酶联免疫吸附试验检测人体曼氏血吸虫感染的抗体

观察对象为107例苏丹急性曼氏血吸虫病和48例急性埃及血吸虫病患者,另以50例经反复粪检和尿检为阴性的非血吸虫病患者为对照。在曼氏血吸虫病例中,75例为肠道型;11例为肝型;16例为肝脾肿大型;5例为肝脾型。所有病例用海蒽酮进行治疗。治后6周,49个病人的粪检或尿检转为阴性。治疗前与治疗后6周,取受试者的血液进行酶联免疫吸附试验(ELISA)。     

安徽省枞阳县凤仪村居民血吸虫病状况调查

目的了解凤仪村居民血吸虫感染及血吸虫病对居民肝、脾损害情况。方法对5～65岁居民进行查病，确定感染情况，同时对受检者用B超进行肝、脾检查。结果人群血吸虫感染率4．81％，各年龄组均有患者，男、女人群肝、脾肿大率差异无统计学意义（P〉0．05），肝纤维化异常率男性高于女性（P〈0．01），随着年龄的增长肝纤维化异常率增高，有病史人群与无病史人群、粪检阳性人群与粪检阴性人群肝、脾肿大率差异有统计学意义（P〈0．01）。结论凤仪村人群血吸虫病病情仍较严重，肝、脾损害明显，同时提示超声检测能评价人群血吸虫病病情。     

安徽省移民建镇试区血吸虫病流行因素调查

目的 调查移民建镇地区血吸虫病流行因素，为制订该类地区血吸虫病控制对策提供依据。方法 选择退人不退耕的单退点和退人又退耕的双退点各2个，采用常规方法调查各试点钉螺分布、人畜感染以及滩地野粪污染情况。结果 移民建镇试区钉螺分布广，单退点感染螺密度较双退点高，两个单退点钉螺感染率分别为0．69％、1．88％，两个双退点钉螺感染率分别为0．39％、0．29％；滩地野粪污染仍较严重，尤其以单退点为甚；人、畜血吸虫感染在单退点相当严重，居民血吸虫抗体阳性率(IHA)高达20％以上，耕牛粪检阳性率最高达34．48％。结论 移民建镇地区依然存在血吸虫病流行因素，单退点血吸虫病流行更为严重。     

胶体染料试纸条试剂盒检测曼氏血吸虫病的初步研究

目的探索日本血吸虫胶体染料试纸条试剂盒(DDIA)用于检测曼氏血吸虫病的可行性。方法采用日本血吸虫DDIA检测从埃及尼罗河地区曼氏血吸虫病流行区采集的曼氏血吸虫病人血清及当地健康人血清。结果34份曼氏血吸虫病人血清DDIA均呈阳性,14份当地健康者血清均为阴性。与用曼氏血吸虫IHA和ELISA法检测结果相同。结论日本血吸虫DDIA也可用于检测曼氏血吸虫病。     

东流观测点家畜血吸虫感染情况分析

目的 了解全国畜血吸虫病流行病学东流观察点家畜血吸虫病的疫情动态。方法 对牛、羊、猪作烘便孵化法，1粪3检，检查家畜感染率，阳性畜计算毛蚴数，判定感染强度，同时进行野粪、家畜放牧情况调查。结果 4种畜血吸虫病感染率依次为黄牛（50．0％）、山羊（29．1％）、水牛（14．3％）、猪（13．3％），阳性牛以轻、重度感染居多，而小牛感染率最高。草滩均有畜粪污染。牛以放牧为主，辅之舍饲，羊散放。结论 牛是观察点主要传染源，限制牛的活动范围和进一步扩大化疗和牧场灭螺，才能有效地控制血吸虫病的流行。     

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。     

采用间接血凝试验(IHA)确定湖区血吸虫病中度流行区化疗对象的可靠性分析

目的分析ＩＨＡ法在湖区血吸虫病中度流行区确定化疗对象的可靠性。方法选择洞庭湖沿岸疫情基本一致的流行村６个,居民感染率均在１０％～１５％之间。每年对其一半人群采用ＩＨＡ法过筛,抗体滴度在１： １０及以上者作为化疗对象,同时用Ｋａｔｏ－Ｋａｔｚ粪检法考核化疗效果。结果ＩＨＡ法阳性者包括了９０．７％～９６．１％的Ｋａｔｏ－Ｋａｔｚ粪检阳性者在内。１９９７、１９９８年ＩＨＡ和粪检都为阳性的人群,１９９９年粪检阴转率为８０．５％和７７．７％。ＩＨＡ和粪检均为阴性的人群,粪检考核阴性率仍保持９６．４％到 ９８． ３％。单就１９９７年粪检阳性者而言,１９０９年粪检阴转率为 ７４． ４％。结论在湖区血吸虫病中度流行区,采用ＩＨＡ确定化疗对象,可将９０％以上的粪检阳性对象和粪检查不出的大量血吸虫病人包括在内,其阳性和阴性结果是可靠的。     

长期口服青蒿琥酯预防日本血吸虫病的现场研究

为了观察长期口服青蒿琥酯预防日本血吸虫病的效果和优化服药方案,在血吸虫病流行区,按随机配对分为青蒿琥酯组和对照组。青蒿琥酯６ｍｇ／ｋｇ顿服,以后每隔１５ｄ服１次,连续１２次,１５ｄ后再加强１次,对照组同期服安慰剂。两组人群于加强后１５ｄ用Ｋａｔｏ－ｋａｔｚ法粪检考核效果为：青蒿琥酯组４３例,粪检全部阴性;对照组５８例,。粪检阳性４例,感染率为６．９％。结果表明,尖血吸虫病疫区的感染季节,长期服青蒿     

安徽省马鞍山市移民建镇试区血吸虫病疫情观察

目的观察移民建镇地区环境改变对血吸虫病疫情的影响，为制定该类地区血吸虫病防治对策提供依据。方法选择马鞍山市退人又退耕的小黄洲村为观察对象，自2002-2005年，采用常规方法调查钉螺分布、人畜感染和滩地野粪污染情况，并观察环境变化情况，分析移民建镇地区血吸虫病疫情变化。结果2002～2005年试区活螺密度呈下降趋势，感染螺密度和钉螺感染率得到有效控制，2005年感染螺密度和钉螺感染率较2002年分别下降了74．28％和37．93％；试区居民血吸虫感染率（IHA法）呈下降趋势；2002年和2003年试区野粪虫卵阳性率分别为2．70％和36．54％，2003年以后未查见阳性野粪；移民建镇后试区滩地开发力度加大。结论移民建镇对控制血吸虫病疫情有积极意义。     

几种血清学方法诊断血吸虫病的敏感性、特异性及重现性的评价

作者指出虽然已有多种的血清学方法用于血吸虫病的诊断,但迄今尚无非常满意的和被普遍接受的一种方法。本文报告在尼日利亚对间接荧光抗体试验(IFA),补体结合试验(CF)和对流免疫电泳试验(COIE)3种方法的敏感性、特异性和重现性进行了评价。血清:3组血清均采自献血员。第1组为阳性参考共26例都是经粪或尿检出虫卵确诊的病人。6例为曼氏血吸虫病患者,20例为埃及血吸虫病患者。第2组阴性对照的均来自非流行区,过去感染史不详,粪及尿检虫卵阴性的20例。第3组592例来自尼日利亚血     

血吸虫病不同流行程度地区IHA与Kato-Katz法检出率的相关性研究

目的了解不同流行程度疫区IHA和Kato-Katz法血吸虫感染检出率之间在的相关性。方法随机选择湖沼型的高度流行村(感染率>10%)、中度流行村(感染率5%～10%之间)、低度流行村(感染率1～5%之间)各2个自然村,每村整群抽样300～500人,在感染季节后,对每人同时采用Kato-Katz法和IHA法检测。结果在受检的1831人中Kato阳性率16.66%、IHA阳性率28.18%、双阳性率6.28%。结论IHA的阳性率与血吸虫卵粪便检出率不相关,而IHA的阳性预测值与其成正相关关系,即随着地区疫情程度的加重,IHA法的筛查阳性率也随之升高。     

Kato-Katz法诊断日本血吸虫病误判因素的研究

目的探讨并分析Kato—Katz法厚涂片中血吸虫卵误判的原因,为今后的血吸虫病查病工作提供帮助。方法对三个试验点的初查Kato—Katz法血吸虫卵阳性片随机抽查5％进行复核;观察Kato—Katz法血吸虫卵阳性片在不同温度和不同时间下虫卵的形态变化。结果三个试验点总的阳性符合率为86．09％,假阳性率为13．91％。随着温度和时间的变化,血吸虫卵的形态也发生改变。结论由于血吸虫卵在Kato—Katz厚涂片中的形态与水洗片中的标准形态差异较大,且受实验条件的影响,很容易造成误判,必须加强质量控制和技术培训。     

Urinary schistosomiasis among schoolchildren in Ibadan, an urban community in south-western Nigeria

The current status of urinary schistosomiasis was assessed in Ibadan, an urban community in south-western Nigeria. Of 1331 children examined for eggs of S. haematobium in their urine, 17.4% were infected. Prevalence in postprimary schoolchildren was significantly (P < 0.01) higher (22.4%) than in primary schoolchildren (12.0%). Intensity of infection based on geometric mean egg count per 10 ml of urine was also higher in postprimary (36.7 eggs/10 ml urine) than primary pupils (29.9 eggs/10 ml urine). Boys had a significantly (P < 0.01) higher infection rate (24.1%) than girls (8.5%), and the intensity of infection was also higher (P < 0.01) in males (39.0 eggs/10 ml urine) than in females (22.1 eggs/10 ml urine). The overall geometric mean intensity of infection was highest (38.8 eggs/10 ml urine) in the 11-15 years age group. 42% of infected children excreted > 50 eggs/10 ml urine. 2.2% excreted S. mansoni eggs in urine. Water contact activities were more frequent (P < 0. 01) in males (31.8%) than females (38.2%). Nine species of snails were encountered, with B. (p) globosus being the the most abundant and widespread. These results show that urinary schistosomiasis is still being actively being transmitted in Ibadan.     

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。     

Accuracy of circulating cathodic antigen tests for rapid mapping of Schistosoma mansoni and S. haematobium infections in Southern Sudan

Objective To evaluate the diagnostic accuracy of a circulating cathodic antigen (CCA) urine dipstick test for detecting Schistosoma mansoni and S. haematobium alongside an integrated rapid mapping survey in Southern Sudan. Methods and Results A total of 373 children aged 5–16 years were included in the study. Of these 26.0% were infected with S. haematobium and 24.5% were infected with S. mansoni, as identified by urine filtration or single Kato–Katz thick smear, respectively. The CCA performed moderately in detecting S. mansoni, with sensitivity of 89.1% and specificity of 74.2%, and poorly in detecting S. haematobium infections, with a sensitivity of 36.8% and specificity of 78.9%. This may be a slight underestimate of true CCA accuracy, since only single stool and urine samples were examined by microscopy. The true ‘gold standard’ for comparison would have been the collection of multiple stool samples over consecutive days. Conclusion The poor CCA accuracy for diagnosis of urinary schistosomiasis means that this test is currently not suitable for rapid mapping of schistosomiasis in areas where both S. mansoni and S. haematobium may be endemic.     

The reliability of self-reported blood in urine and schistosomiasis as indicators of Schistosoma haematobium infection in school children: a study in Muheza District, Tanzania

The use of self-reported blood in urine and schistosomiasis by school children was investigated as a tool to estimate the prevalence of infection with Schistosoma haematobium and to identify infected individuals. A general questionnaire about common health problems, including questions about blood in urine and schistosomiasis, was administered by teachers to 25443 children in 137 primary schools in Muheza District, Tanzania. The prevalence of reported schistosomiasis was calculated for each school and used to select 15 schools across a range in prevalence. All children in the 15 schools (n = 2370) were interviewed again by a nurse and gave a urine sample which was subjected to a quantitative microscopical examination for the eggs of S. haematobium by filtration. The prevalence of reported schistosomiasis by the interview in the 15 schools correlated strongly with the prevalence reported during the questionnaire survey. The prevalence of reported schistosomiasis in the interview was strongly correlated with the prevalence of infection determined by microscopy and consistently under-estimated the latter by around 20% across a range in prevalence from 22% to 93%. The sensitivity of diagnosis by an interview increased almost linearly with the prevalence of infection, so that when the prevalence was high, more infected children reported schistosomiasis. The percentage of children who were correct in their self-diagnosis was independent of the prevalence of infection and of the mean concentration of eggs in urine, and averaged 75%. These findings suggest that self-reported schistosomiasis is a useful method to estimate the prevalence of infection in schools and might be used to identify infected individuals.     

Evaluation of Kato–Katz examination method in three areas with low-level endemicity of schistosomiasis japonica in China: A Bayesian modeling approach

The Kato–Katz technique is widely used to determine faecal egg counts of intestinal schistosomiasis. Although numerous studies have reported considerable underestimation of the ‘true’ infection prevalence while using this method, little is known regarding how many infections are missed as a function of the overall endemicity of intestinal schistosomiasis. In the present study, we used a Bayesian modeling approach to assess how much the Kato–Katz technique underestimates the prevalence of Schistosoma japonicum in three low endemic areas, characterized by different levels of infection. We found that up to 83% of S. japonicum infections were missed in an average when only a single Kato–Katz thick smear was examined. We further analyzed inter- and intra-specimen variation using agreement analysis. The results revealed a clear trend of higher agreement with infection intensity. In addition, our data also confirmed that intra-specimen consistency was better than that of inter-specimen. Our results suggest that a single Kato–Katz thick smear could only detect a certain small part of infections in areas with low endemicity; the disagreement of Kato–Katz results are mainly driven by day-to-day variation of eggs in stool; and light intensities are characterized by very high underestimation rates. There is a pressing need to develop more sensitive diagnostic tools for accurate detection of light infection intensities of schistosome infections.     

An ultra-sensitive assay targeting the circulating anodic antigen for the diagnosis of Schistosoma japonicum in a low-endemic area,People's Republic of China

The downward trend in prevalence and intensity of Schistosoma japonicum infection in the People's Republic of China (P.R. China) has reached a level where accurate methods are required for monitoring the national schistosomiasis control programme and to verify whether transmission has been interrupted. We have assessed the prevalence of active S. japonicum infection by use of an up-converting phosphor lateral-flow (UCP-LF) assay for determination of circulating anodic antigens (CAA) in urine and serum, and compared the findings with those of the Kato–Katz technique for egg detection in stool and an immunohaemagglutination assay (IHA) for specific antibodies in serum. The study was carried out in three villages located in a remaining S. japonicum-endemic area in P.R. China. Overall, 423 individuals were investigated by Kato–Katz, 395 by IHA, 371 with the UCP-LF CAA assay adapted for urine and 178 with the UCP-LF CAA assay applied on serum. The IHA showed the highest number of positive results (n = 107, 27.1%). The UCP-LF CAA urine assay detected 36 CAA positives (9.7%) and the serum-based CAA assay 21 positives (11.8%). The Kato–Katz technique revealed only six positive stool samples (1.4%). Among those 166 individuals with complete data records, sensitivities of the different assays were determined versus a combined ‘gold’ standard, showing the highest sensitivity for the urine CAA assay (93%), followed by the serum CAA (73%) and IHA (53%), whilst triplicate Kato–Katz thick smears had a very low sensitivity (13%). Serum CAA concentrations were about 10-fold higher than in urine and were significantly correlated. Highest prevalences as determined by CAA were found in older age groups (>40 years). Half of the CAA- or egg-positive cases were negative for antibodies by IHA, thereby revealing an important obstacle for the effectiveness of the current schistosomiasis control and elimination efforts. The significantly higher prevalence of active schistosome infections as shown by the urine and serum UCP-LF CAA assays has implications for the national control and elimination programme in P.R. China, particularly in respect to case-finding and intervention strategies.     

Comparative cost-effectiveness of diagnostic tests for urinary schistosomiasis and the implications for school health programmes

The use of self-reported schistosomiasis or blood in urine has received a great deal of interest as a cheap and simple technique for diagnosing individuals infected with Schistosoma haematobium and identifying schools with a high prevalence of infection. Although the answers to questions about the signs and symptoms of urinary schistosomiasis have been shown to be good markers of parasitological infection, a formal cost-effectiveness analysis of their performance in relation to urine filtration and parasitological examination (assumed to be the gold standard) is lacking. Using empirical data on the costs and effectiveness of these techniques in 15 schools in Tanzania, the cost for every correct diagnosis or for every infected child identified was assessed. Although self-reported schistosomiasis was shown to be three times more cost-effective than urine filtration in identifying infected individuals, it would have resulted in a third of the infected children being missed. Use of self-reported schistosomiasis first to identify high-risk schools for mass treatment and then to identify infected children in low-risk schools (for individual treatment) also appeared more cost-effective than urine filtration and would have resulted in only 8% of the infected children not being treated. The use of self-reported schistosomiasis or self-reported blood in urine should be continually supported as a simple, cheap and cost-effective tool for identifying schools at high-risk of schistosomiasis.     

Detection of active schistosome infection by cell-free circulating DNA of Schistosoma japonicum in highly endemic areas in Sorsogon Province,the Philippines

The current status of schistosomiasis in highly endemic areas is difficult to determine by ovum detection because of the superficially low parasite load after mass drug administration, whereas the parasite transmission rates are still high. Cell-free parasite DNA is fragments of parasite-derived DNA existing in the host's body fluids. We conducted population-based studies to test the presence of cell-free schistosome DNA in endemic areas of Sorsogon Province, the Philippines. Schistosome DNA in the serum and urine of Kato–Katz (KK)-positive subjects was detected by PCR (100% sensitivity). Schistosome DNA was also detected from KK-negative subjects (9/22 serum and 10/41 urine samples). Schistosome DNA was found to be network echogenic pattern (NW)-positive (serum 53.3%, urine 42.9%) or NW-negative (serum 25.5%, urine 20.8%) and enzyme-linked immunosorbent assay (ELISA)-positive (serum 47.1%, urine 40%) or ELISA-negative (serum 33.3%, urine 13.3%). These results indicate that cell-free schistosome DNA is a promising diagnostic marker for active schistosome infection in the case of light infection.