Background Passive diagnosis of human African trypanosomiasis(HAT)at the health facility level is a major component of HAT control in Guinea.We examined which clinical signs and symptoms are associated with HAT,and as...Background Passive diagnosis of human African trypanosomiasis(HAT)at the health facility level is a major component of HAT control in Guinea.We examined which clinical signs and symptoms are associated with HAT,and assessed the performance of selected clinical presentations,of rapid diagnostic tests(RDT),and of reference laboratory tests on dried blood spots(DBS)for diagnosing HAT in Guinea.Method The study took place in 14 health facilities in Guinea,where 2345 clinical suspects were tested with RDTs(HAT Sero-K-Set,rHAT Sero-Strip,and SD Bioline HAT).Seropositives underwent parasitological examination(reference test)to confirm HAT and their DBS were tested in indirect enzyme-linked immunoassay(ELISA)/Trypanosoma brucei gambiense,trypanolysis,Loopamp Trypanosoma brucei Detection kit(LAMP)and m18S quantitative PCR(qPCR).Multivariable regression analysis assessed association of clinical presentation with HAT.Sensitivity,specificity,positive and negative predictive values of key clinical presentations,of the RDTs and of the DBS tests for HAT diagnosis were determined.Results The HAT prevalence,as confirmed parasitologically,was 2.0%(48/2345,95%CI:1.5–2.7%).Odds ratios(OR)for HAT were increased for participants with swollen lymph nodes(OR=96.7,95%CI:20.7–452.0),important weight loss(OR=20.4,95%CI:7.05–58.9),severe itching(OR=45.9,95%CI:7.3–288.7)or motor disorders(OR=4.5,95%CI:0.89–22.5).Presence of at least one of these clinical presentations was 75.6%(95%CI:73.8–77.4%)specific and 97.9%(95%CI:88.9–99.9%)sensitive for HAT.HAT Sero-K-Set,rHAT Sero-Strip,and SD Bioline HAT were respectively 97.5%(95%CI:96.8–98.1%),99.4%(95%CI:99.0–99.7%)and 97.9%(95%CI:97.2–98.4%)specific,and 100%(95%CI:92.5–100.0%),59.6%(95%CI:44.3–73.3%)and 93.8%(95%CI:82.8–98.7%)sensitive for HAT.The RDT’s positive and negative predictive values ranged from 45.2–66.7%and 99.2–100%respectively.All DBS tests had specificities≥92.9%.While LAMP and m18S qPCR sensitivities were below 50%,trypanolysis and ELISA/T.b.gambiense had sensitivities of 85.3%(95%CI:68.9–95.0%)and 67.6%(95%CI:49.5–82.6%).Conclusions Presence of swollen lymph nodes,important weight loss,severe itching or motor disorders are simple but accurate clinical criteria for HAT referral in HAT endemic areas in Guinea.Diagnostic performances of HAT Sero-K-Set and SD Bioline HAT are sufficient for referring positives to microscopy.Trypanolysis on DBS may discriminate HAT patients from false RDT positives.展开更多
Background Malaria continues to cause burden in various parts of the world.Haiti,a Caribbean country,is among those aiming to eliminate malaria within a few years.Two surveys were conducted in Haiti during which we ai...Background Malaria continues to cause burden in various parts of the world.Haiti,a Caribbean country,is among those aiming to eliminate malaria within a few years.Two surveys were conducted in Haiti during which we aimed to evaluate the performance of the simple and rapid procedure for ultra-rapid extraction-loop-mediated isothermal amplifcation(PURE-LAMP)method with dried blood spots as an alternative diagnostic method for malaria in the context of low to very low rates of transmission.Methods Febrile and afebrile people were recruited from three administrative divisions within Haiti:Nippes,Sud and Grand’Anse,during the summers of 2017(early August to early September)and 2018(late July to late August).Their blood samples were tested by microscopy,rapid diagnostic tests(RDT),PURE-LAMP and nested PCR to detect Plasmodium infection.Sensitivity,specifcity,positive and negative predictive values and kappa statistics were estimated with the nested PCR results as the gold standard.Results Among 1074 samples analyzed,a positive rate of 8.3%was calculated based on the nested PCR results.Among febrile participants,the rates in 2017 and 2018 were 14.6%and 1.4%,respectively.Three positives were detected among 172 afebrile participants in 2018 by PURE-LAMP and nested PCR,and all three were from the same locality.There was no afebrile participants recruited in 2017.The PURE-LAMP,RDT and microscopy had respective sensitivities of 100%,85.4%and 49.4%.All of the testing methods had specifcities over 99%.Conclusions This study confrmed the high performance of the PURE-LAMP method to detect Plasmodium infection with dried blood spots and recommends its use in targeted mass screening and treatment activities in low endemic areas of malaria.展开更多
目的探讨假性缺陷等位基因携带情况对荧光法检测干血滤纸片酸性葡萄糖苷酶(GAA)活性进行新生儿糖原贮积病n型(G S D n)筛查的影响。方法对2017年5至12月上海交通大学医学院附属新华医院新生儿疾病筛查中心的30507份新生儿干血滤纸片(dri...目的探讨假性缺陷等位基因携带情况对荧光法检测干血滤纸片酸性葡萄糖苷酶(GAA)活性进行新生儿糖原贮积病n型(G S D n)筛查的影响。方法对2017年5至12月上海交通大学医学院附属新华医院新生儿疾病筛查中心的30507份新生儿干血滤纸片(dried blood spot,DBS)通过荧光法检测其酸性a-葡萄糖苷酶(GAA)活性进行GSDII筛查,对筛查疑似阳性新生儿原DBS经GAA基因分析确认其基因突变及假性缺陷等位基因的携带情况。回顾性分析3172例非GSDII人群和36例GSDII患者中假性缺陷等位基因携带情况,采用卡方检验或Fisher确切概率法对假性缺陷等位基因携带频率进行数据统计分析。结果30507份新生儿DBS标本GAA酶活性呈正偏态分布,初次和二级筛查检出29例新生儿疑似阳性,GAA基因分析未发现GSD I I患者,但该29例中24例携带纯合假性缺陷等位基因c.[1726A/A;2065A/A],5例携带杂合假性缺陷等位基因c.[1726G/A;2065G/A]。3172例非GSD I I人群中假性缺陷等位基因c.1726G>A纯合子频率为2.08%(66/3172),当c.1726 G>A纯合突变时,同时发生c.2065 G>A纯合突变频率为100%(66/66),c.[1726A;2065A]单倍体型频率为3.2%(206/6344)。36例GSD I I患者中6例(16.67%,6/36)携带纯合假性缺陷等位基因c.[1726A/A;2065A/A],显著高于非GSDII人群(2.08%,66/3172)(P<0.001,x2=34.517)。结论假性缺陷等位基因在中国人群中携带率较高,可导致荧光法检测GAA酶活性进行新生儿GSDII筛查的假阳性率升高,新生儿筛查后对原干血滤纸片的基因检测可降低其对新生儿筛查的影响。展开更多
文摘Background Passive diagnosis of human African trypanosomiasis(HAT)at the health facility level is a major component of HAT control in Guinea.We examined which clinical signs and symptoms are associated with HAT,and assessed the performance of selected clinical presentations,of rapid diagnostic tests(RDT),and of reference laboratory tests on dried blood spots(DBS)for diagnosing HAT in Guinea.Method The study took place in 14 health facilities in Guinea,where 2345 clinical suspects were tested with RDTs(HAT Sero-K-Set,rHAT Sero-Strip,and SD Bioline HAT).Seropositives underwent parasitological examination(reference test)to confirm HAT and their DBS were tested in indirect enzyme-linked immunoassay(ELISA)/Trypanosoma brucei gambiense,trypanolysis,Loopamp Trypanosoma brucei Detection kit(LAMP)and m18S quantitative PCR(qPCR).Multivariable regression analysis assessed association of clinical presentation with HAT.Sensitivity,specificity,positive and negative predictive values of key clinical presentations,of the RDTs and of the DBS tests for HAT diagnosis were determined.Results The HAT prevalence,as confirmed parasitologically,was 2.0%(48/2345,95%CI:1.5–2.7%).Odds ratios(OR)for HAT were increased for participants with swollen lymph nodes(OR=96.7,95%CI:20.7–452.0),important weight loss(OR=20.4,95%CI:7.05–58.9),severe itching(OR=45.9,95%CI:7.3–288.7)or motor disorders(OR=4.5,95%CI:0.89–22.5).Presence of at least one of these clinical presentations was 75.6%(95%CI:73.8–77.4%)specific and 97.9%(95%CI:88.9–99.9%)sensitive for HAT.HAT Sero-K-Set,rHAT Sero-Strip,and SD Bioline HAT were respectively 97.5%(95%CI:96.8–98.1%),99.4%(95%CI:99.0–99.7%)and 97.9%(95%CI:97.2–98.4%)specific,and 100%(95%CI:92.5–100.0%),59.6%(95%CI:44.3–73.3%)and 93.8%(95%CI:82.8–98.7%)sensitive for HAT.The RDT’s positive and negative predictive values ranged from 45.2–66.7%and 99.2–100%respectively.All DBS tests had specificities≥92.9%.While LAMP and m18S qPCR sensitivities were below 50%,trypanolysis and ELISA/T.b.gambiense had sensitivities of 85.3%(95%CI:68.9–95.0%)and 67.6%(95%CI:49.5–82.6%).Conclusions Presence of swollen lymph nodes,important weight loss,severe itching or motor disorders are simple but accurate clinical criteria for HAT referral in HAT endemic areas in Guinea.Diagnostic performances of HAT Sero-K-Set and SD Bioline HAT are sufficient for referring positives to microscopy.Trypanolysis on DBS may discriminate HAT patients from false RDT positives.
文摘Background Malaria continues to cause burden in various parts of the world.Haiti,a Caribbean country,is among those aiming to eliminate malaria within a few years.Two surveys were conducted in Haiti during which we aimed to evaluate the performance of the simple and rapid procedure for ultra-rapid extraction-loop-mediated isothermal amplifcation(PURE-LAMP)method with dried blood spots as an alternative diagnostic method for malaria in the context of low to very low rates of transmission.Methods Febrile and afebrile people were recruited from three administrative divisions within Haiti:Nippes,Sud and Grand’Anse,during the summers of 2017(early August to early September)and 2018(late July to late August).Their blood samples were tested by microscopy,rapid diagnostic tests(RDT),PURE-LAMP and nested PCR to detect Plasmodium infection.Sensitivity,specifcity,positive and negative predictive values and kappa statistics were estimated with the nested PCR results as the gold standard.Results Among 1074 samples analyzed,a positive rate of 8.3%was calculated based on the nested PCR results.Among febrile participants,the rates in 2017 and 2018 were 14.6%and 1.4%,respectively.Three positives were detected among 172 afebrile participants in 2018 by PURE-LAMP and nested PCR,and all three were from the same locality.There was no afebrile participants recruited in 2017.The PURE-LAMP,RDT and microscopy had respective sensitivities of 100%,85.4%and 49.4%.All of the testing methods had specifcities over 99%.Conclusions This study confrmed the high performance of the PURE-LAMP method to detect Plasmodium infection with dried blood spots and recommends its use in targeted mass screening and treatment activities in low endemic areas of malaria.
文摘目的探讨假性缺陷等位基因携带情况对荧光法检测干血滤纸片酸性葡萄糖苷酶(GAA)活性进行新生儿糖原贮积病n型(G S D n)筛查的影响。方法对2017年5至12月上海交通大学医学院附属新华医院新生儿疾病筛查中心的30507份新生儿干血滤纸片(dried blood spot,DBS)通过荧光法检测其酸性a-葡萄糖苷酶(GAA)活性进行GSDII筛查,对筛查疑似阳性新生儿原DBS经GAA基因分析确认其基因突变及假性缺陷等位基因的携带情况。回顾性分析3172例非GSDII人群和36例GSDII患者中假性缺陷等位基因携带情况,采用卡方检验或Fisher确切概率法对假性缺陷等位基因携带频率进行数据统计分析。结果30507份新生儿DBS标本GAA酶活性呈正偏态分布,初次和二级筛查检出29例新生儿疑似阳性,GAA基因分析未发现GSD I I患者,但该29例中24例携带纯合假性缺陷等位基因c.[1726A/A;2065A/A],5例携带杂合假性缺陷等位基因c.[1726G/A;2065G/A]。3172例非GSD I I人群中假性缺陷等位基因c.1726G>A纯合子频率为2.08%(66/3172),当c.1726 G>A纯合突变时,同时发生c.2065 G>A纯合突变频率为100%(66/66),c.[1726A;2065A]单倍体型频率为3.2%(206/6344)。36例GSD I I患者中6例(16.67%,6/36)携带纯合假性缺陷等位基因c.[1726A/A;2065A/A],显著高于非GSDII人群(2.08%,66/3172)(P<0.001,x2=34.517)。结论假性缺陷等位基因在中国人群中携带率较高,可导致荧光法检测GAA酶活性进行新生儿GSDII筛查的假阳性率升高,新生儿筛查后对原干血滤纸片的基因检测可降低其对新生儿筛查的影响。
