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Acta Parasitologica Sep 2021For the evolution of schistosomiasis in China, a systematic review was provided about the history of the disease and its public health impacts. We aimed to depict the... (Review)
Review
PURPOSE
For the evolution of schistosomiasis in China, a systematic review was provided about the history of the disease and its public health impacts. We aimed to depict the journey from disease discovery to elimination and the experience and lessons learned during the process.
METHODS
We systematically reviewed the Chinese history of schistosomiasis and its public health impacts and collected data on the disease by searching relevant books and articles.
RESULTS
An important milestone for the disease discovery is that Schistosoma japonicum eggs were identified in the two Chinese corpses dating back to around 2180 years ago. The earliest Chinese ancient book documented symptoms resembling schistosomiasis that could date back to about 4700 years ago. The first nationwide survey on the disease in the mid-1950s revealed that schistosomiasis was endemic in 433 counties or cities of 12 provinces and affected about 11.6 million people in China. The Chinese government has provided continuous investment in schistosoiasis control, and the national multifaceted, integrated control programs have been uninterruptedly implemented since 1955. Schistosomiasis control in China can be divided into six stages, and various schistosomiasis control strategies have been developed and adjusted. The number of schistosomiasis cases decreased from 11.6 million in 1950s to 38,000 in 2017 and the number of acute cases decreased from 13,191 in 1989 to only 1 in 2017.
CONCLUSIONS
Schistosomiasis transmission has been under control in all parts of China since 2017. An elimination of schistosomiasis can be achieved in the foreseeable future in China.
Topics: Animals; China; Cities; Humans; Schistosoma japonicum; Schistosomiasis; Snails
PubMed: 33713275
DOI: 10.1007/s11686-021-00357-9 -
Parasitology International Dec 2011Several human genetic variants, HLA antigens and alleles are reportedly linked to post-schistosomal hepatic disorder (PSHD), but the results from these reports are... (Meta-Analysis)
Meta-Analysis Review
Several human genetic variants, HLA antigens and alleles are reportedly linked to post-schistosomal hepatic disorder (PSHD), but the results from these reports are highly inconclusive. In order to estimate overall associations between human genetic variants, HLA antigens, HLA alleles and PSHD, we systematically reviewed and performed a meta-analysis of relevant studies in both post-schistosomal hepatic disorder and post-schistosomal non-hepatic disorder patients. PubMed, Scopus, Google Scholar, The HuGE Published Literature database, Cochrane Library, and manual search of reference lists of articles published before July 2009 were used to retrieve relevant studies. Two reviewers independently selected articles and extracted data on study characteristics and data regarding the association between genetic variants, HLA antigens, HLA alleles and PSHD in the form of 2×2 tables. A meta-analysis using fixed-effects or random-effects models to pooled odds ratios (OR) with corresponding 95% confidence intervals were calculated only if more than one study had investigated particular variation. We found 17 articles that met our eligibility criteria. Schistosoma mansoni and Schistosoma japonicum were reported as the species causing PSHD. Since human genetic variants were only investigated in one study, these markers were not assessed by meta-analysis. Thus, only HLA-genes (a total of 66 HLA markers) were conducted in the meta-analysis. Our meta-analysis showed that human leucocyte antigens HLA-DQB1*0201 (OR=2.64, P=0.018), DQB1*0303 (OR=1.93, P=0.008), and DRB1*0901 (OR=2.14, P=0.002) alleles and HLA-A1 (OR=5.10, P=0.001), A2 (OR=2.17, P=0.005), B5 (OR=4.63, P=0.001), B8 (OR=2.99, P=0.02), and B12 (OR=5.49, P=0.005) serotypes enhanced susceptibility to PSHD, whereas HLA-DQA1*0501 (OR=0.29, P≤0.001) and DQB1*0301 (OR=0.58, P=0.007) were protective factors against the disease. We further suggested that the DRB1*0901-DQB1*0201, DRB1*0901-DQB1*0303 and A1-B8 haplotypes enhanced susceptibility to PSHD, whereas DQA1*0501-DQB1*0301 linkage decreased the risk of PSHD. The result improved our understanding of the association between the HLA loci and PSHD with regard to pathogenic or protective T-cells and provided novel evidence that HLA alleles may influence disease severity.
Topics: Africa; Alleles; Animals; Asia; Databases, Bibliographic; Genetic Linkage; Genetic Predisposition to Disease; Genotype; Haplotypes; Histocompatibility Antigens Class I; Histocompatibility Antigens Class II; Humans; Liver Diseases; Odds Ratio; Schistosoma japonicum; Schistosoma mansoni; Schistosomiasis; Severity of Illness Index; South America
PubMed: 21664486
DOI: 10.1016/j.parint.2011.05.008 -
Parasites & Vectors Oct 2011Praziquantel has been used as first-line drug for chemotherapy of schistosomiasis since 1984. Besides praziquantel, artemether and artesunate have also been used for the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Praziquantel has been used as first-line drug for chemotherapy of schistosomiasis since 1984. Besides praziquantel, artemether and artesunate have also been used for the control of this infectious disease since late 1990s. In this article, we conducted a systematic review and meta-analysis to evaluate the antischistosomal efficacy of different medication strategies including monotherapy or combination therapies of these drugs.
RESULTS
A number of 52 trials from 38 articles published in peer-reviewed journals before July 2011 were selected for analysis after searching the following literature databases: the Cochrane Library, PubMed/Medline, ISI Web of Science, Chinese Biomedicine Literature Database, and China National Knowledge Infrastructure. Our meta-analyses showed that a dosage of 30-60 mg/kg praziquantel compared with placebo produced a protection rate of about 76% (95% CI: 67%-83%) for treating human schistosomiasis, which varied from 70% to 76% with no significant differences among the subspecies S. haematobium, S. japonicum or S. mansoni. Protection rates were higher when praziquantel doses were elevated, as concluded from the nRCTs results: the protection rate of praziquantel at 40 mg/kg was 52% (95% CI: 49%-55%), and it increased to 91% (95% CI: 88%-92%) when the dosages were elevated to 60/80/100 mg/kg divided two or more doses. Multiple doses of artemether or artesunate over 1- or 2-week intervals resulted in protection rates of 65% to 97% for preventing schistosomiasis, and increased doses and shorter medication intervals improved their efficacies. Praziquantel and artemisinin derivatives (artemether or artesunate) in combination resulted in a higher protection rate of 84% (95% CI: 64%-91%) than praziquantel monotherapy for treatment. praziquantel and artesunate in combination had a great protection rate of 96% (95% CI: 78%-99%) for preventing schistosomes infection.
CONCLUSIONS
According to the results, praziquantel remains effective in schistosomiasis treatment, and multiple doses would improve its efficacy; meanwhile, praziquantel is also a good drug for preventing acute schistosomiasis morbidity. It's better to use multiple doses of artemether or artesunate with 1- or 2-week intervals for prevention against schistosome infection. Praziquantel and artemether or artesunate in combination perform better in treatment than praziquantel monotherapy, and they are especially suitable for treating the patients with repeated exposure to infected water.
Topics: Animals; Artemisinins; Dose-Response Relationship, Drug; Humans; Praziquantel; Randomized Controlled Trials as Topic; Schistosoma; Schistosomiasis; Schistosomicides
PubMed: 22004571
DOI: 10.1186/1756-3305-4-201 -
Infectious Diseases of Poverty Jul 2016The 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... (Review)
Review
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.
Topics: Animal Distribution; Animals; China; Gastropoda; Humans; Lakes; Rivers; Schistosoma japonicum; Schistosomiasis japonica; Seasons; Water Movements
PubMed: 27377962
DOI: 10.1186/s40249-016-0156-3 -
Host determinants of reinfection with schistosomes in humans: a systematic review and meta-analysis.PLoS Neglected Tropical Diseases Sep 2014Schistosomiasis is still a major public health burden in the tropics and subtropics. Although there is an effective chemotherapy (Praziquantel) for this disease,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Schistosomiasis is still a major public health burden in the tropics and subtropics. Although there is an effective chemotherapy (Praziquantel) for this disease, reinfection occurs rapidly after mass drug administration (MDA). Because the entire population do not get reinfected at the same rate, it is possible that host factors may play a dominant role in determining resistance or susceptibility to reinfection with schistosomes. Here, we systematically reviewed and meta-analyzed studies that reported associations between reinfection with the principal human-infecting species (S. mansoni, S. japonicum and S. haematobium) and host socio-demographic, epidemiological, immunological and genetic factors.
METHODOLOGY/PRINCIPAL FINDINGS
PubMed, Scopus, Google Scholar, Cochrane Review Library and African Journals Online public databases were searched in October 2013 to retrieve studies assessing association of host factors with reinfection with schistosomes. Meta-analysis was performed to generate pooled odds ratios and standardized mean differences as overall effect estimates for dichotomous and continuous variables, respectively. Quality assessment of included studies, heterogeneity between studies and publication bias were also assessed. Out of the initial 2739 records, 109 studies were included in the analyses, of which only 32 studies with 37 data sets were eligible for quantitative data synthesis. Among several host factors identified, strong positive association was found with age and pre-treatment intensity, and only slightly for gender. These factors are major determinants of exposure and disease transmission. Significant positive association was found with anti-SWA IgG4 level, and a negative overall effect for association with IgE levels. This reconfirmed the concept that IgE/IgG4 balance is a major determinant of protective immunity against schistosomiasis. Other identified determinants were reported by a small number of studies to enable interpretation.
CONCLUSIONS
Our data contribute to the understanding of host-parasite interaction as it affects reinfection, and is a potential tool to guide planning and tailoring of community interventions to target high-risk groups.
Topics: Animals; Disease Susceptibility; Host-Parasite Interactions; Humans; Recurrence; Schistosoma; Schistosomiasis
PubMed: 25211227
DOI: 10.1371/journal.pntd.0003164 -
PLoS Neglected Tropical Diseases 2014Extensive use of praziquantel for treatment and control of schistosomiasis requires a comprehensive understanding of efficacy and safety of various doses for different... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Extensive use of praziquantel for treatment and control of schistosomiasis requires a comprehensive understanding of efficacy and safety of various doses for different Schistosoma species.
METHODOLOGY/PRINCIPAL FINDINGS
A systematic review and meta-analysis of comparative and non-comparative trials of praziquantel at any dose for any Schistosoma species assessed within two months post-treatment. Of 273 studies identified, 55 were eligible (19,499 subjects treated with praziquantel, control treatment or placebo). Most studied were in school-aged children (64%), S. mansoni (58%), and the 40 mg/kg dose (56%); 68% of subjects were in Africa. Efficacy was assessed as cure rate (CR, n=17,017) and egg reduction rate (ERR, n=13,007); safety as adverse events (AE) incidence. The WHO-recommended dose of praziquantel 40 mg/kg achieved CRs of 94.7% (95%CI 92.2-98.0) for S. japonicum, 77.1% (68.4-85.1) for S. haematobium, 76.7% (95%CI 71.9-81.2) for S. mansoni, and 63.5% (95%CI 48.2-77.0) for mixed S. haematobium/S. mansoni infections. Using a random-effect meta-analysis regression model, a dose-effect for CR was found up to 40 mg/kg for S. mansoni and 30 mg/kg for S. haematobium. The mean ERR was 95% for S. japonicum, 94.1% for S. haematobium, and 86.3% for S. mansoni. No significant relationship between dose and ERR was detected. Tolerability was assessed in 40 studies (12,435 subjects). On average, 56.9% (95%CI 47.4-67.9) of the subjects receiving praziquantel 40 mg/kg experienced an AE. The incidence of AEs ranged from 2.3% for urticaria to 31.1% for abdominal pain.
CONCLUSIONS/SIGNIFICANCE
The large number of subjects allows generalizable conclusions despite the inherent limitations of aggregated-data meta-analyses. The choice of praziquantel dose of 40 mg/kg is justified as a reasonable compromise for all species and ages, although in a proportion of sites efficacy may be lower than expected and age effects could not be fully explored.
Topics: Africa; Animals; Anthelmintics; Feces; Humans; Incidence; Intestines; Praziquantel; Schistosoma haematobium; Schistosomiasis haematobia; Schistosomiasis mansoni; Treatment Outcome
PubMed: 25412105
DOI: 10.1371/journal.pntd.0003286 -
Parasitology International Apr 2013Schistosomiasis japonica continues to be an important zoonotic disease in the People's Republic of China (P.R. China), despite decades of dedicated control efforts.... (Meta-Analysis)
Meta-Analysis Review
Schistosomiasis japonica continues to be an important zoonotic disease in the People's Republic of China (P.R. China), despite decades of dedicated control efforts. Different interventions for its control including chemotherapy of humans and animals, mollusciciding, environmental modification, and health education have been implemented at various stages of the control efforts and in different combinations, resulting in remarkable achievements. Here, we present a systematic review and meta-analysis of the documented effectiveness of health education to reduce schistosomiasis japonica transmission in P.R. China. A total of 10 relevant publications were identified and included in the meta-analysis. The reported results indicate that the prevalence of Schistosoma japonicum infection in humans and schistosomiasis-related knowledge are significantly influenced by health education. The implementation of health education over more than 2 years was associated with an overall schistosomiasis japonica prevalence decrease of 6% (95% CI: 2%, 11%) and an overall increase of 51% (95% CI: 41%, 61%) in schistosomiasis-related knowledge after controlling for confounding factors. Among control groups, the prevalence of schistosomiasis japonica and relevant knowledge levels were not significantly influenced. The relative risk (RR) of an infection with S. japonicum following health education lasting more than 2 years was 0.43 (95% CI: 0.24, 0.78). In summary, a considerable effectiveness of health education with regard to preventing S. japonicum infections in P.R. China and increasing relevant knowledge is documented in the extant literature. This suggests that the effectiveness of health education may be considerable, particularly after its long-term implementation.
Topics: Animals; China; Health Education; Health Knowledge, Attitudes, Practice; Humans; Prevalence; Risk; Schistosoma japonicum; Schistosomiasis japonica; Zoonoses
PubMed: 23201566
DOI: 10.1016/j.parint.2012.11.006 -
Experimental Parasitology Apr 2021Schistosome parasites are complex trematode blood flukes responsible for the disease schistosomiasis; a global health concern prevalent in many tropical and sub-tropical...
Schistosome parasites are complex trematode blood flukes responsible for the disease schistosomiasis; a global health concern prevalent in many tropical and sub-tropical countries. While established transcriptomic databases are accessed ad hoc to facilitate studies characterising specific genes or gene families, a more comprehensive systematic updating of gene annotation and survey of the literature to aid in annotation and context is rarely addressed. We have reanalysed an online transcriptomic dataset originally published in 2009, where seven life cycle stages of Schistosoma japonicum were examined. Using the online pathway analysis tool Reactome, we have revisited key data from the original study. A key focus of this study was to improve the interpretation of the gene expression profile of the developmental lung-stage schistosomula, since it is one of the principle targets for worm elimination. Highly enriched transcripts, associated with lung schistosomula, were related to a number of important biological pathways including host immune evasion, energy metabolism and parasitic development. Revisiting large transcriptomic databases should be considered in the context of substantial new literature. This approach could aid in the improved understanding of the molecular basis of parasite biology. This may lead to the identification of new targets for diagnosis and therapies for schistosomes, and other helminths.
Topics: Analysis of Variance; Animals; Cell Degranulation; Datasets as Topic; Glucose Transport Proteins, Facilitative; Host-Parasite Interactions; Life Cycle Stages; Lung; Lung Diseases, Parasitic; Neutrophils; Peptide Elongation Factor 1; Schistosoma japonicum; Schistosomiasis japonica; Transcriptome
PubMed: 33548219
DOI: 10.1016/j.exppara.2021.108080 -
Expert Review of Molecular Diagnostics Mar 2023MicroRNAs are involved in gene regulation in several common liver diseases and may play an essential role in activating hepatic stellate cells. The role of these...
BACKGROUND
MicroRNAs are involved in gene regulation in several common liver diseases and may play an essential role in activating hepatic stellate cells. The role of these post-transcriptional regulators in schistosomiasis needs to be further studied in populations from endemic areas for a better understanding of the disease, the development of new therapeutic approaches, and the use of biomarkers for the prognosis of schistosomiasis.
AREAS COVERED
We performed a systematic review to describe the main human microRNAs identified in non-experimental studies associated with aggravation of the disease in people infected with () and (). Structured searches were carried out in PubMed, Medline, Science Direct, Directory of Open Access Journals, Scielo, Medcarib, and Global Index Medicus databases without time and language restrictions. This is a systematic review following the guidelines of the PRISMA platform.
EXPERT OPINION
The miR-146a-5p, miR-150-5p, let-7a-5p, let-7d-5p, miR-92a- 3p, and miR-532-5p are associated with liver fibrosis in schistosomiasis caused by , revealing that these miRNAs that have been shown to be associated with liver fibrosis are good targets for new studies that evaluate their potential as a biomarker or even treating liver fibrosis in schistosomiasis.
Topics: Animals; Humans; MicroRNAs; Schistosomiasis japonica; Schistosomiasis; Liver Cirrhosis; Schistosoma japonicum; Biomarkers
PubMed: 36803616
DOI: 10.1080/14737159.2023.2182190 -
PLoS Neglected Tropical Diseases Oct 2019Schistosomiasis is a widespread public health concern in the poorest regions of the world. The principal control strategy is regular praziquantel administration to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Schistosomiasis is a widespread public health concern in the poorest regions of the world. The principal control strategy is regular praziquantel administration to school-aged children in endemic areas. With calls for the elimination of schistosomiasis as a public health problem, expanding praziquantel delivery to all community members has been advocated. This systematic review and meta-analysis compares the impact of community-wide and child-targeted praziquantel distribution on schistosomiasis prevalence and intensity in school-aged children.
METHODOLOGY/PRINCIPAL FINDINGS
We searched MEDLINE, Embase and Web of Science to identify papers that reported schistosome prevalence before and after praziquantel administration, either to children only or to all community members. Extracted data included Schistosoma species, drug administration strategy, number of treatment rounds, follow-up interval and prevalence and intensity before and after treatment. We used inverse variance weighted generalised linear models to examine the impact of mass versus targeted drug administration on prevalence reduction, and weighted boxplots to examine the impact on infection intensity reduction. This study is registered with PROSPERO, number CRD42018095377. In total, 34 articles were eligible for systematic review and 28 for meta-analysis. Schistosoma mansoni was reported in 20 studies; Schistosoma haematobium in 19 studies, and Schistosoma japonicum in two studies. Results of generalised linear models showed no detectable difference between mass and targeted treatment strategies on prevalence reduction in school-aged children for S. mansoni (odds ratio 0.47, 95%CI 0.13-1.68, p = 0.227) and S. haematobium (0.41, 95%CI 0.06-3.03, p = 0.358). Box plots also showed no apparent differences in intensity reduction between the two treatment strategies.
CONCLUSIONS/SIGNIFICANCE
The results of this meta-analysis do not support the hypothesis that community-wide treatment is more effective than targeted treatment at reducing schistosomiasis infections in children. This may be due to the relatively small number of included studies, insufficient treatment coverage, persistent infection hotspots and unmeasured confounders. Further field-based studies comparing mass and targeted treatment are required.
Topics: Animals; Child; Databases, Factual; Humans; Praziquantel; Prevalence; Schistosoma haematobium; Schistosoma japonicum; Schistosoma mansoni; Schistosomatidae; Schistosomiasis; Schools
PubMed: 31603895
DOI: 10.1371/journal.pntd.0007808