Objective: To compare diagnostic accuracy and agreement between direct agglutination test and rK39 rapid tests for diagnosis of visceral leishmaniasis in an endemic area, the Doka area in Eastern Sudan.Methods: Stored...Objective: To compare diagnostic accuracy and agreement between direct agglutination test and rK39 rapid tests for diagnosis of visceral leishmaniasis in an endemic area, the Doka area in Eastern Sudan.Methods: Stored sera of confirmed visceral leishmaniasis cases, unconfirmed visceral leishmaniasis-suspects and negative controls were tested by direct agglutination test and rK39 rapid test. The sera were collected from the Doka area in Eastern Sudan. Diagnostic accuracy of direct agglutination test and rK39 rapid test was assessed in terms of sensitivity, specificity, positive predictive value and negative predictive value, estimated at 95% confidence interval(CI). Agreement between the two tests was determined by the kappa(κ) value.Results: Taking lymph node aspiration of Leishmania as a gold standard, direct agglutination test showed 91.0% sensitivity, 99.3% specificity, resulting in a positive and negative predictive value of 99.3% and 91.0%, respectively. In contrast, the sensitivity of rK39 rapid test was 85.2% and specificity 98.6%, resulting in a positive and negative predictive value of 98.5% and 85.9%, respectively. Most(81.3%) of the confirmed visceral leishmaniasis sera revealed strong antibody titers(≥1:6 400). Some sera(n=5) that were positively tested with rK39 rapid test were negative in direct agglutination test(≤1:800);in contrast, direct agglutination test was positive in 12 confirmed visceral leishmaniasis sera that were negatively tested with rK39 rapid test. There was moderate to good agreement between direct agglutination test and rK39 rapid test for confirmed visceral leishmaniasis patients(κ=0.42, 95% CI=0.21-0.63) and control sera(κ=0.80, 95% CI=0.41-1.00).Conclusions: Both direct agglutination test and rK39 rapid test are satisfactory test systems for visceral leishmaniasis diagnosis in East Sudan. Their simplicity makes them ideal for first healthcare in rural areas. These data are relevant also for other East African endemic countries because of the geographical and overlapping distribution of the Leishmania parasite.展开更多
目的克隆并表达分离于我国3种类型的利什曼原虫K26基因,并用其检测我国内脏利什曼病特异性抗体,同时进行效果评价。方法分别将我国新疆喀什(KS-6株)、四川九寨沟县(SC6株)和新疆伽师县(JIASHI-1株)K26基因进行全基因合成并加入Bam H I与...目的克隆并表达分离于我国3种类型的利什曼原虫K26基因,并用其检测我国内脏利什曼病特异性抗体,同时进行效果评价。方法分别将我国新疆喀什(KS-6株)、四川九寨沟县(SC6株)和新疆伽师县(JIASHI-1株)K26基因进行全基因合成并加入Bam H I与Xho I酶切位点,分别将K26基因连接至双酶切的pET32a表达载体,转入大肠埃希菌(E.coli)BL21(DE3)中经1 mmol/L的异丙基-β-D-半乳糖苷(IPTG)进行诱导表达,用组氨酸标签亲和纯化柱(Ni-NTA树脂)纯化重组蛋白。用制备的3种抗原分别作为包被抗原,以酶联免疫吸附试验(ELISA)检测病原学确诊的内脏利什曼病患者及其它寄生虫病患者和健康者的血清中和抗体,以评价其检测的敏感性和特异性。用美国InBios公司rK39试条进行平行检测,比较3种抗原检测的敏感性。结果成功构建利什曼原虫pET32a-K26重组质粒,并在原核细胞中成功表达。以KS-6株、SC6株、JIASHI-1株利什曼原虫重组K26蛋白为包被抗原的ELISA法和rK39试条法检测黑热病患者血清的敏感性分别为90.00%(99/110)、92.73%(102/110)、90.91%(100/110)和93.64%(103/110),共检测45份其他寄生虫病患者(包括日本血吸虫病、疟疾、细粒棘球蚴病、华支睾吸虫病、卫氏并殖吸虫病和弓形虫病)的血清均无交叉反应,健康者血清(40份)也无假阳性反应,特异性均为100.00%。KS-6株、SC6株和JIASHI-1株利什曼原虫重组K26蛋白ELISA法和rK39试条法的阳性检出率差异无统计学意义(χ^(2)_(KS)-6=0.97,P=0.33;χ^(2)_(SC6)=0.07,P=0.79;χ^(2)_(JIASHI)-1=0.57,P=0.45)。3种K26抗原的阳性检出率差异无统计学意义(χ^(2)=0.53,P=0.97)。结论重组K26抗原在内脏利什曼病诊断上具有潜在的应用价值。展开更多
目的建立基于利什曼原虫K26重组抗原(Recombinant K26,rK26)检测内脏利什曼病特异抗体的胶体金免疫层析试条方法,并评价效果。方法用胶体金标记链球菌G蛋白(Streptococcal Protein G,SPG),并将其吸附于交联释放垫上;将利什曼原虫K26重...目的建立基于利什曼原虫K26重组抗原(Recombinant K26,rK26)检测内脏利什曼病特异抗体的胶体金免疫层析试条方法,并评价效果。方法用胶体金标记链球菌G蛋白(Streptococcal Protein G,SPG),并将其吸附于交联释放垫上;将利什曼原虫K26重组抗原作为包被抗原包被于硝酸纤维素膜适当位置,制成检测特异抗体的免疫层析试条。用该试条检测病原学确诊的内脏利什曼病、其它寄生虫病以及健康者血清,以评价其检测的敏感性和特异性。同时用rK39(Recombinant K39,rK39)试条进行平行检测。结果rK26试条法和rK39试条法检测内脏利什曼病患者血清的敏感性分别为91.82%(101/110)和93.64%(103/110);与10份疟疾患者血清、10份日本血吸虫病患者血清、10份细粒棘球蚴病患者血清、5份弓形虫病患者血清、5份并殖吸虫病患者血清和5份华支睾吸虫病患者血清均无交叉反应,40份健康者血清也均为阴性,rK26试条法和rK39试条法的总特异性均为100.00%。rK26试条法和rK39试条法阳性检出率之间的差异无统计学意义(χ^(2)=0.25,P=0.62),2种试条法检测黑热病患者血清的结果一致性较好(κ=0.73)。结论建立的基于利什曼原虫K26重组抗原检测内脏利什曼病的胶体金免疫层析试条敏感性、特异性均较高。展开更多
Visceral leishmaniasis or kala-azar is a potent parasitic infection causing death of thousands of people each year. Medicinal compounds currently available for the treatment of kala-azar have serious side effects and ...Visceral leishmaniasis or kala-azar is a potent parasitic infection causing death of thousands of people each year. Medicinal compounds currently available for the treatment of kala-azar have serious side effects and decreased efficacy owing to the emergence of resistant strains. The type of immune reaction is also to be considered in patients infected with Leishmania donovani （L. donovani）. For complete eradication of this disease, a high level modern research is currently being applied both at the molecular level as well as at the field level. The computational approaches like remote sensing, geographic information system （GIS） and bioinformatics are the key resources for the detection and distribution of vectors, patterns, ecological and environmental factors and genomic and proteomic analysis. Novel approaches like GIS and bioinformatics have been more appropriately utilized in determining the cause of visearal leishmaniasis and in designing strategies for preventing the disease from spreading from one region to another.展开更多
文摘Objective: To compare diagnostic accuracy and agreement between direct agglutination test and rK39 rapid tests for diagnosis of visceral leishmaniasis in an endemic area, the Doka area in Eastern Sudan.Methods: Stored sera of confirmed visceral leishmaniasis cases, unconfirmed visceral leishmaniasis-suspects and negative controls were tested by direct agglutination test and rK39 rapid test. The sera were collected from the Doka area in Eastern Sudan. Diagnostic accuracy of direct agglutination test and rK39 rapid test was assessed in terms of sensitivity, specificity, positive predictive value and negative predictive value, estimated at 95% confidence interval(CI). Agreement between the two tests was determined by the kappa(κ) value.Results: Taking lymph node aspiration of Leishmania as a gold standard, direct agglutination test showed 91.0% sensitivity, 99.3% specificity, resulting in a positive and negative predictive value of 99.3% and 91.0%, respectively. In contrast, the sensitivity of rK39 rapid test was 85.2% and specificity 98.6%, resulting in a positive and negative predictive value of 98.5% and 85.9%, respectively. Most(81.3%) of the confirmed visceral leishmaniasis sera revealed strong antibody titers(≥1:6 400). Some sera(n=5) that were positively tested with rK39 rapid test were negative in direct agglutination test(≤1:800);in contrast, direct agglutination test was positive in 12 confirmed visceral leishmaniasis sera that were negatively tested with rK39 rapid test. There was moderate to good agreement between direct agglutination test and rK39 rapid test for confirmed visceral leishmaniasis patients(κ=0.42, 95% CI=0.21-0.63) and control sera(κ=0.80, 95% CI=0.41-1.00).Conclusions: Both direct agglutination test and rK39 rapid test are satisfactory test systems for visceral leishmaniasis diagnosis in East Sudan. Their simplicity makes them ideal for first healthcare in rural areas. These data are relevant also for other East African endemic countries because of the geographical and overlapping distribution of the Leishmania parasite.
文摘目的克隆并表达分离于我国3种类型的利什曼原虫K26基因,并用其检测我国内脏利什曼病特异性抗体,同时进行效果评价。方法分别将我国新疆喀什(KS-6株)、四川九寨沟县(SC6株)和新疆伽师县(JIASHI-1株)K26基因进行全基因合成并加入Bam H I与Xho I酶切位点,分别将K26基因连接至双酶切的pET32a表达载体,转入大肠埃希菌(E.coli)BL21(DE3)中经1 mmol/L的异丙基-β-D-半乳糖苷(IPTG)进行诱导表达,用组氨酸标签亲和纯化柱(Ni-NTA树脂)纯化重组蛋白。用制备的3种抗原分别作为包被抗原,以酶联免疫吸附试验(ELISA)检测病原学确诊的内脏利什曼病患者及其它寄生虫病患者和健康者的血清中和抗体,以评价其检测的敏感性和特异性。用美国InBios公司rK39试条进行平行检测,比较3种抗原检测的敏感性。结果成功构建利什曼原虫pET32a-K26重组质粒,并在原核细胞中成功表达。以KS-6株、SC6株、JIASHI-1株利什曼原虫重组K26蛋白为包被抗原的ELISA法和rK39试条法检测黑热病患者血清的敏感性分别为90.00%(99/110)、92.73%(102/110)、90.91%(100/110)和93.64%(103/110),共检测45份其他寄生虫病患者(包括日本血吸虫病、疟疾、细粒棘球蚴病、华支睾吸虫病、卫氏并殖吸虫病和弓形虫病)的血清均无交叉反应,健康者血清(40份)也无假阳性反应,特异性均为100.00%。KS-6株、SC6株和JIASHI-1株利什曼原虫重组K26蛋白ELISA法和rK39试条法的阳性检出率差异无统计学意义(χ^(2)_(KS)-6=0.97,P=0.33;χ^(2)_(SC6)=0.07,P=0.79;χ^(2)_(JIASHI)-1=0.57,P=0.45)。3种K26抗原的阳性检出率差异无统计学意义(χ^(2)=0.53,P=0.97)。结论重组K26抗原在内脏利什曼病诊断上具有潜在的应用价值。
文摘目的建立基于利什曼原虫K26重组抗原(Recombinant K26,rK26)检测内脏利什曼病特异抗体的胶体金免疫层析试条方法,并评价效果。方法用胶体金标记链球菌G蛋白(Streptococcal Protein G,SPG),并将其吸附于交联释放垫上;将利什曼原虫K26重组抗原作为包被抗原包被于硝酸纤维素膜适当位置,制成检测特异抗体的免疫层析试条。用该试条检测病原学确诊的内脏利什曼病、其它寄生虫病以及健康者血清,以评价其检测的敏感性和特异性。同时用rK39(Recombinant K39,rK39)试条进行平行检测。结果rK26试条法和rK39试条法检测内脏利什曼病患者血清的敏感性分别为91.82%(101/110)和93.64%(103/110);与10份疟疾患者血清、10份日本血吸虫病患者血清、10份细粒棘球蚴病患者血清、5份弓形虫病患者血清、5份并殖吸虫病患者血清和5份华支睾吸虫病患者血清均无交叉反应,40份健康者血清也均为阴性,rK26试条法和rK39试条法的总特异性均为100.00%。rK26试条法和rK39试条法阳性检出率之间的差异无统计学意义(χ^(2)=0.25,P=0.62),2种试条法检测黑热病患者血清的结果一致性较好(κ=0.73)。结论建立的基于利什曼原虫K26重组抗原检测内脏利什曼病的胶体金免疫层析试条敏感性、特异性均较高。
文摘Visceral leishmaniasis or kala-azar is a potent parasitic infection causing death of thousands of people each year. Medicinal compounds currently available for the treatment of kala-azar have serious side effects and decreased efficacy owing to the emergence of resistant strains. The type of immune reaction is also to be considered in patients infected with Leishmania donovani （L. donovani）. For complete eradication of this disease, a high level modern research is currently being applied both at the molecular level as well as at the field level. The computational approaches like remote sensing, geographic information system （GIS） and bioinformatics are the key resources for the detection and distribution of vectors, patterns, ecological and environmental factors and genomic and proteomic analysis. Novel approaches like GIS and bioinformatics have been more appropriately utilized in determining the cause of visearal leishmaniasis and in designing strategies for preventing the disease from spreading from one region to another.
