Decoding the evolution of preventive chemotherapy schemes for schistosomiasis in China to improve the precise implementation of the WHO guideline on control and elimination of human schistosomiasis / 中国血吸虫病防治杂志

Preventive chemotherapy is one of the pivotal interventions for the control and elimination of schistosomiasis, which is effective to reduce the morbidity and prevalence of schistosomiasis. In order to promote the United Nations' sustainable development goals and the targets set for schistosomiasis control in the Ending the neglect to attain the Sustainable Development Goals: a road map for neglected tropical diseases 2021-2030, WHO released the guideline on control and elimination of human schistosomiasis in 2022, with major evidence-based updates of the current preventive chemotherapy strategy for schistosomiasis. In China where great success has been achieved in schistosomiasis control, the preventive chemotherapy strategy for schistosomiasis has been updated several times during the past seven decades. This article reviews the evolution of the WHO guidelines on preventive chemotherapy and Chinese national preventive chemotherapy schemes, compares the current Chinese national preventive chemotherapy scheme and the recommendations for preventive chemotherapy proposed in the 2022 WHO guideline on control and elimination of human schistosomiasis, and proposes recommendations for preventive chemotherapy during the future implementation of the 2022 WHO guideline, so as to provide insights into schistosomiasis control among public health professionals engaging in healthcare foreign aid.

Endemic situation of schistosomiasis in national surveillance sites of Hunan Province from 2015 to 2019 / 中国血吸虫病防治杂志

Objective To analyze the changes in the endemic situation of schistosomiasis in national surveillance sites of Hunan Province, so as to provide scientific basis for the development of the schistosomiasis elimination programme in the province. Methods According to the requirements of the National Guidelines for Schistosomiasis Surveillance in China (2014 version), a total of 41 national schistosomiasis surveillance sites were assigned in all disease-endemic counties (districts) across Hunan Province. During the period between 2015 and 2019, Schistosoma japonicum infections were monitored in local residents, mobile populations and livestock, and snail status was monitored. The morbidity due to schistosomiasis and snail status was compared between years. Results The sero-prevalence of S. japonicum infections was 2.57% and 1.56% in local residents and mobile populations in national surveillance sites of Hunan Province from 2015 to 2019, respectively, and the sero-prevalence appeared a tendency towards a decline over years. A higher sero-prevalence rate of S. japonicum infections was seen in men than in women (P < 0.01). During the 5-year study period, the sero-prevalence rate of human S. japonicum infections appeared a tendency towards a decline in the marshland, embankment, inner embankment and hilly types of endemic areas over years. There were 44 and 19 egg -positives detected in local residents and 5 and 1 egg-positives in mobile populations in 2015 and 2016 respectively. A total of 9 346 domestic animals were monitored from 2015 to 2019, and 6 egg-positives were detected in 2015 and 2016 (all were bovine). A total of 0.155 billion m2 settings were surveyed from 2015 to 2019, and the mean density of living snails appeared a tendency towards a decline over years, with a 45.79% reduction in 2019 as compared to 2015. However, no S. japonicum infections were identified in snails during the 5-year period. A total of 1 469 mixed snail samples were detected using loop-mediated isothermal amplification (LAMP), and 6 positive snail samples were identified in 2015 (one sample) and 2017 (5 samples). Conclusions The overall endemic situation of schistosomiasis appears a tendency towards a decline in Hunan Province, and the prevalence of S. japonicum infections is at a low level in humans and livestock; however, there is still a risk of schistosomiasis transmission. Improvements of health education, intensification of schistosomiasis examinations in mobile populations and reinforcement of the surveillance-response system is required to consolidate the achievements of schistosomiasis control in Hunan Province.

Effect of integrated schistosomiasis control measures in Hunan Province from 2004 to 2019 / 中国血吸虫病防治杂志

Objective To examine the effect of the integrated schistosomiasis control measures in Hunan Province from 2004 to 2019, so as to provide insights into the development of the schistosomiasis elimination strategy. Methods The integrated schistosomiasis control measures implemented by the health, agriculture, water resources, forestry, land and resources sectors were retrospectively collected in Hunan Province from 2004 to 2019, and the completion of each measure, cost of control measures, Schistosoma japonicum infections in humans and bovines, and snail status were analyzed each year. An index system for assessing the integrated schistosomiasis control effect was constructed using the Delphi method to calculate the integrated schistosomiasis control effect index. In addition, a cost-effect analysis was performed in terms of the decline in the prevalence of S. japonicum infections in humans and bovines, areas with snails in inner embankments, and areas with infected snails. Results A total of 7 110 926 500 Yuan were invested into the integrated schistosomiasis control program of Hunan Province from 2004 to 2019. During the 16-year period, a total of 277 437.12 hm2 snail habitats received molluscicidal treatments, 6 927 230 person-times given expanded chemotherapy, 2 116 247 bovine-times given expanded chemotherapy, 954 850 harmless toilets built, 290 359 bovines fenced, 136 666 bovines eliminated, 141 905 machines used to replace bovines, 39 048.63 hm2 water lands improved as dry lands, 724.12 km irrigation regions improved, 3 994 300 populations covered with safe water, 191 102.89 hm2 forests planted and 38 535.27 hm2 lands leveled. The prevalence of S. japonicum infections was 4.29% in humans and 4.48% in bovines in Hunan Province in 2004, with 2 449.37 hm2 snail habitats in inner embankments and 3 423.74 hm2 infected snail areas. In 2019, the prevalence of S. japonicum infections reduced to 0 in both humans and bovines, and areas of snail habitats reduced to 540.92 hm2 (77.92% reductions), while the areas with infected snails reduced to 0. The overall integrated schistosomiasis control effect index appeared a tendency towards a rise over years since 2004, and the integrated schistosomiasis control effect index was 97.35 in 2019; the annual mean costs for a 1% reduction in the prevalence of S. japonicum infections in 100 populations and 100 bovines were 70.11 Yuan and 4 204.78 Yuan, and the annual mean costs for a 1% reduction in the snail areas in inner embankments and infected snail areas were 2 010.20 Yuan and 1 298.09 Yuan, respectively. Conclusions The integrated control measures achieve remarkable effectiveness for schistosomiasis control in Hunan Province, with a remarkable decline in the prevalence of S. japonicum infections in humans and bovines and great shrinking of snail areas in inner embankments and infected snail areas. Adequate fund investment is required to improve the integrated schistosomiasis control measures and consolidate the control achievements.

[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.

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.

[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.

[Value and evaluation on multidisciplinary treatment of advanced schistosomiasis].

Advanced schistosomiasis, encompassing a wide range of pathologic entities and multi-complications, poses a serious threat on the patients' health. Through comprehensive analysis and evaluation on related aspects regarding clinical classification, main methods of auxiliary examination and treatment (including types of surgical procedure) of advanced schistosomiasis, we think that the individual based multidisciplinary comprehensive treatment according to varying conditions of patients is the most optimal treatment mode of advanced schistosomiasis. It is further proposed that multidisciplinary collaborative diagnosis and treatment system should be undoubtedly established, multidisciplinary case discussions be regularly organized, and treatment expert teams be stably formed, in order to significantly improve the level of diagnosis and treatment of advanced schistosomiasis, so as to reduce the misdiagnosis and improve the therapeutic effect in advanced schistosomiasis control.