as from the local spatial auto-correlation analysis,showing that the number of areas with increased risk was decreasing.Conclusion The comprehensive measures with emphasis on infectious source control seemed effective for schistosomiasis control program.The current distribution characteristics provided us with evidence that the resource assignment could be more reasonably implemented so as to control schistosomiasis in a more effective way.