The Three Gorges Dam: Does it accelerate or delay the progress towards eliminating transmission of schistosomiasis in China?
© The Author(s). 2016
Received: 17 January 2016
Accepted: 17 June 2016
Published: 5 July 2016
The Three Gorges Dam, located in the largest endemic area of schistosomiasis in China, is one of the world’s largest hydroelectric projects to date. Some large-scale hydro projects have resulted in schistosomiasis emergence or re-emergence. Therefore, the dam’s potential impact on the transmission of Schistosoma japonicum has raised concerns from medical researchers worldwide. A systematic literature review, coupled with an analysis of data on the water level and snail density in the Yangtze River was conducted to assess the impact of the dam on schistosomiasis transmission after more than 10 years of operation. The dam has significantly altered the water levels in the Yangtze River according to different seasons. These changes directly impact the ecology of the schistosome snail host. Due to the dam, there has been a reduction in the density of Oncomelania snails and/or changes in the distribution of snails. The prevalence of infection with S. japonicum has decreased in the downstream areas of the dam, including in the Dongting and Poyang Lakes. The prevalence of infection with S. japonicum in humans has decreased from 6.80 % in 2002 (before the dam began operating) to 0.50 % in 2012, and the number of people infected with S. japonicum have decreased from 94 208 in 2002 to 59 200 in 2011 in the Poyang Lake region. The presence of the dam does not seem to affect snail breeding or the prevalence of schistosomiasis in the Three Gorges Reservoir. Overall, the Three Gorges Dam has significantly contributed to changes in hydrology after more than 10 years of the dam operating. The changes caused by the dam, together with integrated control of schistosomiasis, might be accelerating the progress towards eliminating the transmission of S. japonicum in the middle and lower reaches of the Yangtze River. Despite the positive effect the dam is having in controlling S. japonicum transmission, continued surveillance is required to monitor the future ecological impacts of the dam over the long term.
Please see Additional file 1 for translations of the abstract into six official working languages of the United Nations.
The filling of the Three Gorges Reservoir began in June 2003, and its water level rose to 135 metres by the end of 2003, to 156 metres in 2006 and 172 metres in 2008. Since 2009, the water level has been maintained at 175 metres throughout November and December, and is lower in the other months.
It has previously been reported that some large-scale hydro projects (e.g., the Sudanese Gezira-Managil Dam, the Egyptian Aswan High Dam and the Ethiopian Melkasadi Dam) have resulted in schistosomiasis emergence or re-emergence [4–9]. Hence, the potential impact of the Three Gorges Dam on the transmission of Schistosoma japonicum in the Yangtze River basin has raised concerns from researchers worldwide [10–18]. Over the past decades, numerous studies have been carried out to forecast or assess the impact of the dam on the distribution of O. h. hupensis snails and the transmission of S. japonicum [19, 20].
Through a systematic review and an analysis of data on the water level and snail density, we assessed the dam’s impact on S. japonicum transmission after more than 10 years of operation. In this paper, we also discuss the potential implications for national strategies to control and eliminate schistosomiasis.
We conducted a systematic literature review by searching all relevant articles, published up to September 2015, which examined the impacts of the Three Gorges Dam on the transmission of schistosomiasis. Relevant studies were identified from the following electronic databases: PubMed, Science Citation Index Expanded™, China National Knowledge Infrastructure, Wanfang Data, China Science and Technology Journal Database and SINOMED. The following keywords and any combinations thereof were used: “Three Gorges Dam” in combination with “schistosomiasis”, “Schistosoma”, “snail” and “Oncomelania hupensis”. No language restrictions were applied.
Two reviewers independently checked the titles and abstracts of all identified articles for inclusion eligibility. We excluded the following: (1) review articles, (2) dissertations, (3) conference abstracts and presentations, and (4) non peer-reviewed reports. For eligible publications, full papers were retrieved and reviewed by the same two reviewers. They were then grouped into two categories: field simulation studies or prediction studies that were carried out before the dam started operating and therefore did not include data on the impact of the dam on schistosomiasis transmission in the study period; and observational or monitoring studies that were implemented after the dam started operating and were able to include data on the impact of the dam on schistosomiasis transmission in the study period.
Data on changes in the water level and snail density
Daily data on the water level (above sea level, 8:00 AM) at the Chenglingji Hydrological Station (located at the junction of the Yangtze River and Dongting Lake) were collected from 1995 to 2013. In 2005, seven snail surveillance sites (villages) along the Yangtze River were set up to monitor the changes in the density of snails in the bottomland areas of the middle and lower reaches of the Yangtze River (see Fig. 1). In these snail surveillance sites, molluscicides for snail control were either not used or used very sparingly. These bottomland areas were surveyed using the traditional Chinese method of systematic sampling (20 m × 20 m) done annually in the spring . Data on snail density (snail/0.11 m2) were collected from the seven snail surveillance sites from 2005 to 2013.
Calculating the time of how long snail habitats are inundated with water
O. h. hupensis snails are distributed mainly in marshlands that are 25–28 metres in elevation in the Dongting Lake area close to the Chenglingji Hydrological Station . Therefore, we calculated the time of 25 metre, 26 metre, 27 metre and 28 metre elevated marshes being inundated with water. If the water level in a day was higher than the elevation of the marsh, we regarded that marsh to be inundated with water. We estimated the link relative ratio of the days the marshes were inundated with water. The link relative ratio refers to the comparison between the days the marshes were inundated with water in a year and the days they were inundated with water in the previous year. For example, the days a marsh was inundated in 1996 are divided by the days it was inundated in 1995, thus achieving the link relative ratio of 1996.
Predicted impact of the dam on schistosomiasis transmission
Predicted impact of the Three Gorges Dam on the distribution of Oncomelania snails and transmission of S. japonicum
Segment of Yangtze River
Water level rising
Water level decreasing
Hubei (Jianghan Plain)
Jan – May
New habitats for Oncomelania snails would appear.
The probability of humans and livestock becoming infected would increase.
Hunan (Dongting Lake)
Jan – May
The distribution of snails would not be significantly affected, however, the reproduction of snails would be effectively curbed.
The probability of humans and livestock becoming infected would increase and schistosomiasis epidemics would worsen.
Jiangxi (Poyang Lake)
Jan – Mar
The reproduction and distribution of snails would be unaffected or the density of snails would increase, or the density of snails would decrease in the autumn.
The epidemiology of schistosomiasis would be very limitedly affected.
Jan – Apr
Oct – Dec
The distribution of snails would not be significantly affected, however, some new habitats for snails would appear.
The probability of humans and livestock becoming infected would increase.
Feb – Apr
The distribution of snails would be not affected and the density of snails would decrease.
The incidences of schistosome infections in people and livestock would increase.
Before the dam started operating, the Three Gorges Reservoir (see Fig. 1) was free for Oncomelania snails and S. japonicum for Yangtze water in the region was rapid following and collides with the cliffs, sandbars and precipices that flank the river . Some studies reported that great environmental changes (e.g., sedimentation and formation of marshlands) resulting from the dam could form potential habitats for Oncomelania snails [27–29], whereas some simulated studies reported that Oncomelania snails could survive and breed in the Three Gorges Reservoir [30–34]. Some researchers reported that both Oncomelania snails and transmission sources of schistosomiasis might have been introduced into the Three Gorges region due to the dam [35–37]. However, other studies reported that the Three Gorges Reservoir would not be an ideal location for the reproduction of Oncomelania snails, as the dam’s ‘winter-water, summer-land’ operation cycle contradicts with the snails’ ‘winter-land, summer-water’ breeding cycle [38, 39].
Dam’s impact on the water level
Dam’s impact on schistosomiasis transmission
The construction of the Three Gorges Dam commenced in 1994 after decades of research and fierce debate. Benefits of the dam, such as flood control and power generation, are indisputable and the dam has lived up to these expectations. However, this study found that the dam’s impact on the transmission of S. japonicum is different to previous forecasts (see Table 1). Overall, this study found that the changes in hydrology caused by the Three Gorges Dam might be favourable for the control of S. japonicum transmission, based on the results from the observational and monitoring studies [19, 40–50].
There might be several reasons for this. Firstly, the dam has effectively controlled floods and deterred the dispersal of Oncomelania snails, and thus curtailed the infection to humans and animals [52, 53]. For example, some studies reported that the number of patients infected with S. japonicum reduced significantly, and especially that acute S. japonicum cases were rarely seen in the middle and lower reaches of Yangtze River after more than 10 years of the dam’s operation [40, 41, 45]. Secondly, during the first few months of the year, the presence of the dam leads to the production of an early flooded bottomland , and this not only can result in the death of adult Oncomelania snails or reduce their survival rate and oviposition, but is also not a favourable environment for embryo development of Oncomelania eggs . Moreover, after the dam started operating, it has been observed that in the summer, many snail-harbouring marshlands are either not flooded or only flooded for a very short period of time. This is also not favourable for the development of juvenile snails, as Oncomelania snails have to live in water during the early stages of their development . Some studies, together with our monitoring results, showed that the density of Oncomelania snails decreased significantly in many snail-harbouring marshes in the downstream areas of the dam [40, 45–48]. Thirdly, earlier water recessions in the autumn caused by the dam have advanced the exposure time of snail-harbouring marshes, thus they may be suitable for early planting of crops such as wheat and rapeseed. Currently, some of these marshlands have begun to be planted and this has resulted in a significant decrease in the density of Oncomelania snails . Although some farmers spend a longer period of time working on the marshlands and therefore have a higher chance of coming into contact with cercariae-infected water, other people and livestock such as bovines, the primary infection source of S. japonicum transmission in China, are kept away from these marshlands, meaning that the probability of most humans and livestock becoming infected with S. japonicum decreases. In addition, many studies predicted that advanced water recessions in the autumn would lengthen the amount of time humans and livestock spend on the marshlands and increase the incidence of schistosome infections for both humans and livestock [17, 20]. However, an integrated control programme, aiming to reduce the roles of bovines and humans as infection sources, has been implemented in China since 2005 . The control programme consists of agricultural mechanisation, fencing bovines, chemotherapy for humans and bovines, health education, provision of clean water and improved sanitation . Hence, the programme has led to a reduction in the amount of time that humans and livestock spend on marshlands. Up until now, there have been no reports of increased incidence of schistosome infections due to earlier water recessions in the autumn. Fourthly, the dam operates in a so-called ‘winter-water, summer-land’ cycle, which contradicts with the Oncomelania snails’ ‘winter-land, summer-water’ breeding stimulation. In particular, Oncomelania snails struggle to survive in high water levels in the winter, which is the situation due to the dam [38, 50, 51]. Although both Oncomelania snails and human transmission sources for schistosomiasis may have been introduced from schistosomiasis endemic areas into the Three Gorges Dam region , no local sites of Oncomelania snails or locally infected people have been identified so far .
The changes in hydrology caused by the Three Gorges Dam may have an important implication for the Chinese national control strategies that aim to eliminate schistosomiasis. For example, tractors should plant crops such as wheat and rapeseed in the snail-harbouring marshlands that are suitable for early planting of crops due to early water recessions in the autumn. This can reduce the density of Oncomelania snails or even eliminate snails, as well as increase the income of farmers. Of course, farmers should be educated about how to avoid contact with cercariae-infected water when planting on these snail-harbouring marshlands.
Our study had some limitations. Although a large number of articles were found in the course of the systematic review, most of these were excluded due to duplication or irrelevance, and only 55 papers reporting the relationship between the Three Gorges Dam and the transmission of schistosomiasis were included in the study. Most of the included articles were simulation or forecast studies, or used only routine monitoring data to assess the dam’s impact on the transmission of schistosomiasis. Hence, it was difficult for us to systematically and quantitatively analyse the impacts of the Three Gorges Dam on the transmission of schistosomiasis. In view of this limitation, the relationship between the dam and the transmission of schistosomiasis outlined in this study should be interpreted with caution.
There have been significant changes in hydrology since the Three Gorges Dam started operating in 2003. These changes, together with the integrated control programme currently implemented in China, might be accelerating the progress towards the elimination of S. japonicum transmission in the middle and lower reaches of the Yangtze River. Continued surveillance is needed to monitor the longer-term ecological impacts of the dam on the transmission of schistosomiasis.
This work was supported by the National S & T Major Program (Grant Nos. 2012ZX10004-220 and 2008ZX10004-011).
Availability of data and materials
The data supporting the findings in our paper can be found in Center for Tropical Disease Research, Fudan University.
YBZ and SL contributed to the literature search, YBZ and QWJ conducted the monitoring studies, YBZ and QWJ analysed the data, YBZ, SL, YC and QWJ contributed to the writing of the paper. All authors approved publication.
The authors declare that they have no competing interests.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- Ross AG, Sleigh AC, Li Y, Davis GM, Williams GM, Jiang Z, Feng Z, McManus DP. Schistosomiasis in the People’s Republic of China: prospects and challenges for the 21st century. Clin Microbiol Rev. 2001;14:270–95.View ArticlePubMedPubMed CentralGoogle Scholar
- Zhou YB, Yang MX, Zhao GM, Wei JG, Jiang QW. Oncomelania hupensis (Gastropoda: Rissooidea), intermediate host of schistosoma japonicum in China: Genetics and molecular phylogeny based amplified fragment length polymorphisms. Malacologia. 2007;49:367–82.View ArticleGoogle Scholar
- Davis GM, Wilke T, Wu WP, Xu XJ. Ecogenetics of shell sculpture in Oncomelania (Gastropoda) in canals of Hubei, China, and relevance for Schistosome transmission. Malacologia. 2006;48:253–64.Google Scholar
- Teklehaimanot A, Fletcher M. A parasitological and malacological survey of schistosomiasis mansoni in the Beles Valley, northwestern Ethiopia. Trop Med Int Health. 1990;93:12–21.Google Scholar
- Fenwick A. Irrigation in the Sudan and schistosomiasis. In: Service MW, editor. Demography and Vector Born Diseases. Boca Raton, FL: CRC Press; 1989. p. 333–51.Google Scholar
- Strickland G. Providing health services on the Aswan High Dam. World Health Forum. 1982;3:297–300.Google Scholar
- Omer AHS. Schistosomiasis in the Sudan: historical background and the present magnitude of the problem. In: Proceedings of the International Conference on Schistosomiasis, vol. 1978. Cairo, Egypt: Ministry of Health; 1975. p. 121–32.Google Scholar
- Amin MA. Problems and effects of schistosomiasis in irrigation schemes in the Sudan. In: Worthington EB, editor. Arid Land Irrigation in Developing Countries. Oxford, UK: Pergamon Press; 1977. p. 407–11.View ArticleGoogle Scholar
- Khalil BM. The national campaign for the treatment and control of bilharziasis from the scientific and economic aspects. Royal Egyptian Medicine Association. 1949;32:820.Google Scholar
- Li YS, Raso G, Zhao ZY, He YK, Ellis MK, McManus DP. Large water management projects and schistosomiasis control, Dongting Lake region, China. Emerg Infect Dis. 2007;13:973–9.View ArticlePubMedPubMed CentralGoogle Scholar
- Gray DJ, Thrift AP, Williams GM, Zheng F, Li YS, Guo J, Chen H, Wang T, Xu XJ, Zhu R, Zhu H, Cao CL, Lin DD, Zhao ZY, Li RS, Davis GM, McManus DP. Five-year longitudinal assessment of the downstream impact on schistosomiasis transmission following closure of the Three Gorges Dam. PLoS Negl Trop Dis. 2012;6:e1588.View ArticlePubMedPubMed CentralGoogle Scholar
- Stone R. Hydropower. The legacy of the Three Gorges Dam. Science. 2011;333:817.View ArticlePubMedGoogle Scholar
- Seto EY, Wu W, Liu HY, Chen HG, Hubbard A, Holt A, Davis GM. Impact of changing water levels and weather on Oncomelania hupensis hupensis populations, the snail host of Schistosoma japonicum, downstream of the Three Gorges Dam. Ecohealth. 2008;5:149–58.View ArticlePubMedGoogle Scholar
- Engels D, Wang LY, Palmer KL. Control of schistosomiasis in China. Acta Trop. 2005;96:67–8.View ArticlePubMedGoogle Scholar
- Minter A. Breeding snail fever. Three Gorges Dam boosts parasitic infections. Sci Am. 2005;293:21–2.View ArticlePubMedGoogle Scholar
- McManus DP, Gray DJ, Li Y, Feng Z, Williams GM, Stewart D, Rey-Ladino J, Ross AG. Schistosomiasis in the People's Republic of China: the era of the Three Gorges Dam. Clin Microbiol Rev. 2010;23:442–66.Google Scholar
- Zheng J, Gu XG, Xu YL, Ge JH, Yang XX, He CH, Tang C, Cai KP, Jiang QW, Liang YS, Wang TP, Xu XJ, Zhong JH, Yuan HC, Zhou XN. Relationship between the transmission of schistosomiasis japonica and the construction of the Three Gorge Reservoir. Acta Trop. 2002;82:147–56.View ArticlePubMedGoogle Scholar
- Maszle DR, Whitehead PG, Johnson RC, Spear RC. Hydrological studies of schistosomiasis transport in Sichuan Province, China. Sci Total Environ. 1998;216:193–203.View ArticlePubMedGoogle Scholar
- Wu JY, Zhou YB, Chen Y, Liang S, Li LH, Zheng SB, Zhu SP, Ren GH, Song XX, Jiang QW. Three Gorges Dam: Impact of water level changes on the density of Schistosome-transmitting snail Oncomelania hupensis in Dongting Lake Area, China. PLoS Negl Trop Dis. 2015;9:e0003882.View ArticlePubMedPubMed CentralGoogle Scholar
- Zhu HM, Xiang S, Yang K, Wu XH, Zhou XN. Three Gorges Dam and its impact on the potential transmission of schistosomiasis in regions along the Yangtze River. Ecohealth. 2008;5:137–48.View ArticlePubMedGoogle Scholar
- Zhou YB, Liang S, Chen GX, Rea C, He ZG, Zhang ZJ, Wei JG, Zhao GM, Jiang QW. An integrated strategy for transmission control of Schistosoma japonicum in a marshland area of China: findings from a five-year longitudinal survey and mathematical modeling. Am J Trop Med Hyg. 2011;85:83–8.View ArticlePubMedPubMed CentralGoogle Scholar
- Luo ZH, Wei WY, Li ZJ, Ding L, Yuan LP, Xia M, Tang L, Ren GH, Wang JS, Wei GY. Impact of environmental changes on Oncomelania snail distribution in Dongting Lake beach. Chin J Schisto Control. 2012;24:387–92 (in Chinese).Google Scholar
- Xu XJ, Yang XX, Dai YH, Yu GY, Chen LY, Su ZM. Impact of environmental change and schistosomiasis transmission in the middle reaches of the Yangtze River following the Three Gorges construction project. Southeast Asian J Trop Med Public Health. 1999;30:549–55.PubMedGoogle Scholar
- Wang TP, Ge JH, Zhang SQ. Schistosomiasis transmission and ecological environmental changes in Anhui reach after construction of Three Gorges Reservoir. J Pract Parasi Dis. 1998;6:157–63 (in Chinese).Google Scholar
- Liang YS, Huang YX, Song HT, Dai JR, Jiang YD, Man HC, Ji CS, Yang YY, Tian Q, Zhu YC. Impact of variation in water level of the Yangtze River after the construction of the Three Gorges Dam on the transmission of schistosomiasis in Jiangsu, China. II. Observation of effect of advanced spring flooding on the population of snails and survey of frequency of contacting schistosome-infected water both for people and domestic animals in different season. Chin J Schisto Control. 1999;12:210–3. in Chinese.Google Scholar
- Cai KP, Zuo JZ, Ho HB, Zhuo SJ, Hu G. Impact of changes in mud siltation of Dongting Lake on the endemic factors of schistosomiasis after building Three-Gorge Dam. Practical Prev Med. 2000;7:1–3 (in Chinese).Google Scholar
- Zheng J, Gu XG, Xu CL, Wang TP, Xu XJ, He CH, Tang C, Cai KP, Jiang QW, Liang YS, Ge JH, Yang XX, Zheng QS, Yuan HC, Han JJ, Liang S, Wen S, Zuo JJ, Huang YX, Hu WZ, Wang YZ. The relationship between the ecological changes in the construction of the Three Gorges Dam and the transmission of schistosomiasis. Bull Med Res. 2003;32:7–10 (in Chinese).Google Scholar
- Lai J, Gu XG, Xu FS, Wen S, Liang S. Study on the development of snail habitat in Three Gorges Reservoir area inundated temporarily by flood. J Pract Parasit Dis. 2000;8:102–5 (in Chinese).Google Scholar
- He CH, Zhang AH, Guo SL, Pan HM, Lin CX, Wen YZ, Dong MJ, Han JJ. Study on the effects of social and Economic changes on the spreading of schistosomiasis in Hubei area of the reservoir after construction of Three Gorge Dams. Med Soc. 1998;11(6):7–12.Google Scholar
- Xiao BZ, Liao WF, Wu CG, Ji HQ, Wu GH, Luo XJ, Wan SX, Lin XG. The effect of ecological changes in the three Gorges reservoir areas on the prevalence of schistosomiasis. J Trop Med. 2008;8:844–7 (in Chinese).Google Scholar
- Xiao BZ, Liao WF, Ji HQ, Wu CG, Wan SX, Lin XG. Reproduction and Growth of Oncomelania snails under simulated biological environment in Three Gorges area. Chin J Schisto Control. 2004;16:65–6. in Chinese.Google Scholar
- Wei FH, Wang RB, Xu XJ, Xiao BZ, Wu XH, Liu JB, Cai SX, Fu Y, Xu J, Wu CG, Dai YH, Zhou XN, Zheng J. Risk factors of schistosomiasis transmission after Three Gorges construction IPossibility of snails breeding with ecological changes in Three Gorges reservoir areas. Chin J Schisto Control. 2007;19:81–5 (in Chinese).Google Scholar
- Zhou CY, Yang JS, Meng YP, Tang L. Reproduction and Growth of Oncomelania snails under biological environment simulated as Three Gorges area. Chin J Schisto Control. 2004;16:140–1 (in Chinese).Google Scholar
- Wang RB, Xu XJ, Xiao BZ, Wei FH, Wu XH, Zhou XN, Zheng J. Study on the possibility of snail breeding after the ecological changes of the Three Gorges Reservior areas. J Trop Med. 2003;3:399–403 (in Chinese).Google Scholar
- Wu CG, Xiao BZ, Liao WF, Yan W. Analysis of the epidemiological factors of schistosomiasis in the Three Gorges Reservoir areas. J Trop Med. 2005;5:774–6. in Chinese.Google Scholar
- Wei FH, Wang RB, Xu XJ, Liu JB, Fu Y, Zhang J. Investigation on import way of schistosomiasis and Oncomelania snails in Three Gorges Reservoir areas. Chin J Schisto Control. 2004;16:118–21 (in Chinese).Google Scholar
- Xu FS, Wen S, Qian XH, Mao Y, Zhong B, Lei J, Gu XG, Wang MP. The impact of social factors on schistosomiasis prevalence at the Three Gorges Reservoir areas. J Pract Parasit Dis. 1999;7:74–5 (in Chinese).Google Scholar
- Xuan Y, Wang XL, Qu XH, Chen ZJ, Gao YH, Yang XM, Zhang Y, Pan HX. Study on influence of Three Gorges project construction on Oncomelania growth condition in Chongqing section. Chin J Schisto Control. 2012;24:142–5 (in Chinese).Google Scholar
- Xiao RW, Ye JF, Tao LF. Study on Oncomelania snail breeding and spreading in the Three Gorges Reservoir region. In: Collected Works of Ecology and Environment Impact on Three Gorges Project. Beijing, China: China Water Power Press; 1998. p. 159–75 (in Chinese).Google Scholar
- Zhang SQ, Wang TP, He JC, Li HZ, Tian XG, Gao F. Impact on prevalence of schistosomiasis after runs of Three Gorges Reservoir Project in the section of Anhui province. Chin J Prev Med. 2015;49:632–7 (in Chinese).Google Scholar
- Chen YY, Cai SX, Xiao Y, Shan XW, Zhang J, Liu JB. Impact of implementation of Three Gorges Project on schistosomiasis endemic situation in Hubei Province. Chin J Schisto Control. 2014;26:498–503 (in Chinese).Google Scholar
- Li ZJ, Chen HG, Zeng XJ, Liu YM, Chen YY, Dai KJ, Lan WM, Xie SY. Studies on changes of vegetation and Oncomelania hupensis snails in Poyang Lake after impoundment of Three Gorges Project. Chin J Schisto Control. 2014;26:115–20 (in Chinese).Google Scholar
- Li W, Hang DR, You BR, Chen XJ, Chen XJ, Yang K, Liang YS. Effect of environmental change in marshland after implementation of Three Gorges Reservoir Project on schistosomiasis in Jiangsu Province. Chin J Schisto Control. 2013;25:576–80. 584 (in Chinese).Google Scholar
- Zhu R, Zhou YB, Zhang LJ, He ZY, Xu XL, Guo JG, Zhao GM. The impact of water level changes on the Oncomelania snail habitats in Poyang Lake regions before and after the impoundment of Three Gorges reservoir. Chin J Prev Med. 2013;47:219–22 (in Chinese).Google Scholar
- Chen HG, Zeng XJ, Lin DD, Lv SB, Gu XN, Hang CQ, Li ZJ. The changes of hydrological regime in Poyang Lake after runs of Three Gorges Project and its impact on prevalence of schistosomiasis in the lake region. Chin J Schisto Control. 2013;25:444–50 (in Chinese).Google Scholar
- Guo FY, Zhao ZY, Ren MY, Liu GC, Hu BJ, Xia M. Impacts of marshland changes on snail distribution in Dongting Lake after the construction of the Three Gorges Dam. J Trop Dis Parasit. 2012;10:125–7. in Chinese.Google Scholar
- Zhu CF, Zeng QF, Li YY, Lu SB, Huang WJ. Variation of oncomelnia and schistosomiasis in midstream area of Yangtze River after operation of Three Gorges Reservoir. Yangtze River. 2015;46:74–6 (in Chinese).Google Scholar
- Zeng QF, Zhu CF, Li YY. Influence of Three Gorges reservoir operation on oncomelnia and schistosomiasis in Dongting Lake region. Yangtze River. 2015;81(46):51–3. in Chinese.Google Scholar
- Zhu R, Gray DJ, Thrift AP, Williams GM, Zhang Y, Qiu DC, Zheng F, Li YS, Guo J, Zhu HQ, Wu WP, Li RS, McManus DP. A 5-year longitudinal study of schistosomiasis transmission in Shian village, the Anning River Valley, Sichuan Province, the Peoples’ Republic of China. Parasit Vectors. 2011;4:43.View ArticlePubMedPubMed CentralGoogle Scholar
- Xuan Y, Chen ZJ, Qu XH, Gao YH, Yang XM. The Study of Three Gorges Project on Oncomelania hupensis of Chongqing Area. Chin J Zool. 2012;47:71–7 (in Chinese).Google Scholar
- Zhou YB, Zhuang JL, Yang MX, Zhang ZJ, Wei JG, Peng WX, Zhao GM, Zhang SM, Jiang QW. Effects of low temperature on the schistosome-transmitting snail Oncomelania hupensis and the implications of global climate change. Molluscan Res. 2010;30:102–8.Google Scholar
- Wu XH, Zhang SQ, Xu XJ, Huang YX, Steinmann P, Utzinger J, Wang TP, Xu J, Zheng J, Zhou XN. Effect of floods on the transmission of schistosomiasis in the Yangtze River valley, People’s Republic of China. Parasitol Int. 2008;57:271–6.View ArticlePubMedGoogle Scholar
- Zhou YB, Liu QL, Zhao ZY, Chen Y. Survey report on the snail diffusion of 5 villages in Dongting Lake area after flood. Chin J Schisto Control. 1998;11:116–7 (in Chinese).Google Scholar
- Zheng YJ, Zhong JH, Chen XL, Lin DD, Zhao GM, Zhang SJ, Jiang QW. Influence of drowning on survival of Oncomelania. Chin J Schisto Control. 2002;14:46–9 (in Chinese).Google Scholar
- Tao HY, Xia A, Zhao YM, Jiang J. Effect and cost-benefit of Oncomelania snail control by plowing and planting in Jiaobei Beach of Zhenjiang City. Chin J Schisto Control. 2012;24:567–78 (in Chinese).Google Scholar
- Zhou YB, Liang S, Jiang QW. Factors impacting on progress towards elimination of transmission of schistosomiasis japonica in China. Parasit Vectors. 2012;5:275.View ArticlePubMedPubMed CentralGoogle Scholar
- Wang LD, Guo JG, Wu XH, Chen HG, Wang TP, Zhu SP, Zhang ZH, Steinmann P, Yang GJ, Wang SP, Wu ZD, Wang LY, Hao Y, Bergquist R, Utzinger J, Zhou XN. China’s new strategy to block Schistosoma japonicum transmission: experiences and impact beyond schistosomiasis. Trop Med Int Health. 2009;14:1475–83.View ArticlePubMedGoogle Scholar
- Wang RB, Zheng J. Three Gorges Dam project and the transmission of schistosomiasis in China. Chin J Schisto Control. 2003;15:71–4 (in Chinese).Google Scholar
- Zhang SJ, Yu ZH, Wu ZD. The impact of water level change in Jiangxi Province caused by construction of the Three Gorges Dam on the transmission of schistosomiasis in Poyang Lake. J Jiangxi Prev Med. 1995;3:13–6 (in Chinese).Google Scholar
- Wu CG, Zhou XN, Xiao BZ. A comprehensive summary of the relationship between the ecological changes in the construction of the Three Gorges Dam and the transmission of S. japonicum. Parasit Dis Foreign Med Sciences. 2005;32:224–8 (in Chinese).Google Scholar
- Zhang SQ, Wang TP, Ge JH, He JC, Tao CG, Zhang GH, Lu DB, Wu WD. The impact of the Three Gorges Dam construction on the exploitation and utilization of marshland and the prevalence of schistosomiasis in Anhui Province. Chin J Parasit Dis Control. 2000;13:276–8 (in Chinese).Google Scholar
- Zhang SQ, Ge JH, Zhang GH. The impact of water level change in Anhui Province caused by Three Gorges Dam construction on behaviours of people and cattle and schistosomiasis prevalence. Chin J Parasit Dis Control. 1998;11:118–20 (in Chinese).Google Scholar