The Impact of Black Sea Sand Treatment Effectively Reducing Different Type of Pain

Purpose: Low back pain (LBP), Gonarthrosis, knee, and Carpal Tunnel Syndrome have been regarded as affecting more than three-quarters’ of individuals in their lifetime. The aim of this study was conducted to determine and compare the effects of topical patients with sand compared with control related to Gonarthrosis, LBP, knee, and Carpal Tunnel Syndrome pain. Methods: This is a prospective case and control designed study based on 101 pain case with Sand and 101 control subjects. The interventional groups in addition either topical sand or without sand 2 months after the intervention were assessed. We assessed tolerability of an established pain perception scale by the Numeric Rating Scale (NRS). Categorical variables were compared using the chi-square (χ2) test. The paired t-test was used to compare the two groups before and after the intervention. One-way analysis of variance (ANOVA) was employed for comparison of several group means. Results: The study was based on 202 patients, 41 males (20.3%) and 161 females (79.7%). There were statistically significant differences between subjects with and without Sand in term of Gonarthrosis, Rheumatoid Arthritis LBP, knee, and Carpal Tunnel Syndrome pain (p = 0.033). Majority of patients were over age 55 years old (55%) and females 78 (77.2%). The mean score of total pain experience before and after the intervention was 7.41 ± 1.1 for black sand, and 4.24 ± 2.38 for without sand as control group. The mean scores of these 5 groups were highly significant before and after the intervention (p There was statistically highly significant in regarding subjects with Sand as compared with those before Sand after treatment mean score specifically with gonarthrosis before pain 7.23 ± 1.86 vs after treatment 4.54 ± 2.18 p < 0.001;rheumatoid arthritis before 8.28 ± 1.48 vs after treatment 4.80 ± 3.71 p < 0.001;Low Back Pain before 8.42 ± 1.83 vs after treatment 4.37 ± 1.52 p < 0.001;knee pain before 8.93 ± 0.89 vs after treatment 4.24 ± 0.24 p < 0.001;Carpal Tunnel Syndrome before 7.664 ± 1.04 vs after treatment 4.26 ± 1.03 p Conclusion: The current study has revealed that the topical treatments with sand could have a significant effect on the perception of pain compared to those in the control group with respect of gonarthrosis, rheumatoid arthritis, LBP, knee, and Carpal Tunnel Syndrome pain .

Physical fitness before and during the COVID-19 pandemic:Results of annual national physical fitness surveillance among 16,647,699 Japanese children and adolescents between 2013 and 2021

Background:Limited nationally representative evidence is available on temporal trends in physical fitness(PF)for children and adolescents during the coronavirus disease 2019(COVID-19)pandemic.The primary aim was to examine the temporal trends in PF for Japanese children and adolescents before and during the COVID-19 pandemic.The secondary aim was to estimate the concurrent trends in body size(measured as body mass and height)and movement behaviors(exercise,screen,and sleep time).Methods:Census PF data for children in Grade 5(aged 10-11 years)and adolescents in Grade 8(aged 13-14 years)were obtained for the years 2013-2021 from the National Survey of Physical Fitness,Athletic Performance,and Exercise Habits in Japan(n=16,647,699).PF and body size were objectively measured,and movement behaviors were self-reported.Using sample-weighted linear regression,temporal trends in mean PF were calculated before the pandemic(2013-2019)and during the pandemic(2019-2021)with adjustments for age,sex,body size,and exercise time.Results:When adjusted for age,sex,body size,and exercise time,there were significant declines in PF during the pandemic,with the largest declines observed in 20-m shuttle run(standardized(Cohen’s)effect size(ES)=-0.109 per annum(p.a.))and sit-ups performance(ES=-0.133p.a.).The magnitude of the declines in 20-m shuttle run and sit-ups performances were 18-and 15-fold larger,respectively,than the improvements seen before the pandemic(2013-2019),after adjusting for age,sex,body size,and exercise time.During the pandemic,both body mass and screen time significantly increased,and exercise time decreased.Conclusion:Declines in 20-m shuttle run and sit-ups performances suggest corresponding declines in population health during the COVID-19pandemic.

Parental transmission of type 2 diabetes mellitus in a highly endogamous population

AIM: To determine the parental transmission of diabetes mellitus (DM) and evaluate its influence on the clinical characteristics. METHODS: This was a cross sectional study. The survey was carried out in urban and semi-urban primary health care centers. Of the 2400 registered with diagnosed diabetes, 1980 agreed and gave their consent to take part in this study, thus giving a response rate of 82.5%. Face to face interviews were conducted using a structured questionnaire followed by laboratory tests. DM was defined according to the World Health Organization expert group. A trained nurse performedphysical examinations and measurements. RESULTS: Of the study population, 72.9% reported a family history of DM. Family history of DM was significantly higher in females (54.2%; P = 0.04) and in the age group below 30 years (24%; P < 0.001). The prevalence of diabetes was higher among patients with a diabetic mother (25.4% vs 22.1%) and maternal aunts/uncles (31.2% vs 22.2%) compared to patients with a diabetic father and paternal aunts/ uncles. Family history of DM was higher in patients of consanguineous parents (38.5%) than those of non-consanguineous parents (30.2%). The development of type 2 diabetes mellitus (T2DM) complications was higher in patients with either a paternal or maternal history of DM than in those without. No significant difference was observed in the metabolic characteristics of patients with/without family history of DM except for hypertension. Complications were higher in diabetic patients with a family history of DM. CONCLUSION: The present study found a significant maternal effect in transmission of T2DM. Family history is associated with the increased incidence of diabetes.

Comment on"Effect of exposure to ambient PM_(2.5) pollution on the risk of respiratory tract diseases:a meta-analysis of cohort studies"

Dear Editor,We reviewed the paper by Liu et al[1],as part of an umbrella review on PM2.5 and the incidence of respiratory outcomes.We determined that the authors did not account for the PM_(2.5) increments based upon which primary studies reported their results.

Effects of family history and consanguinity in primary immunodeficiency diseases in children in Qatar

Background: The high consanguinity in Middle East increases the risk of genetic diseases, including primary immunodeficiency diseases (PID). Objectives: This study was aimed at determining the rate of positive family history of PID, the overall rate and type of consanguinity, and their effects on delay age during diagnosis of PID. Materials and methods: A retrospective analysis was conducted on 131 children with PID (aged 0 - 14 years) managed at Hamad General Hospital during 1998-2012. Results: Data on 131 patients (75 males & 56 females) of 82 families was analyzed. The most common phenotype of PID was predominantly antibody deficiency (23.7%). The onset age was 24.01 months and delay age 18.7 months. Family history of PID was 66.4% (38.7% in predominantly antibody deficiency and 100% in diseases of immune dysregulation). Positive family history significantly (p = 0.004) reduced the delay age of PID diagnosis by 52.9%. The consanguinity rate was 61.1% (32.3% in the predominantly antibody ID to 96% in the phagocyte defects group), where paternal cousin ranked the highest type (57.5%). Conclusions: This study indicates that family history is common in children with PID and helpful in reducing the delay age. Consanguinity among families of affected children is also high (higher than healthy population). Paternal parallel cousin marriages are the most common type of consanguinity. For a practicing physician, family history is a simple and useful tool when suspecting PID in children. Primary prevention of PID in Middle East communities should consider consanguinity reduction through public awareness and education and premarital counseling programs.

The Impact of Aggressive Behaviour, Sleeping, and Fatigue on Road Traffic Crashes as Comparison between Minibus/Van/Pick-up and Commercial Taxi Drivers

No study has been conducted to determine the relationship between RTC （road traffic crashes） and depression, anxiety and stress scale （DASS-21）, tiredness, fatigues and sleeping. The aim of the present study was to examine the effect of aggressive driver behaviour, fatigue and sleeping on RTC comparison between commercial taxi and minibus/van/pick-up cars drivers. A cross-sectional study included a representative sample of 2,300 drivers of which 1,786 drivers （77.6%） agreed to participate. The Manchester DBQ （Driver Behaviour Questionnaire） was used to measure the aberrant driving behaviours leading to accidents. The study is based on the measurement using the depression anxiety stress scales （DASS-21）. Participants completed a DASS-21 questionnaire with items related to socio-demographic information, BMI （body mass index）, driving experience, fatigue, sleeping, adherence to traffic laws （including speed limits and wearing seat belt）, and drivers＇ driving records. Univariate and multivariate statistical analyses were performed. In a representative sampling, the age distribution of the participants ranged from 25 to 65 years with the mean age 38.3±10.2 and the mean annual mileage （km） per month was 14,587±1,741 （p 〈 0.001）. There was a significant difference found between both group minibus/van/pick-up and commercial taxi drivers regarding of their age group （p 〈 0.001）, education （p = 0.003）, history of accident （p = 0.003）, seat belt use （p = 0.022） time of accident （p = 0.005）; crossing red light （p 〈 0.001）, excessive speed limits （p = 0.002）, BMI group （p = 0.022）, physical activity （p = 0.003）, annual mileage in km （p 〈 0.001）, number of working days （p = 0.010） and hours （p = 0.030）; number of sleeping hours （p = 0.025）, CD music listening （p = 0.010）, mobile phone use （p = 0.001）, soft drinking （p = 0.002） and cigarette smoking habit （p 〈 0.001）. When the history of RTC was assessed, minibus/van/pick-ups were more likely to be involved in accidents compared to commercial taxi drivers and there was a highly statistically significant difference between both groups. Furthermore, minibus/van/pick-up drivers have more sleeping disorders and fatigue severity compared to commercial taxi drivers. This study revealed that minibus/van/pick-up drivers exhibited more depression, anxiety and stress symptoms compared to commercial taxi drivers. DASS-21 variables were found to contribute significantly to the explanation of the RTC involvement rate. Chronic fatigue and acute sleepiness, and overtime or heavy work-load on car drivers significantly increases the risk of a car crash which a car occupant can be injured or killed. Reductions in RTC may be achieved if fewer people drive when they have fatigue or are sleepy or have been deprived of sleep or drive during rush hours.

Increasing our return on investment in science:Start with better behavior

In August of 2022,I gave the opening keynote address at the 5th North American Congress on Biomechanics,in Ottawa,Canada.The topic of my talk was about whether the research ecosystem was getting a reasonable return on its investment in biomedical research.I provided several examples as to why I posed this question.

胸腺恶性肿瘤预后的标准评估方法

胸腺恶性肿瘤相对少见，发病率约2.5-3.2/100万[1,2]，病例也分散在各个医疗中心。现有文献几乎都是单中心的回顾性研究，为获得足够的病例，研究时间往往跨度几十年，报道结果的方式和使用的定义也各不相同，不同的研究结果很难比较。加之胸腺恶性肿瘤的进展、复发模式及致死原因等都具有其一定的特殊性，如何报道其结局显得十分重要。由于胸腺恶性肿瘤患者数量相对有限，从现有的经验中收集信息较为困难，而且存在过度描述和错误结论的风险。因此，专业胸腺肿瘤学术组织（International Thymic Malignacy Interest Group, ITMIG）对临床试验结果的报告制定了一套标准，已被该组织承担的合作项目采用。该标准的广泛应用将增强不同研究结果的可比性。只有采用统一的定义和规范的结果报告，胸腺肿瘤研究才能取得重要进展。2010年以前由外科医生、肿瘤内科医生和统计学家组成的小组共同回顾已有文献使用的评估方法形成初步的建议，再经过一个扩展小组审查，并最终将提炼的建议分发给所有ITMIG成员进行进一步讨论。最后在2010年5月6日的纽约年会上得到ITMIG的认可并被采用。本文就ITMIG标准作一综述。

Association between psychological distress and gastrointestinal symptoms in diabetes mellitus

AIM:To examine the possible association between gastrointestinal symptoms and anxiety and depression in type 2 diabetes mellitus(T2DM).METHODS:The study was a matched case-control study based on a face to face interview with designed diagnostic screening questionnaires for gastrointestinal(GI) symptoms and T2DM,Patient Health Questionnaire(PHQ-9) for depression and General Anxiety Disorders(GAD-7) for anxiety.The questionnaire consisted of questions about symptoms and signs of anxiety and depression disorders.Also,socio-demographic characteristics,life style habits and the family history of patients were collected.It was carried out from June 2010 to May 2011 among Qatari and other Arab nationals over 20 years of age at Primary Health Care Centers of the Supreme Council of Health,Qatar,including patients with diabetes mellitus and healthy subjects over 20 years of age.RESULTS:In the studied sample,most of the studied T2DM patients with GI symptoms(39.3%) and healthy subjects(33.3%) were in the age group 45-54 years(P < 0.001).The prevalence of severe depression(9.5% vs 4.4%,P < 0.001) and anxiety(26.3% vs 13.7%,P < 0.001) was significantly higher in T2DM patients with GI symptoms than in general population.Obesity(35.7% vs 31.2%) and being overweight(47.9% vs 42.8%) were significantly higher in T2DM patients with GI symptoms than in healthy subjects(P = 0.001).Mental health severity score was higher in T2DM patients with GI symptoms than in healthy subjects;depression(8.2 ± 3.7 vs 6.0 ± 3.6) and anxiety(7.6 ± 3.3 vs 6.0 ± 3.7).The most significant GI symptom which was considerably different from controls was early satiety [odds ratio(OR) = 10.8,P = 0.009] in depressed T2DM patients and loose/watery stools(OR = 2.79,P = 0.029) for severe anxiety.Anxiety was observed more than depression in T2DM patients with GI symptoms.CONCLUSION:Gastrointestinal symptoms were significantly associated with depression and anxiety in T2DM patients,especially anxiety disorders.

Aetiology of extracranial carotid free-floating thrombus in a prospective multicentre cohort

Background Carotid free-floating thrombi(FFT)in patients with acute transient ischaemic attack(TIA)/stroke have a high risk of early recurrent stroke.Management depends on aetiology,which can include local plaque rupture,dissection,coagulopathy,malignancy and cardioembolism.Our objectives were to classify the underlying aetiology of FFT and to estimate the proportion of patients with underlying stenosis requiring revascularisation.Methods We prospectively enrolled consecutive patients presenting to three comprehensive stroke centres with acute TIA/stroke and ipsilateral internal carotid artery FFT.The aetiology of FFT was classified as:carotid atherosclerotic disease,carotid dissection,cardioembolism,both carotid atherosclerosis and cardioembolism,or embolic stroke of uncertain source(ESUS).Patients with carotid atherosclerosis were further subclassified as having≥50%or<50%stenosis.Results We enrolled 83 patients with confirmed FFT.Aetiological assessments revealed 66/83(79.5%)had carotid atherosclerotic plaque,4/83(4.8%)had a carotid dissection,10/83(12%)had both atrial fibrillation and carotid atherosclerotic plaque and 3/83(3.6%)were classified as ESUS.Of the 76 patients with atherosclerotic plaque(including those with atrial fibrillation),40(52.6%)had≥50%ipsilateral stenosis.Conclusions The majority of symptomatic carotid artery FFT are likely caused by local plaque rupture,more than half of which are associated with moderate to severe carotid stenosis requiring revascularisation.However,a significant number of FFTs are caused by non-atherosclerotic mechanisms warranting additional investigations.

An exploration of the relationship between wastewater viral signals and COVID-19 hospitalizations in Ottawa,Canada

Monitoring of viral signal in wastewater is considered a useful tool for monitoring the burden of COVID-19,especially during times of limited availability in testing.Studies have shown that COVID-19 hospitalizations are highly correlated with wastewater viral signals and the increases in wastewater viral signals can provide an early warning for increasing hospital admissions.The association is likely nonlinear and time-varying.This project employs a distributed lag nonlinear model(DLNM)(Gasparrini et al.,2010)to study the nonlinear exposure-response delayed association of the COVID-19 hospitalizations and SARS-CoV-2 wastewater viral signals using relevant data from Ottawa,Canada.We consider up to a 15-day time lag from the average of SARS-CoV N1 and N2 gene concen-trations to COVID-19 hospitalizations.The expected reduction in hospitalization is adjusted for vaccination efforts.A correlation analysis of the data verifies that COVID-19 hospital-izations are highly correlated with wastewater viral signals with a time-varying rela-tionship.Our DLNM based analysis yields a reasonable estimate of COVID-19 hospitalizations and enhances our understanding of the association of COVID-19 hospi-talizations with wastewater viral signals.

Clinico-Radiological Correlation in Children with Ataxia Telangiectasia in Qatar

Introduction: Ataxia telangiectasia (AT) is a rare disease characterized by immunodeficiency and neurological manifestations. Ataxia, resulting from cerebella atrophy, runs a progressive incapacitating course. Clinical monitoring of the disease course is mandatory for early treatment. Aim: To study clinical severity of AT and correlate it with the degree of cerebellar atrophy. Patients and Methods: We retrospectively studied all children (less than 14 years) with AT seen at Hamad General Hospital Clinics between 1998-2013. We collected basic demographic data, parental consan-guinity, family history, AT clinical severity scores, and reviewed CBC with differential counts;alpha-fetoprotein, serum immunoglobulins and lymphocyte subsets. Cranial MRI scans of each subject were reviewed by a neuroradiologist. Cerebellar atrophy was visually and semi-quantitatively scored. Results: We analyzed data on 18 AT children (10 males and 8 females), mean age of 76.9 months. 77.8% had a positive family history of AT and 41.7% parental consanguinity. Lymphopenia was observed in 77.8% and high serum alpha-fetoprotein in 87.5% of children. Clinical severity of ataxia was 17.1 ± 8.4 (mean ± SD);86.7% of patients were moderate-severe. MRI cerebellar atrophy score was 1.9 ± 1.3 (mean ± SD), and moderate in 51% of patients. AT clinical severity score correlated (coefficient r = 0.566) but not statistically significant p = 0.088) with MRI cerebellar atrophy scores. Conclusions: Moderate to severe ataxia and marked cerebellar atrophy are quite common in AT children. There is a correlation between AT clinical severity and cerebellar atrophy. Larger prospective studies might further determine the significance of our observations and help practicing practitioners monitor the progression of the disease.

大脑栓子是阿尔茨海默病和血管性痴呆的潜在病因:病例对照研究

目的:比较阿尔茨海默病或血管性痴呆患者与无痴呆对照者之间自发性大脑栓子和静脉-动脉循环分流的发生率。设计:横断面病例对照研究。机构:曼彻斯特的老年精神病二级护理服务中心。

Three Gorges Dam:the changing trend of snail density in the Yangtze River basin between 1990 and 2019

Background The area of Oncomelania hupensis snail remains around 3.6 billion m^(2),with newly emerging and reemergent habitats continuing to appear in recent years.This study aimed to explore the long-term dynamics of snail density before and after the operation of Three Gorges Dam(TGD).Methods Data of snail survey between 1990 and 2019 were collected from electronic databases and national schistosomiasis surveillance.Meta-analysis was conducted to estimate the snail density.Joinpoint model was used to identify the changing trend and inflection point.Inverse distance weighted interpolation(IDW)was used to determine the spatial distribution of recent snail density.Results A total of 3777 snail survey sites with a precise location of village or beach were identified.For the downstream area,snail density peaked in 1998(1.635/0.11 m^(2),95%CI:1.220,2.189)and fluctuated at a relatively high level before 2003,then declined steadily from 2003 to 2012.Snail density maintained lower than 0.150/0.11 m^(2) between 2012 and 2019.Joinpoint model identified the inflection of 2003,and a significant decreasing trend from 2003 to 2012 with an annual percentage change(APC)being−20.56%(95%CI:−24.15,−16.80).For the upstream area,snail density peaked in 2005(0.760/0.11 m^(2),95%CI:0.479,1.207)and was generally greater than 0.300/0.11 m2 before 2005.Snail density was generally lower than 0.150/0.11 m^(2) after 2011.Snail density showed a significant decreasing trend from 1990 to 2019 with an APC being−6.05%(95%CI:−7.97,−7.09),and no inflection was identified.IDW showed the areas with a high snail density existed in Poyang Lake,Dongting Lake,Jianghan Plain,and the Anhui branch of the Yangtze River between 2015 and 2019.Conclusions Snail density exhibited a fluctuating downward trend in the Yangtze River basin.In the downstream area,the operation of TGD accelerated the decline of snail density during the first decade period,then snail density fluctuated at a relatively low level.There still exists local areas with a high snail density.Long-term control and monitoring of snails need to be insisted on and strengthened.

Uptake of Heterologous or Homologous COVID-19 Booster Dose and Related Adverse Events Among Diabetic Patients:A Multicenter Cross-Sectional Study—China,2022

Summary What is already known about this topic?Although a third coronavirus disease 2019(COVID-19)vaccination(booster)dose is highly recommended for diabetic patients,the vaccination behaviors and related adverse events are unclear among diabetic patients with a COVID-19 booster dose.What is added by this report?Diabetic patients with higher postprandial blood glucose,worrying about the safety of the booster dose were less likely to get the vaccine.

A Bayesian model calibration framework for stochastic compartmental models with both time-varying and timeinvariant parameters

We consider state and parameter estimation for compartmental models having both timevarying and time-invariant parameters.In this manuscript,we first detail a general Bayesian computational framework as a continuation of our previous work.Subsequently,this framework is specifically tailored to the susceptible-infectious-removed(SIR)model which describes a basic mechanism for the spread of infectious diseases through a system of coupled nonlinear differential equations.The SIR model consists of three states,namely,the susceptible,infectious,and removed compartments.The coupling among these states is controlled by two parameters,the infection rate and the recovery rate.The simplicity of the SIR model and similar compartmental models make them applicable to many classes of infectious diseases.However,the combined assumption of a deterministic model and time-invariance among the model parameters are two significant impediments which critically limit their use for long-term predictions.The tendency of certain model parameters to vary in time due to seasonal trends,non-pharmaceutical interventions,and other random effects necessitates a model that structurally permits the incorporation of such time-varying effects.Complementary to this,is the need for a robust mechanism for the estimation of the parameters of the resulting model from data.To this end,we consider an augmented state vector,which appends the time-varying parameters to the original system states whereby the time evolution of the time-varying parameters are driven by an artificial noise process in a standard manner.Distinguishing between time-varying and time-invariant parameters in this fashion limits the introduction of artificial dynamics into the system,and provides a robust,fully Bayesian approach for estimating the timeinvariant system parameters as well as the elements of the process noise covariance matrix.This computational framework is implemented by leveraging the robustness of the Markov chain Monte Carlo algorithm permits the estimation of time-invariant parameters while nested nonlinear filters concurrently perform the joint estimation of the system states and time-varying parameters.We demonstrate performance of the framework by first considering a series of examples using synthetic data,followed by an exposition on public health data collected in the province of Ontario.

Impact of meteorological factors on the incidence of childhood hand,foot,and mouth disease(HFMD)analyzed by DLNMs-based time series approach

Background:Hand,foot,and mouth disease(HFMD)has become an emerging infectious disease in China in the last decade.There has been evidence that meteorological factors can influence the HFMD incidence,and understanding the mechanisms can help prevent and control HFMD.Methods:HFMD incidence data and meteorological data in Minhang District,Shanghai were obtained for the period between 2009 and 2015.Distributed lag non-linear models(DLNMs)were utilized to investigate the impact of meteorological factors on HFMD incidence after adjusting for potential confounders of long time trend,weekdays and holidays.Results:There was a non-linear relationship between temperature and HFMD incidence,the RR of 5th percentile compared to the median is 0.836(95%CI:0.671-1.042)and the RR of 95th percentile is 2.225(95%CI:1.774-2.792),and the effect of temperature varied across age groups.HFMD incidence increased with increasing average relative humidity(%)(RR=1.009,95%CI:1.005-1.015)and wind speed(m/s)(RR=1.197,95%CI:1.118-1.282),and with decreasing daily rainfall(mm)(RR=0.992,95%CI:0.987-0.997)and sunshine hours(h)(RR=0.966,95%CI:0.951-0.980).Conclusions:There were significant relationships between meteorological factors and childhood HFMD incidence in Minhang District,Shanghai.This information can help local health agencies develop strategies for the control and prevention of HFMD under specific climatic conditions.

Avian influenza viruses(AIVs) H9N2 are in the course of reassorting into novel AIVs

In 2013, two episodes of influenza emerged in China and caused worldwide concern. A new H7N9 avian influenza virus （AIV） first appeared in China on February 19, 2013. By August 31, 2013, the virus had spread to ten provinces and two metropolitan cities. Of 134 patients with H7N9 influenza, 45 died （Chen et al., 2013; Li et al., 2014）.From then on, epidemics emerged sporadically in China and resulted in several victims.

The Three Gorges Dam:Does it accelerate or delay the progress towards eliminating transmission of schistosomiasis in China?

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 94208 in 2002 to 59200 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.

Spatial distribution and habitat suitability of Biomphalaria straminea,intermediate host of Schistosoma mansoni,in Guangdong,China

Background:Biomphalaria straminea is an invasive vector in China,posing a significant threat to public health.Understanding the factors affecting the establishment of this snail is crucial to improve our ability to manage its dispersal and potential risk of schistosomiasis transmission.This study sought to determine the spatial distribution of B.straminea in China's Mainland and whether environmental factors were divergent between places with and without B.straminea.Methods:A malacological survey of B.straminea was conducted in Guangdong Province,China.Snails were identified using anatomical keys.Water and sediment samples were taken,and their physicochemical properties were analyzed using national standard methods.Landscape and climatic variables were also collected for each site.We compared the environmental characteristics between sites with and without B.straminea using Mann-Whitney U test.We further used generalized linear mixed models to account for seasonal effects.Results:B.straminea was found at six sites,including one in Dongguan and five in Shenzhen.Probability map found a hot spot of B.straminea distribution at Shenzhen and Hong Kong.Sites occupied by B.straminea were characterized by higher median altitude,mean annual precipitation and moderate temperature.Water with snails had higher median concentrations of total nitrogen,nitrate and nitrites,ammoniacal nitrogen,calcium,zinc and manganese but lower dissolved oxygen and magnesium.Sediments with snails had higher median copper,zinc and manganese.B.straminea was associated with maximum temperature of the warmest month(pMCMC<0.001)and sediment zinc(pMCMC<0.001).Conclusions:B.straminea is distributed in Shenzhen and its surrounding areas in Guangdong,China.Sites with and without B.straminea differed in the maximum temperature of the warmest month and sediment zinc.Surveillance should be continued to monitor the dispersal of this snail in China.