Changing trends of neglected tropical diseases in China

Impact of the National Wetland Park in the Poyang Lake Area on Oncomelania hupensis, the Intermediate Host of Schistoma japonicum

In this study, we aimed to understand the influence of ecotourism on the distribution of Oncomelania hupensis and to provide a scientific basis for formulating effective snail control methods in tourism development areas. Poyang Lake National Wetland Park was selected as the pilot area, and sampling surveys were conducted based on comprehensive and detailed investigations of all historical and suspected snail environments according to map data to determine the snail distribution and analyze the impact of tourism development. The results showed that from 2011 to 2021, the positive rates of blood tests and fecal tests tended to decrease among residents of the Poyang Lake area. The positive rates of blood tests and fecal tests in livestock also tended to decrease. The average density of O. hupensis snails decreased, and no schistosomes were detected during infection monitoring in Poyang Lake. The local economy rapidly grew after the development of tourism. The development of ecotourism projects in Poyang Lake National Wetland Park increased the transfer frequency of boats, recreational equipment, and people, but it did not increase the risk of schistosomiasis transmission or the spread of O. hupensis snails. Prevention and monitoring only need to be strengthened in low-endemic schistosomiasis areas to effectively promote economic development due to tourism activities without affecting the health of residents.

Potential Capacity of China's development assistance for health on neglected tropical diseases

Neglected tropical diseases (NTDs) are important health problem in tropical and sub-tropical regions, which afflict more than a billion people worldwide and cause several million deaths every year, especially in Africa. The World Health Organization has called for global efforts to control and eliminate NTDs. China began its health assistance program from 1950s, especially on medical mission dispatched to more than 50 African countries. In this study, a SWOT analysis was used to analyze the current strengths, weaknesses, opportunities, and threats of China's health assistance relating to NTDs, in order to provide the recommendation to promote the activities on international assistance and cooperation on NTDs. Based on this analysis, interventions for NTDs and suggestions for future cooperation relating to NTDs are proposed. In the context of global health, China should strengthen and improve the capacity on health assistance for NTDs control.

Helminthiases in the People's Republic of China: Status and prospects

Helminth infections, many of them listed as neglected tropical diseases by the World Health Organization, remain a public health issue in many parts of the world. The People's Republic of China (P.R. China) stands out due to impressive progress in the control and local elimination of helminth infections. An important contextual factor is P.R. China's sustained social and economic development that allowed implementation of health-related poverty alleviation, improving water, sanitation and hygiene, enhancing information, education and communication, coupled with major engineering and infrastructure development and intersectoral collaboration. Nonetheless, food-borne trematodiases, soil-transmitted helminthiases, echinococcosis, cysticercosis/taeniasis and schistosomiasis still exert a considerable burden in P.R. China, even though the numbers of infected people have decreased substantially since the new millennium. This special issue of Acta Tropica provides a comprehensive update of the current knowledge of the main helminth infections in P.R. China, summarises progress in research and discusses future prospects for gaining and sustaining control towards the final goal of breaking transmission and hence, eliminating helminthiases. It consists of 34 articles with a wide coverage that can be grouped into six domains: (i) epidemiological assessment and disease burden estimates; (ii) diagnostics and antigen characterisation; (iii) drug and vaccine development; (iv) host-parasite interactions and snail genetics; (v) surveillance and public health response; and (vi) capacity building and international cooperation. The control and elimination of helminthiases not only furthers the health and wellbeing of the Chinese people, but also provides innovative approaches, tools and strategies, which can be adopted and applied in other countries and regions of the world where helminthiases still prevail.

Current Status of Schistosomiasis Control and Prospects for Elimination in the Dongting Lake Region of the People's Republic of China

Schistosomiasis japonica is an ancient parasitic disease that has severely impacted human health causing a substantial disease burden not only to the Chinese people but also residents of other countries such as the Philippines, Indonesia and, before the 1970s, Japan. Since the founding of the new People's Republic of China (P. R. China), effective control strategies have been implemented with the result that the prevalence of schistosomiasis japonica has decreased markedly in the past 70 years. Historically, the Dongting Lake region in Hunan province is recognised as one of the most highly endemic for schistosomiasis in the P.R. China. The area is characterized by vast marshlands outside the lake embankments and, until recently, the presence of large numbers of domestic animals such as bovines, goats and sheep that can act as reservoir hosts for Schistosoma japonicum. Considerable social, economic and environmental changes have expanded the Oncomelania hupensis hupensis intermediate snail host areas in the Dongting lake region increasing the potential for both the emergence of new hot spots for schistosomiasis transmission, and for its re-emergence in areas where infection is currently under control. In this paper, we review the history, the current endemic status of schistosomiasis and the control strategies in operation in the Dongting Lake region. We also explore epidemiological factors contributing to S. japonicum transmission and highlight key research findings from studies undertaken on schistosomiasis mainly in Hunan but also other endemic Chinese provinces over the past 10 years. We also consider the implications of these research findings on current and future approaches that can lead to the sustainable integrated control and final elimination of schistosomiasis from the P. R. China and other countries in the region where this unyielding disease persists.

Neglected tropical diseases in the People's Republic of China: progress towards elimination

Since the founding of the People's Republic of China in 1949, considerable progress has been made in the control and elimination of the country's initial set of 11 neglected tropical diseases. Indeed, elimination as a public health problem has been declared for lymphatic filariasis in 2007 and for trachoma in 2015. The remaining numbers of people affected by soil-transmitted helminth infection, clonorchiasis, taeniasis, and echinococcosis in 2015 were 29.1 million, 6.0 million, 366 200, and 166 100, respectively. In 2017, after more than 60 years of uninterrupted, multifaceted schistosomiasis control, has seen the number of cases dwindling from more than 10 million to 37 600. Meanwhile, about 6000 dengue cases are reported, while the incidence of leishmaniasis, leprosy, and rabies are down at 600 or fewer per year. Sustained social and economic development, going hand-in-hand with improvement of water, sanitation, and hygiene provide the foundation for continued progress, while rigorous surveillance and specific public health responses will consolidate achievements and shape the elimination agenda. Targets for poverty elimination and strategic plans and intervention packages post-2020 are important opportunities for further control and elimination, when remaining challenges call for sustainable efforts.

Multi-disciplinary integration of networking through the RNAS+: Research on other target diseases

In 2005, the network decided to increase its number of target diseases to include other helminthic zoonoses such as fascioliasis, clonorchiasis, opisthorchiasis, paragonimiasis and cysticercosis and in the process expanding membership to include South Korea, Vietnam, Thailand and Japan. NTDs were eventually included as awareness is heightened on these diseases affecting poor and developing countries. Researches on clonorchiasis and opisthorchiasis unravel the mechanism by which these diseases eventually predispose to cholangiocarcinoma. The liver cancer associated with these liver fluke infections necessitate the need to clarify the global burden of disease of these infections. The magnitude of these liver fluke diseases in endemic countries like China, Vietnam, Laos, Cambodia and Thailand is described. Success in elimination of lymphatic filariasis in PR China and Cambodia is highlighted to show how intensified multisectoral collaboration and strong political become strong ingredients in elimination of parasitic diseases like LF. New advances are presented that clarify species and strain differences in Fasciola spp., Paragonimus spp., Taenia spp. and Echinococcocus spp. Conventional diagnostic techniques are compared with new serologic techniques that are being developed. New control strategies such as the Lawa model are presented.

From country control programmes to translational research

From the time it was conceptualized in 1998 to the present, RNAS⁺ has largely concentrated on research that will generate results to facilitate control, prevention and elimination of its target diseases. Diagnostics has remained an active field of research in order to develop tools that are appropriate for each stage from the first efforts until attempts to block transmission. For example, with regard to schistosomiasis, chemotherapy has excellent impact on morbidity, while better diagnostics and vaccine research have been promoted to complement the other components of the control programme. The need for surveillance in areas where the prevalence has been brought down to very low levels necessitated development of spatio-temporal tools and ecological models based on geographical information systems (GIS) to produce risk and distribution maps for monitoring and evaluation of programme success. New knowledge and experiences in management of the diseases contribute to the formulation of new schemes in management and treatment. Ways of drawing attention to the disease, such as determining disability weights for use in computation of burden of disease, updating epidemiological profile and unravelling new aspects of the disease provide bases for modifying the operation of control programmes as we move forward. Programme evaluation based on reports of actual implementation of activities brought to the fore problems related to the distribution of chemotherapy as well as social, cultural and behavioural aspects of endemic communities. Importantly, this highlighted the necessity of adapting control activities to specific situations of the endemic areas. New models evolving from reviews of this kind and success stories, such us the elimination of lymphatic filariasis (LF) in PR China and Cambodia are presented.