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1.
Malar J ; 20(1): 50, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33472640

RESUMO

BACKGROUND: The use of rapid diagnostic tests (RDTs) to diagnose malaria is common in sub-Saharan African laboratories, remote primary health facilities and in the community. Currently, there is a lack of reliable methods to ascertain health worker competency to accurately use RDTs in the testing and diagnosis of malaria. Dried tube specimens (DTS) have been shown to be a consistent and useful method for quality control of malaria RDTs; however, its application in National Quality Management programmes has been limited. METHODS: A Plasmodium falciparum strain was grown in culture and harvested to create DTS of varying parasite density (0, 100, 200, 500 and 1000 parasites/µL). Using the dried tube specimens as quality control material, a proficiency testing (PT) programme was carried out in 80 representative health centres in Togo. Health worker competency for performing malaria RDTs was assessed using five blinded DTS samples, and the DTS were tested in the same manner as a patient sample would be tested by multiple testers per health centre. RESULTS: All the DTS with 100 parasites/µl and 50% of DTS with 200 parasites/µl were classified as non-reactive during the pre-PT quality control step. Therefore, data from these parasite densities were not analysed as part of the PT dataset. PT scores across all 80 facilities and 235 testers was 100% for 0 parasites/µl, 63% for 500 parasites/µl and 93% for 1000 parasites/µl. Overall, 59% of the 80 healthcare centres that participated in the PT programme received a score of 80% or higher on a set of 0, 500 and 1000 parasites/ µl DTS samples. Sixty percent of health workers at these centres recorded correct test results for all three samples. CONCLUSIONS: The use of DTS for a malaria PT programme was the first of its kind ever conducted in Togo. The ease of use and stability of the DTS illustrates that this type of samples can be considered for the assessment of staff competency. The implementation of quality management systems, refresher training and expanded PT at remote testing facilities are essential elements to improve the quality of malaria diagnosis.


Assuntos
Antígenos de Protozoários/análise , Técnicas e Procedimentos Diagnósticos/estatística & dados numéricos , Instalações de Saúde , Mão de Obra em Saúde/normas , Ensaio de Proficiência Laboratorial/normas , Malária Falciparum/diagnóstico , Plasmodium falciparum/química , Humanos , Ensaio de Proficiência Laboratorial/métodos , Controle de Qualidade , Manejo de Espécimes , Togo
2.
Mini Rev Med Chem ; 20(12): 1118-1132, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32013848

RESUMO

Schistosomiasis is a chronic parasitic disease caused by a trematode blood fluke of the genus Schistosoma that belongs to the Schistosomatidae family. It is a neglected disease in different regions of Asia. In this review, 218 articles (between 2000 and 2017) related to the topic were collected from PubMed and Google scholar and reviewed. After thoroughly reading collected articles, due to irrelevant topic requirements, 94 articles were excluded. Articles that have data associated with Asian regions are considered. In Asia, the disease is prevalent in China, Philippines, Indonesia, Yemen, Nepal and Laos, etc. While in Pakistan, India and Bangladesh, the disease is not endemic and very few cases were reported. The disease was eliminated from Japan and Iran. The current review highlights the geographical distribution among Asian countries, transmission patterns, diagnosis, control strategies based on the use of anthelmintic plants and management practices implemented in Asia for the control of schistosomiasis. However, new implementations to treat schistosomiasis in humans should be proved to eliminate the disease finally in the future. This review emphasizes the biological control of schistosomiasis for the eradication of the disease from Asia in the near future.


Assuntos
Schistosoma/isolamento & purificação , Esquistossomose/diagnóstico , Animais , Antígenos de Protozoários/análise , Antígenos de Protozoários/imunologia , Ásia/epidemiologia , Efeitos Psicossociais da Doença , DNA de Protozoário/análise , DNA de Protozoário/metabolismo , Humanos , Estágios do Ciclo de Vida , Schistosoma/imunologia , Schistosoma/fisiologia , Esquistossomose/economia , Esquistossomose/epidemiologia , Esquistossomose/parasitologia
3.
PLoS One ; 13(12): e0208583, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30589853

RESUMO

INTRODUCTION: Internal and external quality control (QC) of rapid diagnostic tests (RDTs) is important to increase reliability of RDTs currently used to diagnose malaria. However, cross-checking of used RDTs as part of quality assurance can rarely be done by off-site personnel because there is no guarantee of retaining visible test lines after manufacturers' recommended reading time. Therefore, this study examined the potential of using Fionet™ technology for remote RDT quality monitoring at seven clinics, identifying reasons for making RDT processing and interpretation errors, and taking corrective actions for improvement of diagnosis and consequently improved management of febrile patients. METHODS: The study was conducted at seven military health facilities in Mainland Tanzania and utilized RDTs capable of detecting Plasmodium falciparum specific Histidine-rich protein 2 (Pf-HRP2) and the genus specific Plasmodium lactate dehydrogenase (pLDH) for other species of plasmodium (P. vivax, P. malariae or P. ovale; pan-pLDH). Patients' data and images of processed RDTs from seven clinics were uploaded on a Fionet web portal and reviewed regularly to monitor preparation procedures and visual interpretation of test results compared to automated analysis using the Deki reader of RDT. Problems detected were rapidly communicated to remote laboratory personnel at the clinic for corrective action and follow-up of patients who were falsely diagnosed as negative and missed treatment. Factors contributing to making errors in visual interpretation of RDT results were analyzed during visits to the health facilities. RESULTS: A total of 1,367 (1.6%) out of 83,294 RDT test images uploaded to the Fionet portal had discordant test results of which 822 (60.1%) and 545 (39.9%) were falsely reported as negative and positive, respectively. False negative and false positive test results were common for a single test line in 515 (62.7%) and 741 (54.2%) tests, respectively. Out of 1,367 RDT images assessed, 98 (7.2%) had quality problems related to preparation procedures of which 95(96.9%) errors were due to putting too much blood on the sample well or insufficient buffer in the respective wells. The reasons for discrepant results included, false reporting of none existent lines in 526 (38.5%) tests, missing a faint positive line in 493 (36.1%), missing a strong positive line in 248(18.1%) and errors caused by poorly processed RDTs in 96 (7.2%) tests. Among the false negative tests (n = 822), 669 (48.9%) patients were eligible for follow-up and only 339 (48.5%) were reached and 291 (85.8%) received appropriate anti-malaria therapy. CONCLUSION: Fionet technology enabled remote monitoring of RDT quality issues, identifying reasons contributing to laboratory personnel making errors and provided a rapid method to implement corrective actions at remote sites to improve malaria diagnosis and consequently improved health care management of febrile patients infected with malaria.


Assuntos
Testes Diagnósticos de Rotina , Pessoal de Saúde , Malária/diagnóstico , Análise e Desempenho de Tarefas , Adolescente , Adulto , Antígenos de Protozoários/análise , Criança , Pré-Escolar , Erros de Diagnóstico , Testes Diagnósticos de Rotina/normas , Feminino , Instalações de Saúde , Humanos , Lactente , Recém-Nascido , L-Lactato Desidrogenase/análise , L-Lactato Desidrogenase/normas , Masculino , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/análise , Proteínas de Protozoários/normas , Controle de Qualidade , Tanzânia , Adulto Jovem
4.
ACS Infect Dis ; 2(12): 917-922, 2016 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-27696820

RESUMO

The α-Gal antigen [Galα(1,3)Galß(1,4)GlcNAcα] is an immunodominant epitope displayed by infective trypomastigote forms of Trypanosoma cruzi, the causative agent of Chagas disease. A virus-like particle displaying a high density of α-Gal was found to be a superior reagent for the ELISA-based serological diagnosis of Chagas disease and the assessment of treatment effectiveness. A panel of sera from patients chronically infected with T. cruzi, both untreated and benznidazole-treated, was compared with sera from patients with leishmaniasis and from healthy donors. The nanoparticle-α-Gal construct allowed for perfect discrimination between Chagas patients and the others, avoiding false negative and false positive results obtained with current state-of-the-art reagents. As previously reported with purified α-Gal-containing glycosylphosphatidylinositol-anchored mucins, the current study also showed concentrations of anti-α-Gal IgG to decrease substantially in patients receiving treatment with benznidazole, suggesting that the semiquantitative assessment of serum levels of this highly abundant type of antibody can report on disease status in individual patients.


Assuntos
Doença de Chagas/diagnóstico , Trissacarídeos/análise , Trypanosoma cruzi/isolamento & purificação , Anticorpos Antiprotozoários/análise , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/análise , Antígenos de Protozoários/imunologia , Doença de Chagas/parasitologia , Ensaio de Imunoadsorção Enzimática , Humanos , Trissacarídeos/imunologia , Trypanosoma cruzi/genética , Trypanosoma cruzi/imunologia , Vírus/genética , Vírus/metabolismo
5.
Mem Inst Oswaldo Cruz ; 110(7): 929-35, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26560984

RESUMO

We present a set of data on human and chicken Toxoplasma gondii seroprevalence that was investigated and analysed in light of groundwater vulnerability information in an area endemic for waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to select sites for water collection from wells for T. gondii oocyst testing and for collecting blood from free-range chickens and humans for anti-T. gondii serologic testing. Serologic testing of human specimens was done using conventional commercial tests and a sporozoite-specific embryogenesis-related protein (TgERP), which is able to differentiate whether infection resulted from tissue cysts or oocysts. Water specimens were negative for the presence of viable T. gondii oocysts. However, seroprevalence in free-range chickens was significantly associated with vulnerability of groundwater to surface contamination (p < 0.0001; odds ratio: 4.73, 95% confidence interval: 2.18-10.2). Surprisingly, a high prevalence of antibodies against TgERP was detected in human specimens, suggesting the possibility of a continuous contamination of drinking water with T. gondii oocysts in this endemic setting. These findings and the new proposed approach to investigate and analyse endemic toxoplasmosis in light of groundwater vulnerability information associated with prevalence in humans estimated by oocyst antigens recognition have implications for the potential role of hydrogeological assessment in researching waterborne toxoplasmosis at a global scale.


Assuntos
Galinhas/parasitologia , Água Doce/parasitologia , Oocistos , Toxoplasma/imunologia , Toxoplasmose/epidemiologia , Doenças Transmitidas pela Água/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/análise , Brasil/epidemiologia , Criança , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Protozoários/análise , Estudos Soroepidemiológicos , Toxoplasma/isolamento & purificação , Toxoplasmose/diagnóstico , Toxoplasmose/transmissão , Toxoplasmose Animal/diagnóstico , Toxoplasmose Animal/epidemiologia , Doenças Transmitidas pela Água/diagnóstico , Doenças Transmitidas pela Água/transmissão , Adulto Jovem
6.
Mem. Inst. Oswaldo Cruz ; 110(7): 929-935, Nov. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-764583

RESUMO

We present a set of data on human and chicken Toxoplasma gondiiseroprevalence that was investigated and analysed in light of groundwater vulnerability information in an area endemic for waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to select sites for water collection from wells for T. gondiioocyst testing and for collecting blood from free-range chickens and humans for anti-T. gondiiserologic testing. Serologic testing of human specimens was done using conventional commercial tests and a sporozoite-specific embryogenesis-related protein (TgERP), which is able to differentiate whether infection resulted from tissue cysts or oocysts. Water specimens were negative for the presence of viable T. gondiioocysts. However, seroprevalence in free-range chickens was significantly associated with vulnerability of groundwater to surface contamination (p < 0.0001; odds ratio: 4.73, 95% confidence interval: 2.18-10.2). Surprisingly, a high prevalence of antibodies against TgERP was detected in human specimens, suggesting the possibility of a continuous contamination of drinking water with T. gondiioocysts in this endemic setting. These findings and the new proposed approach to investigate and analyse endemic toxoplasmosis in light of groundwater vulnerability information associated with prevalence in humans estimated by oocyst antigens recognition have implications for the potential role of hydrogeological assessment in researching waterborne toxoplasmosis at a global scale.


Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Galinhas/parasitologia , Água Doce/parasitologia , Oocistos , Toxoplasma/imunologia , Toxoplasmose/epidemiologia , Doenças Transmitidas pela Água/epidemiologia , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/análise , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática , Proteínas de Protozoários/análise , Estudos Soroepidemiológicos , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/diagnóstico , Toxoplasmose Animal/epidemiologia , Toxoplasmose/diagnóstico , Toxoplasmose/transmissão , Doenças Transmitidas pela Água/diagnóstico , Doenças Transmitidas pela Água/transmissão
7.
PLoS One ; 10(3): e0120367, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25803815

RESUMO

Greece, a malaria-free country since 1974, has experienced re-emergence of Plasmodium vivax autochthonous malaria cases in some agriculture areas over the last three years. In early 2012, an integrated control programme (MALWEST Project) was launched in order to prevent re-establishment of the disease. In the context of this project, the rapid diagnostic tests (RDT) of SD Bioline Malaria Ag Pf/Pan that detects hrp-2 and pan-LDH antigens were used. The aim of this study was to assess the field application of the RDT for the P. vivax diagnosis in comparison to light microscopy and polymerase chain reaction (PCR). A total of 955 samples were tested with all three diagnostic tools. Agreement of RDT against microscopy and PCR for the diagnosis of P. vivax was satisfactory (K value: 0.849 and 0.976, respectively). The sensitivity, specificity and positive predictive value of RDT against PCR was 95.6% (95% C.I.: 84.8-99.3), 100% (95% C.I.: 99.6-100.0) and 100% (95% CI: 91.7-100.0) respectively, while the sensitivity, specificity and positive predictive value of RDT against microscopic examination was 97.4% (95% C.I.: 86.1-99.6), 99.4% (95% C.I.: 98.6-99.8) and 86.1% (95% CI: 72.1-94.7), respectively. Our results indicate that RDT performed satisfactory in a non-endemic country and therefore is recommended for malaria diagnosis, especially in areas where health professionals lack experience on light microscopy.


Assuntos
Testes Diagnósticos de Rotina/métodos , Malária Vivax/diagnóstico , Malária Vivax/epidemiologia , Plasmodium vivax/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Protozoários/análise , Criança , Pré-Escolar , Testes Diagnósticos de Rotina/economia , Grécia/epidemiologia , Humanos , Lactente , Microscopia/economia , Microscopia/métodos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/economia , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Adulto Jovem
8.
BMC Bioinformatics ; 13: 309, 2012 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-23170965

RESUMO

BACKGROUND: Epitope prediction using computational methods represents one of the most promising approaches to vaccine development. Reduction of time, cost, and the availability of completely sequenced genomes are key points and highly motivating regarding the use of reverse vaccinology. Parasites of genus Leishmania are widely spread and they are the etiologic agents of leishmaniasis. Currently, there is no efficient vaccine against this pathogen and the drug treatment is highly toxic. The lack of sufficiently large datasets of experimentally validated parasites epitopes represents a serious limitation, especially for trypanomatids genomes. In this work we highlight the predictive performances of several algorithms that were evaluated through the development of a MySQL database built with the purpose of: a) evaluating individual algorithms prediction performances and their combination for CD8+ T cell epitopes, B-cell epitopes and subcellular localization by means of AUC (Area Under Curve) performance and a threshold dependent method that employs a confusion matrix; b) integrating data from experimentally validated and in silico predicted epitopes; and c) integrating the subcellular localization predictions and experimental data. NetCTL, NetMHC, BepiPred, BCPred12, and AAP12 algorithms were used for in silico epitope prediction and WoLF PSORT, Sigcleave and TargetP for in silico subcellular localization prediction against trypanosomatid genomes. RESULTS: A database-driven epitope prediction method was developed with built-in functions that were capable of: a) removing experimental data redundancy; b) parsing algorithms predictions and storage experimental validated and predict data; and c) evaluating algorithm performances. Results show that a better performance is achieved when the combined prediction is considered. This is particularly true for B cell epitope predictors, where the combined prediction of AAP12 and BCPred12 reached an AUC value of 0.77. For T CD8+ epitope predictors, the combined prediction of NetCTL and NetMHC reached an AUC value of 0.64. Finally, regarding the subcellular localization prediction, the best performance is achieved when the combined prediction of Sigcleave, TargetP and WoLF PSORT is used. CONCLUSIONS: Our study indicates that the combination of B cells epitope predictors is the best tool for predicting epitopes on protozoan parasites proteins. Regarding subcellular localization, the best result was obtained when the three algorithms predictions were combined. The developed pipeline is available upon request to authors.


Assuntos
Algoritmos , Antígenos de Protozoários/análise , Epitopos de Linfócito B/análise , Epitopos de Linfócito T/análise , Leishmania/genética , Leishmania/imunologia , Área Sob a Curva , Simulação por Computador , Epitopos de Linfócito B/genética , Epitopos de Linfócito T/genética , Genoma de Protozoário , Vacinas Protozoárias/genética , Vacinas Protozoárias/imunologia , Software
9.
Curr Opin Infect Dis ; 25(5): 555-63, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22907279

RESUMO

PURPOSE OF REVIEW: The global significance of cryptosporidiosis is widespread and far-reaching. In this review, we present recent data about strain diversity and the burden of disease, along with developments in therapeutic and preventive strategies. RECENT FINDINGS: Cryptosporidium is an emerging pathogen that disproportionately affects children in developing countries and immunocompromised individuals. Without a diagnostic tool amenable for use in developing countries, the burden of infection and its relationship to growth faltering, malnutrition, and diarrheal mortality remain underappreciated. Disease incidence is also increasing in industrialized countries largely as a result of outbreaks in recreational water facilities. Advances in molecular methods, including subtyping analysis, have yielded new insights into the epidemiology of cryptosporidiosis. However, without practical point-of-care diagnostics, an effective treatment for immunocompromised patients, and a promising vaccine candidate, the ability to reduce the burden of disease in the near future is limited. This is compounded by inadequate coverage with antiretroviral therapy in developing countries, the only current means of managing HIV-infected patients with cryptosporidiosis. SUMMARY: Cryptosporidiosis is one of the most important diarrheal pathogens affecting people worldwide. Effective methods to control and treat cryptosporidiosis among high-risk groups present an ongoing problem in need of attention.


Assuntos
Efeitos Psicossociais da Doença , Criptosporidiose , Antígenos de Protozoários/análise , Antiparasitários/uso terapêutico , Criptosporidiose/diagnóstico , Criptosporidiose/tratamento farmacológico , Criptosporidiose/epidemiologia , Criptosporidiose/prevenção & controle , Cryptosporidium/isolamento & purificação , Países Desenvolvidos , Países em Desenvolvimento , Saúde Global , Humanos
10.
Mikrobiyol Bul ; 45(4): 765-7, 2011 Oct.
Artigo em Turco | MEDLINE | ID: mdl-22090311

RESUMO

Intestinal parasites are the important etiological agents of water and food related diarrhea cases which are frequently seen during summer/early autumn seasons in developing countries. This point prevalence study was aimed to determine the protozoal antigen positivity rate in diarrhea cases admitted to the emergency service in one single day. A total of 198 diarrheal patients (90 male, 108 female; age range: 1-82 years, mean age: 29 years) who were admitted to the emergency service of Ankara Training and Research Hospital were included in the study. Macroscopic and direct microscopic examinations were performed for the stool samples of patients, and the samples which yielded pathological microscopic findings (e.g. presence of leukocytes, erythrocytes, and trophozoits) were investigated in terms of Entamoeba histolytica adhesin antigen, Giardia intestinalis cyst antigen and Cryptosporidium oocyst antigen by commercial ELISA kits (Techlab, USA). Macroscopic examination of the stool samples revealed that 60 (30%) of them had blood and mucous, 137 (69%) were watery and one sample had normal appearance. Pathologic results were obtained for 96 (48.5%) of the samples by microscopic examination: 36 (37.5%) revealed erythrocytes, 90 (93.7%) had leukocytes and 3 (1.5%) had G.intestinalis trophozoites. Since Shigella spp. were cultured in two of these 96 samples, these two cases were omitted from the study and 94 samples were investigated by ELISA assays. G.intestinalis was detected in 13 (13.8%) and E.histolytica in 2 (2.1%) samples while Cryptosporidium antigen was not detected in any of the samples by the ELISA assays. It was concluded that ELISA antigen assays were rapid and cost-effective methods for the determination of the causative agent in cases of diarrhea.


Assuntos
Antígenos de Protozoários/análise , Diarreia/parasitologia , Enteropatias Parasitárias/epidemiologia , Infecções por Protozoários/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Análise Custo-Benefício , Cryptosporidium/imunologia , Cryptosporidium/isolamento & purificação , Diarreia/epidemiologia , Entamoeba histolytica/imunologia , Entamoeba histolytica/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/economia , Ensaio de Imunoadsorção Enzimática/normas , Fezes/citologia , Fezes/parasitologia , Feminino , Giardia lamblia/imunologia , Giardia lamblia/isolamento & purificação , Humanos , Lactente , Enteropatias Parasitárias/parasitologia , Masculino , Pessoa de Meia-Idade , Prevalência , Infecções por Protozoários/parasitologia , Turquia/epidemiologia , Adulto Jovem
11.
Travel Med Infect Dis ; 6(4): 234-9, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18571115

RESUMO

Giardia lamblia is responsible for causing diarrhoeal diseases in humans. Infection occurs by fecal-oral route and is considered an important water pathogen, since many water surfaces are infected by cysts. Most studies involve cyst concentration procedures, followed by conventional microscopy, but are often tedious and influenced by fatigue. Our main objective was to optimize a specific flow cytometric (FC) protocol for detection of G. lamblia, to establish its sensibility limit and also the cyst viability. G. lamblia cysts (Waterborne, Inc., USA) were used for protocol optimization. FC analysis was performed using cyst suspensions stained with serial concentrations of a fluorescein-labelled mouse monoclonal antibody (Giardia-a-Glo, Waterborne). Serial concentrations (2 x 10(5), 1 x 10(5), 2 x 10(4), 1 x 10(4), 2 x 10(3), 1 x 10(3), 2 x 10(2) and 1 x 10(2)cysts/ml) were stained with the optimized antibody concentration and analysed by FC. Specificity and sensibility limit of the method were established using both prokaryotic (Escherichia coli, Staphylococcus aureus) and eukaryotic microorganisms (Candida albicans, Cryptosporidium parvum oocysts). Dead cysts were stained with 5.0 microg/ml of propidium iodide (PI, Sigma), with and without the specific fluorescent antibody. As the antibody concentration decreased, a decline of peak intensity was registered; 1.5 microg/ml was considered as the optimal antibody concentration, yielding a histogram clearly separated. We established a threshold of detection of 2 x 10(2)cysts/ml. Below threshold limit fluorescence was not enough to allow the discrimination of cysts. The staining procedure was shown to be specific, no cross-reaction occurring with bacteria, fungi or parasites. When using both antibody and PI, we could distinguish the viable cyst. With the use of specific antibodies, a distinct cellular population corresponding to cysts could be represented in the FC histogram.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos de Protozoários/imunologia , Citometria de Fluxo/métodos , Giardia lamblia/crescimento & desenvolvimento , Giardia lamblia/isolamento & purificação , Água/parasitologia , Animais , Antígenos de Protozoários/análise , Fluoresceína , Giardia lamblia/imunologia , Humanos , Sensibilidade e Especificidade , Coloração e Rotulagem/métodos
12.
Trans R Soc Trop Med Hyg ; 102(7): 699-704, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18513771

RESUMO

A rapid antigen assay for malaria was performed on blood samples collected during a simultaneous outbreak of falciparum malaria and vivax malaria on a remote island in the Indonesian archipelago. During the outbreak, a total of 89 patients (4.3% of the population) were diagnosed with malaria within a week. Microscopic examination revealed 78 malaria slide-positive cases, of whom 49 (62.8%) were identified as P. falciparum, 7 (9.0%) as P. vivax and 22 (28.2%) as mixed P. falciparum and P. vivax infections. The rapid malaria assay showed excellent correlation with expert-confirmed routine microscopy for P. falciparum and P. vivax monoinfections and mixed infections with a parasite density >50 parasites/microl. Several slide-negative blood samples collected from febrile patients with clinical malaria tested positive in the rapid test. The estimated sensitivity calculated for the rapid test (91.0%) was slightly higher than that of microscopy (87.6%). The result indicates that rapid antigen detection for malaria could be a useful alternative to microscopy to reduce the workload during emergency outbreak situations.


Assuntos
Antígenos de Protozoários/análise , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito/normas , Kit de Reagentes para Diagnóstico/normas , Adolescente , Adulto , Animais , Criança , Surtos de Doenças/prevenção & controle , Feminino , Humanos , Malária Falciparum/epidemiologia , Malária Vivax/epidemiologia , Masculino , Microscopia/métodos , Pessoa de Meia-Idade , Parasitemia/diagnóstico , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Kit de Reagentes para Diagnóstico/economia , Sensibilidade e Especificidade , Fatores de Tempo
13.
Nat Rev Microbiol ; 4(9 Suppl): S7-20, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17003770

RESUMO

The replacement of conventional antimalarial drugs with high-cost, artemisinin-based alternatives has created a gap in the successful management of malaria. This gap reflects an increased need for accurate disease diagnosis that cannot be met by traditional microscopy techniques. The recent introduction of rapid diagnostic tests (RDTs) has the potential to meet this need, but successful RDT implementation has been curtailed by poor product performance, inadequate methods to determine the quality of products and a lack of emphasis and capacity to deal with these issues. Economics and a desire for improved case management will result in the rapid growth of RDT use in the coming years. However, for their potential to be realized, it is crucial that high-quality RDT products that perform reliably and accurately under field conditions are made available. In achieving this goal, the shift from symptom-based diagnosis to parasite-based management of malaria can bring significant improvements to tropical fever management, rather than represent a further burden on poor, malaria-endemic populations and their overstretched health services.


Assuntos
Antígenos de Protozoários/análise , Acessibilidade aos Serviços de Saúde/normas , Testes Imunológicos , Malária/diagnóstico , Antígenos de Protozoários/isolamento & purificação , Humanos , Testes Imunológicos/economia , Testes Imunológicos/normas , Controle de Qualidade
14.
São Paulo med. j ; 123(6): 282-285, Nov.-Dec. 2005. tab
Artigo em Inglês | LILACS | ID: lil-420120

RESUMO

CONTEXTO E OBJETIVO: A giardíase é comum no Brasil. Para o diagnóstico laboratorial, o método mais empregado é o exame microscópico de amostras fecais. O método imunoenzimático (ELISA) também é utilizado. O objetivo deste trabalho é verificar as vantagens e desvantagens do método microscópico quando comparado ao imunoenzimático para o diagnóstico de Giardia lamblia em uma única amostra fecal. TIPO DE ESTUDO E LOCAL: Estudo prospectivo, duplo cego, no Laboratório de Parasitologia, Faculdade de Medicina da Fundação ABC. MÉTODOS: As amostras foram preparadas para exame de acordo com os tradicionais métodos de sedimentação (Hoffman, Pons e Janer) e Faust. Um resultado positivo significa o encontro de Giardia lamblia por um dos métodos ou ambos. O kit Prospect ELISA foi utilizado para detecção do antígeno específico de Giardia lamblia, de acordo com as instruções do fabricante. Os resultados foram expressos em escala visual como negativos ou positivos (+, ++, +++ ou ++++). RESULTADOS: O teste ELISA é positivo mesmo quando uma significante proporção das correspondentes amostras examinadas por microscopia ainda é negativa, sendo esta tendência estatisticamente significante (p < 0,001). A concordância de resultados entre os dois métodos é apenas moderada (0,5 pelo teste kappa). CONCLUSÃO: O teste ELISA é recomendável quando se busca uma elevada sensibilidade para a detecção de antígenos específicos de Giardia lamblia, como em estudos de prevalência. Para a prática diária, recomendamos o método microscópico, que tem custo muito menor e pode detectar outros parasitas na mesma amostra. A baixa taxa de positividade do método no exame de uma única amostra pode ser contornada pelo exame de três amostras, como recomendado pela maioria dos autores.


Assuntos
Humanos , Animais , Antígenos de Protozoários/análise , Ensaio de Imunoadsorção Enzimática/normas , Fezes/parasitologia , Giardia lamblia/isolamento & purificação , Giardíase/diagnóstico , Microscopia/normas , Distribuição de Qui-Quadrado , Custos e Análise de Custo , Método Duplo-Cego , Ensaio de Imunoadsorção Enzimática/economia , Giardia lamblia/imunologia , Giardíase/parasitologia , Microscopia/economia , Estudos Prospectivos
15.
Med Parazitol (Mosk) ; (3): 22-5, 2005.
Artigo em Russo | MEDLINE | ID: mdl-16212090

RESUMO

The authors compared the sensitivity and specificity of currently available methods for laboratory diagnosis of trichomoniasis, by examining 971 persons. The highest frequency of T. vaginalis was detected by studies of a stained smear (37.4%), culture tests (19.0%); polymerase chain reaction (PCR) (17.1%), immunofluorescence tests (12.7%), wet smear test (2.7%). Enzyme immunoassay yielded positive results in 36.2% of cases. The use of PCR and culture tests frequently provided similar results (92.0%). The authors have proposed an algorithm of a laboratory study including wet smear microscopy, PCR, and culture tests as basic methods. They have noted the higher detection rates of T. vaginalis when analyzing during draining physiotherapeutic procedures (endocervical vibratory massage with vacuum aspiration in females and pneumovibratory massage of the prostate with endourethral chemotrypsin electrophoresis in males).


Assuntos
Tricomoníase/diagnóstico , Trichomonas vaginalis/isolamento & purificação , Animais , Anticorpos Antiprotozoários/análise , Antígenos de Protozoários/análise , Meios de Cultura , DNA de Protozoário/análise , Feminino , Imunofluorescência , Humanos , Imunoensaio , Masculino , Microscopia de Contraste de Fase , Reação em Cadeia da Polimerase , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade , Coloração e Rotulagem , Sucção , Trichomonas vaginalis/genética , Trichomonas vaginalis/crescimento & desenvolvimento , Trichomonas vaginalis/imunologia , Esfregaço Vaginal
17.
Sao Paulo Med J ; 123(6): 282-5, 2005 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-16444388

RESUMO

CONTEXT AND OBJECTIVE: Giardiasis is common in Brazil. For laboratory diagnosis, the method most utilized is microscopic examination of fecal samples, but the immunoenzymatic method is also available. The aim of this work was to verify the advantages and drawbacks of immunoassaying versus microscopy for diagnosing Giardia lamblia, when a single fecal sample is analyzed. DESIGN AND SETTING: Prospective, double-blind study at the parasitology laboratory of Faculdade de Medicina da Fundação ABC. METHODS: Samples were prepared according to the traditional sedimentation (Hoffman, Pons and Janer) and Faust methods. Results were deemed positive when Giardia lamblia was found by one or both methods. The Prospect ELISA kit was used for detecting Giardia lamblia-specific antigen, in accordance with the manufacturer's instructions. Results were expressed on a visual scale as negative or positive (+, ++, +++ or ++++). RESULTS: The ELISA test was positive even when a significant proportion of corresponding samples examined by microscopy were negative. This trend was statistically significant (p < 0.001). The overall concordance of results between the ELISA test and microscopic examination of single samples was only moderate (0.50 by kappa test). CONCLUSION: The ELISA test is useful when just searching for Giardia lamblia, because of its high sensitivity. For daily practice, we recommend microscopy, which is much cheaper and can also detect other parasites. The low positivity of single samples in this method can be overcome by using three samples, as recommended by most authors.


Assuntos
Antígenos de Protozoários/análise , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Giardia lamblia/isolamento & purificação , Giardíase/diagnóstico , Animais , Distribuição de Qui-Quadrado , Custos e Análise de Custo , Método Duplo-Cego , Ensaio de Imunoadsorção Enzimática/economia , Ensaio de Imunoadsorção Enzimática/normas , Giardia lamblia/imunologia , Humanos , Microscopia , Estudos Prospectivos
18.
J Assoc Physicians India ; 51: 759-61, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14651134

RESUMO

OBJECTIVE: A firm diagnosis of visceral leishmaniasis (VL) requires demonstration of the parasite in splenic or bone marrow aspirate. The aim of this prospective study was to assess the usefulness of K39 strip test as a noninvasive method of diagnosing visceral leishmaniasis under field conditions by testing serum antibody to the leishmanial antigen K39. MATERIAL AND METHODS: One drop of serum/blood was applied to the sample application pad on the test strip, which was diluted with 2 drops of chase buffer solution. The development of two visible red lines indicates the presence of IgG anti-K39. In the first phase of the study (2001), a total of 200 patients (Active VL-70, ex-VL-30, healthy endemic control-20 and patients with other tropical diseases-80) were tested with the K39 strip test at the School of Tropical Medicine, Kolkata. In the second phase of the study (2002), the test was applied in a remote tribal area of West Bengal where an epidemic of VL had occurred. Thirty-two patients were identified in 207 villagers of the affected area; all of them were tested with the K39 strip test. RESULTS: In the first phase, all VL and ex-VL cases gave positive results (100%). Ten percent of the healthy endemic controls were positive. The test results were negative in all other prevalent tropical diseases (100%). The estimated sensitivity of the test was 100% and the specificity was 98.18%. In the second phase of the study, all 32 patients of the epidemic were shown to be positive. All patients were treated with sodium stibogluconate injections and they recovered uneventfully. CONCLUSIONS: K39 strip test is ideal for rapid reliable field diagnosis of visceral leishmaniasis. The test has high sensitivity and specificity but it remains positive long after treatment (up to 3 years).


Assuntos
Antígenos de Protozoários/análise , Antígenos de Protozoários/imunologia , Leishmania/imunologia , Leishmaniose Visceral/diagnóstico , Proteínas de Protozoários/análise , Testes Sorológicos/instrumentação , Testes de Aglutinação , Animais , Anticorpos Antiprotozoários/sangue , Estudos de Casos e Controles , Custos e Análise de Custo , Feminino , Humanos , Índia , Masculino , Fitas Reagentes/economia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
J Clin Microbiol ; 39(1): 332-4, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11136793

RESUMO

A study comparing the Triage Micro Parasite Panel (Biosite Diagnostics, Inc., San Diego, Calif.) to conventional O&P examination (O&P) was performed using patient fecal specimens. Five hundred twenty-three stool samples were compared. Nineteen specimens were found to be positive by Triage, and 29 were found to be positive by O&P. Seven specimens were positive for Giardia lamblia, four were positive for Entamoeba histolytica/E. dispar, and three were positive for Cryptosporidium parvum as determined by both methods. There was one false positive by Triage (C. parvum) and four false negatives by O&P (two G. lamblia, one E. histolytica/E. dispar, and one C. parvum). The Triage test accurately detected all 18 specimens that contained one of the three organisms that it was designed to detect. The Triage test is a rapid, easy-to-use enzyme immunoassay for the detection of G. lamblia, E. histolytica/E. dispar, and C. parvum in fresh or fresh-frozen fecal specimens. These data suggest that the Triage test can be used as a screen for the immediate testing of stool specimens for these three pathogenic parasites. If Triage test results are negative, O&P can be performed if parasitic infections other than G. lamblia, E. histolytica/E. dispar, or C. parvum are suspected.


Assuntos
Fezes/parasitologia , Técnicas Imunoenzimáticas , Enteropatias Parasitárias/diagnóstico , Infecções por Protozoários/diagnóstico , Animais , Antígenos de Protozoários/análise , Criptosporidiose/diagnóstico , Criptosporidiose/parasitologia , Cryptosporidium parvum/isolamento & purificação , Entamoeba/isolamento & purificação , Entamoeba histolytica/isolamento & purificação , Entamebíase/diagnóstico , Entamebíase/parasitologia , Giardia lamblia/isolamento & purificação , Giardíase/diagnóstico , Giardíase/parasitologia , Humanos , Técnicas Imunoenzimáticas/economia , Enteropatias Parasitárias/parasitologia , Infecções por Protozoários/parasitologia , Kit de Reagentes para Diagnóstico/economia , Sensibilidade e Especificidade
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