Background:There is significant need for accurate diagnostic tools for Cryptosporidium spp.and Qiordia duodenalis infections in resource limited countries where diarrhoeal disease caused by these parasites is often pr...Background:There is significant need for accurate diagnostic tools for Cryptosporidium spp.and Qiordia duodenalis infections in resource limited countries where diarrhoeal disease caused by these parasites is often prevalent.The present study assessed the diagnostic performance of three commercially available rapid diagnostic tests(RDTs)based on faecal-antigen detection for Cryptosporidium spp.and/or G.duodenalis infections in stool samples of children admitted with severe acute malnutrition(SAM)and diarrhoea.An established multiplex PCR was used as reference test.Methods:Stool samples from children with SAM and diarrhoea enrolled in a randomized controlled trial(registered at clinicaltrials.gov/ct2/show/NCT02246296)in Malawi(n=175)and Kenya(n=120)between December 2014 and December 2015 were analysed by a multiplex PCR for the presence of Cryptosporidium sppv G.duodenalis or Entomoebo histolytica parasite DNA.Cryptosporidium-positive samples were species typed using restriction fragment length polymorphism analysis.A sub-sample of the stool specimens(n=236)was used for testing with three different RDTs.Diagnostic accuracy of the tests under evaluation was assessed using the results of PCR as reference standard using MedCalc software.Pearson Chi-square test and Fisher's exact test were used to determine(significant)difference between the number of cryptosporidiosis or giardiasis cases found by PCR in Malawi and Kenya.The overall diagnostic accuracy of each RDT was calculated by plotting a receiver operating characteristic(ROC)curve for each test and to determine the area under the curve(AUC)using SPSS8 software.Results:Prevalence of Cryptosporidium spp.by PCR was 20.0 and 21.7%in Malawi and Kenya respectively,mostly C.hominis.G.duodenalis prevalence was 23.4 and 5.8%in Malawi and Kenya respectively.E histolytica was not detected by PCR.RDT testing followed the same pattern of prevalence.RDT sensitivities ranged for cryptosporidiosis from 42.9 to 76.9%and for G.duodenalis from 48.2 to 85.7%.RDT specificities ranged from 88.4 to 100%for Cryptosporidium spp.and from 91.2 to 99.2%for G.duodenalis infections.Based on the estimated area under the curve(AUC)values,all tests under evaluation had an acceptable overall diagnostic accuracy(>0.7),with the exception of one RDT for Cryptosporidium spp.in Malawi.Conclusions:All three RDTs for Cryptosporidium spp.and Giardia duodenalis evaluated in this study have a moderate sensitivity,but sufficient specificity.The main value of the RDTs is within their rapidness and their usefulness as screening assays in surveys for diarrhoea.展开更多
Background:Fever remains a major public health problem.In Burkina Faso,more than half of febrile children are considered not to be infected by malaria.This study prospectively assessed probable(treatable)causes of fev...Background:Fever remains a major public health problem.In Burkina Faso,more than half of febrile children are considered not to be infected by malaria.This study prospectively assessed probable(treatable)causes of fever in Burkinabe children.Methods:A prospective study was conducted among febrile children(≥37.5°C)under 5 years of age presenting at four health facilities and one referral hospital in rural Burkina Faso.From each participant,blood was collected for malaria microscopy and culture,urine for dipstick testing and culturing if tested positive for leucocytes and nitrite,stool for rotavirus/adenovirus testing,culture and parasitology,and a nasopharyngeal swab for culture.Results:In total 684 febrile children were included in the study.Plasmodium falciparum malaria was found in 49.7%(340/684)of the participants and non-malaria infections in 49.1%(336/684)of children.The non-nalaria infections included gastro-intestinal infections(37.0%),common bacterial pathogens of nasopharynx(24.3%),bacterial bloodstream infections(6.0%)and urinary tract infections(1.8%).Nearly 45%(154/340)of the malaria infected children were co-infected with non-nalaria infections,but only 3.2%(11/340)of these co-infections could be considered as a possible alternative cause of fever.In contrast,in the malaria microscopy negative children 18.0%(62/344)of the infections could be the probable cause of the fever.Pathogens were not isolated from 23.7%(162/684)of the febrile cases.Conclusions:Malaria remains the most common pathogen found in febrile children in Burkina Faso.However,a relative high number of febrile children had non-malaria infections.The correct diagnosis of these non-malaria fevers is a major concern,and there is an urgent need to develop more point-of-care diagnostic tests and capacities to identify and treat the causes of these fevers.展开更多
基金This research project was financially supported Stichting Dioraphte(The Netherlands).
文摘Background:There is significant need for accurate diagnostic tools for Cryptosporidium spp.and Qiordia duodenalis infections in resource limited countries where diarrhoeal disease caused by these parasites is often prevalent.The present study assessed the diagnostic performance of three commercially available rapid diagnostic tests(RDTs)based on faecal-antigen detection for Cryptosporidium spp.and/or G.duodenalis infections in stool samples of children admitted with severe acute malnutrition(SAM)and diarrhoea.An established multiplex PCR was used as reference test.Methods:Stool samples from children with SAM and diarrhoea enrolled in a randomized controlled trial(registered at clinicaltrials.gov/ct2/show/NCT02246296)in Malawi(n=175)and Kenya(n=120)between December 2014 and December 2015 were analysed by a multiplex PCR for the presence of Cryptosporidium sppv G.duodenalis or Entomoebo histolytica parasite DNA.Cryptosporidium-positive samples were species typed using restriction fragment length polymorphism analysis.A sub-sample of the stool specimens(n=236)was used for testing with three different RDTs.Diagnostic accuracy of the tests under evaluation was assessed using the results of PCR as reference standard using MedCalc software.Pearson Chi-square test and Fisher's exact test were used to determine(significant)difference between the number of cryptosporidiosis or giardiasis cases found by PCR in Malawi and Kenya.The overall diagnostic accuracy of each RDT was calculated by plotting a receiver operating characteristic(ROC)curve for each test and to determine the area under the curve(AUC)using SPSS8 software.Results:Prevalence of Cryptosporidium spp.by PCR was 20.0 and 21.7%in Malawi and Kenya respectively,mostly C.hominis.G.duodenalis prevalence was 23.4 and 5.8%in Malawi and Kenya respectively.E histolytica was not detected by PCR.RDT testing followed the same pattern of prevalence.RDT sensitivities ranged for cryptosporidiosis from 42.9 to 76.9%and for G.duodenalis from 48.2 to 85.7%.RDT specificities ranged from 88.4 to 100%for Cryptosporidium spp.and from 91.2 to 99.2%for G.duodenalis infections.Based on the estimated area under the curve(AUC)values,all tests under evaluation had an acceptable overall diagnostic accuracy(>0.7),with the exception of one RDT for Cryptosporidium spp.in Malawi.Conclusions:All three RDTs for Cryptosporidium spp.and Giardia duodenalis evaluated in this study have a moderate sensitivity,but sufficient specificity.The main value of the RDTs is within their rapidness and their usefulness as screening assays in surveys for diarrhoea.
基金This study was financially supported by The Netherlands Organization for Health Research and Development(ZonMw,project no.205300005,RAPDIF:a rapid diagnostic test for undifferentiated fevers)The funder had not influence on the design of the study and the interpretation of the results。
文摘Background:Fever remains a major public health problem.In Burkina Faso,more than half of febrile children are considered not to be infected by malaria.This study prospectively assessed probable(treatable)causes of fever in Burkinabe children.Methods:A prospective study was conducted among febrile children(≥37.5°C)under 5 years of age presenting at four health facilities and one referral hospital in rural Burkina Faso.From each participant,blood was collected for malaria microscopy and culture,urine for dipstick testing and culturing if tested positive for leucocytes and nitrite,stool for rotavirus/adenovirus testing,culture and parasitology,and a nasopharyngeal swab for culture.Results:In total 684 febrile children were included in the study.Plasmodium falciparum malaria was found in 49.7%(340/684)of the participants and non-malaria infections in 49.1%(336/684)of children.The non-nalaria infections included gastro-intestinal infections(37.0%),common bacterial pathogens of nasopharynx(24.3%),bacterial bloodstream infections(6.0%)and urinary tract infections(1.8%).Nearly 45%(154/340)of the malaria infected children were co-infected with non-nalaria infections,but only 3.2%(11/340)of these co-infections could be considered as a possible alternative cause of fever.In contrast,in the malaria microscopy negative children 18.0%(62/344)of the infections could be the probable cause of the fever.Pathogens were not isolated from 23.7%(162/684)of the febrile cases.Conclusions:Malaria remains the most common pathogen found in febrile children in Burkina Faso.However,a relative high number of febrile children had non-malaria infections.The correct diagnosis of these non-malaria fevers is a major concern,and there is an urgent need to develop more point-of-care diagnostic tests and capacities to identify and treat the causes of these fevers.