Status Of Schistosomiasis Research Articles

Endemic status of schistosomiasis in People's Republic of China in 2019

This report presented the endemic status of schistosomiasis in the People's Republic of China at a national level in 2019, and analyzed the data collected from the national schistosomiasis prevention and control system and 455 national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis in China, Shanghai, Zhejiang, Fujian, Guangdong and Guangxi continued to consolidate the achievements of schistosomiasis elimination, Sichuan Province achieved transmission interruption, Jiangsu newly achieved the standard of transmission interruption and 5 provinces of Yunnan, Hubei, Anhui, Jiangxi and Hunan maintained transmission control by the end of 2019. There were 450 endemic counties (cities, districts) endemic for schistosomiasis, including 28 500 endemic villages covering 70 667 800 people at risk of infections. Among the 450 endemic counties (citis, districts), 66.89% (301/450), 28.44% (128/450) and 4.67% (21/450) kept the criteria of elimination, transmission interruption and transmission control of schistosomiasis, respectively. By the end of 2019, a total of 30 170 advanced schistosomiasis cases were documented in China. In 2019, a total of 12 090 712 individuals received inquiry examinations and 1 740 764 were positive; 5 158 369 individuals received serological tests and 89 753 were seropositive. A total of 327 475 individuals received stool examinations and 5 were positive, including one case of acute schistosomiasis. In 2019, snail survey was performed in 19 726 endemic villages in China and Oncomelania snails were found in 7 322 villages, accounting for 37.12% of all surveyed villages, with 6 villages with emerging snail habitats. Snail survey covered an area of 585 286.24 hm2 and 174 270.42 hm2 snail habitats were found, including emerging snail habitats of 64.20 hm2; however, no infected snails were identified. In 2019, a total of 605 965 bovines were raised in the schistosomiasis endemic areas of China, and 183 313 received serological examinations, with 1 176 positives detected, while 134 978 bovines received stool examinations, with 7 positives identified. In 2019, there were 28 557 patients with schistosomiasis receiving praziquantel chemotherapy, and expanded chemotherapy was given to 1 008 083 person-times; there were 7 bovines with schistosomiasis receiving praziquantel chemotherapy, and 296 053 herd-times expanded chemotherapy was given to bovines. In 2019, snail habitats at an area of 128 754.26 hm2 were given chemical treatment, and the actual area of chemical treatment was 69 605.55 hm2, while environmental improvements were performed in snail habitats covering an area of 2 847.00 hm2. Data from the 455 national schistosomiasis surveillance sites of China showed that the mean Schistosoma japonicum infection rates were both zero in humans and bovines in 2019, and no infected snails were found. The results demonstrate that the overall endemic situation of schistosomiasis remains at a lower infection level in China; however, there is still a risk of schistosomiasis transmission. To achieve the target set in the National Thirteenth Five-Year Plan for Schistosomiasis Control and consolidate the achievements of schistosomiasis control, precision control on schistosomiasis still needs to be reinforced in China.

A study on positive school children as indicators of schistosomiasis status in their families.

This study aimed to evaluate schistosomiasis positive school children as indicators of infection in their families. Four hundred and sixteen stool samples of children from two primary schools were examined microscopically for Schistosoma mansoni (S. mansoni) after Kato-Katz. Equal numbers from families of schistosomiasis positive and negative school children were examined by Kato-Katz. Circulating cathodic antigen (CCA) cassette test was performed on 100 Kato-Katz negative children to detect missed S. mansoni cases if any. S. mansoni infection rates among the primary school children were 15.3% and 1.6% in high and low prevalence schools respectively. Sixty five percent of school children had light intensity infection. Family members were either negative or exhibited a prevalence rate as low as 5-6% whether related to positive or negative children. A higher infection rate of S. mansoni was detected by the CCA test compared to the Kato-Katz. Conclusively, children can be good indicators of their particular families in areas of limited resources and low endemicity. Efforts are required to permit large scale use of CCA cassette test.

Flood disasters and schistosomiasis control

Currently, the endemic situation of schistosomiasis has dropped to the lowest level in China; however, there are still factors affecting the transmission of schistosomiasis. Flood disasters may pose a great impact on the transmission of schistosomiasis and even affect the progress of schistosomiasis control and the consolidation of schistosomiasis control achievements. In 2020, major flood disasters occur across China. This paper analyzes the current status of schistosomiasis and the impact of flood disasters on the transmission of schistosomiasis in China, and systematically describes the assessment of and response to schistosomiasis transmission risk before flood disasters, the prevention of Schistosoma japonicum infections during flood disasters and the assessment of the endemic situation of schistosomiasis and surveillance of schistosomiasis after flood disasters. It is considered that schistosomiasis control is an important part of conventional schistosomiasis control activities and an important part of anti-flood and schistosomiasis-preventive activities in flood disaster-affected areas. It is recommended that emergence response interventions are implemented in a scientific and well-organized manner to avoid or reduce the risk of schistosomiasis transmission caused by flood disasters. In addition, the research on early surveillance and forecast approaches for schistosomiasis should be emphasized and reinforced to provide the scientific and precise tools for achieving the goal of the 13th Five-year Plan for Schistosomiasis Control and elimination of schistosomiasis in China.

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.

Surveillance on schistosomiasis in five provincial-level administrative divisions of the People\u2019s Republic of China in the post-elimination era

BackgroundThe People’s Republic of China (P. R. China) has made significant progress on schistosomiasis control. Among the 12 provincial-level administrative divisions (PLADs) with schistosomiasis endemic in P. R. China, Guangdong, Shanghai, Fujian, Guangxi and Zhejiang PLADs (following as five PLADs) had successively eliminated schistosomiasis during 1985–1995. However, consolidation of the schistosomiasis elimination in these five PLADs remains challenging. In the current study, we sought to understand the epidemic situation in these post-elimination areas and their surveillance capabilities on schistosomiasis.MethodsAnnual data reflecting the interventions and surveillance on human beings, cattle and snails based on county level from 2005 to 2016 were collected through the national schistosomiasis reporting system and the data were analyzed to understand the epidemic status of schistosomiasis in the five PLADs. A standardized score sheet was designed to assess the surveillance capacity for schistosomiasis of selected disease control agencies in five PLADs and ten counties. Assessment on surveillance capacity including schistosomiasis diagnostic skills, identification of snails’ living and infection status and knowledge about schistosomiasis and its control were made. Descriptive analysis was used to analyze the epidemic status and evaluation results on surveillance capacities.ResultsThe assessments showed that no local cases in humans and cattle or infected snail were found in these five PLADs since 2005. However, from 2005 to 2016, a total of 221 imported cases were detected in Zhejiang, Shanghai and Fujian, and 11.98 hm2 of new snail habitats were found in Zhejiang, Shanghai and Guangxi. In addition, snail infestation reoccurred in 247.55 hm2 of former snail habitats since 2011. For the surveillance capacity assessment, the accuracy rate of IHA and MHT were 100 and 89.3%, respectively. All participants could judge the living status of snails accurately and 98.1% on the infection status of snails. The accuracy rate of the questionnaire survey was 98.0%.ConclusionsElimination of schistosomiasis was consolidated successfully in five PLADs of P. R. China due to effective and strong post-elimination surveillance. Comprehensive consolidation strategies should be focused on the elimination of residual snails and the prevention of imported infection sources to consolidate the achievements of schistosomiasis control.

Parasitic infections and environmental influences on verbal memory and learning potential of isiZulu speaking pre-school children

This study aimed to explore the effects of parasitic infections, demographic, and contextual factors on verbal memory and learning potential. Applying a cross sectional, experimental, and comparative design, we sampled 112 black pre-school children from a historically poor rural South African region (females = 45%; mean age = 5.9 years, SD = 0.778 years). We gathered data on their schistosomiasis status, the rate of soil-transmitted helminths, and their performance on the Ingwavuma Memory and Learning Test (IMLT). Following independent sample t-tests, results showed the children with mild schistosomiasis and soil-transmitted helminth to have comparative cognitive skills to non-infected peers. The socio-ecological variables of poor diet, under-resourcing of the pre-schools, and lack of experience with verbal memory tasks were important determinants of the children’s memory and learning scores.

Challenges and countermeasures of schistosomiasis control in Hunan Province in the new era

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.

Strategy for the South-South cooperation on schistosomiasis control under the Belt and Road Initiative

Following the concerted efforts for nearly 70 years, great successes have been achieved in the national schistosomiasis control programme in China. Currently, the national schistosomiasis control programme in China is facing the challenges to solve the problems during the"final mile"stage towards schistosomiasis elimination, and contribute Chinese experiences, Chinese strategy and Chinese wisdom to the global schistosomiasis control programmes, so as to facilitate the transformation of the joint efforts in the Belt and Road Initiative to a high-quality development, thereby well supporting the activities on global health security. This paper analyzes the current global status of schistosomiasis and the challenges of the global schistosomiasis control programmes, describes the basis for the cooperation on schistosomiasis control among the countries along the Belt and Road Initiative, illustrates the challenges for translation of Chinese experiences and techniques in schistosomiasis control to other diseaseendemic countries, and proposes the patterns and prospects of the South-South cooperation on schistosomiasis control under the Belt and Road Initiative.

Survey of Schistosomiasis in Saint Lucia: Evidence for Interruption of Transmission

.Saint Lucia at one time had levels of schistosomiasis prevalence and morbidity as high as many countries in Africa. However, as a result of control efforts and economic development, including more widespread access to sanitation and safe water, schistosomiasis on the island has practically disappeared. To evaluate the current status of schistosomiasis in Saint Lucia, we conducted a nationally representative school-based survey of 8–11-year-old children for prevalence of Schistosoma mansoni infections using circulating antigen and specific antibody detection methods. We also conducted a questionnaire about available water sources, sanitation, and contact with fresh water. The total population of 8–11-year-old children on Saint Lucia was 8,985; of these, 1,487 (16.5%) provided urine for antigen testing, 1,455 (16.2%) provided fingerstick blood for antibody testing, and 1,536 (17.1%) answered the questionnaire. Although a few children were initially low positives by antigen or antibody detection methods, none could be confirmed positive by follow-up testing. Most children reported access to clean water and sanitary facilities in or near their homes and 48% of the children reported contact with fresh water. Together, these data suggest that schistosomiasis transmission has been interrupted on Saint Lucia. Additional surveys of adults, snails, and a repeat survey among school-age children will be necessary to verify these findings. However, in the same way that research on Saint Lucia generated the data leading to use of mass drug administration for schistosomiasis control, the island may also provide the information needed for guidelines to verify interruption of schistosomiasis transmission.

Contributions and achievements on schistosomiasis control and elimination in China by NIPD-CTDR.

Being a zoonotic parasitic disease, schistosomiasis was widely spread in 12 provinces of Southern China in the 1950s, severly harming human health and hindering economic development. The National Institute of Parasitic Diseases at the Chinese Center for Diseases Control and Prevention, and Chinese Center for Tropical Diseases Research (NIPD-CTDR), as the only professional institution focussing on parasitic diseases at the national level, has played an important role in schistosomiasis control in the country. In this article, we look back at the changes of schistosomiasis endemicity and the contribution of NIPD-CTDR to the national schistosomiasis control programme. We review NIPD-CTDR's activities, including field investigations, design of control strategies and measures, development of diagnostics and drugs, surveillance-response of endemic situation, and monitoring & evaluation of the programme. The NIPD-CTDR has mastered the transmission status of schistosomiasis, mapped the snail distribution, and explored strategies and measures suitable for different types of endemic areas in China. With a good understanding of the life cycle of Schistosoma japonicum and transmission patterns of the disease, advanced research carried out in the NIPD-CTDR based on genomics and modern technology has made it possible to explore highly efficient and soft therapeutic drugs and molluscicides, making it possible to develop new diagnostic tools and produce vaccine candidates. In the field, epidemiological studies, updated strategies and targeted intervention measures developed by scientists from the NIPD-CTDR have contributed significantly to the national schistosomiasis control programme. This all adds up to a strong foundation for eliminating schistosomiasis in China in the near future, and recommendations have been put forward how to reach this goal.

Endemic status of schistosomiasis in People's Republic of China in 2018

This report presented the endemic status of schistosomiasis in the People's Republic of China at a national level in 2018, and analyzed the data collected from the national schistosomiasis prevention and control system and 453 national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis in China, 5 provinces (municipality and autonomous region), including Shanghai, Zhejiang, Fujian, Guangdong and Guangxi, continued to consolidate the achievements of schistosomiasis elimination, Sichuan Province achieved transmission interruption and 6 provinces of Yunnan, Jiangsu, Hubei, Anhui, Jiangxi and Hunan achieved transmission control by the end of 2018. There were 450 endemic counties (cities, districts) covering 260 million people, specifically including 28 456 endemic villages covering 70.059 7 million people at risk of infection. Among the 450 endemic counties (cities, districts), 58.44% (263/450), 27.56% (124/450) and 14.00% (63/450) reached the criteria of elimination, transmission interruption and transmission control, respectively. By the end of 2018, a total of 29 214 advanced schistosomiasis cases were documented in China. In 2018, a total of 11.127 6 million individuals received inquiry examinations and 2.062 9 million were positive; 7.191 4 million individuals received serological tests and 138.5 thousand of them were positive, 532.2 thousand individuals received stool examinations and 8 were positive in China. In 2018, snail survey was performed in 19 821 endemic villages and Oncomehania snails were found in 7 321 villages, accounting for 36.94% of all surveyed villages, with 3 newly detected villages with snails in China. Snail survey covered an area of 590 241.01 hm2 and 168 319.41 hm2 snail habitats were found, including emerging snail habitats of 61.28 hm2; however, no infected snails were identified. In 2018, a total of 646 823 bovines were raised in the schistosomiasis endemic areas of China, and 225 258 received serological examinations, with 2 638 positives detected, while 164 803 bovines received stool examinations, with 2 positives identified. In 2018, there were 90 388 patients with schistosomiasis receiving praziquantel chemotherapy, and expanded chemotherapy was given to 1 490 594 person-times; there were two bovines with schistosomiasis receiving praziquantel chemotherapy, and expanded chemotherapy was given to 352 577 bovine-times; chemical treatment was conducted in an area of 141 660.87 hm2, including an actual mollusciciding area of 75 308.26 hm2, and environmental improvements were performed in an area of 4 738.37 hm2 in China. Data from the 453 national schistosomiasis surveillance sites of China showed that the mean Schistosoma japonicum infection rates were 0.001 5% and zero in humans and bovines in 2018, respectively, and no infected snails were found. The results demonstrate that the endemic situation of schistosomiasis appears a tendency towards a continuous decline in China; however, there is still a risk of schistosomiasis transmission, and challenges remain in achieving the target set in the Thirteenth Five-Year National Plan for Schistosomiasis Control in 2020 in some regions.

Endemic situation of schistosomiasis in People's Republic of China from 2010 to 2017

To understand the epidemic trend of schistosomiasis in China from 2010 to 2017 so as to provide the scientific evidence for schistosomiasis elimination. The information of schistosomiasis control nationwide from 2010 to 2017 was collected, including the endemic of population, status of livestock control, and Oncomelania hupensis snail control. Microsoft Excel was applied for datum management and analysis. From 2010 to 2017, the epidemic of schistosomiasis in China dropped significantly. The decreasing amplitude of estimated number of patients nationwide was 88.46%. Seventy-one acute schistosomiasis patients were reported and 12.68% (9/71) of them were imported. The decreasing rate of cultivated cattle was 50.09%, and the accumulative number of schistosome-infected cattle was 17 239, and the average positive rate of stool examinations decreased from 1.04% to 0.000 22%. The area with snails nationwide was 373 596.18 to 363 068.95 hm2, and the new detected area with snails was 46.71 to 1 346.73 hm2. The area with schistosome-infected snails was 171.68 hm2 in 2012 and it was 9.25 hm2 in 2013. In 72 key monitoring points of 7 endemic provinces, there were 17 schistosome positive points of water body in 2010 and 6 points in 2016. There were some high risk-factors related to schistosomiasis transmission including schisto-some-infected cattle, dogs, and field rats, and the field stools, and the pasture in the area with snails in schistosomiasis monitoring points. The endemic status of schistosomiasis in China has dropped significantly, and the transmission level is very low. However, the infectious source and risk factors in the endemic environments have not be eliminated. Therefore, the infectious source control, health education, snail control, and transmission monitoring should be strengthened, so as to promote the progress of schistosomiasis elimination.

Is there a gap between health education content and practice toward schistosomiasis prevention among schoolchildren along the shores of Lake Victoria in Kenya?

Despite provision of preventive measures against schistosomiasis such as mass drug administration (MDA), the prevalence of Schistosoma mansoni remains high in communities living near Lake Victoria. This study aimed to analyse the status of schistosomiasis, including its prevalence, health education, knowledge, attitudes, and practices (KAP) among pupils, and water use in schools in Mbita situated along the shores of Lake Victoria. Four primary schools were selected as target schools and pupils in classes six and seven were recruited as study participants. The prevalence of S. mansoni was examined by Kato-Katz method. Simultaneously, a KAP survey toward schistosomiasis was conducted among the pupils. Health education contents were extracted from textbooks. All primary schools in the study site were surveyed regarding how each secured water used for daily school life. The prevalence of S. mansoni was 56% and 36% in 2015 and 2016, respectively. 60–70% of pupils chose a correct answer for the mode of transmission. More than 70% of pupils answered that bathing in Lake Victoria causes Schistosoma infection; however, more than 70% of pupils bathed in Lake Victoria sometimes or every day. According to the science textbook, “avoiding contact with contaminated water” is the way to prevent schistosomiasis; however, 66% of schools asked pupils to bring water from Lake Victoria. The prevalence of S. mansoni among pupils remains high. Schoolchildren are taught to avoid contact with contaminated water but are often asked to fetch water from the lake. From the school health viewpoint, health education that reflects the social and cultural context of the community in the contents and teaching methods are needed. In addition to this, provision of sanitation infrastructure is needed. A comprehensive and innovative approach which harmonises central and local governments and other stakeholders, as well as community is important to prevent schistosomiasis.

The epidemiological status of schistosomiasis in P. R. China after the World Bank Loan Project, 2002–2017

World Bank Loan Project (WBLP) for schistosomiasis control conducted from 1992 to 2001, resulted in significant reduction of schistosomiasis morbidity and mortality in People’s Republic of China (P.R. China), with implementation of morbidity control. Thereafter, an integrated control strategy, which targeted blocking disease transmission from reservoir hosts to the environment, was initiated in order to conquer schistosomiasis rebound after WBLP completion. Data obtained from the national schistosomiasis control reporting systems was collected and analyzed. The number of confirmed cases and infected cattle decreased significantly from 2002 to 2017, while no infected snails were found by dissection for four consecutive years. However, lake and marshland regions and some parts areas of Yunnan Province require attention for rigorous schistosomiasis control efforts. There is need to strengthen precise interventions and sensitive surveillance to achieve schistosomiasis elimination in P.R. China.

PO 8449 SCHISTOSOMA HAEMATOBIUMINFECTION INCREASES THE NUMBER OF MALARIA EPISODES IN CHILDREN LIVING IN RURAL AREAS AROUND LAMBARéNé, GABON

BackgroundIn sub-Saharan Africa,Plasmodiumspp. infection prevalence very often overlaps with helminth infections, particularly with schistosomiasis which is reported to be the second parasitic infection after malaria in terms of prevalence. Interaction between both infections has been reported earlier. Schistosomiasis is typically a chronic disease, whereas malaria occurs in episodes, particularly in children. In this study, we assessed the effect ofSchistosoma haematobiuminfection on clinical malaria among children.MethodsA longitudinal study was conducted from June 2016 to February 2018. Volunteers without any known chronic condition were included. Thick blood smear (TBS) was performed monthly at participants’ homes. For any medical concern including malaria-like symptoms and visible haematuria, participants were invited to come to CERMEL for diagnosis and treatment. Light microscopy was performed to detect malaria parasites andSchistosomaeggs, using TBS and urine filtration technique, respectively. Over the study course, participants found to be infected were treated accordingly. Schistosomiasis status was determined at the end of the follow-up.ResultsAmong the 351 volunteers included in the study, schistosomiasis status was available for 260. Mean age was 12.3 year (SD 4.6) with a 0.96 women-to-men sex ratio. Of those, 112/260 (43.1%) [37.0%–49.3%] participants were positive forS. haematobium, and a total of 132 (51%) children developed 230 malaria attacks. Those with schistosomiasis had a 1.5:1 [1.1–2.0] risk to develop malaria compared to their uninfected counterparts. The mean number of malaria episodes per child over the study course was higher among children with schistosomiasis compared to those without (2.03 vs 1.57, p-value=0.015).ConclusionS. haematobiuminfection was associated with increased susceptibility to develop malaria (by increasing the risk to develop a malaria episode) and, consequently, a higher malaria incidence.

PO 8503 EPIDEMIOLOGY, CO-INFECTIONS AND HAEMATOLOGICAL FEATURES OF SCHISTOSOMIASIS IN SCHOOL-AGED CHILDREN LIVING IN LAMBARÉNÉ, GABON

BackgroundSchistosomiasis is a highly prevalent parasitic infection in Central Africa, where co-endemicity with other parasitic infections is common, and schistosomiasis outcomes can be affected by those other infections. Therefore, proper schistosomiasis control needs epidemiological data accounting for co-infections, too. In this present study, our objective was to determine the epidemiological situation around schistosomiasis in Lambaréné.MethodsA cross-sectional study was conducted among school-aged children living in Lambaréné. Urine filtration exam was performed for the detection of Schistosoma eggs. Kato-Katz and stool culture (Coproculture and Harada-Mori) techniques were used for the detection of soil-transmitted helminths. Detection of Plasmodium spp. and blood microfilariae was performed applying light microscopy. Risk factors for schistosomiasis and factors associated with schistosomiasis were investigated; haematology parameters evaluated.ResultsA total of 614 school children with available schistosomiasis status were included in the analysis. Mean age was 10.9 (SD=2.7) years, with a 0.95 boy-to-girl sex ratio. The prevalence of schistosomiasis was 26%. No risk factors except human-water contact were associated with schistosomiasis. Only Trichuris trichiura co-infection was associated with an increased odd (aOR=2.3, p-value=0.048) to be infected with schistosomiasis. Full blood counts showed a decrease of haemoglobin level and increase of WBC and platelet levels among the schistosoma-infected children. Haematuria was found associated with schistosomiasis (aOR=14.5, p-value<0.001) and was suitable to predict the disease.ConclusionThe prevalence of schistosomiasis is moderate in Lambaréné where human-water contact remains the main risk factor and praziquantel is available for treatment. Trichuriasis is associated with increased risk to be infected. Children with schistosomiasis exhibit a distinct full blood count profile and haematuria is found to be more suitable to predict infection. However, it is desirable to implement comprehensive approaches beyond chemotherapy for schistosomiasis control in this area as recommended by WHO.

Endemic status of schistosomiasis in People's Republic of China in 2017

This report presents the endemic status of schistosomiasis in the People's Republic of China at national level in 2017, and analyzes the data collected from the national schistosomiasis prevention and control system and 457 national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) being endemic of schistosomiasis japonica in P. R. China, 5 provinces (municipality and autonomous region), i.e., Shanghai, Zhejiang, Fujian, Guangdong and Guangxi, continued to consolidate the status of elimination of schistosomiasis. Sichuan Province achieved the transmission interruption and 6 provinces of Yunnan, Jiangsu, Hubei, Anhui, Jiangxi and Hunan kept the transmission control by the end of 2017. There were 450 endemic counties (cities, districts) covering 259 million people, specifically including 28 544 endemic villages of 70 324.5 thousand people at risk. Among the 450 endemic counties (cities, districts), 47.78% (215/450), 34.00% (153/450) and 18.22% (82/450) reached the criteria of elimination, transmission interruption and transmission control, respectively. By the end of 2017, a total of 8 401 113 individuals received schistosomiasis examinations and 14 individuals were parasitologically diagnosed, decreased by 97.67% compared with 600 cases in 2016. It was estimated of 37 601 cases of schistosome infection, decreased by 30.95% compared with 54 454 cases in 2016. One acute schistosomiasis case was reported in 2017. There were 29 407 advanced schistosomiasis cases documented in 2017. Oncomelania hupensis snail surveys were performed in 19 784 endemic villages and O. hupensis snails were found in 7 310 villages, accounting for 36.95% of total villages, with 19 newly detected villages with snails.The snail survey covered an area of 622454.49 hm2 and snails were found in an area of 172501.56 hm2, including a newly detected area of 208.54 hm2. No schistosome-infected snails were found in 2017. A total of 737 016 bovines were raised in the schistosomiasis endemic areas. Of them, 454 830 bovines received the examinations for schistosome infection, and 1 bovine was stool examination positive. There were 119 326 schistosomiasis cases receiving chemotherapy in 2017, with 1 973 968 individuals undergoing expanded chemotherapy; one bovine with schistosomiasis receiving chemotherapy, with 418 925 bovines undergoing expanded chemotherapy. A total of 144 605.31 hm2 area with snail was controlled by using molluscicides, with actual molluscicide-treated area of 73 755.37 hm2; and 5 002.92 hm2 area with snail was treated by environmental modification. Based on the data from the 457 national schistosomiasis surveillance sites, the mean Schistosoma japonicum infection rate was 0.001 6% and 0 in humans and bovines, respectively. No schistosome-infected snails were found by microscopic examinations in all the surveillance sites, and 7 snail samples with schistosome nucleic acid positive were detected by loopmediated isothermal amplification (LAMP) among 6 surveillance sites. The results demonstrate a continuous decline trend on the endemic situation of schistosomiasis in P. R. China. However, the risk of epidemic rebound still exists in some regions and it is still a challenge to achieve the target set by the Thirteenth Five-Year National Plan for Schistosomiasis Control in 2020.

Progress and challenges of schistosomiasis elimination in China

Schistosomiasis is an old and geographically widespread parasitic disease that severely damages human health and affects socioeconomic development in China. The implementation of the integrated strategy with emphasis on controlling the source of Schistosoma japonicum infection and the National Mid- and Long-Term Plan for Schistosomiasis Prevention and Control (2004-2015) in China greatly facilitated the progress towards the elimination of schistosomiasis in China. Since transmission control of schistosomiasis was achieved in 2015, the goal of the national schistosomiasis control program has moved to transmission interruption and elimination in China. Because of the impacts of natural and social factors, and the new situation, new task and new demands following the continuous decline in the endemic situation of schistosomiasis, several challenges exist to achieve the goal of schistosomiasis elimination nationwide. This paper analyzed the current endemic status of schistosomiasis, progress and challenges of schistosomiasis elimination, and proposed some suggestions for the national chistosomiasis elimination program in China.

Impact of Mothers' Schistosomiasis Status During Gestation on Children's IgG Antibody Responses to Routine Vaccines 2 Years Later and Anti-Schistosome and Anti-Malarial Responses by Neonates in Western Kenya.

The potential consequences of parasitic infections on a person’s immune responsiveness to unrelated antigens are often conjectured upon in relationship to allergic responses and autoimmune diseases. These considerations sometimes extend to whether parasitic infection of pregnant women can influence the outcomes of responses by their offspring to the immunizations administered during national Expanded Programs of Immunization. To provide additional data to these discussions, we have enrolled 99 close-to-term pregnant women in western Kenya and determined their Schistosoma mansoni and Plasmodium falciparum infection status. At 2 years of age, when the initial immunization schedule was complete, we determined their children’s IgG antibody levels to tetanus toxoid, diphtheria toxoid, and measles nucleoprotein (N-protein) antigens using a multiplex assay. We also monitored antibody responses during the children’s first 2 years of life to P. falciparum MSP119 (PfMSP119), S. mansoni Soluble Egg Antigen (SEA), Ascaris suum hemoglobin (AsHb), and Strongyloides stercoralis (SsNIE). Mothers’ infections with either P. falciparum or S. mansoni had no impact on the level of antibody responses of their offspring or the proportion of offspring that developed protective levels of antibodies to either tetanus or diphtheria antigens at 2 years of age. However, children born of S. mansoni-positive mothers and immunized for measles at 9 months of age had significantly lower levels of anti-measles N-protein antibodies when they were 2 years old (p = 0.007) and a lower proportion of these children (62.5 vs. 90.2%, OR = 0.18, 95% CI = 0.04–0.68, p = 0.011) were considered positive for measles N-protein antibodies. Decreased levels of measles antibodies may render these children more susceptible to measles infection than children whose mothers did not have schistosomiasis. None of the children demonstrated responses to AsHb or SsNIE during the study period. Anti-SEA and anti-PfMSP119 responses suggested that 6 and 70% of the children acquired schistosomes and falciparum malaria, respectively, during the first 2 years of life.

Endemic status of schistosomiasis in People's Republic of China in 2016

This report presents the endemic status of schistosomiasis in the People's Republic of China at national level in 2016, and analyzes the data collected from the national schistosomiasis prevention and control system and 454 national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) of endemic of schistosomiasis japonica in P. R. China, 5 provinces (municipality and autonomous region), i.e., Shanghai, Zhejiang, Fujian, Guangdong and Guangxi, had achieved elimination, and 7 provinces of Sichuan, Yunnan, Jiangsu, Hubei, Anhui, Jiangxi and Hunan had achieved transmission control by the end of 2016. There are 451 endemic counties (cities, districts) covering 257 million people, specifically including 29 692 endemic villages of 69.39 million people at risk. Among the 451 endemic counties (cities, districts), 35.25 % (159/451), 42.35% (191/451) and 22.39% (101/451) reached the criteria of elimination, transmission interruption and transmission control, respectively in 2016. By the end of 2016, it was estimated of 54 454 infections of schistosome, decreased by 29.46% compared with 77 194 in 2015. No acute schistosomiasis case was reported in 2016. There were 30 573 advanced schistosomiasis cases documented in 2016. A total of 8 500 710 individuals received schistosomiasis examinations and 600 individuals were parasitologically diagnosed, decreased by 83.36% compared with 3 606 in 2015. The Oncomelania hupensis snail survey was performed in 22 140 endemic villages and O. hupensis snails were found in 7 106 villages, accounting for 32.109% of the total villages, with 20 newly detected villages with snails. The snail survey covered area of 813 963.91 hm2 and snails were found in an area of 235 096.04 hm2, including a newly detected area of 1 346.48 hm2. No schistosome-infected snails were found in 2016. A total of 881 050 bovines were raised in the schistosomiasis endemic area. Of them, 510 468 bovines received examinations, resulting in 8 schistosome-infected bovines. There were 147 642 schistosomiasis cases receiving drug treatment in 2016, with 2 303 555 individuals undergoing expanded chemotherapy; there were 9 bovines with schistosomiasis receiving drug treatment, with 439 857 bovines undergoing expanded chemotherapy; a total of 139 483.84 hm2 area with snail control by using molluscicides, with actual molluscicide-treated area of 73 941.75 hm2; and 3 101.52 hm2 snail habitants were treated by environmental modification. Based on the data from the 454 national schistosomiasis surveillance sites, the mean Schistosoma japonicum infection rate was 0.02% and 0.0078% in humans and bovines, respectively. No schistosome-infected snails were found in all the surveillance sites. The results demonstrate a decline in the endemicity of schistosomiasis in P. R. China compared with the level of 2015. However, the distribution area of snails in China is still large and the infection source of schistosomiasis still exists to some extent in some endemic areas; in some regions, the task to reach the standard of transmission interruption is still arduous. There are still objective factors of epidemic and transmission and risk factors of endemic reversal and rebound for schistosomiasis. So, further control and effective surveillance as well as accurate prevention and control should be implemented to promote the elimination process on schistosomiasis in P. R. China.