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Acta Tropica May 2023Schistosoma japonicum remains endemic in China and the Philippines. Substantial progress has been made in the control of Japonicum in both China and the Philippines.... (Review)
Review
BACKGROUND
Schistosoma japonicum remains endemic in China and the Philippines. Substantial progress has been made in the control of Japonicum in both China and the Philippines. China is reaching elimination thanks to a concerted effort of control strategies. Mathematical modelling has been a key tool in the design of control strategies, in place of expensive randomised-controlled trials. We conducted a systematic review to investigate mathematical models of Japonicum control strategies in China and the Philippines.
METHODS
We conducted a systematic review on July 5, 2020, in four electronic bibliographic databases - PubMed, Web of Science, SCOPUS and Embase. Articles were screened for relevance and for meeting the inclusion criteria. Data extracted included authors, year of publication, year of data collection, setting and ecological context, objectives, control strategies, main findings, the form and content of the model including its background, type, representation of population dynamics, heterogeneity of hosts, simulation period, source of parameters, model validation and sensitivity analysis. Results After screening, 19 eligible papers were included in the systematic review. Seventeen considered control strategies in China and two in the Philippines. Two frameworks were identified; the mean-worm burden framework and the prevalence-based framework, the latter of which increasingly common. Most models considered human and bovine definitive hosts. There were mixed additional elements included in the models, such as alternative definitive hosts and the role of seasonality and weather. Models generally agreed upon the need for an integrated control strategy rather than reliance on mass drug administration alone to sustain reductions in prevalence.
CONCLUSIONS
Mathematical modelling of Japonicum has converged from multiple approaches to modelling using the prevalence-based framework with human and bovine definitive hosts and find integrated control strategies to be most effective. Further research could investigate the role of other definitive hosts and model the effect of seasonal fluctuations in transmission.
Topics: Animals; Cattle; Humans; Schistosoma japonicum; Schistosomiasis japonica; Models, Theoretical; Computer Simulation; China
PubMed: 36907291
DOI: 10.1016/j.actatropica.2023.106873 -
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 -
International Journal of Epidemiology Aug 2023Schistosomiasis is a water-borne parasitic disease estimated to have infected >140 million people globally in 2019, mostly in sub-Saharan Africa. Within the goal of...
BACKGROUND
Schistosomiasis is a water-borne parasitic disease estimated to have infected >140 million people globally in 2019, mostly in sub-Saharan Africa. Within the goal of eliminating schistosomiasis as a public health problem by 2030 in the World Health Organization (WHO) Roadmap for neglected tropical diseases, other regions cannot be neglected. Empirical estimates of the disease burden in Southeast Asia largely remain unavailable.
METHODS
We undertook a systematic review to identify empirical survey data on schistosomiasis prevalence in Southeast Asia using the Web of Science, ScienceDirect, PubMed and the Global Atlas of Helminth Infections, from inception to 5 February 2021. We then conducted advanced Bayesian geostatistical analysis to assess the geographical distribution of infection risk at a high spatial resolution (5 × 5 km) using the prevalence, number of infected individuals and doses needed for preventive chemotherapy.
RESULTS
We identified 494 Schistosoma japonicum surveys in the Philippines and Indonesia, and 285 in Cambodia and Laos for S. mekongi. The latest estimates suggest that 225 [95% credible interval (CrI): 168-285] thousand in the endemic areas of Southeast Asian population were infected in 2018. The highest prevalence of schistosomiasis was 3.86% (95% CrI: 3.40-4.31) in Laos whereas the lowest was 0.29% in Cambodia (95% CrI: 0.22-0.36). The estimated number of praziquantel doses needed per year was 1.99 million (95% CrI: 1.92-2.03 million) for the entire population in endemic areas of Southeast Asia.
CONCLUSIONS
The burden of schistosomiasis remains far from the WHO goal and our estimates highlighted areas to target with strengthened interventions against schistosomiasis.
Topics: Humans; Bayes Theorem; Schistosomiasis; Helminthiasis; Prevalence; Cambodia
PubMed: 36478466
DOI: 10.1093/ije/dyac227 -
Tropical Medicine and Infectious Disease Nov 2022Schistosomiasis is a neglected tropical disease affecting 40 million women of childbearing age worldwide. Its global disease prevalence among pregnant women is still... (Review)
Review
Schistosomiasis is a neglected tropical disease affecting 40 million women of childbearing age worldwide. Its global disease prevalence among pregnant women is still unknown. This meta-analysis determined the pooled prevalence of schistosomiasis among pregnant women globally. Additionally, this study also determined the pooled prevalence based on infection intensity based on eggs per gram. Observational studies on the prevalence of schistosomiasis among pregnant patients were obtained from Medline, Scopus, and CINAHL from January 2001 until August 2020. A review of titles and abstracts was done independently by six reviewers. The quality of the included studies was assessed using the Newcastle-Ottawa Scale for case-control, cohort, and cross-sectional studies. A total of 27 studies were included in the meta-analysis and meta-regression. The pooled prevalence of was 13.44 (CI: 8.90-19.80) per 100 observations, while the pooled prevalence of was 12.18 (CI: 4.47-29.12) per 100 observations. The prevalence of infection in one study was 53.54 (CI: 43.23-63.62) per 100 observations. Our results showed a prevailing health problem of schistosomiasis during pregnancy in various countries worldwide. This strengthens the need to conduct more schistosomiasis research, prevention, and control programs in pregnant women.
PubMed: 36355896
DOI: 10.3390/tropicalmed7110354 -
Acta Tropica Oct 2021Praziquantel (PZQ), the only choice of chemotherapy for schistosomiasis recommended by World Health Organization (WHO), has been widely used over 40 years. The... (Meta-Analysis)
Meta-Analysis
Praziquantel (PZQ), the only choice of chemotherapy for schistosomiasis recommended by World Health Organization (WHO), has been widely used over 40 years. The long-term, and rapid expansion of, PZQ use for disease control across a large populations continues to raise concern regarding the potential for emergence and establishment of drug resistance. Recent research has also proposed that the long survival and low sensitivity of unpaired worms, derived from either incomplete treatment cure rates or single-sex schistosome infections within final hosts, could exacerbate the risk of PZQ resistance (PZQ-R) emerging. With the aim of assessing whether PZQ efficacy amongst S. japonicum may have changed over time in China, we performed a unique systematic review and meta-analyses on datasets which evaluated the efficacy of PZQ via laboratory assays of field S. japonicum isolates on experimental mice over time. Relevant published literatures from four electronic bibliographic databases and lists of article references were searched. Two indexes, d, a measure used in meta-analyses for worm burden difference between two groups, and r, a traditional measure for worm reduction percentage after treatment but without considering sample size were calculated for each study. A total of 25 papers including 127 experimental studies with eligible data on 2230 mice were retrieved. The pooled d (D) was 3.91 (3.56-4.25) and pooled r (R) was 54.52% (52.55%-56.52%). D significantly increased over time, whereas R non-significantly decreased; both estimates were significantly associated with the total drug dose. Such findings suggested no evidence of PZQ-R emergence S. japonicum to date. However, we consider the potential role of parasite origins, PZQ dosage, and single versus mixed gender infections of the results published to date, and the avenues now needed for further research.
Topics: Animals; Anthelmintics; Drug Resistance; Mice; Praziquantel; Schistosoma japonicum; Schistosomiasis japonica
PubMed: 34273315
DOI: 10.1016/j.actatropica.2021.106048 -
PLoS Neglected Tropical Diseases Mar 2021Most of national schistosomiasis elimination programmes in Asia are relying on stool examination, particularly Kato Katz stool examination technique for regular... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Most of national schistosomiasis elimination programmes in Asia are relying on stool examination, particularly Kato Katz stool examination technique for regular transmission monitoring. However, the Kato-Katz technique has shown low sensitivity for the detection of light-intensity infections, and therefore highly sensitive diagnostic tools are urgently required to monitor prevalence of infection in low transmission settings. The objective of this systematic review was to evaluate and synthesize the performance of diagnostic tests for detecting Schistosoma japonicum and S. mekongi infection in people living in endemic areas.
METHODOLOGY/PRINCIPAL FINDINGS
We comprehensively searched these nine electronic databases and other resources until July 2019, with no language or publication limits: PubMed, EMBASE, MEDLINE, Web of Science, BIOSIS Citation Index, HTA, CINAHL PLUS, The Cochrane Library, and PsycINFO. We included original studies that assessed diagnostic performance using antibody, antigen, and molecular tests with stool examination test as a reference standard. Two reviewers independently extracted a standard set of data and assessed study quality. We estimated the pooled estimates of sensitivity and specificity for each index test. We used diagnostic odds ratio to determine the overall accuracy and hierarchical summary receiver operating characteristics (HSROC) curve to assess the index tests performance. Fifteen studies (S. japonicum [n = 13] and S. mekongi [n = 2]) testing 15,303 participants were included in the review. Five studies reported performance of enzyme-linked immunosorbent assay (ELISA), seven studies reported indirect hemagglutination assay (IHA), and four studies reported polymerase chain reaction (PCR) for detecting S. japonicum. The pooled sensitivity and specificity were 0.93 (95% CI: 0.84-0.98) and 0.40 (95% CI: 0.29-0.53) for ELISA, 0.97 (95% CI: 0.90-0.99) and 0.66 (95% CI: 0.58-0.73) for IHA, and 0.89 (95% CI: 0.71-0.96) and 0.49 (95% CI: 0.29-0.69) for PCR respectively. A global summary indicated the best performance for IHA, closely followed by ELISA. We were unable to perform meta-analysis for S. mekongi due to insufficient number of studies.
CONCLUSIONS/SIGNIFICANCE
IHA showed the highest detection accuracy for S. japonicum. Further studies are needed to determine the suitable diagnostic methods to verify the absence of transmission of S. mekongi and also to compare detection accuracy against more sensitive reference standards such as PCR.
Topics: Animals; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique, Indirect; Humans; Polymerase Chain Reaction; Schistosoma; Schistosoma japonicum
PubMed: 33730048
DOI: 10.1371/journal.pntd.0009244 -
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 -
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 -
Wellcome Open Research 2020Schistosomiasis is one of the most prevalent neglected tropical diseases (NTDs) with an estimated 229 million people requiring preventive treatment worldwide....
Schistosomiasis is one of the most prevalent neglected tropical diseases (NTDs) with an estimated 229 million people requiring preventive treatment worldwide. Recommendations for preventive chemotherapy strategies have been made by the World Health Organization (WHO) whereby the frequency of treatment is determined by the settings prevalence. Despite recent progress, many countries still need to scale up treatment and important questions remain regarding optimal control strategies. This paper presents a systematic review of the economic evaluations of human schistosomiasis interventions. A systematic review of the literature was conducted on 22nd August 2019 using the PubMed (MEDLINE) and ISI Web of Science electronic databases. The focus was economic evaluations of schistosomiasis interventions, such as cost-effectiveness and cost-benefit analyses. No date or language stipulations were applied to the searches. We identified 53 relevant health economic analyses of schistosomiasis interventions. Most studies related to followed by Several studies also included other NTDs. In Africa, most studies evaluated preventive chemotherapy, whereas in China they mostly evaluated programmes using a combination of interventions (such as chemotherapy, snail control and health education). There was wide variation in the methodology and epidemiological settings investigated. A range of effectiveness metrics were used by the different studies. Due to the variation across the identified studies, it was not possible to make definitive policy recommendations. Although, in general, the current WHO recommended preventive chemotherapy approach to control schistosomiasis was found to be cost-effective. This finding has important implications for policymakers, advocacy groups and potential funders. However, there are several important inconsistencies and research gaps (such as how the health benefits of interventions are quantified) that need to be addressed to identify the resources required to achieve schistosomiasis control and elimination.
PubMed: 32587899
DOI: 10.12688/wellcomeopenres.15754.2 -
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