加藤(Kato)法虫卵计数高估偏差的实验观察

血吸虫病的诊断以粪中查出血吸虫卵最为确实,定量诊断尤为准确,且操作程序愈简便,造成技术误差的机会愈小。1954年Kato和Miura介绍了粪便厚涂片的检验技术,方法简便。此后几经改进,目前已广为采用。方法的准确性业经Katz N等(1968,1970)、Chaia G等(1968)和TeesdaleCH、Amin MA(1976)等学者多次实验证明,对粪中加入的虫卵,与其他方法相比,Kato厚涂片虫卵计数法回收率最高,检得的平均虫卵数亦居首位。作者在血吸虫病防治实际工作中发现用Kato法对同一受检者的两张平行涂片,镜下计得的虫卵数,往往先制备的一张多于后一张。为探讨存在上述现象的原因,通过实验观察发现Kato厚涂片虫卵数的     

溢出法收集检测粪液中寄生虫卵的初步实验研究

本文介绍了一种新的收集寄生虫卵的方法一“溢出法”。该法具有集卵效果好,精密度高,操作简便的优点,在对粪液等检样作寄生虫卵数测定中具有推广应用价值。     

不同化学染色法对日本血吸虫虫卵染色的效果分析

目的探索不同化学染色法对日本血吸虫虫卵染色的效果,以期获得在镜检下可分辨虫卵和粪渣的染色方法,为粪检血吸虫虫卵的计算机自动化识别奠定基础。方法用AO-EB、罗丹明、中性红、酸性品红、甲苯胺兰、台盼蓝、考马斯亮蓝和孔雀绿等化学染料,选择3个不同浓度和2个不同温度条件,分别对含日本血吸虫虫卵粪液进行染色、涂片镜检,用虫卵和粪渣反差程度作为主要评价指标,比较各种方法的染色效果。结果在8种化学染色方法中,以AO-EB染色和中性红染色的虫卵与粪渣其反差最大,镜下粪涂片中虫卵易于辨认,AO-EB法和中性红法的检出率分别为67.5%和65.0%,明显高于改良加藤法的检出率(40.0%)。结论AO-EB法和中性红染色法有助于提高粪检血吸虫虫卵检出率。     

洪氏虫卵计数法与青霉素瓶定量饱和盐水漂浮虫卵连续计数法比较

收集感染犬钩口线虫新鲜犬粪便,称取1、0.2 g,分别采用青霉素瓶定量饱和盐水漂浮法作虫卵计数,出现虫卵的片数分别为25张和11张,克粪虫卵数(EPG)分别为1 648和1 425,表明标本量影响检验结果。称取1 g粪便,采用改良洪氏虫卵计数法检查,EPG为1 316,仅为青霉素瓶定量饱和盐水漂浮法的79.9%(1316/1648)。     

直接涂片、饱和盐水漂浮两种粪检方法检出虫卵效果的比较

直接涂片、饱和盐水漂浮为目前广为多用的粪检肠道寄生虫虫卵的两种方法。为验证这两种方法的检出效果,我们于1984年3月间,在杭州市七堡小学对2～4年级100名学生作了粪检结果比较观察。方法每人一粪,分别作直接涂片(每份粪涂片2张)和饱和盐水漂浮检查。饱和盐水漂浮法,用塑料小圆杯漂浮,每杯覆盖玻片2次(即2张载玻片)。然后分别镜检虫卵,检到虫卵为阳性。     

孵化法常规操作过程中血吸虫虫卵散失的分析

目前在基本消灭血吸虫病地区作病原诊断主要采用孵化法,采用各种综合查病方案时亦都含有此法。本文就孵化法常规操作过程中是否存在虫卵散失及其方式等进行了探讨。 材料与方法 一、实验对象 供实验室研究用的已知阳性病人粪便,取自无锡市郊区未经治疗的患者。现场考查是吴县外垮塘公社普查对象,由当地化验员作粪     

单漂法与双漂法检出钩虫卵的效果比较

饱和盐水漂浮法是检查钩虫卵常用的一种方法。以往文献报道的饱和盐水漂浮法都是取１次粪样盖１次玻片的方法（下称单漂法）。能否采用取２次粪样盖２次玻片的方法（下称双漂法）来提高漂浮法对钩虫卵的检出率呢？我们在调查南陵县中洲村钩虫感染的同时,对这 问题进行了探讨。１材料与方法１．１单漂法取粪样１次,用饱和盐水漂浮法［１］操作。１．２双漂法取相同粪样２次,用饱和盐水漂浮法重复操作。２结果与讨论 对实验区５８例居民,用以上２种方法对比检测同一份粪便。结果单漂法检出钩虫卵阳性１８例,双漂法检出钩虫卵阳性２１例。…     

四种粪检方法对肠道线虫感染的检出效果比较

1 材料与方法在江苏省兴化市荻垛乡西茆村对1周岁以上居民进行粪检,共对比检查161人。每份粪样分别作直接涂片(取粪约5mg),Kato-Katz法(定量板取粪41.7mg,常规检查1片),饱和盐水浮聚法(金属圈取粪样500mg,镜检1片)和钩蚴培养法(试管滤纸法)检查,发现虫卵和钩虫幼虫判为阳性。Ka-to’s法作定量计算,每片虫卵数乘以23.98即为克粪虫卵数(EPG)。 2 结果肠道线虫总感染率为81.4％(131/161)。其中蛔虫、钩虫、鞭虫的感染率分别为52.2％(84/161)、59.0％(95/161)、21.1％(34/161)。平均EPG     

环介导等温扩增法检测粪样中日本血吸虫虫卵DNA的效果评估

目的评估环介导等温扩增(loop mediated isothermal amplification,LAMP)法检测粪样中日本血吸虫(Schistosoma japonicum)虫卵DNA的效果,并评价其检测流行区现场牛野外粪样的效果。方法取1 g新鲜的日本血吸虫虫卵阴性牛粪,分别加入5个新鲜日本血吸虫虫卵、50μl日本血吸虫虫卵排泄分泌产物(egg secretion product,ESP)制备人工模拟阳性粪样。用粪DNA提取试剂盒分别提取加入虫卵的未经研磨或研磨2 min后的人工模拟阳性粪样、加入虫卵ESP的粪样和阴性粪样的DNA,以日本血吸虫28S核糖体DNA(r DNA)为检测靶基因,用LAMP法、PCR法检测,评估LAMP法检测粪样中日本血吸虫虫卵DNA的效果。收集2012-2014年湖南、湖北、江西、安徽等4省日本血吸虫病流行区的牛野外粪样221份,研磨后同法提取DNA,用LAMP法检测,并与PCR法、孵化法的检测结果进行比较,评价其检测流行区现场野外粪样的效果。结果LAMP法检测加入虫卵粪样并经研磨后提取的DNA、加入虫卵ESP粪样提取的DNA均为阳性反应,呈绿色;而加入虫卵粪样未经研磨提取的DNA、阴性粪样DNA则为阴性反应,呈棕色;PCR检测的结果与LAMP法检测结果相近。LAMP法、PCR法和孵化法检测血吸虫病流行区牛野外粪样的阳性率分别为5.43%(12/221)、4.52%(10/221)、0.90%(2/221)。LAMP法的阳性率明显高于孵化法(P0.05),LAMP法与PCR法阳性率差异无统计学意义(P0.05)。结论 LAMP法可用于检测流行区现场野外粪样的日本血吸虫虫卵DNA,其现场应用价值有待进一步验证。     

口服吡喹酮对小鼠体内曼氏血吸虫虫卵的作用

本实验用卵谱法和孵化法观察吡喹酮(PZQ)间隔9天两次口服给药对感染小鼠体内血吸虫虫卵的影响。 雄性体重20—25g远交系ICR小鼠,经皮肤感染波多黎各株曼氏血吸虫尾蚴200条。感染后第57天用加藤法检测粪内平均卵数/g(EPG),EPG为936的小鼠划入非治疗     

集卵薄涂片法检测牛粪中血吸虫卵含量的研究

本文比较了薄涂片法和透明法的虫卵回收率。结果表明,在三种虫卵梯度,薄涂片法的虫卵回收率,分别为透明法的18、4.2和3.5倍,前者的变异系数明显低于后者;现场检查34头孵化阳性黄牛的结果也证实薄涂片法优于透明法。薄涂片法检查半量粪渣(制6张涂片)的虫卵估计值和标准差与全量粪渣结果相似,可以代替全量粪渣检查。在感染度较高的地区,可以抽样检查1/4粪渣,制3张涂片检查,从而减少工作量。     

荣宝对血吸虫病畜粪虫卵影响的实验观察

目的观察荣宝对家畜粪便中血吸虫卵的杀灭作用。方法在含有血吸虫卵的家畜新鲜集卵粪渣中按0.5%、1.0%、2.0%、3.0%的比例分组加入荣宝混合,同时按0.25%、0.5%、1.0%、2.0%的荣宝比例分别与同一新鲜粪便作直接搅拌。另外,制作高度10.0cm和18.5cm的粪柱,并按1.0%和3.0%的比例分别在粪柱底面和顶层洒上荣宝,各组以相同的粪便和方法作对照,处理一定时间后,抽样（高度组在粪柱中部取样）观察各组毛蚴孵化情况。结果荣宝与集卵粪渣混合或与新鲜粪便直接搅拌处理24h以上时,集卵粪渣加入0.5%-3.0%比例荣宝、新鲜粪便加入0.25%-2.0%比例荣宝的粪便中血吸虫卵均不能孵化;如果混合处理在2h以下时,集卵粪渣中加入0.5%-1.0%荣宝仍可见毛蚴孵出,加入2.0%-3.0%荣宝则不能,最佳药物浓度为1.0%-2.0%,有效处理时间24h以上。10.0cm高度粪柱中加入3.0%荣宝处理4d或1.0%荣宝处理5d开始不能孵出毛蚴;18.5cm高度粪柱中加入1.0%或3.0%荣宝处理8d尚可见到毛蚴孵出。所有对照组在各处理时间均可孵出毛蚴。结论荣宝具有杀灭家畜粪便中血吸虫卵的作用,其粪、药混合处理方式优于分层处理。     

2020年云南省血吸虫病传播风险评估结果分析

目的 评估云南省 2020 年的血吸虫病传播风险,为制定防治方案和措施提供依据。 方法 选取云南省巍山、弥渡、大理、宁蒗 4 个县(市)作为风险评估对象,每县(市)选择 2 个流行乡镇,每个乡镇选取 1 个行政村开展评估工作。 整理分析 2018—2020 年评估村的血吸虫病疫情和防治资料;2020 年对评估村进行现场螺情和野粪调查,综合评估血吸虫病传播风险。 结果 疫情资料显示,7 个被评估村 2018—2020 年均未查到病人、病畜和感染性钉螺。 现场钉螺调查结果显示,历史有螺环境系统抽样捕获活螺 10 只,有螺框出现率为 6. 52%(3 / 46),活螺平均密度为 0. 22 只 / 0. 11 m2;环境抽查 3 248 框,捕获活螺 2 只。 现有螺环境系统抽样捕获活螺 1 082 只,有螺框出现率为 4. 01%(297 / 7 413),活螺平均密度为 0. 15 只 / 0. 11 m2;环境抽查 2 627 框,捕获活螺 31 只。 捡获的活螺进行 LAMP 检测,结果均为阴性。 共捡获野粪 261 份,其中牛粪 54 份(20. 69%)、狗粪 129 份(49. 43%)、马属动物(驴、骡)粪 33 份(12. 64%)、猪粪 7 份(2. 68%)、羊粪 21 份(8. 05%)、人粪 17 份(6. 51%),经顶管孵化法均未检出阳性。被评估县风险等级为Ⅲ级。 结论 当前云南省血吸虫病传播处于低风险状态,但家畜存栏数量大、家畜散放、野粪种类和数量较多、历史有螺环境钉螺复现等情况依然存在,提示今后需继续加强实施综合防治措施,建立完善的风险评估及监测机制,巩固防治成果。     

Pooled Testing for Effective Estimation of the Prevalence of Schistosoma mansoni

Rapid and accurate identification of the prevalence of schistosomiasis is key for control and eradication of this devastating disease. The current screening standard for intestinal schistosomiasis is the Katz-Kato method, which look for eggs on slides of fecal matter. Although work has been done to estimate prevalence using the number of eggs on a slide, the procedure is much faster if the laboratory only reports the presence or absence of eggs on each slide. To further help reduce screening costs while maintaining accuracy, we propose a pooled method for estimating prevalence. We compare it to the standard individualed method, investigating differences in efficiency, measured by the number of slides read, and accuracy, measured by mean square error of estimation. Complication is introduced by the unknown and varying sensitivity of the procedure with population prevalence. The DeVlas model for the worm and egg distributions in the population describes how test sensitivity increases with age of the epidemic, as prevalence and intensity of infection increase, making the problem fundamentally different from earlier work in pooling. Previous literature discusses varying sensitivity with the number of positive samples within a pool, known as the “dilution effect.” We model both the dilution effect and varying sensitivity with population prevalence. For model parameter values suited to younger age groups, the pooled method has less than half the mean square error of the individualed method. Thus, we can use half as many slides while maintaining accuracy. Such savings might encourage more frequent measurements in regions where schistosomiasis is a serious but neglected problem.     

Persistence of eggs and hepatic fibrosis after treatment of Schistosoma mansoni-infected mice.

In 1971 we estimated that Schistosoma mansoni eggs in the tissues of mice were destroyed with an approximate half-life of four weeks. Our present results of five experiments suggest that egg destruction is not as rapid, and no significant destruction of eggs was detected for up to 26 weeks after treatment. However, in these experiments, a mean of 60% of the eggs in intestinal tissues were found in the feces at the time of treatment. In previously reported experiments, only 15% of gut eggs were passed in the feces. We now believe that underestimation of the number of eggs passed in the feces led to an overestimation of the number of eggs destroyed in the tissues. We analyzed liver eggs separately because eggs lost from this site are unaffected by eggs passed in the feces. No significant decrease in liver eggs occurred in the present experiments, but reanalysis of previously published data showed significant egg destruction in the liver in several experiments, although at a much slower rate than previously estimated. However, inspection of the data in the previously published and present experiments does not show a convincing difference in the number of eggs in the liver after treatment. The persistence of egg shells is probably not important in the pathogenesis of disease, but is of concern in calculating worm fecundity. Hepatic collagen levels increased markedly two weeks after treatment and subsequently decreased significantly in some, but not all, experiments.     

羊在日本血吸虫病传播中的作用 Ⅳ 羊体内血吸虫的发育及粪便中虫卵数量和分布

目的阐明日本血吸虫在山羊体内生长发育和虫卵随粪便排出的强度与时间分布,为控制和消除羊在血吸虫 病传播中的作用提供基础数据。方法建立山羊日本血吸虫病动物模型,采用定期收集粪便并进行粪便病原学检查,及 定期解剖等方法,分析比较山羊感染血吸虫尾蚴后成虫获得量、感染不同时间后羊体内血吸虫数量变化和虫体内含虫卵 数量,以及羊粪中血吸虫虫卵数量变化与时间分布特征。结果解剖6只血吸虫感染山羊,共检获成虫415条,平均每只 山羊成虫获得率为34.58%（23.00%～45.50%）。感染200条/只尾蚴的5只山羊在感染2、5 、8、11个月和14个月后分别获 得47、93、77、74条和73条成虫,感染8～14个月后获得的成虫数与之相近,未见明显减少;解剖所获雌虫体内含虫卵数 量分别为（200.00±42.33）、（226.20±45.88）、（168.20±25.85）、（183.80±55.13）个和（190.80±53.53）个,感染后2个月与14个 月雌虫体内血吸虫虫卵数差异无统计学意义（t = 0.301,P = 0.771）。10只羊感染血吸虫后排出虫卵的平均开放前期为 （37.70±3.02）d。羊感染血吸虫后2～14个月,共开展粪便孵化7批次,分别有30、23、14、1次和2次粪孵毛蚴密度为 “++++”、“+++”、“++”、“+”和“-”,孵化毛蚴密度分布构成比分别为42.86%、32.86%、20.00%、1.43%和2.86%。结论山 羊感染血吸虫后约有1/3的尾蚴可发育为成虫,虫卵开放前期为（37.70±3.02）d,感染血吸虫后14个月以内成虫数、雌虫 含虫卵数和粪便中虫卵数未见显著减少。本研究提示,感染性山羊在血吸虫病传播中的作用持续时间较长,且无“自愈” 证据,是日本血吸虫病重要的传染源。     

改良加藤厚涂片法检查土源性线虫卵的检出效果

目的 分析改良加藤厚涂片法（Kato-Katz）1 送3 检中单次涂片检出率规律,并探索单次涂片检出率与粪便中虫卵密度的相互关系。方法 2006~2010 年,每年9~11 月在安徽省蒙城县监测点采集3周岁以上常住居民的粪便,采用改良加藤厚涂片法（1 送3 检）检查蛔虫、鞭虫和钩虫卵;以片均虫卵数（eggs per slide,EPS）作为描述粪便虫卵密度的计算单位。对虫卵在3 张涂片中的各自出现概率进行分析和对比。结果 3 张涂片的虫卵出现率差异均无统计学意义。当EPS<2 时,单张涂片的虫卵平均出现率为52.26%;当EPS≥16 时,单张涂片虫卵出现率可达99.26%。结论 单张涂片的虫卵平均出现率与EPS 存在一定关联。     

Infectivity and development of the human strain of Hymenolepis nana in ICR mice

In order to study the infectivity and development of the human strain of Hymenolepis nana in mice, a human strain of H. nana was inoculated into ICR mice. H. nana eggs were concentrated by the sedimentation method and inoculated by a disposable syringe (1 ml) connected to a long needle (8 cm) into the stomach of mice. Mouse feces were examined daily beginning day 5 after inoculation and the mice were sacrificed from days 19 to 65 post-infection (PI). The infection rate and worm recovery rate were 69% and 17%, respectively. The prepatent period ranged from 7 to 23 days. Autoinfection was found to occur in an ICR mouse infected with 60 eggs; 102 worms were recovered from its small intestinal lumen on day 19 PI. One row of hooklets was found on the scolex and the mean number of hooks was 19. The average length, width, and number of segments were 51 mm, 0.6 mm, and 1,099, respectively. The mean length and number of immature segments were 9 mm and 414 segments, mature segments 20 mm and 390 segments, and gravid segments 22 mm and 295 segments. The average length, width, and number of segments in 26 autoinfected worms were 11.5 mm, 0.3 mm, and 189 segments. The mean length and number of immature segments were 3.9 mm and 41 segments, mature segments 4.4 mm and 65 segments, and gravid segments 3.2 mm and 83 segments, respectively.     

Parasitological and histopathological studies on rhesus monkeys infected with Chinese mainland strain of Schistosoma japonicum.

Fifteen rhesus monkeys were infected by cutaneous exposure each with 200 or 300 cercariae of Schistosoma japonicum. The dynamic distribution of schistosomula in the skin showed that 77-90% of them were found in the connective tissue, while 10-23% migrated in the hair follicles and sebaceous glands at different time intervals after cercarial penetration. Dead schistosomula recovered from the skin varied from 8.7% to 28.7%. The average rate of adult worm recovery was 74.4% and 61.3% in the 6th and 15th weeks of infection, thereafter the rate decreased to 32.3% and 9.0% in the 19th and 42nd weeks, respectively. The mean length of mature pair-worms was 13.2 +/- 2.3 mm in male and 18.0 +/- 1.9 mm in female 6 weeks of worm age. Afterwards the body length of females and their sexual gland diminished markedly. The mean prepatent period was 35.0 +/- 0.6 days. The average size of mature eggs in the feces was 86.6 +/- 5.4 x 64.3 +/- 3.6 microns, and the peak of eggs passage in the feces occurred between 7th and 15th weeks after infection, later on the number of eggs markedly decreased. Skin reaction to the primary infection was slight. The pathological changes observed in liver were chiefly cellular infiltration of portal spaces and the lesions produced by egg granulomas. The mean volume of single-egg granulomas of the productive stage in liver was 22.7 +/- 10.5 mm3 x 10(-3). The most intensive damages in the gastro-intestinal tract were observed in the large intestine.(ABSTRACT TRUNCATED AT 250 WORDS)