Efficacy and side effects of praziquantel in the treatment of Schistosomiasis mansoni in schoolchildren in Shesha Kekele Elementary School,Wondo Genet,Southern Ethiopia

Objective:To evaluate the efficacy and side effects of praziquantel(PZQ) in the treatment of schistosomiasis in Ethiopia.Methods:In a cross-sectional study,stool specimens were collected from randomly selected 299 school children in Shesha Kekele Elementary School,Wondo Genet, Southern Ethiopia,in April 2010.Stool specimens were examined using a single Kato-Katz thick smear for Schistosoma mansoni(5.mansoni) ova.Children who were found positive for S.mansoni were treated with a single oral dose of PZQ at 40 mg/kg bw and interviewed for treatment-related symptoms 24 hours after drug administration.Four weeks post-treatment,stool specimens were collected from the same children and examined following the same procedure as in the pretreatment.Drug efficacy was determined based on cure and egg reduction rates.Results:Pretreatment prevalence of S.mansoni infection was 74.9%with geometric mean egg count of 268. The evaluated generic PZQ produced an overall cure rate of 73.6%(P<0.000 1,OR:8.33,CI:5.3-13.1) and egg reduction rate of 68.2%(P=0.03,F=0.64).The cure rate showed significant association with age(x^2=H,P=0.004),the highest rate being observed in the 15-22 age group.83%of S. mansoni infected children showed various treatment-related symptoms,the most frerjiient being headache,nausea,and abdominal pain.These symptoms were associated with age(P<0.001) and pre-treatment intensity of infection(P<0.05).Conclusions:The present observations revealed relatively lower cure and egg reduction rates of the PZQ evaluated as compared to previous reports for other PZQ brands in Ethiopia.Hence,in depth studies are recommended to clarify whether the present relatively lower cure rate is the actual cure rate of the praziquantel evaluated,treatment failure,or reduced susceptibility of the parasite.Treatment-related side effects observed were transient and tolerable.

Effects of albendazole,artesunate,praziquantel and miltefosine,on Opisthorchis viverrini cercariae and mature metacercariae

Objective:To explore larvicidal effects of anthelmintic drugs on Opisthorchis viverrini(O.viverrini) for alternative approach to interrupting its cycle for developing a field-based control program.Methods:The larvicidal activities of albendazole(A1),artesunate(Ar),praziquantel(Pzq) and miltefosine(Mf) on O.viverrini cercariae and mature metacercariae were investigated.Lethal concentrations(LC_(50) and LC_(95)) of these drugs were determined.Mature metacercariae previously exposed to various concentrations of the drugs were administered to hamsters.Worms were harvested 30 d post infection and worm recovery rates calculated.Al,Ar,Pzq and Mf produced morphological degeneration and induced shedding tails of cercariae after 24 h exposure.Results:The LC_(50) and LC_(95) of Al,Ar,Pzq and Mf on cercariae were 0.720 and 1.139,0.350 and 0.861,0.017 and 0.693,and 0.530 and 1.134 ppm,respectively.LC_(50) and LC_(95) of Ar on mature metacercariae were 303.643 and 446.237 ppm and of Mf were 289.711 and 631.781 ppm,respectively but no lethal effect in Pzq-and Al-treated groups(up to 1 ppt).No worms were found in hamsters administered Pzq-treated metacercariae.The adult worms from Al-treated metacercariae were significantly bigger in size compared to the control group(P<0.05).Fecundity and body width were greater in adults from Mf-treated metacercariae compared to the control group(P<0.05).Conclusions:The larvicidal effects of these drugs were high efficacy to O.viverrini cercariae but lesser efficacy to metacercariae.It should be further studied with the eventual aim of developing a field-based control program.

Schistosomiasis control in Senegal:results from community data analysis for optimizing preventive chemotherapy intervention with praziquantel

Background Over the past two decades,preventive chemotherapy(PC)with praziquantel(PZQ)is the major strategy for controlling schistosomiasis in Senegal.The objective of this analysis was to update the endemicity of schistosomiasis at community level for better targeting mass treatment with PZQ in Senegal.Methods Demographic and epidemiological data from 1610 community health areas were analyzed using the schistosomiasis community data analysis tool of Expanded Special Project for Elimination of Neglected Tropical Diseases which developed by World Health Organization/Africa Ofce(WHO/AFRO).The tool uses a WHO/AFRO decision tree for areas without epidemiological data to determine whether mass treatment should be continued at community level.Descriptive analysis was performed.Results Overall,the endemicity of 1610 community health areas were updated based on the data from the district endemicity(33.5%)and the form of Join request for selected PC medicine(40.5%).Up to 282(17.5%)and 398(24.7%)of community health areas were classifed as moderate and high endemicity.41.1%of communities were non endemic.High endemicity was more important in Tambacounda,Saint Louis,Matam,Louga and Kedougou.A change in endemicity category was observed when data was disagregted from district level to community level.Implementation units classifed non endemic were more important at community level(n=666)compared to district level(n=324).Among 540 areas previously classifed high endemic at district level,392(72.6%)remained high prevalence category,while 92(17.0%)became moderate,43(8.0%)low and 13(2.4%)non-endemics at community level.Number of implementation units requiring PC was more important at district level(1286)compared to community level(944).Number of school aged children requiring treatment was also more important at district level compared to community level.Conclusions The analysis to disaggregate data from district level to community level using the WHO/AFRO schistosomiasis sub-district data optimization tool provide an update of schistosomiasis endemicity at community level.This study has allowed to better target schistosomiasis interventions,optimize use of available PZQ and exposed data gaps.

Artesunate Effect on Schistosome Thioredoxin Glutathione Reductase and Cytochrome c Peroxidase as New Molecular Targets in Schistosoma mansoni-infected Mice

Objective To investigate the possible effect of artesunate （ART） on schistosome thioredoxin glutathione reductase （TGR） and cytochrome c peroxidase （CcP） in Schistosoma mansoni-infected mice. Methods A total of 200 laboratory bred male Swiss albino mice were divided into 4 groups （50 mice in each group）. Group I： infected untreated group （Control group） received a vehicle of 1% sodium carbonyl methylcellulose （CMC-Na）; Group II： infected then treated with artesunate; Group III infected then treated with praziquantel, and group IV： infected then treated with artesunate then praziquantel. Adult S. mansoni worms were collected by Animal Perfusion Method, tissue egg counted, TGR, and CcP mRNA Expression were estimated of in $. mansoni adult worms by semi-quantitative rt-PCR. Results Semi-quantitative rt-PCR values revealed that treatment with artesunate caused significant decrease in expression of schistosome TGR and CcP in comparison to the untreated group. In contrast, the treatment with praziquantel did not cause significant change in expression of these genes. The results showed more reduction in total worm and female worm count in combined ART-PZQ treated group than in monotherapy treated groups by either ART or PZO, Moreover, complete disappearance （100%） of tissue eggs was recorded in ART-PZQ treated group with a respective reduction rate of 95.9% and 68.4% in ART- and PZQ-treated groups. Conclusion The current study elucidated for the first time that anti-schistosomal mechanisms of artesunate is mediated via reduction in expression of schistosome TGR and CcP. Linking these findings, addition of artesunate to praziquantel could achieve complete cure outcome in treatment of schistosomiasis.

Controlling schistosomiasis with praziquantel:How much longer without a viable alternative?

The current approach of morbidity control of schistosomiasis,a helminth disease of poverty with considerable public health and socioeconomic impact,is based on preventive chemotherapy with praziquantel.There is a pressing need for new drugs against this disease whose control entirely depends on this single drug that has been widely used over the past 40 years.We argue that a broader anthelminthic approach supplementing praziquantel with new antischistosomals targeting different parasite development stages would not only increase efficacy but also reduce the risk for drug resistance.Repositioning drugs already approved for other diseases provides a shortcut to clinical trials,as it is expected that such drugs rapidly pass the regulatory authorities.The antischistosomal properties of antimalarial drugs(e.g.,semisynthetic artemisinins,synthetic trioxolanes,trioxaquines and mefloquine)and of drugs being developed or registered for other purposes(e.g.,moxidectin and miltefosin),administered alone or in combination with praziquantel,have been tested in the laboratory and clinical trials.Another avenue to follow is the continued search for new antischistosomal properties in plants.Here,we summarise recent progress made in schistosomiasis chemotherapy,placing particular emphasis on repositioning of existing drugs against schistosomiasis.

Effect of Chinese herbal compound on liver fibrosis in rabbits with schistosomiasis by B-ultrasound

Objective: To explore the value of B-ultrasound on the evaluation of the effects of traditional Chinese medicine compound of Radix astragali , Salvia miltiorrhiza and Angelica sinensis , and TCM + praziquantel on liver fibrosis in rabbits with schistosomiasis. Methods: The hepatic fibrosis model in rabbits with schistosomiasis was established. The experimental animals (24 rabbits) were randomly divided into four groups (group A, B, C and D, n =6). Group A (control group) was only treated by praziquantel; Group B was treated by mixture of Radix astragali and Salvia miltiorrhiza + praziquantel; Group C was treated by mixture of Radix astragali and Angelica sinensis + praziquantel; Group D was treated by mixture of Radix astragali, Salvia miltiorrhiza and Angelica sinensis + praziquantel. Then B-ultrasonogram was used to evaluate the effects. Results: Each group showed certain curative effect on liver fibrosis in rabbits with schistosomiasis. The efficacy of group B, C and D was better than group A, and that of group D was the best. The differences in long diameter, thickness diameter, transverse diameter and portal vein inner diameter of liver before and after treatment were statistically significant ( P <0.05). The liver function indexes and liver fibrosis indexes were significantly improved after treatment ( P <0.05). Conclusions: The mixture of Radix astragali, Salvia miltiorrhiza and Angelica sinensis combined with Western medicine treatment can obviously improve the efficacy on liver fibrosis of schistosomiasis.

Factors associated with coverage of praziquantel for schistosomiasis control in the communitydirect intervention (CDI) approach in Mali (West Africa)

Background:Despite the progress made in the control of Neglected Tropical Diseases(NTD),schistosome and soil-transmitted helminth infections are far from being effectively managed in many parts of the world.Chemotherapy,the key element of all control strategies,is faced with some difficulties in terms of access to treatment.Our study aims to describe the factors involved in the success or failure of the community-directed intervention(CDI)approach through control programmes,which aims to achieve consistent high coverage at affordable and sustainable costs in endemic areas.Methods:The CDI approach was carried out from December 2007 to October 2008 in ten villages of the district of Diéma,Mali.At inclusion,each child part of the study’s sample was interviewed and submitted for a physical examination.The study focused on:data collection,treatment of the eligible population,evaluation of the treatment coverage,performance of community drug distributors(CDDs),and the involvement and perception of populations.Results:A total of 8,022 eligible people were studied with a mean coverage rate of 76.7%.Using multiple regression,it was determined that receiving praziquantel as treatment was associated with five factors:belonging to the Fulani or Moorish ethnic minority versus the Bambara/Soninke,use of the central versus the house-to-house drug distribution mode,the ratio of the population to the number of CDDs,the lack of supervision and belonging to the age group of 15 years or above(p<0.05).As well as that,it was found that the presence of parallel community-based programmes(HIV,tuberculosis)that provide financial incentives for community members discouraged many CDDs(who in most cases are volunteers)to participate in the CDI approach due to a lack of incentives.Conclusions:The findings indicate that the success of the CDI approach depends on,amongst other things,the personal characteristics of the respondents,as well as on community factors.

Developing a comprehensive response for treatment of children under 6 years of age with schistosomiasis:research and development of a pediatric formulation of praziquantel

Schistosomiasis is a parasitic disease caused by blood flukes.The disease is caused by an inflammatory reaction to parasite eggs retained in the liver,bladder and reproductive organs.According to 2017 World Health Organization(WHO)estimates 220 million people are potentially infected,from which probably 10%are children under 6 years of age.The regular treatment approach of a single,oral dose of 40 mg/kg body weight with praziquantel however,is difficult for children under the age of 6,leaving them without a treatment option.In order to address this important gap in treatment target populations,an international public-private partnership that works on a not-for-profit basis in the field of drug research and development for schistosomiasis was established in 2012.This is called the Pediatric Praziquantel Consortium.Its mission was and continues to be to develop,register and provide access to a suitable pediatric praziquantel formulation for treating schistosomiasis in preschool-age children(3-6 months up to 6 years).The Target Product Profile for the pediatric formulation of praziquantel that would be suitable to treat children as young as 3-6 months was then defined by a group of experts,including members from the Pediatric Praziquantel Consortium partner organizations as well as experts from WHO(as observer)and schistosomiasis endemic countries.The development of the drug is ongoing and the Pediatric Praziquantel Consortium aims to submit the regulatory dossier for marketing approval in endemic countries and WHO prequalification in 2018/19 with approval and product launch for schistosomiasis pediatric case management in key endemic countries in 2019.Ultimately,the goal is for the product to be considered for a large-scale mass distribution program by 2022.

Comparative Study of the Impact of Climate Variability on Prevalence of Urinary Schistosomiasis： Cases at Sunyani Regional Hospital and among School Children in Atronie, Sunyani

A study has been conducted to determine the impact of climate variability on Schistosoma haematobium infection among patients and school children in Sunyani between 2006 and 2009. Urine samples from the subjects were collected and examined in the laboratory using the Filteration technique for the detection and quantification ofSchistosoma haematobium eggs. The prevalence rate of urinary schistosomiasis at the Sunyani Regional Hospital for 2006, 2007, 2008 and 2009 were found to be 0.24%, 0.55%, 0.55% and 0.75% respectively while that for Methodist Junior High School in 2008 and 2009 were 60.1% and 60.3% respectively. A decrease in the relative humidity and average annual rainfall were identified as factors contributory to the increase in urinary schistosomiasis prevalence rate. The temperature values obtained throughout the study period did not have any significant effect on the prevalence rate. The temperature values, however, were those that enhanced cercarial incubation （15-35 ℃） with a resultant increase in shedding of cercariae leading to more infections among water contacts. The infection rate due to the stream Amama was 20.1%, while that due to river Tano was 36.6%. The highest risk group was children aged 15-19 years. Praziquantel was administered to treat the infection, producing a cure rate of 93%. Recognition of urinary schistosomiasis as a public health problem in Ghana is the main challenge to prevention and control of the disease.

Epidemiology of pediatric schistosomiasis in hard-to-reach areas and populations:a scoping review

Background Schistosomiasis affects over 250 million people worldwide.Despite children and the poor being key risk groups,limited research and control activities target pre-school aged children(PSAC)and hard-to-reach populations.As endemic countries shift the goals of their schistosomiasis programs from morbidity control to disease elimination,there is a need for inclusive planning to cover all affected age groups from all geographical areas and populations to achieve sustainable impact and health equity.Methods We conducted searches in MEDLINE,Web of Science,Embase(Ovid),and LILACS per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses—Extension for Scoping Reviews(PRISMA-ScR)guidelines.Quality assessment of identified articles was done using the Joanna Briggs Institute Prevalence Critical Appraisal Tool.Relevant study data were extracted from the articles and entered into Microsoft Excel 2016 for descriptive analysis.Results From the 17,179 screened articles,we identified 13 eligible studies on schistosomiasis in PSAC living in hard-to-reach areas and populations.All identified studies were from sub-Saharan Africa.The mean sample size of the retained studies was 572,with a balanced sex distribution among the young children sampled in each study.Ten studies investigated Schistosoma mansoni,one investigated Schistosoma haematobium,while two covered both S.mansoni and S.haematobium in the target population.The prevalence of S.mansoni among PSAC in the included studies was estimated at 12.9%in Ghana,80.3–90.5%in Kenya,35.0%in Madagascar,9.6–78.0%in Senegal,11.2–35.4%in Sierra Leone,44.4–54.9%in Tanzania and 39.3–74.9%in Uganda.Out of the three studies that investigated S.haematobium,the presence of the infection was reported in only one study carried out in Nigeria.Schistosome infections reported in nearly all studies included in this review were of light intensity.Only one study conducted in Nigeria documented visible hematuria in 17.7%of the PSAC studied.Conclusions The findings document the high prevalence of schistosomiasis among PSAC in hard-to-reach populations and underscore the need to consider this population subgroup when designing the expansion of preventive chemotherapy and schistosomiasis control activities.

Efficacy of praziquantel in the treatment of Schistosoma haematobium infection among school-age children in rural communities of Abeokuta, Nigeria

Background:Chemotherapy with praziquantel(PZQ)has been the cornerstone of schistosomiasis control over the last two decades.Being the only available drug for the treatment of over 200 million people worldwide,continuous monitoring of PZQ efficacy under the pressure of widespread use is therefore advocated.Methods:The efficacy of taking two doses of oral PZQ for the treatment of Schistosoma haematobium was examined among school children in Nigeria.Urine specimens were collected from 350 school children and examined using the filtration technique.Blood was collected for packed cell volume(PCV)estimation,and the weight and height of each child were estimated.S.haematobium egg positive pupils were treated with two oral doses of PZQ at 40 mg/kg with a four-week interval in between.Drug efficacy was determined based on the egg reduction rate(ERR).Results:Among 350 school children,245(70.0%)-of which 132 were males and 113 were females,with an age range of 4 to 15 years-were diagnosed with S.haematobium.All the 245 infected children received a single oral dose of 40 mg/kg PZQ twice with a four-week interval in between and were followed up for 12 weeks.At four,eight and twelve weeks post treatment,the ERR was 57.1%,77.6%and 100%,respectively.The ERR was significantly higher among the children with a light infection compared to those with a heavy infection.One hundred and twenty-one children were egg negative at four weeks post treatment,among which 1(6.3)and 120(52.4%)had heavy and light infections,respectively.Following the second round of treatment,the cure rate at eight weeks and twelve weeks was 85.3%and 100%,respectively.Conclusion:This study demonstrated the efficacy of taking two doses of oral PZQ for the treatment of urinary schistosomiasis among school children in Nigeria.

Putting the treatment of paediatric schistosomiasis into context

Despite increased international efforts to control schistosomiasis using preventive chemotherapy,several challenges still exist in reaching the target populations.Until recently,preschool-aged children had been excluded from the recommended target population for mass drug administration,i.e.primary school children aged 6-15 years.Our studies and those of others provided the evidence base for the need to treat preschool-aged children that led to recommendations by the World Health Organization to include preschool-aged children in treatment programmes in 2010.The major challenge now lies in the unavailability of a child-size formulation of the appropriate anthelmintic drug,praziquantel.The currently available formulation of praziquantel presents several problems.First,it is a large tablet,making it difficult for young children and infants to swallow it and thus requires its breaking/crushing to allow for safe uptake.Second,it is bitter so it is often mixed with a sweetener to make it palatable for young children.Third,the current formulation of 600 mg does not allow for flexible dose adjustments for this age group.Thus,there is a need to formulate a child-appropriate praziquantel tablet.This paper discusses the target product profile for paediatric praziquantel,as well as knowledge gaps pertinent to the successful control of schistosome infection and disease in preschool-aged children.

A novel and effective hyperthermia method for Schistosomiasis japonica prevention and treatment

The emerging resistance to schistosoma has been paid much attention and is in urgent need for a novel strategy to control the prevalent parasitic zoonosis. In this study, the efficiency of hyperthermia therapy was investigated by the skin hyperthermia device. The survival rate of cercariae decreased from 68.15 % （37 ℃, 5 min） to 0 （49℃, 10 min） with the thermal dosages increased, which proved the preventing effect of hyperthermia therapy （P 〈 0.05）. Therapeutic effects were assessed in Schistosoma japonicum-infected BALB/c mice. When the cercarial contact region of the skin was treated at 45-49℃ for 5 min within 8 h of infection, worm reduction rate （WRR） reached 74 %-83 % （P 〈 0.01）. The sensitivity of adult schistosoma to heat was also investigated using microwave intraperitoneal hyperthermia （thermal dosages 42-43℃, 20 min）. The WRR, hepatic shift rates and egg reduction rates were 23.7 %, 40 % and 30 %, respectively, comparing with 80.2 %, 59.6 % and 53.9 % of praziquantel （PZQ）-treated group. Encouraging results have been obtained that hyperthermia can effectively kill schistosomula, especially with the appearance of cercarial dermatitis, while PZQ lacks efficacy against the cercariae. Thus, hyperthermia therapy would show significant benefit in preventing and treatment of schistosoma, especially in the early stage.

A 12-year follow-up of intestinal schistosomiasis in pre-school-aged children in Assoni Village, Eastern Senegal

Background:To monitor the prevalenee of schistosomiasis in school-aged children(SAC),the National Bilharzia Control Program(PNLB)was set up by the Senegalese authorities;however,geographically isolated Bedik ethnic groups that did not benefit from this program were found to be heavily infected with Schistosoma mansoni.This observation led us to implement a new schistosomiasis control program in 2008 under the aegis of the non-governmental organi-zation wLe KaTcedratwand in partnership with the PNLB/WHO to monitor the prevalence of schistosomiasis in this area.In the village of Assoni,where 100%of SAC were infected,analysis of the stools of pre-school-aged children(PSAC)showed that they were massively infected,so we decided to focus our program on them.

Elimination of schistosomiasis requires multifactorial diagnostics: evidence from high- and low-prevalence areas in the Nile Delta, Egypt

Background:Schistosomiasis is one of the neglected tropical diseases(NTDs)selected for worldwide elimination in the near future.Egypt has made strong progress against its two endemic species of Schistosoma mansoni and S.haematobium.The former is prevalent in the Nile Delta with the latter dominating in the Nile south of Cairo.Innovative efforts are needed to reach the goal as further reduction of the prevalence has stalled due to ongoing transmission.In this study we aimed to explore the difference between low and high prevalence villages with regard to knowledge attitude and practice about schistosomiasis,utilization of health services,infection and transmission indices.Methods:A hybrid cross-sectional longitudinal study was conducted with three annual follow-ups conducted during 1994-1996.We used a representative systematic random sampling technique investigating 993 individuals from the high prevalence village and 614 from the low prevalence village.Data were analyzed using SPSS,comparing proportions with the Chi square test and means with the Student t test,and ANOVA.Results:Compliance of faecal sampling and chemotherapy was above 70%in both villages over the whole study period.Selective praziquantel treatment resulted in a significant reduction of prevalence and intensity of infection in both villages,dropping from 35.8%prevalence to 20.6%,in the low-prevalence village,and from 69.5 to 45.9%in the high-prevalence one.Intensity of infection at the base line was 30 eggs per gram(EPG)of stool in the low-prevalence village versus 105 EPG in the high-prevalence village.However,after the second round,reinfection rebounded by 22%in the high-prevalence village,while a slight improvement of the infection indices was demonstrated in the low-prevalence one.The level of knowledge was modest in both villages:people knew about self-protection and treatment,but not much about the role of human excreta for schistosomiasis transmission.While all participants maintained that using the water from the canals was inevitable,inhabitants in the high-prevalence village showed significantly lower scores reflecting higher water contact compared to the low-prevalence one.Many of them(67%)did not utilize the health centre at all compared to 26%of the people in the low-prevalence village.Interestingly,private clinics were seen as the primary source of health care by both villages,but more frequently so in the high-prevalence village(used by 87.2%of the inhabitants)compared to the low-prevalence one(59.8%).Conclusions:Even if chemotherapy works well as reflected by the observed downregulation of intensity of infection in both villages,reinfection continued due to difficulties to avoid water contact.Efforts must be made to make people understand the role of human excreta for transmission.There is also a need to make people better trust the medical services available.

Schistosomal(bilharzial)polyps:Travel through the colon and beyond

Schistosomiasis(bilharziasis)is a major neglected tropical disease.It is endemic in many tropical and subtropical communities.Schistosomal polyps(S.polyps)are not uncommon presentation of this infection.Although the colon is the most commonly affected organ,many other organs are affected.S.polyps are associated with a variable range of morbidity independent of the Schistosomal infection.S.polyps are frequently described in endemic areas and increasingly reported in non-endemic areas mainly among immigrants and visitors to the endemic areas.This review aimed to increase awareness of practitioners,especially gastroenterologists,for this peculiar type of polyps caused by this neglected infection hence improving patient outcomes.Web-based search of different databases was conducted for the literature focusing the development of S.polyps in the colon and other organs with analysis of the clinical manifestations,diagnosis and treatment.The following key words were used in the search,“Schistosomiasis”OR“Bilharziasis”AND“Polyps”OR“Polyp”AND“Colon”OR“Small intestine”OR“Duodenum”OR“Stomach”OR“Esophagus”OR”Gallbladder”OR”Pharynx”OR“Larynx”OR“Trachea”OR”Urinary bladder”OR“Ureter”OR“Renal Pelvis”OR“Urethra”.All publication types including case reports,case series,original research,and review articles were retrieved and analyzed.S.polyps are not infrequent presentation of acute or chronic Schistosomal infection.S.polyps are described in many organs including the bowel,genitourinary tract,skin,gallbladder and the larynx.Presentation of S.polyps is variable and depends on the site,number as well as the polyp size.The relationship of S.polyps to malignant transformation is a matter of discussion.Presence of S.polyps is sometimes the only manifestation of Schistosomiasis.Small polyps can be treated medically with praziquantel,while large accessible polyps are amendable for endoscopic excision through different polyp resection techniques.However,huge,complicated,non-accessible and suspicious polyps are indicated for surgical management or advanced endoscopic resection when appropriate.Clinicians and endoscopists should be aware about these facts when treating patients living in,immigrated from or visiting endemic areas.

青蒿琥酯和吡喹酮防治血吸虫病相互作用的研究

本文就血吸虫病预防药青蒿琥酯与血吸虫病治疗药吡喹酮的相互作用进行了初步探讨，实验结果表明：小鼠口服青蒿琥酯300mg／kg对第7天、第8天的童虫有杀灭作用，减虫率为71．6％，减雌率为72％；口服吡喹酮300mg／kg对第7天童虫无效，对第30天成虫有明显杀灭作用，减虫率为72％，减雌率为78．3％；青蒿琥酯与吡喹酮同时服，或者先服吡喹酮后服青蒿琥酯均明显影响青蒿琥酯的杀童虫作用；先服青蒿琥酯而后服吡喹酮时，吡喹酮不影响青蒿琥酯的杀童虫作用。无论青蒿琥酯在服吡喹酮前服用，或后服用，或同时服用均明显影响吡喹酮的治疗效果。

洞庭湖渔民血吸虫感染情况及化疗效果分析

目的 调查洞庭湖渔民感染血吸虫的严重程度 ,评估其化疗防治效果。 方法 2 0 0 1年 11月选择湖南省岳阳县麓角镇洞庭湖水上作业渔民 ,询问血吸虫感染与化疗史。用改良加藤法检查虫卵和毛蚴孵化法检查毛蚴 ,酶联免疫吸附测定 (ELISA)和间接血凝试验 (IHA)检测抗可溶性虫卵抗原 (SjSEA )的抗体 ,B超检查肝 /脾病变程度。人群顿服吡喹酮 40mg/kg ,一个感染季节过后复查。用SPSS软件进行分析。 结果 ①询问调查渔民 2 68人 ,“经常”或“间常”接触疫水的人数占 90 7% ;近 5年每年平均化疗人数占 2 4 0 % ,从未化疗者占 3 9 4% ;②粪检阳性率为 68 1% (111/163 ) ,克粪虫卵数 (EPG )为 48 77,男性均显著高于女性。 11～ 2 0岁阳性率最高(83 3 % ) ,“经常”或“间常”接触疫水与从未化疗的两种人群阳性率分别为 76 3 % (10 6/13 9)和 79 7% (5 1/64 ) ;③IHA检测阳性率为 88 0 % ,ELISA检测阳性率为 78 7% ,均明显高于粪检阳性率 ;④肝 /脾受损率为 77 4% (82 /10 6) ,其中 ,肝实质呈Ⅱ～Ⅲ级纤维化病变者占 3 7 7% ,肝肿率为 5 8 5 % ,脾肿率为 19 8% ;⑤多次化疗人群感染率和EPG显著低于从未化疗人群 ;⑥复查结果表明 ,化疗人群粪检阳性率 (3 5 4% )和EPG (3 6 13 )较未化疗人群(5 6 5 %和 68

洞庭湖区采用吡喹酮化疗降低血吸虫病患病率和传播的效果研究

在洞庭湖区血吸虫病严重流行区,采用选择性群体化疗、选择性群体化疗加易感地带药物灭螺和单纯治疗粪检阳性对象3种对策,3年后居民患病率分别下降为62.9％、59.2％和14.1％。水上流动渔船民采用群体化疗,血吸虫病患病率仅下降41.5％。家畜群体化疗组,感染率下降77.6％,只治粪检阳性组化疗前后感染率无变化。3种对策实际污染指数下降分别为74.7％、84.6％和36.2％。前2种对策虽下降幅度比较大,但都未达到阻断传播的阈值,感染螺密度和哨鼠感染率均维持在较高水平。

血吸虫对吡喹酮抗药性的研究 Ⅹ日本血吸虫中国大陆株对吡喹酮敏感性的现场调查

目的现场评价日本血吸虫中国大陆株对吡喹酮的敏感性。方法在云南、江苏、江西、湖南和湖北等5个省的血吸虫病流行区,选择11个村作为调查现场。在血吸虫病非传播季节,采用粪检法(Kato-Katz法和/或尼龙袋集卵孵化法)筛选出病人;以吡喹酮40mg/kg一次顿服对粪检阳性病人实施抗血吸虫治疗;治疗后6周采用相同方法复查粪便;阳性者仍按40mg/kg吡喹酮顿服进行第2次治疗;首次治疗后12周,对所有已治者(包括第2次治疗者)进行再次粪便复查。结果在11个流行村共粪检村民4760人,阳性者584人,其中505人经吡喹酮首次治疗后6周复查粪便,480人转阴,治愈率为95.1%;21例首次治疗后粪检仍然阳性者予以第2次治疗。在首次治疗后12周,对所有已治者(包括第2次治疗者)进行再次粪便复查,未发现粪检阳性者。结论尽管在我国血吸虫病主要流行区采用吡喹酮实施大规模化疗已达10余年,但现场至今尚未发现日本血吸虫中国大陆株对吡喹酮敏感性下降的证据。