快速免疫色谱测试法诊断恶性疟的初步观察

目的：评价快速免疫色谱测试法（ＩＣＴ）在我国疟区门诊疟疾的适用性。方法：以镜检结果为对照，用ＩＣＴ方法检测门诊“四热”病人中的恶性疟。结果：ＩＣＴ检测恶性疟的敏感性和特异性分别为９４．７％和９０．３％，与间日疟无交叉，检测不同性别和民族人群阳性率间的差别无显著意义。结论：ＩＣＴ较镜检诊断恶性疟更为快速且简便，更适于在疟区门诊应用。     

快速免疫色谱测试法诊断恶性疟的初步观察

目的：评价快速免疫色谱测试法（ＩＣＴ）在我国疟区门诊疟疾的适用性。方法：以镜检结果为对照，用ＩＣＴ方法检测门诊“四热”病人中的恶性疟。结果：ＩＣＴ检测恶性疟的敏感性和特异性分别为９４．７％和９０．３％，与间日疟无交叉，检测不同性别和民族人群阳性率间的差别无显著意义。结论：ＩＣＴ较镜检诊断恶性疟更为快速且简便，更适于在疟区门诊应用。     

双重免疫色谱技术检测恶性疟和间日疟的初步观察

用双重免疫色谱技术（ＩＣＴ）对疟区门诊的“四热”病人进行疟疾检查,以镜检结果为对照,评价ＩＣＴ诊断疟疾的效果。检测９３例,敏感度和特异性恶性疟为９１．７％和９４．７％,间日疟为８８．２％和１００％,两者之间无交叉反应。显示双重ＩＣＴ检测疟疾快速简便,准确性高,且能区分虫种,具有广阔的应用前景。     

疟疾复合PCR检测系统的建立

目的：建立简易、快速的复合ＰＣＲ系统,用于检测间日疟、恶性疟及混合感染。方法：以疟原虫小亚单位核糖体核糖核酸基因为靶片段,设计疟原虫属特异性上游引物Ｓ１和间日疟原虫、恶性疟原虫种特异性下游引物Ｓ２和Ｓ３,建立双温度点复合ＰＣＲ扩增系统并用于临床血样的检测。结果：从间日疟原虫和恶性疟原虫感染血样中分别扩增出７０５ｂｐ和５７５ｂｐ特定扩增带,而食蟹猴疟原虫、诺氏疟原虫及健康人血样均未见扩增带。检测原虫水平达２－１０虫／μｌ全血。限制性内切酶酶切分析证实扩增产物为目的片段。检测１０４份镜检确诊疟疾患者血样,其中８１份与镜检结果相符,并查出镜检未发现的１７份混合感染和２份虫种鉴别失误的恶性疟。结论：本系统敏感性高,特异性强,操作简便,可在一次扩增中同时检出间日疟和恶性疟两种原虫。     

PCR检测疟疾混合感染的现场应用研究

目的 评价PCR检测技术在间日疟与恶性疟混合感染区诊断疟疾的现场应用价值。方法 采集海南省疟疾混合感染流行区304份滤纸干血滴样本，根据红内期疟原虫SSUrRNA基因序列，设计合成3条引物．采用PCR技术在同一反应体系中扩增出间日疟原虫和恶性疟原虫不同的DNA片段，检测现场所采样本中的间日疟原虫或恶性疟原虫DNA；同时与镜检法进行比较。结果 在304份样本中，PCR法阳性15份，其中间日疟7份．恶性疟8份；镜检法阳性11份，其中间日疟6份，恶性疟5份。镜检阳性的样本PCR均为阳性；镜检阴性而PCR阳性的4份样本，其扩增产物经限制性酶切鉴定，证实为间日疟原虫或恶性疟原虫DNA。结论 此PCR检测体系灵敏、特异．对诊断或鉴别诊断间日疟原虫和恶性疟原虫混合感染具有实用价值。     

PCR检测疟疾混合感染的现场应用研究

目的　评价PCR检测技术在间日疟与恶性疟混合感染区诊断疟疾的现场应用价值。　方法　采集海南省疟疾混合感染流行区 3 0 4份滤纸干血滴样本 ,根据红内期疟原虫SSUrRNA基因序列 ,设计合成 3条引物 ,采用PCR技术在同一反应体系中扩增出间日疟原虫和恶性疟原虫不同的DNA片段 ,检测现场所采样本中的间日疟原虫或恶性疟原虫DNA ;同时与镜检法进行比较。　结果　在 3 0 4份样本中 ,PCR法阳性 15份 ,其中间日疟 7份 ,恶性疟 8份 ;镜检法阳性11份 ,其中间日疟 6份 ,恶性疟 5份。镜检阳性的样本PCR均为阳性 ;镜检阴性而PCR阳性的 4份样本 ,其扩增产物经限制性酶切鉴定 ,证实为间日疟原虫或恶性疟原虫DNA。　结论　此PCR检测体系灵敏、特异 ,对诊断或鉴别诊断间日疟原虫和恶性疟原虫混合感染具有实用价值。     

套式PCR检测蚊体内疟原虫的研究

目的建立一种敏感、特异而快速的检测蚊体内疟原虫的方法。方法采用套式PCR方法,对人工感染间日疟原虫的嗜人按蚊、感染恶性疟和混合感染间日疟与恶性疟的大劣按蚊以及流行季节现场捕获的中华按蚊体内的疟原虫进行检测。结果28批人工感染间日疟原虫的嗜人按蚊、2批人工感染恶性疟的大劣按蚊和1批混合感染间日疟与恶性疟的大劣按蚊的检测结果与镜检结果符合率为100%;589只现场捕获的中华按蚊中,发现间日疟原虫阳性2只,阳性率为0.34%。结论本方法能快速而敏感地检出蚊体内不同种疟原虫。     

应用巢式PCR评价低流行区疟疾诊断结果

目的初步评价大连市疾控人员对疟疾的诊断能力,为低流行区疟疾诊断方法的选择提供理论依据。方法收集2010--2012年大连市上报的27例疟疾阳性病例的血液样本．应用巢式PCR（nest—PCR）方法对诊断结果进行复核：以复核结果为标准,比较镜检和快速诊断试剂盒（rapid diagnosistest．RDT）方法的检测敏感性及对虫种鉴定的正确率。结果27份样本的巢式PCR结果为恶性疟23份,间日疟2份,卵形疟l份,阴性1份,无混合感染。镜检对阳性样本的敏感度为76．9％（20／26）,远低于RDT方法的96．2％（25／26）;镜检和RDT联合使用,敏感度可达100％。对虫种的鉴别,镜检对阳性样本的正确检测率为50％（13／26）：RDT方法仅能鉴别恶性疟和非恶性疟．对恶性疟阳性样本的正确检测率为100％（23／23）。结论采用镜检和RDT联合应用的方法,能够提高检测的敏感性。建议在有条件的疾控单位建立人体疟原虫的分子检测体系．更有效地防止对疟疾病例的漏诊和误诊。     

应用聚合酶链反应在海南检测间日疟原虫的效果

目的： 建立适合疟疾流行区现场应用的ＰＣＲ 检测间日疟的方法, 并在现场与常规涂片镜检法进行比较。方法： 通过改良血样的采集及模板处理, 设计引物及优化反应条件等, 建立简便、敏感与特异的ＰＣＲ检测间日疟原虫的方法, 并在海南省疟疾流行区对３１０ 例间日疟患者与镜检法进行比较。结果： ＰＣＲ 检测间日疟原虫具有特异性, 其敏感性为１０ 个原虫／μｌ。ＰＣＲ检测和镜检法的阳性率分别为３４．２％ 和３１．９％ , 与ＰＣＲ比较, 镜检法有５ 例误诊或漏诊。结论： 此ＰＣＲ 法可用于现场检测间日疟患者。     

PCR鉴别诊断间日疟及恶性疟的研究

目的 :在同一反应体系中建立能鉴别诊断间日疟与恶性疟的 PCR检测方法。方法 :根据红内期疟原虫 SSUr RNA编码基因序列 ,设计合成 3个引物 ,采用聚合酶链反应技术 ,在同一反应体系中 ,间日疟原虫和恶性疟原虫分别预期被扩增出 34 1bp和 4 31bp的 DNA条带。结果 :间日疟原虫和恶性疟原虫模板在同一反应体系中分别被扩增出预期大小的 DNA片段 ,并经限制性酶切证实 ;杜氏利什曼原虫、弓形虫、健康人血及空白对照均无特异性扩增条带 ;以该检测体系至少可检出原虫血症为 2 .56× 10 ^-7间日疟原虫感染和 1.0 8× 10 ^-5恶性疟原虫感染 ;69份镜检阳性的间日疟和 2份恶性疟患者血样 PCR检测均为阳性 ,1例发热待查患者PCR诊断为间日疟 ,与镜检复查结果一致 ,所有疟疾阳性标本中未检出混合感染 ,2 0份健康人血 PCR均为阴性。结论 :该检测体系灵敏、特异 ,对于诊断间日疟和恶性疟以及鉴别间日疟原虫和恶性疟原虫混合感染具有一定的应用价值。     

Field evaluation of the ICT malaria P.f/P.v immunochromatographic test for diagnosis of Plasmodium falciparum and P.vivax infection in forest villages of Chhindwara, central India

A rapid new immunochromatographic test (ICT malaria P.f/P.v) for diagnosis of Plasmodium falciparum and P.vivax was evaluated against thick blood smears in forest villages of Chhindwara, Madhya Pradesh, where both Plasmodium falciparum and P.vivax are prevalent. 344 symptomatic patients (Gond ethnic tribe) in five villages were screened by field staff of the Malaria Research Centre in October 1999. For P.falciparum, the ICT was 97.5% sensitive and 88% specific, with a positive predictive value (PPV) of 87.6% and a negative predictive value (NPV) of 97.6%. For P.vivax the sensitivity was only 72%, the specificity 99%, with a PPV of 92% and an NPV of 96%. Although a negative test result was inadequate to exclude parasitaemia < or = 300/microl for P.falciparum and < or = 1500/microl for P.vivax, the test is potentially useful in remote areas.     

Diagnosis of imported malaria by Plasmodium lactate dehydrogenase (pLDH) and histidine-rich protein 2 (PfHRP-2)-based immunocapture assays.

This study was conducted to evaluate the performance of two rapid non-microscopic assays: Plasmodium lactate dehydrogenase (pLDH) assay (OptiMAL) and Plasmodium falciparum histidine-rich protein 2 (PfHRP-2) assay (ICT Malaria). The assays were used to detect malaria infection in 515 immigrants living in Kuwait. The performance of both assays was compared to that of microscopy of Giemsa-stained thick blood films and to each other. Of the 515 patients tested, 163 were positive for malaria parasites by microscopy of thick blood film. Of these, 87 were infected with Plasmodium vivax parasites, 63 with P. falciparum, 1 with Plasmodium malariae, and 12 had mixed infections of P. falciparum and P. vivax. The PfHRP-2 assay detected 53 P. falciparum infections and, as expected, failed to detect all but one case of P. vivax. Three cases of mixed infections were also not detected by this assay. The pLDH assay detected 56 P. falciparum cases and 77 P. vivax infections but failed to detect 4 cases of mixed infections. Compared to microscopy, the performance of both the assays to diagnose P. falciparum infection was comparable. The sensitivity for the PfHRP-2 assay was 82% with a specificity of 99.0% and for the pLDH assay the sensitivity was 89% with a specificity of 99.5%. The PfHRP-2 assay detected 4 false positive cases, 2 of which were also detected by the pLDH assay. These patients reported treatment with chloroquine in the last 2-5 weeks. Though the immunocapture diagnostic assays may be helpful in certain situations, microscopy of thick blood film is still the method of choice in diagnosing imported malaria.     

复式PCR检测恶性疟原虫与间日疟原虫的研究

目的： 建立在同一次扩增中即可鉴别患者感染的疟原虫虫种的复式ＰＣＲ检测方法。方法： 根据恶性疟原虫（Ｐ．ｆ．）中度重复基因序列ｐＢＲＫ１－１４ 和间日疟原虫（Ｐ．ｖ．）线粒体细胞色素Ｃ氧化酶基因ＣＯＩＩＩ合成引物,采用经优化的ＰＣＲ反应体系, 对疟原虫ＤＮＡ模板进行扩增。结果： Ｐ．ｆ．与Ｐ．ｖ．分别被扩增出２０６ 和３７０ ｂｐ 大小的ＤＮＡ片段,与人白细胞ＤＮＡ 无交叉;用该反应体系至少可检测出原虫血症为５×１０－ ７的Ｐ．ｆ．感染和１．０２×１０－ ６ Ｐ．ｖ．感染; 自云南疟疾流行区采集的７８３份滤纸干血滴样本中, 复式ＰＣＲ法阳性检出率为８５．８％ , 误诊率为０, 漏诊率为０．１％ , 而镜检法依次分别为８４．９％ 、３．１％ 和１．０％ , 两者符合率为９５．８％ 。结论： 本复式ＰＣＲ检测疟原虫较镜检敏感、特异, 适用于我国恶性疟与间日疟混合流行区的疟疾诊断、流行病学调查、药物的疗效考核和献血员的筛选等。     

ELISA检测云南按蚊环子孢子蛋白的评价

目的　采用酶联免疫吸附测定(ELISA)技术检测疟疾媒介按蚊环子孢子蛋白(CSP),评价ELISA用于云南疟疾媒介按蚊传疟效能调查的可行性。　方法　现场捕获疟疾媒介按蚊经产蚊,每只蚊镜检3叶唾腺子孢子感染率,ELISA检测另3叶唾腺CSP;用含间日疟原虫配子体的患者血人工喂饲微小按蚊,11d后同法镜检唾腺子孢子感染率及ELISA检测唾腺CSP。在种植场捕获8种按蚊(微小按蚊、中华按蚊、多斑按蚊、迷糊按蚊、可赫按蚊、带足按蚊、菲律宾按蚊和须喙按蚊 )各龄成蚊,ELISA检测唾腺CSP。　结果　①现场捕获经产蚊1010只,镜检唾腺子孢子阳性7只,阳性率为0.69%;ELISA检测唾腺CSP阳性8只,阳性率为0.79%;其中6只蚊两项检测均为阳性,阳性率为0.59%。两法比较,差异无显著性意义(P>0.05)。②人工感染36只微小按蚊,镜检唾腺子孢子阳性27只,阳性率为75.0%;ELISA检测唾腺CSP阳性29只,阳性率为80.6%;其中有26只蚊两项检测(Pv2 10CSP)均阳性,阳性率为72.2%。两法比较,差异无显著性意义(P>0.05)。③种植场捕获8种按蚊各龄成蚊4675只,ELISA检测唾腺CSP阳性11只,阳性率为0.24%;其中Pv210阳性9只,Pf2A10阳性2只;微小按蚊、中华按蚊和多斑按蚊ELISA检测阳性     

间日疟原虫、恶性疟原虫和伯氏疟原虫各期的提纯和分离

用纤维素(Cellulose,CF-11)过滤去除白细胞后再用 Percoll 密度梯度离心方法提纯分离间日疟(P.v.)、恶性疟(P.f.)和伯氏疟(P.b.)3种疟原虫。经纤维素过滤后,P.v.病人血和P.b.感染鼠血中白细胞去除率分别平均达 94.7％和 75.4％,而且不影响原虫密度和各期构成比。多个 Percoll 不连续梯度离心测试3种疟原虫裂殖体、滋养体、环状体和未感染红细胞的相对平均密度(kg/L):P.v.分别为 1.059、1.072、1.096 和 1.099;P.f.分别为 1.070、1.079、1.10 和 1.10,配子体 1.085;P.b.分别为 1.059、1.062、1.103 和 1.104。并据此选择各自合适的 Percoll 梯度分离3 种疟原虫,将裂殖体、滋养体同环状体分开,获取原虫纯度(原虫数/100 个红细胞),P.v.由分离前 0.8％至分离后 93.5％,P.f.由2.3％至100％,P.b.由 30.6％至93％,分别提高 113.8、43.4和 2倍。     

食蟹猴疟原虫和恶性疟原虫两种抗原检测不同疟区人群中间接荧光抗体的实用性

[目的 ]比较食蟹猴疟原虫 (P c.)和恶性疟原虫 (P f.)两种抗原在不同疟区人群疟疾抗体检测的实用性。 [方法 ]1997年 5～ 10月在海南省间日疟和恶性疟混合流行区及河南省单纯间日疟区用P c 和P f 两种抗原测试人群疟疾抗体。 [结果 ]在海南省间日疟和恶性疟混合流行区P c 和P f 两种抗原检测人群疟疾间接荧光抗体阳性率分别为 37 4%和 31 3% ,其阳性符合率为 83 9% ;河南省单纯间日疟流行区的P f和P c两种抗原阳性率分别为 2 3 0 %和 9 7% ,阳性GMRT分别为 42 9%和 2 9 3%。 [结论 ]间日疟和恶性疟混合流行区P f和P c两种抗原均可用于人群疟疾抗体的检测 ,而单纯间日疟地区则以P c 抗原为优。     

Comparison of three antigen detection methods for diagnosis and therapeutic monitoring of malaria: a field study from southern Vietnam

OBJECTIVES: To compare the sensitivity, specificity and post-treatment persistence of three commonly used rapid antigen detection methods. METHOD: We studied 252 Vietnamese patients aged from 4 to 60 years, 157 with falciparum and 95 with vivax malaria and 160 healthy volunteers. An initial blood sample was taken for microscopy, and OptiMAL, immunochromatographic test (ICT) malaria P.f./P.v. and Paracheck-Pf tests. Patients with falciparum malaria were treated with an artesunate-based combination regimen and those with vivax malaria received chloroquine. Eighty-seven patients with falciparum malaria who were initially positive for one of the antigen tests and who remained blood smear-negative underwent follow-up testing over 28 days. RESULTS: Paracheck-Pf was the most sensitive test for Plasmodium falciparum (95.8% vs. 82.6% for ICT malaria P.f./P.v. and 49.7% for OptiMAL). Specificities were all 100%. For vivax malaria, OptiMAL performed better than ICT malaria P.f./P.v. (sensitivities 73.7% and 20.0%, respectively), with 100% specificity in both cases. All tests had low sensitivities (< or = 75.0%) at parasitaemias < 1000/microl regardless of malaria species. During follow-up, Paracheck-Pf remained positive in the greatest proportion of patients, especially at higher parasitaemias (> 10,000/microl). Residual OptiMAL positivity occurred only in a relatively small proportion of patients (< 10%) with parasitaemias > 10,000/microl during the first 2 weeks after treatment. CONCLUSIONS: Although microscopy remains the gold standard for malaria diagnosis, Paracheck-Pf may prove a useful adjunctive test in uncomplicated falciparum malaria in southern Vietnam. OptiMAL had the lowest sensitivity for P. falciparum but it might have a use in the diagnosis of vivax malaria and perhaps to monitor efficacy of treatment for falciparum malaria where microscopy is unavailable.