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1.
J Clin Microbiol ; 54(8): 2104-8, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27252459

RESUMO

Viral load testing is the WHO-recommended monitoring assay for patients on HIV antiretroviral therapy (ART). Point-of-care (POC) assays may help improve access to viral load testing in resource-limited settings. We compared the performance of the Alere Q NAT POC viral load technology (Alere Technologies, Jena, Germany), measuring total HIV RNA using finger prick capillary whole-blood samples collected in a periurban health center, with that of a laboratory-based plasma RNA test (Roche Cobas Ampliprep/Cobas TaqMan v2) conducted on matched venous blood samples. The whole-blood Alere Q NAT POC assay produced results with a bias of 0.8593 log copy/ml compared to the laboratory-based plasma assay. However, at above 10,000 copies/ml, the bias was 0.07 log copy/ml. Using the WHO-recommended threshold to determine ART failure of 1,000 copies/ml, the sensitivity and specificity of the whole-blood Alere Q NAT POC assay were 96.83% and 47.80%, respectively. A cutoff of 10,000 copies/ml of whole blood with the Alere Q NAT POC assay appears to be a better predictor of ART failure threshold (1,000 copies/ml of plasma), with a sensitivity of 84.0% and specificity of 90.3%. The precision of the whole-blood Alere Q NAT POC assay was comparable to that observed with the laboratory technology (5.4% versus 7.5%) between detectable paired samples. HIV POC viral load testing is feasible at the primary health care level. Further research on the value of whole-blood viral load to monitor antiretroviral therapy is warranted.


Assuntos
Infecções por HIV/virologia , Sistemas Automatizados de Assistência Junto ao Leito , Atenção Primária à Saúde/métodos , RNA Viral/sangue , Carga Viral/métodos , Adolescente , Adulto , Idoso , Criança , Estudos Transversais , Monitoramento de Medicamentos/métodos , Feminino , Alemanha , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Moçambique , Sensibilidade e Especificidade , Adulto Jovem
2.
South Afr J HIV Med ; 25(1): 1571, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39228917

RESUMO

Background: Dual HIV/syphilis testing may be an acceptable intervention to identify men with sexually transmitted infections (STIs) and at risk of HIV acquisition. Objectives: We sought to determine the acceptability, and performance of dual HIV/syphilis testing among men attending voluntary medical male circumcision (VMMC) services at six public sector facilities in Gauteng. Method: This was a cross-sectional study at VMMC facilities. Men ≥ 18 years were enrolled. The men had (1) a questionnaire administered, (2) on-site dual HIV/syphilis testing with First Response HIV1+2/Syphilis Combo Card Test by routine lay counsellors, and (3) a blood specimen collected for centralised laboratory testing for HIV and syphilis serology. We evaluated pre-test and post-test acceptability and performance compared to serological testing. Results: Of the 679 men analysed (median age 32.1 years), 96.7% of HIV-negative men preferred testing for HIV and syphilis simultaneously. Of the 675 men tested for syphilis, 28 (4.7%) tested positive (past or recent). In the laboratory, 43/609 (7.1%) had syphilis infection detected, with 9/609 (1.5%) having recent syphilis. There was sub-optimal sensitivity for HIV detection (90.9%; 95% confidence interval [CI]: 88.5% - 93.3%), and for past/recent syphilis (55.8%; 95% CI: 51.9% - 59.8%), improving to 88.9% (95% CI: 86.4% - 91.4%) for recent syphilis. Specificities were > 99% for HIV and syphilis (past or recent). Post-test acceptability was 96.6% and willingness to pay for future testing was 86.1%. Conclusion: Dual HIV/syphilis testing was acceptable but had sub-optimal sensitivity for HIV and syphilis. Syphilis detection was adequate for recent infection.

3.
PLoS One ; 13(6): e0198344, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29912987

RESUMO

BACKGROUND: Failure to timely diagnose HIV in infants is a major barrier for scaling-up paediatric antiretroviral treatment (ART). WHO recommends birth testing for earlier diagnosis and to improve test coverage, but current diagnosis takes 2-3 weeks to complete, thereby limiting the ability of care givers to provide follow-on care, especially in low-resource settings. We evaluated the benefit of implementing rapid diagnosis of HIV at birth in primary health care maternity wards in Mozambique. METHODS AND FINDINGS: Infants born to HIV-infected mothers delivering consecutively at eight primary health care clinics were tested within 24 hours of delivery using on-site POC (Alere q HIV1/2 Detect) and standard laboratory (Roche COBAS AmpliPrep/TaqMan HIV-1 qualitative assay v2.0) testing. Infants were also tested at 4-6 weeks of age with both assays. Of 2,350 HIV-exposed infants enrolled in this implementation research study, 33 tested HIV-positive at birth on both assays. Sensitivity and specificity of POC testing compared with laboratory testing at birth were 100% (95% CI 89·4-100·0) and 100% (95% CI 99·8-100·0), respectively. At 4-6 weeks of age, 61 infants were identified as HIV-positive; of these 29 (47·5%) had a positive test at birth. Testing at both birth and 4-6 weeks identified 71 HIV-positive infants compared with 61 infants by testing at 4-6 weeks alone, a 16% increase. Two infants tested positive at birth but tested HIV-negative during follow-up. CONCLUSIONS: Adding POC birth testing to the 4-6 week screen may increase access to HIV diagnosis and expedite ART initiation in primary health care settings within low resource settings. Guidance on appropriate confirmatory HIV testing algorithms for birth testing is needed.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , HIV-1/genética , Estudos de Coortes , Diagnóstico Precoce , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Moçambique , Testes Imediatos , Guias de Prática Clínica como Assunto , Atenção Primária à Saúde , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade , Tempo para o Tratamento
4.
AIDS ; 32(11): 1453-1463, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29746301

RESUMO

OBJECTIVE: We measured the effect of point-of-care (POC) early infant HIV testing on antiretroviral therapy initiation rates and retention in care among infants in Mozambique. DESIGN: A cluster-randomized trial was conducted in 16 primary healthcare centres providing either on-site POC arm (n = 8) or referred laboratory [standard-of-care (SOC) arm; n = 8] infant HIV testing. METHODS: The primary outcomes were the proportion of HIV-positive infants initiating antiretroviral therapy within 60 days of sample collection, and the proportion of HIV-positive infants who initiated antiretroviral therapy that were retained in care at 90 days of follow-up. RESULTS: The proportion of HIV-positive infants initiating antiretroviral therapy within 60 days of sample collection was 89.7% (157 of 175) for the POC arm and 12.8% (13 of 102) for the SOC arm [relative risk (RR)(adj) 7.34; P < 0.001]. The proportion of HIV-positive infants who initiated antiretroviral therapy that were retained in care at 90 days of follow-up was 61.6% (101 of 164) for the POC arm and 42.9% (21 of 49) for the SOC arm [RR(adj) 1.40; P < 0.027]. The median time from sample collection to antiretroviral therapy initiation was less than 1 day (interquartile range: 0-1) for the POC arm and 127 days (44-154; P < 0.001) for the SOC arm. CONCLUSION: POC infant HIV testing enabled clinics to more rapidly diagnose and provide treatment to HIV-infected infants. This reduced opportunities for pretreatment loss to follow-up and enabled a larger proportion of infants to receive test results and initiate antiretroviral therapy. The benefits of faster HIV diagnosis and antiretroviral treatment may also improve early retention in care.


Assuntos
Antirretrovirais/uso terapêutico , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Adesão à Medicação/estatística & dados numéricos , Sistemas Automatizados de Assistência Junto ao Leito , Retenção nos Cuidados/estatística & dados numéricos , Diagnóstico Precoce , Feminino , Humanos , Lactente , Masculino , Moçambique , Estudos Prospectivos
5.
PLoS One ; 12(1): e0169497, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28060886

RESUMO

The long delay in returning test results during early infant diagnosis of HIV (EID) often causes loss-to-follow-up prior to antiretroviral treatment (ART) initiation in resource-limited settings. A point-of-care (POC) test may help overcome these challenges. We evaluated the performance of the LYNX p24 Antigen POC test in Mozambique. 879 HIV-exposed infants under 18 months of age were enrolled consecutively at three primary healthcare clinics (PHC). Lancet heel-drawn blood was tested on-site by nurses using a prototype POC test for HIV Gag p24 antigen detection. Results of POC testing were compared to laboratory-based nucleic acid testing on dried blood spots. A comparison of the effect of sensitivity and timely test results return on successful diagnosis by POC and laboratory-based platforms was also calculated. The sensitivity and specificity of the LYNX p24 Ag test were 71.9%; (95% confidence interval [CI]: 58.5-83.0%) and 99.6% (95% CI: 98.9-99.9%), respectively. The predictive value of positive and negative tests were 93.2% (95% CI: 81.3-98.6%) and 97.9% (95% CI: 96.8-98.8%), respectively. Overall agreement was high (Cohen Kappa = 0.80; 95% CI: 0.71-0.89). Despite its lower sensitivity, the POC test had the potential to provide test results to up to 81% more patients compared to the laboratory-based test. This prototype POC p24 assay was feasible for use in PHCs but demonstrated low sensitivity for HIV detection. POC EID technologies that perform below standard recommendations may still be valuable diagnostic tools in settings with inefficient EID networks.


Assuntos
Proteína do Núcleo p24 do HIV , Infecções por HIV/diagnóstico , HIV-1 , Testes Imediatos , Fármacos Anti-HIV/uso terapêutico , Pré-Escolar , Estudos Transversais , Diagnóstico Precoce , Feminino , Proteína do Núcleo p24 do HIV/imunologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , Lactente , Recém-Nascido , Masculino , Moçambique/epidemiologia , Testes Imediatos/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Padrão de Cuidado , Fluxo de Trabalho
6.
J Transl Med ; 4: 33, 2006 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-16907973

RESUMO

BACKGROUND: The World Health Organization (WHO)'s "3 x 5 program" has spurred efforts to place 3 million people on combination antiretroviral therapy (ART) for treatment of AIDS in resource-limited countries. Paradoxically, the cost of CD4+ T-lymphocyte count essential for decision-making to commence HIV positive adults on ART as well as for monitoring responses to ART remains unaffordable in most resource-limited countries. Thus, low-cost methods for enumerating CD4+ T-lymphocyte are urgently needed. OBJECTIVE: To evaluate Cyflow cytometry (Cyflow SL, Partec, Munster, Germany) for enumeration of absolute CD4+ T-lymphocyte in subtype C HIV-1 seropositive subjects using FACSCount (Becton and Dickinson, Immunocytometry Systems, San Jose, CA, USA) as the "predicate method". METHODS: A total of 150 HIV-1 seropositive subjects were included in the evaluation exercise. Fifty-eight specimens were collected from pregnant HIV-1 seropositive women (subtype C drug resistance study). Twenty-seven specimens were collected from women and their spouses with AIDS followed in a Duke ART study to assess the immunologic and virologic responses to generic ART, comprising Stavudine, Lamivudine and Nevirapine (Stalanev, Varichem Labs, Harare, Zimbabwe). Sixty-five specimens were collected from AIDS patients enrolled in an ongoing Kaposi Sarcoma (KS) study to investigate impact of ART on KS progression. Enumeration of CD4+ T-lymphocytes using FACSCount is routinely conducted for all the three studies. The Medical Research Council of Zimbabwe and Medicines Control Authority of Zimbabwe approved the studies. Whole blood was collected in EDTA vacutainer tubes and aliquoted into two tubes (200 microL in each). CD4+ T-lymphocyte counts were enumerated using a Cyflow counter, in the Department of Immunology and a FACSCount in the Department of Obstetrics and Gynaecology within 6 hours of phlebotomy following manufacturers' instructions. RESULTS: Using linear regression analysis, there was a very strong correlation (R = 0.991) between the overall CD4+ T-lymphocyte counts obtained by FACSCount and those obtained by Cyflow. When data analysis was stratified by study groups, there was a strong correlation between the FACSCount and Cyflow CD4+ T-lymphocyte counts from subjects in the three independent studies; Subtype C resistance (R2 = 0.987), Duke ART (R2 = 0.980) and KS (R2 = 0.994), Table 1. Using Bland-Altman plots, the overall, absolute CD4+ T lymphocytes obtained by the two methods were in excellent agreement (mean difference 1.21, 95% Confidence Interval {CI): -2.1 to 3.3). For the 0-250 CD4+ T-lymphocytes range, the CD4 counts obtained using FACSCount were also in good agreement with those obtained using Cyflow counter (mean difference = 2.6 cells/microL, 95% CI: -1.1 to 6.3). Similarly, in the 251-500 (mean difference 1.0, cells/microL, 95% CI: -3.7 to 5.6) and the 501-1200 (mean difference = 0.29 cells/microL, 95% CI: -8.1 to 8.7) CD4 T-lymphocytes range, good agreement was observed. CONCLUSION: The Cyflow counter is as accurate as the FACSCount in enumerating absolute CD4+ T-lymphocytes in the range 1-1200 cells/muL. Cyflow cytometry is relatively affordable, easy to use technology that is useful not only in identifying HIV seropositive individuals who require ART but also for monitoring immunologic responses to ART.

7.
PLoS One ; 11(10): e0165163, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27780216

RESUMO

BACKGROUND: In resource-limited countries, CD4 T-cell (CD4) testing continues to be used for determining antiretroviral therapy (ART) initiation eligibility and opportunistic infection monitoring. To support expanded access to CD4 testing, simple and robust technologies are necessary. We conducted this study to evaluate the performance of a new Point-of-Care (POC) CD4 technology, the MyT4, compared to conventional laboratory CD4 testing. METHODS: EDTA venous blood from 200 HIV-positive patients was tested in the laboratory using the MyT4 and BD FACSCalibur™. RESULTS: The MyT4 had an r2 of 0.82 and a mean bias of 12.3 cells/µl. The MyT4 had total misclassifications of 14.7% and 8.8% when analyzed using ART eligibility thresholds of 350 and 500 cells/µl, respectively. CONCLUSIONS: We conclude that the MyT4 performed well in classifying patients using the current ART initiation eligibility thresholds in Mozambique when compared to the conventional CD4 technology.


Assuntos
Contagem de Linfócito CD4/instrumentação , Infecções por HIV/imunologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos Transversais , Definição da Elegibilidade , Feminino , Soropositividade para HIV , Humanos , Masculino , Pessoa de Meia-Idade , Moçambique , Sistemas Automatizados de Assistência Junto ao Leito , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
8.
J Transl Med ; 3(1): 6, 2005 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-15683549

RESUMO

BACKGROUND: Serologic tests for HIV infection in infants less than 18 months do not differentiate exposure and infection since maternally acquired IgG antibodies may be detected in infants. Thus, the gold standard for diagnosis of HIV-1 infection in infants under the age of 2 years is DNA or reverse transcriptase polymerase chain reaction. There is an urgent need to evaluate alternative and cost effective laboratory methods for early diagnosis of infant HIV-1 infection as well as identifying infected infants who may benefit from cotrimoxazole prophylaxis and/or initiation of highly active antiretroviral therapy. METHODS: Whole blood was collected in EDTA from 137 infants aged 0 to 18 months. DNA polymerase chain reaction was used as the reference standard for diagnosis of HIV-1 infection. T-cell subset profiles were determined by flow cytometry. RESULTS: Seventy-six infants were DNA PCR positive while 61 were negative. The median CD4 counts of PCR negative infants were significantly higher than those of the PCR positive infants, p < 0.001. The median CD4/CD8 ratio and the %CD4 of the PCR positive infants were both significantly lower than those of the negative infants, p < 0.001. The CD4/CD8 ratio had a >98% sensitivity for diagnosis of HIV-1 infection and a specificity of >98%. CONCLUSION: The CD4/CD8 ratio appears useful in identifying HIV-infected infants. The development of lower cost and more robust flow cytometric methods that provide both CD4/CD8 ratio and %CD4 may be cost-effective for HIV-1 diagnosis and identification of infants for cotrimoxazole prophylaxis and/or highly active antiretroviral therapy.

9.
PLoS One ; 10(8): e0135744, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26308345

RESUMO

INTRODUCTION: Anemia, syphilis and HIV are high burden diseases among pregnant women in sub-Saharan Africa. A quasi-experimental study was conducted in four health facilities in Southern Mozambique to evaluate the effect of point-of-care technologies for hemoglobin quantification, syphilis testing and CD4+ T-cell enumeration performed within maternal and child health services on testing and treatment coverage, and assessing acceptability by health workers. METHODS: Demographic and testing data on women attending first antenatal care services were extracted from existing records, before (2011; n = 865) and after (2012; n = 808) introduction of point-of-care testing. Study outcomes per health facility were compared using z-tests (categorical variables) and Wilcoxon rank-sum test (continuous variables), while inverse variance weights were used to adjust for possible cluster effects in the pooled analysis. A structured acceptability-assessment interview was conducted with health workers before (n = 22) and after (n = 19). RESULTS: After implementation of point-of-care testing, there was no significant change in uptake of overall hemoglobin screening (67.9% to 83.0%; p = 0.229), syphilis screening (80.8% to 87.0%; p = 0.282) and CD4+ T-cell testing (84.9% to 83.5%; p = 0.930). Initiation of antiretroviral therapy for treatment eligible women was similar in the weighted analysis before and after, with variability among the sites. Time from HIV diagnosis to treatment initiation decreased (median of 44 days to 17 days; p<0.0001). A generally good acceptability for point-of-care testing was seen among health workers. CONCLUSIONS: Point-of-care CD4+ T-cell enumeration resulted in a decreased time to initiation of antiretroviral therapy among treatment eligible women, without significant increase in testing coverage. Overall hemoglobin and syphilis screening increased. Despite the perception that point-of-care technologies increase access to health services, the variability in results indicate the potential for detrimental effects in some settings. Local context needs to be considered and services restructured to accommodate innovative technologies in order to improve service delivery to expectant mothers.


Assuntos
Anemia/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito/estatística & dados numéricos , Diagnóstico Pré-Natal , Sífilis/diagnóstico , Adulto , Antirretrovirais/uso terapêutico , Contagem de Linfócito CD4/métodos , Linfócitos T CD4-Positivos/imunologia , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Humanos , Centros de Saúde Materno-Infantil , Moçambique , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Estudos Retrospectivos , Serviços de Saúde Rural , Inquéritos e Questionários , Sorodiagnóstico da Sífilis/métodos , Adulto Jovem
10.
Hum Immunol ; 63(11): 1026-32, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12392855

RESUMO

HIV-1 mRNA levels (virus load) were quantified for 191 pulmonary tuberculosis (TB) patients and 132 HIV-1 seropositive controls. Human leukocyte antigen (HLA) class I and II genes were typed for 188 patients and 121 HIV-1 seropositive controls. The mean log virus load was higher among cases than HIV-1 seropositive controls (p < 0.0001). Among the controls, mean log virus load was higher among males than females (p = 0.04). There was no association between virus load and homozygosity at HLA class I and II among the controls. In contrast, among the cases, HLA-DRB1 homozygosity was associated with high virus load (p = 0.008), conferring risk for rapid progression to AIDS, thus lending support to the heterozygote advantage hypothesis. The observed decreased virus load in HLA-DRB-1 heterozygotes may be due to a better control of M. tb. infection in the context of HIV-1 disease.


Assuntos
Síndrome da Imunodeficiência Adquirida/imunologia , Genes MHC da Classe II , HIV-1/isolamento & purificação , Antígenos HLA-DR/genética , RNA Viral/análise , Tuberculose/imunologia , Síndrome da Imunodeficiência Adquirida/virologia , Adulto , Idoso , Contagem de Linfócito CD4 , Feminino , HIV-1/genética , Cadeias HLA-DRB1 , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Teste Tuberculínico , Tuberculose/virologia , Carga Viral , Zimbábue
11.
J Acquir Immune Defic Syndr ; 67(1): e1-4, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24933096

RESUMO

OBJECTIVE: To evaluate the accuracy of a point-of-care (POC) nucleic acid-based test (NAT) for early infant HIV diagnosis (EID) in primary health clinics in Mozambique. METHODS: POC and laboratory NAT EID tests were conducted on matched blood samples collected from 827 HIV-exposed infants younger than 18 months who were enrolled consecutively at 4 periurban primary health clinics and the central hospital in Maputo. Lancet heel draw blood collected by nurses was tested on site for HIV-1/-2 RNA on the Alere HIV NAT POC device and also used to create dried blood spots for later laboratory EID testing on the Roche Cobas Taqman/Ampliprep instrument. Results were used to determine the sensitivity, specificity, and agreement between the POC and laboratory NAT EID tests. RESULTS: The sensitivity and specificity of POC NAT EID testing were 98·5% (95% confidence interval (CI): 91.7 to 99.9, n = 65) and 99·9% (95% CI: 99.3 to 100, n = 762), respectively, compared with laboratory EID tests. Overall agreement was high (Cohen kappa = 0·981; 95% CI: 0.96 to 1.00). Positive (98·5%; 95% CI: 96·3 to 100) and negative 99.9% (95% CI: 99.7 to 100) test agreement was also high. CONCLUSIONS: Primary health care nurses accurately performed POC NAT EID testing within primary health care clinics. On-site nucleic acid-based EID testing is technically feasible in clinic settings and could be used in efforts to improve access to pediatric HIV antiretroviral treatment.


Assuntos
Infecções por HIV/diagnóstico , Infecções por HIV/virologia , HIV-1/isolamento & purificação , Instituições de Assistência Ambulatorial , Estudos Transversais , Método Duplo-Cego , Diagnóstico Precoce , Infecções por HIV/sangue , HIV-1/genética , Humanos , Lactente , Moçambique , Reação em Cadeia da Polimerase , Estudos Prospectivos , RNA Viral/química , RNA Viral/genética , Sensibilidade e Especificidade
12.
PLoS One ; 7(10): e47459, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23118871

RESUMO

The expansion of HIV antiretroviral therapy into decentralized rural settings will increasingly require simple point-of-care (POC) diagnostic tests that can be used without laboratory infrastructure and technical skills. New POC test devices are becoming available but decisions around which technologies to deploy may be biased without systematic assessment of their suitability for decentralized healthcare settings. To address this, we developed a standardized, quantitative scorecard tool to objectively evaluate the operational characteristics of POC diagnostic devices. The tool scores devices on a scale of 1-5 across 30 weighted characteristics such as ease of use, quality control, electrical requirements, shelf life, portability, cost and service, and provides a cumulative score that ranks products against a set of ideal POC characteristics. The scorecard was tested on 19 devices for POC CD4 T-lymphocyte cell counting, clinical chemistry or hematology testing. Single and multi-parameter devices were assessed in each of test categories. The scores across all devices ranged from 2.78 to 4.40 out of 5. The tool effectively ranked devices within each category (p<0.01) except the CD4 and multi-parameter hematology products. The tool also enabled comparison of different characteristics between products. Agreement across the four scorers for each product was high (intra-class correlation >0.80; p<0.001). Use of this tool enables the systematic evaluation of diagnostic tests to facilitate product selection and investment in appropriate technology. It is particularly relevant for countries and testing programs considering the adoption of new POC diagnostic tests.


Assuntos
Contagem de Linfócito CD4/instrumentação , Testes Diagnósticos de Rotina/métodos , Infecções por HIV/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Contagem de Linfócito CD4/normas , Linfócitos T CD4-Positivos/citologia , Testes Diagnósticos de Rotina/normas , HIV/isolamento & purificação , Infecções por HIV/terapia , Humanos , Controle de Qualidade
13.
PLos ONE ; 11(10): 1-8, Out 25, 2016. tab, graf
Artigo em Inglês | RSDM, SES-SP | ID: biblio-1524644

RESUMO

Background In resource-limited countries, CD4 T-cell (CD4) testing continues to be used for determining antiretroviral therapy (ART) initiation eligibility and opportunistic infection monitoring. To support expanded access to CD4 testing, simple and robust technologies are necessary. We conducted this study to evaluate the performance of a new Point-of-Care (POC) CD4 technology, the MyT4, compared to conventional laboratory CD4 testing. Methods EDTA venous blood from 200 HIV-positive patients was tested in the laboratory using the MyT4 and BD FACSCalibur™. Results The MyT4 had an r 2 of 0.82 and a mean bias of 12.3 cells/µl. The MyT4 had total misclassifications of 14.7% and 8.8% when analyzed using ART eligibility thresholds of 350 and 500 cells/µl, respectively. Conclusions We conclude that the MyT4 performed well in classifying patients using the current ART initiation eligibility thresholds in Mozambique when compared to the conventional CD4 technology.


Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Contagem de Linfócito CD4/instrumentação , Humanos , Infecções por HIV/imunologia , Pré-Escolar , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Soropositividade para HIV , Alergia e Imunologia , Homens , Pessoa de Meia-Idade , Moçambique
14.
AIDS ; 25(6): 807-12, 2011 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-21378535

RESUMO

OBJECTIVE: To evaluate the accuracy of point-of-care tests (POCTs) for CD4 cell, clinical chemistry and hemoglobin in primary healthcare clinics in Mozambique. DESIGN AND METHODS: POCT and laboratory-based assays were conducted on adult HIV-positive patients enrolled consecutively at primary healthcare clinics in Mozambique. Patients were tested on-site with POCT CD4 (Pima), clinical chemistry (Reflotron) and hemoglobin (HemoCue) devices using finger prick blood. Results obtained on paired blood samples were used for agreement analysis (bias and limits of agreement). Repeatability analysis was also performed for POCT CD4 cell counting. RESULTS: Primary health nurses operating the Pima, Reflotron and HemoCue POCT devices produced results with low levels of bias for CD4(+) T-cell counts (-52.8 cells/µl), alanine aminotransferase (-0.2 U/l), aspartate aminotransferase (-4.0 U/l) and hemoglobin (0.95 g/dl). CD4(+) T-cell counts in paired specimens of finger prick and venous blood tested on the POCT CD4 device were in close agreement (bias -9 cells/µl, coefficient of variation 10.6%). The repeatability of POCT CD4 cell counting was similar to that observed with laboratory instruments (bias -6.2 cells/µl, coefficient of variation 10.7% vs. bias -5.7 cells/µl, coefficient of variation 7.5%). CONCLUSION: Primary health clinic nurses generated accurate results for CD4(+) T-cell counts, liver enzymes and hemoglobin using simple POC devices on finger prick samples at decentralized antiretroviral therapy (ART) clinics. POC diagnostics to monitor ART at primary healthcare level is technically feasible and should be utilized in efforts to decentralize HIV care and treatment.


Assuntos
Terapia Antirretroviral de Alta Atividade/efeitos adversos , Contagem de Linfócito CD4 , Infecções por HIV/sangue , Atenção Primária à Saúde/normas , Adolescente , Adulto , Idoso , Monitoramento de Medicamentos , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Moçambique , Sistemas Automatizados de Assistência Junto ao Leito , Adulto Jovem
16.
J. clin. microbiol ; 54(4): 2104-2108, Jul 25. 2016. tab, graf
Artigo em Inglês | AIM, RSDM | ID: biblio-1525635

RESUMO

Viral load testing is the WHO-recommended monitoring assay for patients on HIV antiretroviral therapy (ART). Point-of-care (POC) assays may help improve access to viral load testing in resource-limited settings. We compared the performance of the Alere Q NAT POC viral load technology (Alere Technologies, Jena, Germany), measuring total HIV RNA using finger prick capillary whole-blood samples collected in a periurban health center, with that of a laboratory-based plasma RNA test (Roche Cobas Ampliprep/Cobas TaqMan v2) conducted on matched venous blood samples. The whole-blood Alere Q NAT POC assay produced results with a bias of 0.8593 log copy/ml compared to the laboratory-based plasma assay. However, at above 10,000 copies/ml, the bias was 0.07 log copy/ml. Using the WHO-recommended threshold to determine ART failure of 1,000 copies/ml, the sensitivity and specificity of the whole-blood Alere Q NAT POC assay were 96.83% and 47.80%, respectively. A cutoff of 10,000 copies/ml of whole blood with the Alere Q NAT POC assay appears to be a better predictor of ART failure threshold (1,000 copies/ml of plasma), with a sensitivity of 84.0% and specificity of 90.3%. The precision of the whole-blood Alere Q NAT POC assay was comparable to that observed with the laboratory technology (5.4% versus 7.5%) between detectable paired samples. HIV POC viral load testing is feasible at the primary health care level. Further research on the value of whole-blood viral load to monitor antiretroviral therapy is warranted.


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Atenção Primária à Saúde , Atenção Primária à Saúde/métodos , RNA Viral/sangue , Infecções por HIV/virologia , Sensibilidade e Especificidade , Carga Viral/métodos , Moçambique , Infecções por HIV/terapia , Monitoramento de Medicamentos/métodos
17.
PLos ONE ; 10(8): 1-6, out.26.2015. ilus, graf
Artigo em Inglês | SES-SP, RSDM | ID: biblio-1526339

RESUMO

Introduction: Anemia, syphilis and HIV are high burden diseases among pregnant women in sub-Saharan Africa. A quasi-experimental study was conducted in four health facilities in Southern Mozambique to evaluate the effect of point-of-care technologies for hemoglobin quantification, syphilis testing and CD4+ T-cell enumeration performed within maternal and child health services on testing and treatment coverage, and assessing acceptability by health workers. Methods: Demographic and testing data on women attending first antenatal care services were extracted from existing records, before (2011; n = 865) and after (2012; n = 808) introduction of point-of-care testing. Study outcomes per health facility were compared using z-tests (categorical variables) and Wilcoxon rank-sum test (continuous variables), while inverse variance weights were used to adjust for possible cluster effects in the pooled analysis. A structured acceptability-assessment interview was conducted with health workers before (n = 22) and after (n = 19). Results: After implementation of point-of-care testing, there was no significant change in uptake of overall hemoglobin screening (67.9% to 83.0%; p = 0.229), syphilis screening (80.8% to 87.0%; p = 0.282) and CD4+ T-cell testing (84.9% to 83.5%; p = 0.930). Initiation of antiretroviral therapy for treatment eligible women was similar in the weighted analysis before and after, with variability among the sites. Time from HIV diagnosis to treatment initiation decreased (median of 44 days to 17 days; p<0.0001). A generally good acceptability for point-of-care testing was seen among health workers. Conclusions: Point-of-care CD4+ T-cell enumeration resulted in a decreased time to initiation of antiretroviral therapy among treatment eligible women, without significant increase in testing coverage. Overall hemoglobin and syphilis screening increased. Despite the perception that point-of-care technologies increase access to health services, the variability in results indicate the potential for detrimental effects in some settings. Local context needs to be considered and services restructured to accommodate innovative technologies in order to improve service delivery to expectant mothers.


Assuntos
Humanos , Feminino , Gravidez , Adulto , Diagnóstico Pré-Natal , Anemia/diagnóstico , Complicações Infecciosas na Gravidez , Sorodiagnóstico da Sífilis , Linfócitos T CD4-Positivos , Sífilis/diagnóstico , Infecções por HIV , Estudos Retrospectivos , Contagem de Linfócito CD4 , Serviços de Saúde Rural , Antirretrovirais , Centros de Saúde Materno-Infantil , Moçambique
18.
J Acquir Immune Defic Syndr ; 39(4): 391-4, 2005 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16010158

RESUMO

The gold standard for diagnosis of HIV-1 infection in infants under the age of 2 years is DNA or reverse transcriptase polymerase chain reaction. However, these tests are expensive and therefore not available in resource-limited countries. With the increasing availability of antiretroviral drugs for prevention of mother-to-child transmission of HIV and treatment of AIDS in resource-poor countries, there is an urgent need to develop cheaper, alternative, and cost-effective laboratory methods for early diagnosis of infant HIV-1 infection that will be useful in identifying infected infants who may benefit from early cotrimoxazole prophylaxis or commencement of antiretroviral therapy. We evaluated an alternative method, the enzyme-linked immunosorbent assay-based qualitative ultrasensitive p24 antigen assay for diagnosis of subtype C HIV-1 infection in infants under the age of 2 years using DNA polymerase chain reaction as the reference method. The assay showed a sensitivity of 96.7% (95% CI: 93.0-100) for detection of HIV-1 infection among infants 0-18 months of age with a specificity of 96.1% (95% CI: 91.7-100). These evaluated parameters were not statistically different between infants aged 0-6 and 7-18 months. The ultrasensitive p24 antigen assay is a useful diagnostic test for detection of HIV-1 infection among infants aged 0-18 months.


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Proteína do Núcleo p24 do HIV/sangue , Infecções por HIV/diagnóstico , Infecções por HIV/virologia , HIV-1/classificação , Humanos , Lactente , Recém-Nascido , Sensibilidade e Especificidade , Zimbábue
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