Five year impact of chemotherapy on morbidity attributable to Schistosoma japonicum infection in the Dongting Lake region

Objective To determine changes in the last 5 years of the fraction of acute and chronic symptoms attributable to schistosomiasis japonica in fishing communities with moderate endemicity in the Dongting Lake region of China. Method Complete medical histories, physical examinations, and stool samples were obtained from 1909 individuals (53% male) ranging in age from 4 to 81 years. Age, sex, occupation, frequency of water contact, number of times treated for schistosomiasis, and last year of treatment were tested as potential effect modifiers and confounders. Results Overall, there were very few infected cases and very little variation in any prevalence ratio with infection intensity, sex, age, year of last treatment, number of times treated or frequency of water contact. The attributable fraction of liver enlargement in one village was estimated at 0.114 (11.4%), although this was not significantly > 0 (95% CI; ? 0.008–0.237). Conclusion The chemotherapy-based schistosomiasis control programme in this locality has succeeded in reducing attributable morbidity to undetectable levels, but many uncertainties remain about sustaining control efforts in the future. Both old and new control strategies will have to be examined if the health and well-being of these people are to be maintained into the next millennium, given that periodic chemotherapy will not be accepted indefinitely.     

The morbidity attributable to Schistosoma japonicum infection in 3 villages in Dongting Lake region, Hunan Province, PR China

In common with other helminth infections, symptoms associated with Schistosoma japonicum infection have a low specificity, and many infections are asymptomatic. The presence of the parasite in a sick individual from an endemic area does not mean that S. japonicum is the aetiological agent. However, estimates of the proportion of all symptomatic episodes in a community attributable to S. japonicum infection can be used to determine its public health impact. Using parasitological and morbidity survey data from 3 villages in China, the fractions of diarrhoea, bloody stool, and abdominal pain episodes that were attributable to S. japonicum infection were estimated. The association between hepatomegaly and S. japonicum infection was also assessed. For all morbidity indicators, it was found that individuals with higher infection intensities were at greater risk of morbidity. The highest risk indicator of morbidity associated with S. japonicum infection was bloody stools. Logistic regression revealed that factors related to village and sex were important confounders of the relation between infection and the risk of morbidity. The fraction of the population in each village estimated to be suffering morbidity attributable to S. japonicnm infection was low, due to the low prevalence of infection. However, the results suggest that some sick individuals may have been diagnosed as false negatives for S. japonicum infection.     

鄱阳湖区居民化疗后血吸虫再感染和新感染规律的研究

目的 探讨鄱阳湖区日本血吸虫病流行区人群血吸虫再感染和新感染的规律.方法 1995～2004年（1995～1999年/新华村、2000～2004年/渚溪村）采用血吸虫病病原学检查方法（Kato-Katz法）对疫区5～65岁的常住居民进行连续5年纵向观察.结果 疫区人群血吸虫感染率和感染度呈逐年下降趋势.新华村和渚溪村的人群血吸虫感染率分别从16.29%和12.0%,下降到4.86%和7.42% 新华村和渚溪村的人群感染度分别从0.92±3.72和0.41±1.83下降到0.17±1.08和0.28±1.46 居民再感染年间波动较大,新华村11.29%～23.21%,渚溪村7.14%～27.78%,新感染总体稳定,两村均在4%至9%左右徘徊.结论 化疗仍是控制病情的主要手段,再感染率高低与化疗前病人感染度无相关关系.     

Helminth infections, morbidity indicators and schistosomiasis treatment history in three villages, Dongting Lake region, PR China

In order to estimate the public health impact of helminth infections, and to provide baseline data for interventions, parasitological and morbidity surveys were conducted among inhabitants of three villages in Dongting Lake region, Hunan Province, China. Ascaris lumbricoides was found to be the most common helminth infection, followed by Trichuris trichiura and Schistosoma japonicum . Left liver enlargement was the most common indicator of morbidity. Observed numbers of multiple species infections closely correlated with expected figures generated from a simple probabilistic model. Heterogeneity was observed in age and sex‐standardized infection and morbidity prevalences among the villages and occupations. Males had higher levels of infection, were more likely to suffer morbidity, and were more likely to have been treated for schistosomiasis than women. The prevalence of each morbidity indicator was positively correlated with the number of times of treatment for schistosomiasis, and negatively correlated with number of years since last treatment. The results imply that treatment history for S. japonicum infection may be a good indicator of current morbidity risk.     

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268人,“经常”或“间常”接触疫水的人数占907%;近5年每年平均化疗人数占240%,从未化疗者占394%;②粪检阳性率为681%(111/163),克粪虫卵数(EPG)为4877,男性均显著高于女性。 11～20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 763 %(106/139)和797%(51/64);③IHA检测阳性率为880%,ELISA检测阳性率为787%,均明显高于粪检阳性率;④肝/脾受损率为774%(82/10 6),其中,肝实质呈Ⅱ～Ⅲ级纤维化病变者占377%,肝肿率为585%,脾肿率为198%;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(354%)和EPG(3613)较未化疗人群(565%和684     

鄱阳湖区血吸虫病高度流行区全民化疗后居民依从性的研究

世界银行贷款中国血吸虫病控制项目的总政策是:在血吸虫病高度流行区(感染率≥15%)实行全民化疗,其化疗覆盖率要求达到95%。为了解项目执行以来,居民的化疗依从性和实际服药情况,本研究采用问卷的形式,对659名居民1992～1997每年的化疗情况进行回顾性调查,并对调查对象中感染者与非感染者的化疗覆盖率以及实际服药情况进行比较。材料和方法1　调查地点江西省新建县南矶山乡,该乡地处鄱阳湖中,涨水季节为一孤岛,全乡总人口为4782人,职业以半农半渔为主,历史上血吸虫病感染高达90%(1985年)。80年代末,江西省鄱阳湖区大区域规划控制血吸虫病时,…     

间接血凝试验对洞庭湖区渔船民血吸虫感染的诊断效能

目的　评价间接血凝试验（indirect haemagglutination test, IHA）对洞庭湖区渔船民血吸虫感染的诊断效能,为完善渔船民血吸虫病监测方案提供参考依据。方法　2014—2019年在洞庭湖区渔船民集散地血吸虫病检测点对渔船民进行血清学和病原学检查;其中2014—2016年同时采用IHA法和改良加藤法或尼龙绢集卵孵化法进行检测;2017—2019年先采用IHA法进行血清学筛查,阳性者再采用改良加藤法或尼龙绢集卵孵化法进行病原学检查。以2014—2016年病原学检查结果为金标准,计算IHA法检测渔船民血吸虫感染的灵敏度和特异度,对不同特征及年份渔船民血清学检测阳性率进行比较。结果　2014—2019年在洞庭湖区渔船民集散地共设立了306个血吸虫病检测点,累计筛查渔船民143 360人·次。2014—2016年IHA法检测渔船民血吸虫感染的灵敏度分别为69.9%、97.3%和96.1%（[χ2] = 74.6,P < 0.05）,特异度分别为70.9%、74.5%和71.9%（[χ2] = 29.4,P < 0.05）。2014—2019年,渔船民血检阳性率从30.3%降至1.8%,总体呈下降趋势（Z = 1 552.4,P < 0.05）;男性、45～＜ 60岁组、专业渔民及船民血检阳性率相对较高。结论　 2014—2019年洞庭湖区渔船民血吸虫病血检阳性率呈逐年下降趋势,IHA法用于该地区渔船民血吸虫病筛查的诊断效能较好。     

鄱阳湖区日本血吸虫感染与人群行为学空间分布研究

 目的  利用地面和空间数据分析血吸虫感染与环境空间的关系。方法选择鄱阳湖区重疫区村进行居民血吸虫感染状况及行为学调查，利用GPS采集相关的空间数据，通过ArcGIS和SAS软件进行统计分析。结果  居民血吸虫平均感染率为18. 08%，其中渔（船）民最高，为41.18%，农民和学生的血吸虫感染率>10%；居民居住的地理位置与血吸虫感染密切相关。结论湖区血吸虫病高危人群为离沿湖居住较近的居民，其是湖区血吸虫病防治的重点人群。       

日本血吸虫病低度流行区吡喹酮薄膜衣片临床疗效及不良反应评价

【摘要】 目的  评价日本血吸虫病低度流行区吡喹酮薄膜衣片对血吸虫病患者的疗效。 方法  选择1 个血吸虫病低度流行村,对5~60岁常住居民采用毛蚴孵化法进行粪检,并统计患者感染度（EPG）。阳性者分别采用60mg/kg 或40mg/kg 吡喹酮薄膜衣片进行病原学治疗。治疗6 周后粪检复查,评估吡喹酮薄膜衣片疗效,阳性者采用相同治疗进行第2 次治疗;同时观察吡喹酮服药后的不良反应发生情况。 结果  87 例观察对象中,有吡喹酮抗虫治疗史1 次者43例,2 次以上者44例;中度感染37例（EPG：216~312）,轻度感染50例（ EPG：24~96）;第1 次治疗使用吡喹酮薄膜衣片60mg/kg 37例,40mg/kg 50例,复查均未查见毛蚴或虫卵。患者不良反应发生率为17.24%。 结论  在日本血吸虫病低度流行区,吡喹酮薄膜衣片对血吸虫感染者具有较高敏感性。     

鄱阳湖区血吸虫病疫区居民肝脾超声图像特征及转归评估

目的观察鄱阳湖区血吸虫病疫区居民肝、脾超声图像特征及其转归,探讨超声显像(B超)在评估血吸虫病病情及其变化中的应用价值。方法1995年和2007年先后在江西省鄱阳湖区同一血吸虫病重疫区村对常住居民同时采用病原学方法和B超进行检查。结果1995年与2007年居民粪检阳性率分别为16.29%和8.54%,差异有统计学意义(P0.01);居民肝、脾肿大率分别为8.82%和20.33%、8.54%和21.34%,差异均无统计学意义(P均0.05);门静脉内径异常率分别为32.47%和6.50%,肝实质异常率分别为34.85%和51.83%,差异均有统计学意义(P均0.01)。居民肝实质I级的发展具有双向性,2007年检查结果表明,1995年肝实质Ⅰ级者中有29.90%恢复正常,34.02%发展为Ⅱ级以上。B超各项指标的改变与居民职业、血吸虫感染与否有关。结论B超可用于诊断疫区居民血吸虫病病情和病理损伤,但其反映早期病变的敏感指标或评估病情状况的综合指标还有待进一步研究。     

口服蒿甲醚控制重疫区血吸虫病及预防急性感染

目的观察口服蒿甲醚控制日本血吸虫病重疫区人群感染及预防急性感染的效果.方法在鄱阳湖区血吸虫病易感季节(5～10月)对重疫区村居民采用15 d间隔口服蒿甲醚预防感染.同时设对照组,口服安慰剂.结果感染季节结束后,实验组人群粪检阳性率为0.83%,无急性感染发生;对照组粪检阳性率为15.01%,发生3例急性感染.结论每15天间隔口服蒿甲醚1次,对重疫区人群有良好的保护作用,保护率为94.47%,有利于控制人群感染;对防止急性感染也有明显效果.     

我国血吸虫病免疫诊断发展的回顾与展望

诊断在血吸虫病防治活动中始终处于中心位置,为防治活动的计划、实施和防治效果评价等各环节提供必要的信息和科学依据,可具体用于在个体或群体水平上确定化疗对象、评价化疗、预防和传播控制的效果以及传播控制或阻断后监测。迄今为止,寄生虫学检查,即从流行区人的粪便中查见虫卵,仍是血吸虫病唯一的确定诊断途径和手段。20世纪80年代以前,当三价锑化合物作为抗血吸虫主要化疗药物时,因其较高的毒性,通过寄生虫学检查获得确定诊断是决定个体化疗的必需前提和依据。自20世纪80年代初,新型抗血吸虫药物吡喹酮引入我国血吸虫病防治以来,因其安…     

A drug-based intervention study on the importance of buffaloes for human Schistosoma japonicum infection around Poyang Lake, People's Republic of China

Schistosomiasis japonica is a zoonosis of major public health importance in southern China. We undertook a drug intervention to test the hypothesis that buffalo are major reservoirs for human infection in the marshlands/lake areas, where one million people are infected. We compared human and buffalo infection rates and intensity in an intervention village (Jishan), where humans and buffalo were treated with praziquantel, and a control village (Hexi), where only humans were treated, in the Poyang Lake region. Over the four-year study, human incidence in Jishan decreased but increased in Hexi. Adjustment of incidence by age, sex, water exposure, year, and village further confirmed the decreased human infection in Jishan. Chemotherapy for buffaloes resulted in a decrease in buffalo infection rates in Jishan, which coincided with the reduction in human infection rates there in the last two years of the study. Mathematical modeling predicted that buffalo are responsible for 75% of human transmission in Jishan.     

中国日本血吸虫病流行区学龄儿童感染率用于评估社区人群感染率的研究

目的分析学龄儿童日本血吸虫感染率与社区人群感染率之间的相关关系。方法通过检索CNKI和PubMed,收集1990-2009年公开发表的在中国大陆开展的有关年龄分层日本血吸虫感染率的相关文献,采取最小二乘法和极大似然法,以线性回归和logistic回归对学龄儿童与社区总人群、学龄儿童与社区中其他人群日本血吸虫感染率之间的关系进行拟合分析,以期找到最适的回归拟合。结果变换后的logistic回归拟合学龄儿童与社区人群日本血吸虫感染率之间关系的效果最好,回归系数aG、bG、aI、bI、aA、bA值分别为0.4718、6.8462、0.7985、9.6128、0.1619和4.2688。结论学龄儿童日本血吸虫感染率可考虑作为评估中国社区人群日本血吸虫感染率的一个指标。     

江滩型流行区夏、秋人群血吸虫新感染和再感染的研究

目的了解江滩型地区夏、秋感染季节后人群血吸虫新感染和再感染情况，为制定符合该类地区特点的血吸虫病防治对策提供依据。方法选择-江滩型流行区，分别在6月、9月下旬和12月上旬随机抽取≥5周岁常住沿江居民500人，采用Kato-Katz法进行1粪3检，阳性者计算克粪虫卵数（EPG）。每次粪检后对阳性及有明确疫水接触史者均给予病原治疗。以连续2次均接受检查者为分析对象。结果人群血吸虫新感染率夏季为14．9%（55／370），秋季为2．0％（6／293），夏季显著高于秋季（x^2=32．154，P〈0．001）；人群再感染率夏季为4．0％（1／25），秋季为8．8％（6／68），差异无显著性（x^2=0．115，P=0．735）。结论在江滩型地区经过一个春季感染后，夏季是人群年度血吸虫新感染的主要季节，秋季再感染率较高。     

日本血吸虫核糖体蛋白SjRPS4、SjRPL7 DNA疫苗对小鼠免疫保护作用研究

目的研究日本血吸虫核糖体蛋白SjRPS4、SjRPL7DNA疫苗对小鼠免疫保护作用。方法大量制备pcD-NA3.0/SjRPS4和pcDNA3.0/SjRPL7质粒DNA疫苗,昆明小鼠40只,随机均分为A、B、C和D组,A组为生理盐水(NS)组,每次肌肉注射100μL生理盐水;B组每只小鼠的股四头肌注射100μgpcDNA3.0裸质粒DNA;C组为pcDNA3.0/SjRPS4真核重组质粒组,每次肌肉注射质粒100μg/100μL;D组为pcDNA3.0/SjRPL7真核重组质粒组,每次肌肉注射质粒100μg/100μL。每隔2w同量加强免疫1次,共3次。末次免疫后第2w测定免疫各组血清特异性抗体效价后,经小鼠腹部皮肤人工感染20±1条日本血吸虫尾蚴。感染后第42d处死小鼠,计算减虫率和减卵率。结果与NS对照组比较,pcDNA3.0/SjRPS4和pcDNA3.0/SjRPL7免疫组小鼠均获得了较显著的减虫率、肝减卵率、肠减卵率、每雌子宫减卵率。统计学处理,均有显著性差异。结论pcDNA3.0/SjRPS4和pcDNA3.0/SjRPL7DNA疫苗对小鼠均有较强的免疫保护效果。     

CD4+ T-cell counts, CD4+/CD8+ T-cell count ratios, and antibody levels in migrant fishermen infected with Schistosoma japonicum in the Dongting Lake, China

In this study, CD4(+) and CD8(+) T cells and antibody levels were measured in 94 migrant fishermen infected with Schistosoma japonicum from Dongting Lake, China. Prevalence among these fishermen was high (63.8%), with a mean infection intensity of 61.4 +/- 3.8 epg, and included a high proportion of individuals (39.4%) with substantial parenchymal fibrosis (stages > or = 2/3). The CD4(+)/CD8(+) ratio in men (1.34 +/- 0.11) was significantly lower than that of women (1.58 +/- 0.15). CD4(+) T cells and the ratio of CD4(+)/CD8(+) were significantly decreased both in subjects infected with S. japonicum and those with parenchymal fibrosis. However, levels of total IgA, IgM, and anti-schistosome egg antigen IgG correlated positively with infection intensity and pathologic lesion number. These results suggest an imbalance between cell-mediated and humoral immunity in these fishermen, the precise cause of which remains undetermined.