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Kwizera R, Mande E, Omali D, Okurut S, Nabweyambo S, Nabatanzi R, Nakanjako D, Meya DB. Translational research in Uganda: linking basic science to bedside medicine in a resource limited setting. J Transl Med 2021; 19:76. [PMID: 33593378 PMCID: PMC7887792 DOI: 10.1186/s12967-021-02747-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/10/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Translational research is a process of applying knowledge from basic biology and clinical trials to techniques and tools that address critical medical needs. Translational research is less explored in the Ugandan health system, yet, it is fundamental in enhancing human health and well-being. With the current high disease burden in Uganda, there are many opportunities for exploring, developing and utilising translational research. MAIN BODY In this article, we described the current state, barriers and opportunities for translational research in Uganda. We noted that translational research is underutilised and hindered by limited funding, collaborations, laboratory infrastructure, trained personnel, equipment and research diversity. However, with active collaborations and funding, it is possible to set up and develop thriving translational research in Uganda. Researchers need to leverage existing international collaborations to enhance translational research capacity development. CONCLUSION Expanding the integration of clinical and translational research in Uganda health care system will improve clinical care.
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Affiliation(s)
- Richard Kwizera
- Translational Research Laboratory, Department of Research, Infectious Diseases Institute, College of Health Sciences, Makerere University, P.O Box 22418, Kampala, Uganda.
| | - Emmanuel Mande
- Translational Research Laboratory, Department of Research, Infectious Diseases Institute, College of Health Sciences, Makerere University, P.O Box 22418, Kampala, Uganda
| | - Denis Omali
- Translational Research Laboratory, Department of Research, Infectious Diseases Institute, College of Health Sciences, Makerere University, P.O Box 22418, Kampala, Uganda
| | - Samuel Okurut
- Translational Research Laboratory, Department of Research, Infectious Diseases Institute, College of Health Sciences, Makerere University, P.O Box 22418, Kampala, Uganda
| | - Sheila Nabweyambo
- Translational Research Laboratory, Department of Research, Infectious Diseases Institute, College of Health Sciences, Makerere University, P.O Box 22418, Kampala, Uganda
| | - Rose Nabatanzi
- Translational Research Laboratory, Department of Research, Infectious Diseases Institute, College of Health Sciences, Makerere University, P.O Box 22418, Kampala, Uganda
| | - Damalie Nakanjako
- Translational Research Laboratory, Department of Research, Infectious Diseases Institute, College of Health Sciences, Makerere University, P.O Box 22418, Kampala, Uganda
- Department of Medicine, School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
| | - David B Meya
- Translational Research Laboratory, Department of Research, Infectious Diseases Institute, College of Health Sciences, Makerere University, P.O Box 22418, Kampala, Uganda
- Department of Medicine, School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
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Liu L, Deng R, Lan Y, Li L, Li M, Su B, Gnanashanmugam D, Tang YW, Wu H, Wang J, Cai X, Zhang T. Multicenter evaluation of Xpert HIV-1 viral load assay for HIV quantification in China. J Med Virol 2020; 92:3295-3300. [PMID: 32652607 DOI: 10.1002/jmv.26295] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 07/07/2020] [Indexed: 11/09/2022]
Abstract
New approaches to increase HIV-1 testing and HIV-1 viral load (VL) monitoring are needed for people living with HIV (PLHIV) in China. The Xpert HIV-1 VL assay was prequalified by the World Health Organization in 2017 but has not been evaluated in China. A multicenter evaluation was conducted to assess the accuracy of the Cepheid Xpert HIV-1 VL assay compared to the Abbott RealTime HIV-1 assay in China. Overall agreement was seen in 558 of 562 specimens (99.29%) with a κ value of 0.962. Pearson's coefficient between the two assays was 0.943. Analyzed by the Bland-Altman method, the mean bias was -0.54 log10 copies/mL, and 94.05% results fell within the 95% confidence limit of agreement (-1.248 to 0.168 log10 copies/mL). The coefficient of variation of the Cepheid Xpert HIV-1 VL assay ranged from 0.61% to 1.55%, as determined by testing eight positive plasma specimens with three different lots on different days. Due to its simplicity, random-access, rapid turnaround time, and accuracy, the Xpert HIV-1 VL assay can be used in local hospitals and clinics that bear the burden of identifying and treating HIV patients in China.
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Affiliation(s)
- Lifeng Liu
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory for HIV/AIDS Research, Beijing, China
| | - Renni Deng
- Department of Medical Laboratory, Chongqing Public Health Medical Center, Chongqing, China
| | - Yun Lan
- Infectious Disease Institute, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Li Li
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory for HIV/AIDS Research, Beijing, China
| | - Mei Li
- Department of Medical Laboratory, Chongqing Public Health Medical Center, Chongqing, China
| | - Bin Su
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory for HIV/AIDS Research, Beijing, China
| | | | | | - Hao Wu
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory for HIV/AIDS Research, Beijing, China
| | - Jing Wang
- Department of Medical Laboratory, Chongqing Public Health Medical Center, Chongqing, China
| | - Xiaoli Cai
- Infectious Disease Institute, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Tong Zhang
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory for HIV/AIDS Research, Beijing, China
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Wali A, Khan D, Safdar N, Shawani Z, Fatima R, Yaqoob A, Qadir A, Ahmed S, Rashid H, Ahmed B, Khan S. Prevalence of tuberculosis, HIV/AIDS, and hepatitis; in a prison of Balochistan: a cross-sectional survey. BMC Public Health 2019; 19:1631. [PMID: 31801496 PMCID: PMC6894348 DOI: 10.1186/s12889-019-8011-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 11/27/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Human Immunodeficiency Virus (HIV), Hepatitis, and Tuberculosis (TB) are three primary communicable infections have the likely potential to cause severe morbidity in prison settings. The prison has the most favorable environment for the transmission of infections. We conducted this survey to determine the prevalence and feasibility of rapid diagnostic tests in an active screening of these infectious diseases in prison. METHODS This cross-sectional survey conducted in central Jail Gaddani, one of the largest prisons in the Balochistan province of Pakistan. All prisoners, jail staffs, and staff's family members participated. Informed consent obtained from each participant before the screening. Van equipped with digital X-ray linked with Computer-Aided Detection for TB (CAD4TB) software used for testing. Sputum samples tested on Xpert for MTB/RIF assay and blood specimens collected for HIV and hepatitis serology. Diagnosed TB patients enrolled for treatment at Basic Management Unit (BMU), reactive on hepatitis Rapid Diagnostic Tools (RDTs) were referred for further testing and management, while HIV reactive referred to Anti Retro Viral (ARV) center for Anti Retro Viral Treatment (ART). RESULTS A total of 567 participants offered screening, 63% (356) prisoners, 23% (129) staff's family members, and 14% (82) jail staffs. Among tested 10.3% (58/562) were hepatitis seropositive (Hepatitis-C 41 [7.29%] Hepatitis-B, 16 [2.84%] Hepatitis B&C both, 01 [0.17%]). In reactive participants, 49 were prisoners, 08 were jail staffs, and 01 was the staff's family member. HIV seropositive was 4% (24/566), and all were prisoners. Almost 99% (565/567) screened by digital X-ray, 172 (30%) were with abnormal CAD4TB suggestion (score > 50), out of them sputum of 26% (148) tested on Xpert, and 2% (03) found Mycobacterium tuberculosis Positive (MTB+). A total of five TB patients were detected; out of two were diagnosed clinically. Co-morbidities observed in 15 patients, (01 TB/HIV co-infected, 12 HIV/HCV, 01 HIV/HBV, and 01 HBV/HCV). CONCLUSION The high frequency of infectious diseases in prison is alarming. For limiting the transmission of infections among prison and community, immediate steps are needed to be taken for improvement of prisons condition by application of recommended screening protocols at the time of the first entry of prisoners in prisons.
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Affiliation(s)
- Ahmad Wali
- Provincial Tuberculosis Control Program, Health Department Government of Balochistan, Building Western Bypass Link Brewery Road, Quetta, Balochistan, Pakistan. .,National Tuberculosis Control Program, Ministry of NHSR&C, Islamabad, Pakistan.
| | - Dawood Khan
- Provincial AIDS Control Program, Quetta, Balochistan, Pakistan
| | - Nauman Safdar
- Social and Health Inequalities Network Pakistan, Quetta, Pakistan.,University of Bergen, Bergen, Norway
| | - Zeenat Shawani
- Provincial Tuberculosis Control Program, Health Department Government of Balochistan, Building Western Bypass Link Brewery Road, Quetta, Balochistan, Pakistan
| | - Razia Fatima
- National Tuberculosis Control Program, Ministry of NHSR&C, Islamabad, Pakistan
| | - Aashifa Yaqoob
- National Tuberculosis Control Program, Ministry of NHSR&C, Islamabad, Pakistan
| | - Aurangzeb Qadir
- National Tuberculosis Control Program, Ministry of NHSR&C, Islamabad, Pakistan
| | - Sultan Ahmed
- Provincial Tuberculosis Control Program, Health Department Government of Balochistan, Building Western Bypass Link Brewery Road, Quetta, Balochistan, Pakistan
| | | | - Bashir Ahmed
- Provincial Tuberculosis Control Program, Health Department Government of Balochistan, Building Western Bypass Link Brewery Road, Quetta, Balochistan, Pakistan
| | - Shereen Khan
- Faculty of Bolan Medical University, Quetta, Pakistan
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Tinarwo P, Zewotir T, Yende-Zuma N, Garrett NJ, North D. An Evaluation to Determine the Strongest CD4 Count Covariates during HIV Disease Progression in Women in South Africa. Infect Dis Ther 2019; 8:269-284. [PMID: 30756260 PMCID: PMC6522572 DOI: 10.1007/s40121-019-0235-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Past endeavours to deal with the obstacle of expensive Cluster of Difference 4 (CD4+) count diagnostics in resource-limited settings have left a long trail of suggested continuous CD4+ count clinical covariates that turned out to be a potentially important integral part of the human immunodeficiency virus (HIV) treatment process during disease progression. However, an evaluation to determine the strongest candidates among these CD4+ count covariates has not been well documented. METHODS The Centre for the AIDS Programme of Research in South Africa (CAPRISA) initially enrolled HIV-negative (phase 1) patients into different study cohorts. The patients who seroconverted (237) during follow-up care were enrolled again into a post-HIV infection cohort where they were further followed up with weekly to fortnightly visits up to 3 months (phase 2: acute infection), monthly visits from 3-12 months (phase 3: early infection) and quarterly visits thereafter (phase 4: established infection) until antiretroviral therapy (ART) initiation (phase 5). The CD4+ count and 46 covariates were repeatedly measured at each phase of the HIV disease progression. A multilevel partial least squares approach was applied as a variable reduction technique to determine the strongest CD4+ count covariates. RESULTS Only 18 of the 46 investigated clinical attributes were the strongest CD4+ count covariates and the top 8 were positively and independently associated with the CD4+ count. Besides the confirmatory lymphocytes, these were basophils, albumin, haematocrit, alkaline phosphatase (ALP), mean corpuscular volume (MCV), platelets, potassium and monocytes. Overall, electrolytes, proteins and red blood cells were the dominant categories for the strongest covariates. CONCLUSION Only a few of the many previously suggested continuous CD4+ count clinical covariates showed the potential to become an important integral part of the treatment process. Prolonging the pre-treatment period of the HIV disease progression by effectively incorporating and managing the covariates for long-term influence on the CD4+ cell response has the potential to delay challenges associated with ART side effects.
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Affiliation(s)
- Partson Tinarwo
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Durban, South Africa.
| | - Temesgen Zewotir
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Durban, South Africa
| | - Nonhlanhla Yende-Zuma
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Nigel J Garrett
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Delia North
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Durban, South Africa
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Bystryak S, Bandwar RP, Santockyte R. A flow-through cell counting assay for point-of-care enumeration of CD4 T-cells. J Virol Methods 2019; 271:113672. [PMID: 31145920 DOI: 10.1016/j.jviromet.2019.05.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/07/2019] [Accepted: 05/25/2019] [Indexed: 11/28/2022]
Abstract
CD4 T-cell count is a priority for staging HIV disease and guiding clinical management as part of HIV care. Conventional CD4 T-cell enumeration methods based on flow cytometry are expensive, require well-trained personnel, and are challenging to use in rural, resource-scarce areas. A simple CD4 T-cell count test that can be used at point-of care, the Flow-Through cell Counting Assay (FTCA), is described in this article. The FTCA is based on the use of: 1) a special membrane that selectively retains white blood cells (WBCs); 2) a sample delivery system; and 3) optical signal detection. To show the feasibility of the FTCA, a proof-of-concept prototype of the FTCA cassette and digital camera or handheld reflectance meter were used for obtaining quantitative assay results within 30 min. The results show that the FTCA allows for quantitative enumeration of CD4 T-cells in the clinically relevant range of CD4 T-cell concentrations. The advantages of the FTCA technology, including simplicity, short analysis time, and portability, suggest that FTCA has great potential for use in clinical practice and wide applicability for other cell-based diagnostic tests.
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Affiliation(s)
- Simon Bystryak
- Allied Innovative Systems, 13 Watchung Avenue, Suite 102, Chatham, New Jersey 07928, USA.
| | - Rajiv P Bandwar
- Allied Innovative Systems, 13 Watchung Avenue, Suite 102, Chatham, New Jersey 07928, USA
| | - Rasa Santockyte
- Allied Innovative Systems, 13 Watchung Avenue, Suite 102, Chatham, New Jersey 07928, USA
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Vojnov L, Taegtmeyer M, Boeke C, Markby J, Harris L, Doherty M, Peter T, Ford N. Performance of non-laboratory staff for diagnostic testing and specimen collection in HIV programs: A systematic review and meta-analysis. PLoS One 2019; 14:e0216277. [PMID: 31048881 PMCID: PMC6497381 DOI: 10.1371/journal.pone.0216277] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/17/2019] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND In most high HIV burden countries, many HIV patients do not have reliable access to required diagnostic laboratory tests. Task shifting of clinical tasks to lower cadres of health care workers and lay counselors has been successful in scaling up treatment for HIV and may also be an effective strategy in expanding access to essential diagnostic testing. METHODS We screened major electronic databases between 1 January 2005 to 26 August 2018 to identify studies assessing ease of use and accuracy of task shifting of HIV-related diagnostic testing and/or specimen collection to non-laboratory health staff. Two independent reviewers screened all titles and abstracts for studies that analyzed diagnostic accuracy, patient impact, ease-of-use, or cost-effectiveness. Studies were assessed for quality, bias, and applicability following the QUADAS-2 framework. We generated summary estimates using random-effects meta-analyses. RESULTS We identified 42 relevant studies. Overall, point-of-care CD4 testing performed by non-laboratory staff had a mean bias of -54.44 (95% CI: -72.40 --36.48) compared to conventional laboratory-based. Though studies were limited, the diagnostic accuracy of point-of-care alanine transaminase enzyme (ALT) and hemoglobin testing performed by non-laboratory staff was comparable to conventional laboratory-based testing by laboratory professionals. Point-of-care testing and/or specimen collection were generally found to be acceptable and easy to use for non-laboratory staff. CONCLUSIONS Task shifting of testing using point-of-care technologies to non-laboratory staff was comparable to laboratory professionals operating the same technology in the laboratory. Some variability was observed comparing the performance of point-of-care CD4 testing by non-laboratory staff to conventional laboratory-based technologies by laboratory professionals indicating potential lower performance was likely technological rather than operator caused. The benefits of task shifting of testing may outweigh any possible harms as task shifting allows for increased decentralization, access of specific diagnostics, and faster result delivery.
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Affiliation(s)
- Lara Vojnov
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Miriam Taegtmeyer
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Caroline Boeke
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Jessica Markby
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Lindsay Harris
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Meg Doherty
- World Health Organization, Geneva, Switzerland
| | - Trevor Peter
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Nathan Ford
- World Health Organization, Geneva, Switzerland
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Kohatsu L, Bolu O, Schmitz ME, Chang K, Lemwayi R, Arnett N, Mwasekaga M, Nkengasong J, Mosha F, Westerman LE. Evaluation of Specimen Types for Pima CD4 Point-of-Care Testing: Advantages of Fingerstick Blood Collection into an EDTA Microtube. PLoS One 2018; 13:e0202018. [PMID: 30138398 PMCID: PMC6107158 DOI: 10.1371/journal.pone.0202018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 07/26/2018] [Indexed: 12/28/2022] Open
Abstract
INTRODUCTION Effective point-of-care testing (POCT) is reliant on optimal specimen collection, quality assured testing, and expedited return of results. Many of the POCT are designed to be used with fingerstick capillary blood to simplify the blood collection burden. However, fingerstick blood collection has inherent errors in sampling. An evaluation of the use of capillary and venous blood with CD4 POCT was conducted. METHODS Three different specimen collection methods were evaluated for compatibility using the Alere Pima CD4 assay at 5 HIV/AIDS healthcare sites in Dar es Salaam, Tanzania. At each site, whole blood specimens were collected from enrolled patients by venipuncture and fingerstick. Pima CD4 testing was performed at site of collection on venipuncture specimens (Venous) and fingerstick blood directly applied to a Pima CD4 cartridge (Capillary-Direct) and collected into an EDTA microtube (Capillary-Microtube). Venous blood was also tested at the laboratory by the reference CD4 method and Pima for comparison analysis. RESULTS All three specimen collection methods were successfully collected by healthcare workers for use with the Pima CD4 assay. When compared to the reference CD4 method, Pima CD4 testing with the Capillary-Microtube method performed similarly to Venous, while Pima CD4 counts with the Capillary-Direct method were slightly more biased (-20 cells/μL) and variable (-229 to +189 cells/μL limit of agreement). Even though all three collection methods had similar invalid Pima testing rates (10.5%, 9.8%, and 8.3% for Capillary-Direct, Capillary-Microtube, and Venous respectively), the ability to perform repeat testing with Capillary-Microtube and Venous specimens increased the likelihood of acquiring a valid CD4 result with the Pima assay. CONCLUSIONS Capillary blood, either directly applied to Pima CD4 cartridges or collected in an EDTA microtube, and venous blood are suitable specimens for Pima CD4 testing. The advantages of capillary blood collection in an EDTA microtube are that it uses fingerstick collection which mimics venous blood and allows extra testing without additional blood collection.
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Affiliation(s)
- Luciana Kohatsu
- United States Centers for Disease Control & Prevention, Center for Global Health, Division of Global HIV/AIDS, Atlanta, Georgia, United States of America
| | - Omotayo Bolu
- United States Centers for Disease Control & Prevention, Center for Global Health, Division of Global HIV/AIDS, Atlanta, Georgia, United States of America
| | - Mary E. Schmitz
- United States Centers for Disease Control & Prevention, Dar es Salaam, Tanzania
- Allan Rosenfield Global Health Fellowship, Association of Schools and Programs of Public Health, Washington DC, United States of America
| | - Karen Chang
- United States Centers for Disease Control & Prevention, Dar es Salaam, Tanzania
- Allan Rosenfield Global Health Fellowship, Association of Schools and Programs of Public Health, Washington DC, United States of America
| | - Ruth Lemwayi
- African Field Epidemiology Network, Dar es Salaam, Tanzania
| | - Nichole Arnett
- United States Centers for Disease Control & Prevention, Center for Global Health, Division of Global HIV/AIDS, Atlanta, Georgia, United States of America
| | - Michael Mwasekaga
- United States Centers for Disease Control & Prevention, Dar es Salaam, Tanzania
| | - John Nkengasong
- United States Centers for Disease Control & Prevention, Center for Global Health, Division of Global HIV/AIDS, Atlanta, Georgia, United States of America
| | - Fausta Mosha
- African Field Epidemiology Network, Dar es Salaam, Tanzania
- Ministry of Health Community Development Gender Elderly and Children, Government of Tanzania, Dar es Salaam, Tanzania
| | - Larry E. Westerman
- United States Centers for Disease Control & Prevention, Center for Global Health, Division of Global HIV/AIDS, Atlanta, Georgia, United States of America
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Wei TY, Fu Y, Chang KH, Lin KJ, Lu YJ, Cheng CM. Point-of-Care Devices Using Disease Biomarkers To Diagnose Neurodegenerative Disorders. Trends Biotechnol 2017; 36:290-303. [PMID: 29242004 DOI: 10.1016/j.tibtech.2017.11.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 11/16/2017] [Accepted: 11/17/2017] [Indexed: 12/16/2022]
Abstract
Neurodegenerative disorders such as Alzheimer's, Parkinson's, and Huntington's diseases are highly prevalent and immensely destructive to the health and well-being of individuals and their families across the globe. Neurodegenerative diseases are characterized by the gradual loss of neural tissue in the central nervous system. Clearly, early diagnosis of the onset of neurodegeneration is vital and beneficial. Current diagnostic methods rely heavily on symptoms or autopsy results, thus overlooking early diagnosis, the only opportunity for amelioration. However, appropriately selected and used biomarker diagnostics provide a solution. This article reviews the development and application of biomarker-related diagnostics for neurodegenerative disease with specific recommendations for point-of-care (POC) methodology. These advantageous approaches may offer a solution to existing obstacles and limitations to neurodegenerative disease treatment.
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Affiliation(s)
- Ting-Yen Wei
- Interdisciplinary Program of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan; These authors contributed equally
| | - Yun Fu
- Department of Dermatology, Chang Gung Memorial Hospital Linkou Medical Center, Taoyuan 33305, Taiwan; These authors contributed equally
| | - Kuo-Hsuan Chang
- Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center and College of Medicine, Chang Gung University, Taoyuan 33305, Taiwan
| | - Kun-Ju Lin
- Animal Molecular Imaging Center and Department of Nuclear Medicine, Chang Gung Memorial Hospital Linkou Medical Center, Taoyuan 33305, Taiwan
| | - Yu-Jen Lu
- Department of Neurosurgery, Chang Gung Memorial Hospital Linkou Medical Center and College of Medicine, Chang Gung University, Taoyuan 33305, Taiwan.
| | - Chao-Min Cheng
- Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
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Kaindjee-Tjituka F, Sawadogo S, Mutandi G, Maher AD, Salomo N, Mbapaha C, Neo M, Beukes A, Gweshe J, Muadinohamba A, Lowrance DW. Task-shifting point-of-care CD4+ testing to lay health workers in HIV care and treatment services in Namibia. Afr J Lab Med 2017; 6:643. [PMID: 29159139 PMCID: PMC5684646 DOI: 10.4102/ajlm.v6i1.643] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 07/02/2017] [Indexed: 01/10/2023] Open
Abstract
INTRODUCTION Access to CD4+ testing remains a common barrier to early initiation of antiretroviral therapy among persons living with HIV/AIDS in low- and middle-income countries. The feasibility of task-shifting of point-of-care (POC) CD4+ testing to lay health workers in Namibia has not been evaluated. METHODS From July to August 2011, Pima CD4+ analysers were used to improve access to CD4+ testing at 10 selected public health facilities in Namibia. POC Pima CD4+ testing was performed by nurses or lay health workers. Venous blood samples were collected from 10% of patients and sent to centralised laboratories for CD4+ testing with standard methods. Outcomes for POC Pima CD4+ testing and patient receipt of results were compared between nurses and lay health workers and between the POC method and standard laboratory CD4+ testing methods. RESULTS Overall, 1429 patients received a Pima CD4+ test; 500 (35.0%) tests were performed by nurses and 929 (65.0%) were performed by lay health workers. When Pima CD4+ testing was performed by a nurse or a lay health worker, 93.2% and 95.2% of results were valid (p = 0.1); 95.6% and 98.1% of results were received by the patient (p = 0.007); 96.2% and 94.0% of results were received by the patient on the same day (p = 0.08). Overall, 97.2% of Pima CD4+ results were received by patients, compared to 55.4% of standard laboratory CD4+ results (p < 0.001). CONCLUSIONS POC CD4+ testing was feasible and effective when task-shifted to lay health workers. Rollout of POC CD4+ testing via task-shifting can improve access to CD4+ testing and retention in care between HIV diagnosis and antiretroviral therapy initiation in low- and middle-income countries.
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Affiliation(s)
| | | | - Graham Mutandi
- US Centers for Disease Control and Prevention, Windhoek, Namibia
| | - Andrew D. Maher
- US Centers for Disease Control and Prevention, Windhoek, Namibia
| | - Natanael Salomo
- US Centers for Disease Control and Prevention, Windhoek, Namibia
| | - Claudia Mbapaha
- US Centers for Disease Control and Prevention, Windhoek, Namibia
| | - Marytha Neo
- US Centers for Disease Control and Prevention, Windhoek, Namibia
| | - Anita Beukes
- US Centers for Disease Control and Prevention, Windhoek, Namibia
| | - Justice Gweshe
- Directorate of Special Programs, Ministry of Health and Social Services, Windhoek, Namibia
| | - Alexinah Muadinohamba
- Directorate of Special Programs, Ministry of Health and Social Services, Windhoek, Namibia
| | - David W. Lowrance
- Directorate of Special Programs, Ministry of Health and Social Services, Windhoek, Namibia
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Performance evaluation of BD FACSPresto™ point of care CD4 analyzer to enumerate CD4 counts for monitoring HIV infected individuals in Nigeria. PLoS One 2017; 12:e0178037. [PMID: 28542359 PMCID: PMC5444776 DOI: 10.1371/journal.pone.0178037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 05/08/2017] [Indexed: 11/19/2022] Open
Abstract
Background Despite the upsurge in support and intervention of donor agencies in HIV care and treatment programing in Sub-Sahara African, antiretroviral (ART) programs are still confronted with access and coverage challenges which influence enrolment of new patients. This study investigated the validity of point of care BD FACSPresto™ CD4 analyzer for CD4+ cell count, overall agreement, correlation, sensitivity, and specificity in comparison to a reference standard flow cytometry method. We also assessed the feasibility of use among non-laboratorians. Methods Blood samples from 300 HIV infected individuals were analyzed for CD4+ T cell and CD4%, using finger prick capillary sample from 150 PMTCT clients and 150 ART clients at Murtala Mohammed Specialist Hospital, Kano, Nigeria. Their venous samples were compared on a flow cytometry reference method using BD FACSCount CD4+ count system. The accuracy of the BD FACSPresto machine in comparison to BD FACSCount was evaluated. Statistical analysis was carried out using STATA (version 12). Bland-Altman method and correlation analysis were used to analyze agreement between both measurements. In addition, sensitivity and specificity of both measurements were determined. Statistical significance was set at p-value <0.05. Results The mean bias and limit of agreement for CD4+ count between BD FACSPresto and BD FACS count machine were 7.49 (95% CI: 2.44 to 12.54) and -8.14 to 96.39 respectively. Further analysis revealed close agreement between BD FACSPresto and BD FACSCount with no significant difference between the two methods (p = .0.95). Using a threshold of 500 cells/μL, sensitivity and specificity of BD FACSPresto were 95.1% and 97.1% respectively, compared to BD FACSCount. There was no statistically significant difference in the misclassification between BD FACSPresto and BD FACSCount results (p = 0.23). Furthermore, sensitivity and specificity were similar when BD FACSPresto machine was operated by a nurse or laboratory scientist, there was no substantial difference in testing variability observed between laboratory and non-laboratory operators using the BD FACSPresto analyzer. Conclusions Overall, BD FACSPresto Point of Care CD4+ count finger stick capillary blood results is a reliable method in comparison to venous sample cytometry method and no significant difference variability observed between laboratory personnel and non-laboratory operators. The BD FACSPresto is simple, more robust and easy to use equipment without significant variability in reliability by non-laboratory health care workers hence will be a valuable instrument in increasing access and coverage of CD4 estimations in developing countries. The introduction of the BD FACSPresto POC analyzer has a high potential in reducing patients waiting time and improving the overall quality of ART service and clients’ satisfaction especially in rural settings.
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Lean and Agile Point-of-Care Diagnostic Services Quality Systems Management for Low- and Middle-Income Countries. ACTA ACUST UNITED AC 2016. [DOI: 10.1097/poc.0000000000000111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Sitoe N, Macamo R, Meggi B, Tobaiwa O, Loquiha O, Bollinger T, Vojnov L, Jani I. Performance Evaluation of the MyT4 Technology for Determining ART Eligibility. PLoS One 2016; 11:e0165163. [PMID: 27780216 PMCID: PMC5079624 DOI: 10.1371/journal.pone.0165163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 10/07/2016] [Indexed: 12/02/2022] Open
Abstract
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.
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Affiliation(s)
- Nádia Sitoe
- Instituto Nacional de Saúde, Maputo, Mozambique
- * E-mail:
| | - Rosa Macamo
- Instituto Nacional de Saúde, Maputo, Mozambique
| | | | - Ocean Tobaiwa
- Clinton Health Access Initiative, Maputo, Mozambique
| | | | | | - Lara Vojnov
- Clinton Health Access Initiative, Maputo, Mozambique
| | - Ilesh Jani
- Instituto Nacional de Saúde, Maputo, Mozambique
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Pham MD, Agius PA, Romero L, McGlynn P, Anderson D, Crowe SM, Luchters S. Performance of point-of-care CD4 testing technologies in resource-constrained settings: a systematic review and meta-analysis. BMC Infect Dis 2016; 16:592. [PMID: 27769181 PMCID: PMC5073828 DOI: 10.1186/s12879-016-1931-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/13/2016] [Indexed: 01/02/2023] Open
Abstract
Background Point-of-care (POC) CD4 testing increases patient accessibility to assessment of antiretroviral therapy eligibility. This review evaluates field performance in low and middle-income countries (LMICs) of currently available POC CD4 technologies. Methods Eight electronic databases were searched for field studies published between January 2005 and January 2015 of six POC CD4 platforms: PointCare NOW™, Alere Pima™ CD4, Daktari™ CD4 Counter, CyFlow® CD4 miniPOC, BD FACSPresto™, and MyT4™ CD4. Due to limited data availability, meta-analysis was conducted only for diagnostic performance of Pima at a threshold of 350 cells/μl, applying a bivariate multi-level random-effects modelling approach. A covariate extended model was also explored to test for difference in diagnostic performance between capillary and venous blood. Results Twenty seven studies were included. Published field study results were found for three of the six POC CD4 tests, 24 of which used Pima. For Pima, test failure rates varied from 2 to 23 % across study settings. Pooled sensitivity and specificity were 0.92 (95 % CI = 0.88–0.95) and 0.87 (95 % CI = 0.85–0.88) respectively. Diagnostic performance by blood sample type (venous vs. capillary) revealed non-significant differences in sensitivity (0.94 vs 0.89) and specificity (0.86 vs 0.87), respectively in the extended model (Wald χ2(2) = 4.77, p = 0.09). Conclusions POC CD4 testing can provides reliable results for making treatment decision under field conditions in low-resource settings. The Pima test shows a good diagnostic performance at CD4 cut-off of 350 cells/μl. More data are required to evaluate performance of POC CD4 testing using venous versus capillary blood in LMICs which might otherwise influence clinical practice. Electronic supplementary material The online version of this article (doi:10.1186/s12879-016-1931-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Minh D Pham
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia. .,Department of Epidemiology and Preventive Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia.
| | - Paul A Agius
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Lorena Romero
- The Alfred Hospital, The Ian Potter Library, Melbourne, VIC, Australia
| | - Peter McGlynn
- Department of Epidemiology and Preventive Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia
| | - David Anderson
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.,Department of Immunology, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia
| | - Suzanne M Crowe
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.,Department of Infectious Diseases, The Alfred Hospital and Monash University, Melbourne, Australia
| | - Stanley Luchters
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.,Department of Epidemiology and Preventive Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia.,Department of Obstetrics and Gynecology, International Centre for Reproductive Health, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
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Pham MD, Agius PA, Romero L, McGlynn P, Anderson D, Crowe SM, Luchters S. Acceptability and feasibility of point-of-care CD4 testing on HIV continuum of care in low and middle income countries: a systematic review. BMC Health Serv Res 2016; 16:343. [PMID: 27484023 PMCID: PMC4971709 DOI: 10.1186/s12913-016-1588-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 07/27/2016] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND CD4 testing is, and will remain an important part of HIV treatment and care in low and middle income countries (LMICs). We report the findings of a systematic review assessing acceptability and feasibility of POC CD4 testing in field settings. METHODS Electronic databases were searched for studies published in English between 2005 and 2015 that describe POC CD4 platforms. Studies conducted in LMICs and under field conditions outside a laboratory environment were eligible. Qualitative and descriptive data analysis was used to present the findings. RESULTS Twelve studies were included, 11 of which were conducted in sub-Saharan countries and used one POC CD4 test (The Alere Pima CD4). Patients reported positively regarding the implementation of POC CD4 testing at primary health care and community level with ≥90 % of patients accepting the test across various study settings. Health service providers expressed preference toward POC CD4 testing as it is easy-to-use, efficient and satisfied patients' needs to a greater extent as compared to conventional methods. However, operational challenges including preference toward venous blood rather than finger-prick sampling, frequent device failures and operator errors, quality of training for test operators and supervisors, and increased staff workload were also identified. CONCLUSIONS POC CD4 testing seems acceptable and feasible in LIMCs under field conditions. Further studies using different POC CD4 tests available on the market are required to provide critical data to support countries in selection and implementation of appropriate POC CD4 technologies.
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Affiliation(s)
- Minh D Pham
- Burnet Institute, Melbourne, VIC, Australia.
- Department of Epidemiology and Preventive Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia.
| | | | - Lorena Romero
- The Alfred Hospital, The Ian Potter Library, Melbourne, VIC, Australia
| | - Peter McGlynn
- Department of Epidemiology and Preventive Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia
| | - David Anderson
- Burnet Institute, Melbourne, VIC, Australia
- Department of Immunology, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia
| | - Suzanne M Crowe
- Burnet Institute, Melbourne, VIC, Australia
- Department of Infectious Diseases, The Alfred hospital Melbourne, Melbourne, Australia
- Monash School of Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia
| | - Stanley Luchters
- Burnet Institute, Melbourne, VIC, Australia
- Department of Epidemiology and Preventive Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia
- International Centre for Reproductive Health, Department of Obstetrics and Gynecology, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
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Makadzange AT, Bogezi C, Boyd K, Gumbo A, Mukura D, Matubu A, Ndhlovu CE. Evaluation of the FACSPresto, a New Point of Care Device for the Enumeration of CD4% and Absolute CD4+ T Cell Counts in HIV Infection. PLoS One 2016; 11:e0157546. [PMID: 27388763 PMCID: PMC4936750 DOI: 10.1371/journal.pone.0157546] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 06/01/2016] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Enumeration of CD4+ T lymphocytes is important for pre-ART disease staging and screening for opportunistic infections, however access to CD4 testing in resource limited settings is poor. Point of care (POC) technologies can facilitate improved access to CD4 testing. We evaluated the analytical performance of a novel POC device the FACSPresto compared to the FACSCalibur as a reference standard and to the PIMA, a POC device in widespread use in sub-Saharan Africa. METHOD Specimens were obtained from 253 HIV infected adults. Venous blood samples were analyzed on the FACSPresto and the FACSCalibur, in a subset of 41 samples additional analysis was done on the PIMA. RESULTS The absolute CD4 count results obtained on the FACSPresto were comparable to those on the FACSCalibur with low absolute (9.5cells/μl) and relative bias (3.2%). Bias in CD4% values was also low (1.06%) with a relative bias of 4.9%. The sensitivity was lower at a CD4 count threshold of ≤350cells/μl compared with ≤500cells/μl (84.9% vs. 92.8%) resulting in a high upward misclassification rate at low CD4 counts. Specificity at thresholds of ≤350cells/μl and ≤500cells/μl were 96.6% and 96.8% respectively. The PIMA had a high absolute (-68.6cells/μl) and relative bias (-10.5%) when compared with the FACSCalibur. At thresholds of ≤350cells/μl and ≤500cells/μl the sensitivity was 100% and 95.5% respectively; specificity was 85.7% and 84.2% respectively. The coefficients of repeatability were 4.13%, 5.29% and 9.8% respectively. DISCUSSION The analytic performance of the FACSPresto against the reference standard was very good with better agreement and precision than the PIMA. The FACSPresto had comparable sensitivity at a threshold of 500 cells/μl and better specificity than the PIMA. However the FACSPresto showed reduced sensitivity at low CD4 count thresholds. CONCLUSION The FACSPresto can be reliably used as a POC device for enumerating absolute CD4 count and CD4% values.
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Affiliation(s)
- Azure Tariro Makadzange
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Medicine, University of Zimbabwe College of Health Sciences, Harare, Zimbabwe
- * E-mail:
| | - Carola Bogezi
- Department of Medicine, University of Zimbabwe College of Health Sciences, Harare, Zimbabwe
| | - Kathryn Boyd
- Department of Medicine, University of Zimbabwe College of Health Sciences, Harare, Zimbabwe
| | - Anesu Gumbo
- Department of Medicine, University of Zimbabwe College of Health Sciences, Harare, Zimbabwe
| | - Dorinda Mukura
- Department of Obstetrics and Gynecology, UZ-UCSF Collaborative Project, University of Zimbabwe College of Health Sciences, Harare, Zimbabwe
| | - Allen Matubu
- Department of Obstetrics and Gynecology, UZ-UCSF Collaborative Project, University of Zimbabwe College of Health Sciences, Harare, Zimbabwe
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Skhosana M, Reddy S, Reddy T, Ntoyanto S, Spooner E, Ramjee G, Ngomane N, Coutsoudis A, Kiepiela P. PIMA™ point-of-care testing for CD4 counts in predicting antiretroviral initiation in HIV-infected individuals in KwaZulu-Natal, Durban, South Africa. South Afr J HIV Med 2016; 17:444. [PMID: 29568605 PMCID: PMC5843260 DOI: 10.4102/sajhivmed.v17i1.444] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 03/22/2016] [Indexed: 12/22/2022] Open
Abstract
Introduction Limited information is available on the usefulness of the PIMA™ analyser in predicting antiretroviral treatment eligibility and outcome in a primary healthcare clinic setting in disadvantaged communities in KwaZulu-Natal, South Africa. Materials and methods The study was conducted under the eThekwini Health Unit, Durban, KwaZulu-Natal. Comparison of the enumeration of CD4+ T-cells in 268 patients using the PIMA™ analyser and the predicate National Health Laboratory Services (NHLS) was undertaken during January to July 2013. Bland-Altman analysis to calculate bias and limits of agreement, precision and levels of clinical misclassification at various CD4+ T-cell count thresholds was performed. Results There was high precision of the PIMA™ control bead cartridges with low and normal CD4+ T-cell counts using three different PIMA™ analysers (%CV < 5). Under World Health Organization (WHO) guidelines (≤ 500 cells/mm3), the sensitivity of the PIMA™ analyser was 94%, specificity 78% and positive predictive value (PPV) 95%. There were 24 (9%) misclassifications, of which 13 were false-negative in whom the mean bias was 149 CD4+ T-cells/mm3. Most (87%) patients returned for their CD4 test result but only 67% (110/164) of those eligible (≤ 350 cells/mm3) were initiated on antiretroviral therapy (ART) with a time to treatment of 49 days (interquartile range [IQR], 42–64 days). Conclusion There was adequate agreement between PIMA™ analyser and predicate NHLS CD4+ T-cell count enumeration (≤ 500 cells/mm3) in adult HIV-positive individuals. The high PPV, sensitivity and acceptable specificity of the PIMA™ analyser technology lend it as a reliable tool in predicting eligibility and rapid linkage to care in ART programmes.
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Affiliation(s)
- Mandisa Skhosana
- Department of Paediatrics and Child Health, University of KwaZulu-Natal, South Africa.,Medical Research Council of South Africa, HIV Prevention Research Unit, South Africa
| | - Shabashini Reddy
- Medical Research Council of South Africa, HIV Prevention Research Unit, South Africa
| | - Tarylee Reddy
- Medical Research Council of South Africa, Biostatistics Unit, South Africa
| | - Siphelele Ntoyanto
- Medical Research Council of South Africa, HIV Prevention Research Unit, South Africa
| | - Elizabeth Spooner
- Department of Paediatrics and Child Health, University of KwaZulu-Natal, South Africa.,Medical Research Council of South Africa, HIV Prevention Research Unit, South Africa
| | - Gita Ramjee
- Medical Research Council of South Africa, HIV Prevention Research Unit, South Africa
| | | | - Anna Coutsoudis
- Department of Paediatrics and Child Health, University of KwaZulu-Natal, South Africa
| | - Photini Kiepiela
- Medical Research Council of South Africa, HIV Prevention Research Unit, South Africa
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Daneau G, Buyze J, Wade D, Diaw PA, Dieye TN, Sopheak T, Florence E, Lynen L, Kestens L. CD4 results with a bias larger than hundred cells per microliter can have a significant impact on the clinical decision during treatment initiation of HIV patients. CYTOMETRY PART B-CLINICAL CYTOMETRY 2016; 92:476-484. [PMID: 26917223 DOI: 10.1002/cyto.b.21366] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 02/05/2016] [Accepted: 02/16/2016] [Indexed: 11/11/2022]
Abstract
BACKGROUND CD4 counts are currently used to assess HIV patients for treatment eligibility and to monitor antiretroviral response to treatment. The emerging point-of-care devices could fill an important gap in resource-limited settings. However, the accuracy of CD4-counting instruments is diverse and data on how CD4 measurement errors have an impact on clinical decisions are lacking. METHODS Clinicians were queried on the use of CD4 results in their clinical setting. Subsequently, the effect of CD4 measurement errors on treatment initiation was put in a statistical model. Based on clinical CD4 databases from Belgium, Cambodia, and Senegal, the percentage of unchanged clinical decisions was calculated (treatment initiation should start within a 3-month delay [one visit]) for escalating CD4 measurement errors, taking into account the strict or preventive application of CD4 thresholds at 350 or 500 cells/µl used by clinicians. RESULTS To ensure that the treatment was initiated appropriately for at least 95% of patients, an error of 5 - 10 cells/µl was allowed. This is significantly smaller than the bias of ±50 cells/µl most clinicians considered acceptable. For limits of agreement (LOA, 1.96 x error) of 100 cells/µl, corresponding to most CD4 instrument evaluations, the misclassification rate of patients was found to be 3 - 28% at the threshold of 350 cells/µl (strict or flexible), and 13 - 20% at 500 cells/µl. CONCLUSIONS The maximum allowed CD4 bias on results from new CD4 technologies should not exceed 50 cells/µl (LOA 100 cells/µl) when applied for treatment initiation, to ensure at least 72% of correct clinical decisions. © 2016 International Clinical Cytometry Society.
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Affiliation(s)
- Géraldine Daneau
- Department of Biomedical Sciences, Immunology Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Jozefien Buyze
- Department of Clinical Sciences, HIV/AIDS and infectious diseases Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Djibril Wade
- Department of Biomedical Sciences, Immunology Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Immunology Unit, Laboratory of Bacteriology Virology, Le Dantec University Teaching Hospital, Check Anta Diop University, Dakar, Senegal.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Papa Alassane Diaw
- Immunology Unit, Laboratory of Bacteriology Virology, Le Dantec University Teaching Hospital, Check Anta Diop University, Dakar, Senegal
| | - Tandakha Ndeye Dieye
- Immunology Unit, Laboratory of Bacteriology Virology, Le Dantec University Teaching Hospital, Check Anta Diop University, Dakar, Senegal
| | - Thai Sopheak
- Infectious Diseases Department, Sihanouk Hospital Center of HOPE, Phnom Penh, Cambodia
| | - Eric Florence
- Department of Clinical Sciences, HIV/AIDS and infectious diseases Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Lutgarde Lynen
- Department of Clinical Sciences, HIV/AIDS and infectious diseases Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Luc Kestens
- Department of Biomedical Sciences, Immunology Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
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Lancaster KE, Powers KA, Lungu T, Mmodzi P, Hosseinipour MC, Chadwick K, Go VF, Pence BW, Hoffman IF, Miller WC. The HIV Care Continuum among Female Sex Workers: A Key Population in Lilongwe, Malawi. PLoS One 2016; 11:e0147662. [PMID: 26808043 PMCID: PMC4726447 DOI: 10.1371/journal.pone.0147662] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 01/06/2016] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE The HIV care continuum among female sex workers (FSW), a key population, has not been well characterized, especially within the generalized epidemics of sub-Saharan Africa. This was the first study to characterize the HIV care continuum among FSW in Lilongwe, Malawi. METHODS From July through September 2014, we used venue-based sampling to enroll 200 adult FSW in Lilongwe, Malawi into a cross-sectional evaluation assessing HIV care continuum outcomes. Seropositive FSW, identified using HIV rapid testing, received rapid CD4 counts in addition to viral loads using dried blood spots. We calculated proportions of HIV-infected FSW who had history of care, were on ART, and had suppressed viral load and we used Poisson regression to estimate the associations of demographic characteristics and transmission risk behaviors with each outcome. RESULTS HIV seroprevalence was 69% (n = 138). Among all FSW the median age was 24 years (IQR: 22-28). Among the 20% who were newly diagnosed and reported previously testing negative, the median time since last HIV test was 11 months (interquartile range: 3-17). The majority (69%) of HIV-infected FSW had a history of HIV care, 52% reported current ART use, and 45% were virally suppressed. Of the FSW who reported current ART use, 86% were virally suppressed. Transmission risk behaviors were not associated with continuum outcomes. CONCLUSIONS FSW in Lilongwe were predominately young and have a high HIV prevalence. Only half of HIV-infected FSW reported current ART use, but the majority of those on ART were virally suppressed. To reduce ongoing transmission and improve health outcomes, increased HIV testing, care engagement, and ART coverage is urgently needed among FSW. Universal testing and treatment strategies for all FSW in Malawi must be strongly considered.
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Affiliation(s)
- Kathryn Elizabeth Lancaster
- Department of Epidemiology, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
| | - Kimberly A. Powers
- Department of Epidemiology, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Thandie Lungu
- UNC Project Malawi, University of North Carolina at Chapel Hill, Lilongwe, Malawi
| | - Pearson Mmodzi
- UNC Project Malawi, University of North Carolina at Chapel Hill, Lilongwe, Malawi
| | - Mina C. Hosseinipour
- UNC Project Malawi, University of North Carolina at Chapel Hill, Lilongwe, Malawi
- Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | | | - Vivian F. Go
- Department of Health Behavior, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Brian W. Pence
- Department of Epidemiology, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Irving F. Hoffman
- UNC Project Malawi, University of North Carolina at Chapel Hill, Lilongwe, Malawi
- Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - William C. Miller
- Department of Epidemiology, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
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Bwana P, Vojnov L, Adhiambo M, Akinyi C, Mwende J, Prescott M, Mwau M. The BD FACSPresto Point of Care CD4 Test Accurately Enumerates CD4+ T Cell Counts. PLoS One 2015; 10:e0145586. [PMID: 26720601 PMCID: PMC4697849 DOI: 10.1371/journal.pone.0145586] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/04/2015] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE Currently 50% of ART eligible patients are not yet receiving life-saving antiretroviral therapy (ART). Financial constraints do not allow most developing countries to adopt a universal test and offer ART strategy. Decentralizing CD4+ T cell testing may, therefore, provide greater access to testing, ART, and better patient management. We evaluated the technical performance of a new point-of-care CD4+ T cell technology, the BD FACSPresto, in a field methods comparison study. METHODS 264 HIV-positive patients were consecutively enrolled and included in the study. The BD FACSPresto POC CD4+ T cell technology was placed in two rural health care facilities and operated by health care facility staff. We compared paired finger-prick and venous samples using the BD FACSPresto and several existing reference technologies, respectively. RESULTS The BD FACSPresto had a mean bias of 67.29 cells/ul and an r(2) of 0.9203 compared to the BD FACSCalibur. At ART eligibility thresholds of 350 and 500 cells/ul, the sensitivity to define treatment eligibility were 81.5% and 77.2% and the specificities were 98.9% and 100%, respectively. Similar results were observed when the BD FACSPresto was compared to the BD FACSCount and Alere Pima. The coefficient of variation (CV) was less than 7% for both the BD FACSCalibur and BD FACSPresto. CD4+ T cell testing by nurses using the BD FACSPresto at rural health care facilities showed high technical similarity to test results generated by laboratory technicians using the BD FACSPresto in a high functioning laboratory. CONCLUSIONS The BD FACSPresto performed favorably in the laboratory setting compared to the conventional reference standard technologies; however, the lower sensitivities indicated that up to 20% of patients tested in the field in need of treatment would be missed. The BD FACSPresto is a technology that can allow for greater decentralization and wider access to CD4+ T cell testing and ART.
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Affiliation(s)
- Priska Bwana
- Kenya Medical Research Institute, Nairobi, Kenya
| | - Lara Vojnov
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | | | | | - Joy Mwende
- Kenya Medical Research Institute, Nairobi, Kenya
| | - Marta Prescott
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Matilu Mwau
- Kenya Medical Research Institute, Nairobi, Kenya
- * E-mail:
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Liang J, Duan S, Ma YL, Wang JB, Su YZ, Zhang H, Ou CY, Hao L, Qi MS, Bulterys M, Westerman L, Jiang Y, Xiao Y. Evaluation of PIMA point-of-care CD4 analyzer in Yunnan, China. Chin Med J (Engl) 2015; 128:890-5. [PMID: 25836608 PMCID: PMC4834004 DOI: 10.4103/0366-6999.154283] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: CD4 count is used to determine antiretroviral therapy (ART) eligibility. In China, flow cytometers are mostly located in urban areas with limited access by patients residing in remote areas. In an attempt to address this issue, we conducted a study to validate the performance of Alere PIMA point-of-care CD4 analyzer. Methods: Venous and finger-prick blood specimens were collected from HIV-positive participants from two voluntary counseling and testing sites in Yunnan Province. Both venous and finger-prick blood specimens were tested with the PIMA analyzer. Venous blood specimens tested with the Becton Dickinson FACSCalibur were used as a reference. Results: Venous specimens from 396 and finger-prick specimens from 387 persons were available for analysis. CD4 counts by PIMA correlated well with those from FACSCalibur with an R2 of 0.91 for venous blood and 0.81 for finger-prick blood. Compared to FACSCalibur, the PIMA analyzer yielded lower counts with a mean bias of − 47.0 cells/μl (limit of agreement, [LOA]: −204–110 cells/μl) for venous blood and −71.0 cells/μl (LOA: −295–153 cells/μl) for finger-prick blood. For a CD4 threshold of 350 cells/μl, the positive predictive value (PPV) of PIMA was 84.2% and 75.7% and the negative predictive value (NPV) was 97.6% and 95.8% for venous and finger-prick blood, respectively. For an ART threshold of 500 cells/μl, the corresponding PPV was 90.3% and 84.0% and NPV was 94.3% and 93.4%, respectively. Conclusions: CD4 counting using venous blood with PIMA analyzers is a feasible alternative to a large flow cytometer to determine ART eligibility.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Yao Xiao
- Department of AIDS/STD Prevention, National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
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Scott LE, Campbell J, Westerman L, Kestens L, Vojnov L, Kohastsu L, Nkengasong J, Peter T, Stevens W. A meta-analysis of the performance of the Pima™ CD4 for point of care testing. BMC Med 2015; 13:168. [PMID: 26208867 PMCID: PMC4515022 DOI: 10.1186/s12916-015-0396-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The Alere point-of-care (POC) Pima™ CD4 analyzer allows for decentralized testing and expansion to testing antiretroviral therapy (ART) eligibility. A consortium conducted a pooled multi-data technical performance analysis of the Pima CD4. METHODS Primary data (11,803 paired observations) comprised 22 independent studies between 2009-2012 from the Caribbean, Asia, Sub-Saharan Africa, USA and Europe, using 6 laboratory-based reference technologies. Data were analyzed as categorical (including binary) and numerical (absolute) observations using a bivariate and/or univariate random effects model when appropriate. RESULTS At a median reference CD4 of 383 cells/μl the mean Pima CD4 bias is -23 cells/μl (average bias across all CD4 ranges is 10 % for venous and 15% for capillary testing). Sensitivity of the Pima CD4 is 93% (95% confidence interval [CI] 91.4% - 94.9%) at 350 cells/μl and 96% (CI 95.2% - 96.9%) at 500 cells/μl, with no significant difference between venous and capillary testing. Sensitivity reduced to 86% (CI 82% - 89%) at 100 cells/μl (for Cryptococcal antigen (CrAg) screening), with a significant difference between venous (88%, CI: 85% - 91%) and capillary (79%, CI: 73% - 84%) testing. Total CD4 misclassification is 2.3% cases at 100 cells/μl, 11.0% at 350 cells/μl and 9.5 % at 500 cells/μl, due to higher false positive rates which resulted in more patients identified for treatment. This increased by 1.2%, 2.8% and 1.8%, respectively, for capillary testing. There was no difference in Pima CD4 misclassification between the meta-analysis data and a population subset of HIV+ ART naïve individuals, nor in misclassification among operator cadres. The Pima CD4 was most similar to Beckman Coulter PanLeucogated CD4, Becton Dickinson FACSCalibur and FACSCount, and less similar to Partec CyFlow reference technologies. CONCLUSIONS The Pima CD4 may be recommended using venous-derived specimens for screening (100 cells/μl) for reflex CrAg screening and for HIV ART eligibility at 350 cells/μl and 500 cells/μl thresholds using both capillary and venous derived specimens. These meta-analysis findings add to the knowledge of acceptance criteria of the Pima CD4 and future POC tests, but implementation and impact will require full costing analysis.
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Affiliation(s)
- Lesley E Scott
- Department of Molecular Medicine and Haematology, Faculty of Health Science, School of Pathology, University of the Witwatersrand, 7 York Road Parktown, Johannesburg, South Africa.
| | | | | | - Luc Kestens
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium. .,Laboratory of Immunology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
| | - Lara Vojnov
- Clinton Health Access Initiative, Boston, MA, USA.
| | | | | | - Trevor Peter
- Clinton Health Access Initiative, Boston, MA, USA.
| | - Wendy Stevens
- Department of Molecular Medicine and Haematology, Faculty of Health Science, School of Pathology, University of the Witwatersrand, 7 York Road Parktown, Johannesburg, South Africa. .,National Health Laboratory Service, Johannesburg, South Africa.
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Fajardo E, Metcalf C, Piriou E, Gueguen M, Maman D, Chaillet P, Cox V, Rumaney MB, Tunggal S, Kosack C, Roberts T. Errors generated by a point-of-care CD4+ T-lymphocyte analyser: a retrospective observational study in nine countries. Bull World Health Organ 2015; 93:623-30. [PMID: 26478626 PMCID: PMC4581638 DOI: 10.2471/blt.14.146480] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 05/14/2015] [Accepted: 05/21/2015] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE To estimate the proportion of invalid results generated by a CD4+ T-lymphocyte analyser used by Médecins Sans Frontières (MSF) in field projects and identify factors associated with invalid results. METHODS We collated 25,616 CD4+ T-lymphocyte test results from 39 sites in nine countries for the years 2011 to 2013. Information about the setting, user, training, sampling technique and device repair history were obtained by questionnaire. The analyser performs a series of checks to ensure that all steps of the analysis are completed successfully; if not, an invalid result is reported. We calculated the proportion of invalid results by device and by operator. Regression analyses were used to investigate factors associated with invalid results. FINDINGS There were 3354 invalid test results (13.1%) across 39 sites, for 58 Alere PimaTM devices and 180 operators. The median proportion of errors per device and operator was 12.7% (interquartile range, IQR: 10.3-19.9) and 12.1% (IQR: 7.1-19.2), respectively. The proportion of invalid results varied widely by country, setting, user and device. Errors were not associated with settings, user experience or the number of users per device. Tests performed on capillary blood samples were significantly less likely to generate errors compared to venous whole blood. CONCLUSION The Alere Pima CD4+ analyser generated a high proportion of invalid test results, across different countries, settings and users. Most error codes could be attributed to the operator, but the exact causes proved difficult to identify. Invalid results need to be factored into the implementation and operational costs of routine CD4+ T-lymphocyte testing.
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Affiliation(s)
- Emmanuel Fajardo
- Médecins Sans Frontières (MSF), Southern Africa Medical Unit (SAMU), Waverly Business Park, 303 A&B, Cape Town, South Africa
| | - Carol Metcalf
- Médecins Sans Frontières (MSF), Southern Africa Medical Unit (SAMU), Waverly Business Park, 303 A&B, Cape Town, South Africa
| | | | | | | | | | | | - Maryam B Rumaney
- Médecins Sans Frontières (MSF), Southern Africa Medical Unit (SAMU), Waverly Business Park, 303 A&B, Cape Town, South Africa
| | | | - Cara Kosack
- MSF, Diagnostic Network, Amsterdam, Netherlands
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Koss CA, Jarlsberg LG, den Boon S, Cattamanchi A, Davis JL, Worodria W, Ayakaka I, Sanyu I, Huang L. A Clinical Predictor Score for 30-Day Mortality among HIV-Infected Adults Hospitalized with Pneumonia in Uganda. PLoS One 2015; 10:e0126591. [PMID: 25962069 PMCID: PMC4427329 DOI: 10.1371/journal.pone.0126591] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 04/05/2015] [Indexed: 12/02/2022] Open
Abstract
Background Pneumonia is a major cause of mortality among HIV-infected patients. Pneumonia severity scores are promising tools to assist clinicians in predicting patients’ 30-day mortality, but existing scores were developed in populations infected with neither HIV nor tuberculosis (TB) and include laboratory data that may not be available in resource-limited settings. The objective of this study was to develop a score to predict mortality in HIV-infected adults with pneumonia in TB-endemic, resource-limited settings. Methods We conducted a secondary analysis of data from a prospective study enrolling HIV-infected adults with cough ≥2 weeks and <6 months and clinically suspected pneumonia admitted to Mulago Hospital in Kampala, Uganda from September 2008 to March 2011. Patients provided two sputum specimens for mycobacteria, and those with Ziehl-Neelsen sputum smears that were negative for mycobacteria underwent bronchoscopy with inspection for Kaposi sarcoma and testing for mycobacteria and fungi, including Pneumocystis jirovecii. A multivariable best subsets regression model was developed, and one point was assigned to each variable in the model to develop a clinical predictor score for 30-day mortality. Results Overall, 835 patients were studied (mean age 34 years, 53.4% female, 30-day mortality 18.2%). A four-point clinical predictor score was identified and included heart rate >120 beats/minute, respiratory rate >30 breaths/minute, oxygen saturation <90%, and CD4 cell count <50 cells/mm3. Patients’ 30-day mortality, stratified by score, was: score 0 or 1, 12.6%, score 2 or 3, 23.4%, score 4, 53.9%. For each 1 point change in clinical predictor score, the odds of 30-day mortality increased by 65% (OR 1.65, 95% CI 1.39-1.96, p <0.001). Conclusions A simple, four-point scoring system can stratify patients by levels of risk for mortality. Rapid identification of higher risk patients combined with provision of timely and appropriate treatment may improve clinical outcomes. This predictor score should be validated in other resource-limited settings.
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Affiliation(s)
- Catherine A. Koss
- Department of Medicine, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail:
| | - Leah G. Jarlsberg
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, San Francisco General Hospital, University of California San Francisco, San Francisco, California, United States of America
| | - Saskia den Boon
- Makerere University–University of California San Francisco Research Collaboration, Kampala, Uganda
| | - Adithya Cattamanchi
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, San Francisco General Hospital, University of California San Francisco, San Francisco, California, United States of America
- Makerere University–University of California San Francisco Research Collaboration, Kampala, Uganda
| | - J. Lucian Davis
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, San Francisco General Hospital, University of California San Francisco, San Francisco, California, United States of America
- Makerere University–University of California San Francisco Research Collaboration, Kampala, Uganda
| | - William Worodria
- Makerere University–University of California San Francisco Research Collaboration, Kampala, Uganda
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
- Department of Medicine, Mulago National Referral and Teaching Hospital, Kampala, Uganda
| | - Irene Ayakaka
- Makerere University–University of California San Francisco Research Collaboration, Kampala, Uganda
| | - Ingvar Sanyu
- Makerere University–University of California San Francisco Research Collaboration, Kampala, Uganda
| | - Laurence Huang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, San Francisco General Hospital, University of California San Francisco, San Francisco, California, United States of America
- Makerere University–University of California San Francisco Research Collaboration, Kampala, Uganda
- HIV/AIDS Division, Department of Medicine, San Francisco General Hospital, University of California San Francisco, San Francisco, California, United States of America
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Pinto IC, Sabidó M, Pereira AB, Mello MB, de Melo Xavier Shimizu A, Protti BL, Benzaken AS. Field Evaluation of a Point-of-Care CD4 Analyzer for Monitoring HIV Patients in the Interior of the Amazon Region, Brazil. PLoS One 2015; 10:e0121400. [PMID: 25905775 PMCID: PMC4408088 DOI: 10.1371/journal.pone.0121400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 01/31/2015] [Indexed: 01/02/2023] Open
Abstract
Objective To evaluate the accuracy of the PIMA point-of-care CD4 analyzer (PIMA) under field conditions in comparison to the current CD4 count system (FACSCalibur), and to evaluate the operational suitability and acceptability of health professionals (HP) and HIV-patients in using the PIMA in health clinics in the Amazon Region. Methods CD4 counts were measured onsite by the PIMA using fingerprick blood and in the reference laboratory by both the PIMA and FACSCalibur using venous blood. We used the Bland–Altman method to estimate the mean bias, and calculated the sensitivity and specificity at <200 and <500 cell/μL thresholds. Patients (n = 404) and HP (n = 7) were interviewed on the acceptability and operational suitability of the PIMA. Results Using fingerprick blood (n = 337), the PIMA showed a concordance correlation coefficient (Rc) of 0.81, mean difference of -111.9 cell/μL, 93.1%/98.5% sensitivity, and 89.2%/56.7% specificity at <200 and <500 cell/μL thresholds, respectively. Venous blood (n = 340) showed an Rc of 0.89, mean difference of -83.4 cell/μL, 98.3%/97.5% sensitivity, and 93.9%/66.0% specificity at <200 and <500 cell/μL thresholds, respectively. The capillary PIMA was well accepted and found operationally appropriate by patients and HP. Conclusions The agreement between both instruments was poor and the PIMA underestimated CD4 cell counts, which was more pronounced at CD4 counts ≥500 cell/μl. The PIMA’s performance with fingerprick blood was less reliable than its performance with venous blood. In Brazil, where antiretroviral treatment is initiated regardless of CD4 counts, the PIMA’s systematic bias towards CD4 underestimation may limit its role for monitoring HIV-patients.
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Affiliation(s)
- Ione Conceição Pinto
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD), Manaus, Amazonas, Brazil
| | - Meritxell Sabidó
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD), Manaus, Amazonas, Brazil; TransLab, Department of Medical Sciences, Universitat de Girona, Catalunya, Spain
| | | | - Maeve B Mello
- Joint United Nations Programme on HIV/AIDS (UNAIDS), Brasilia, Brazil
| | | | - Bruna Lovizutto Protti
- Departamento de DST, Aids e Hepatites Virais, Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasília, Brazil
| | - Adele Schwartz Benzaken
- Departamento de DST, Aids e Hepatites Virais, Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasília, Brazil; Instituto Leônidas e Maria Deane, Oswaldo Cruz Foundation, Manaus, Brazil
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Laboratory and field evaluation of the Partec CyFlow miniPOC for absolute and relative CD4 T-cell enumeration. PLoS One 2015; 10:e0116663. [PMID: 25688553 PMCID: PMC4331543 DOI: 10.1371/journal.pone.0116663] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 12/11/2014] [Indexed: 12/05/2022] Open
Abstract
Background A new CD4 point-of-care instrument, the CyFlow miniPOC, which provides absolute and percentage CD4 T-cells, used for screening and monitoring of HIV-infected patients in resource-limited settings, was introduced recently. We assessed the performance of this novel instrument in a reference laboratory and in a field setting in Senegal. Methodology A total of 321 blood samples were obtained from 297 adults and 24 children, all HIV-patients attending university hospitals in Dakar, or health centers in Ziguinchor. Samples were analyzed in parallel on CyFlow miniPOC, FACSCount CD4 and FACSCalibur to assess CyFlow miniPOC precision and accuracy. Results At the reference lab, CyFlow miniPOC, compared to FACSCalibur, showed an absolute mean bias of -12.6 cells/mm3 and a corresponding relative mean bias of -2.3% for absolute CD4 counts. For CD4 percentages, the absolute mean bias was -0.1%. Compared to FACSCount CD4, the absolute and relative mean biases were -31.2 cells/mm3 and -4.7%, respectively, for CD4 counts, whereas the absolute mean bias for CD4 percentages was 1.3%. The CyFlow miniPOC was able to classify HIV-patients eligible for ART with a sensitivity of ≥ 95% at the different ART-initiation thresholds (200, 350 and 500 CD4 cells/mm3). In the field lab, the room temperature ranged from 30 to 35°C during the working hours. At those temperatures, the CyFlow miniPOC, compared to FACSCount CD4, had an absolute and relative mean bias of 7.6 cells/mm3 and 2.8%, respectively, for absolute CD4 counts, and an absolute mean bias of 0.4% for CD4 percentages. The CyFlow miniPOC showed sensitivity equal or greater than 94%. Conclusion The CyFlow miniPOC showed high agreement with FACSCalibur and FACSCount CD4. The CyFlow miniPOC provides both reliable absolute CD4 counts and CD4 percentages even under the field conditions, and is suitable for monitoring HIV-infected patients in resource-limited settings.
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Malagun M, Nano G, Chevallier C, Opina R, Sawiya G, Kivavia J, Kalinoe A, Nathaniel K, Kaminiel O, Millan J, Carmone A, Dini M, Palou T, Topma K, Lavu E, Markby J. Multisite evaluation of point of care CD4 testing in Papua New Guinea. PLoS One 2014; 9:e112173. [PMID: 25426710 PMCID: PMC4245096 DOI: 10.1371/journal.pone.0112173] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 10/13/2014] [Indexed: 11/18/2022] Open
Abstract
Laboratory-based CD4 monitoring of HIV patients presents challenges in resource limited settings (RLS) including frequent machine breakdown, poor engineering support and limited cold chain and specimen transport logistics. This study assessed the performance of two CD4 tests designed for use in RLS; the Dynal assay and the Alere PIMA test (PIMA). Accuracy of Dynal and PIMA using venous blood was assessed in a centralised laboratory by comparison to BD FACSCount (BD FACS). Dynal had a mean bias of −50.35 cells/µl (r2 = 0.973, p<0.0001, n = 101) and PIMA −22.43 cells/µl (r2 = 0.964, p<0.0001, n = 139) compared to BD FACS. Similar results were observed for PIMA operated by clinicians in one urban (n = 117) and two rural clinics (n = 98). Using internal control beads, PIMA precision was 10.34% CV (low bead mean 214.24 cells/µl) and 8.29% (high bead mean 920.73 cells/µl) and similar %CV results were observed external quality assurance (EQA) and replicate patient samples. Dynal did not perform using EQA and no internal controls are supplied by the manufacturer, however duplicate testing of samples resulted in r2 = 0.961, p<0.0001, mean bias = −1.44 cells/µl. Using the cut-off of 350 cells/µl compared to BD FACS, PIMA had a sensitivity of 88.85% and specificity of 98.71% and Dynal 88.61% and 100%. A total of 0.44% (2/452) of patient samples were misclassified as “no treat” and 7.30% (33/452) “treat” using PIMA whereas with Dynal 8.91% (9/101) as “treat” and 0% as “no treat”. In our setting PIMA was found to be accurate, precise and user-friendly in both laboratory and clinic settings. Dynal performed well in initial centralized laboratory evaluation, however lacks requisite quality control measures, and was technically more difficult to use, making it less suitable for use at lower tiered laboratories.
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Affiliation(s)
- Malin Malagun
- Clinton Health Access Initiative, Port Moresby, Papua New Guinea
| | - Gideon Nano
- National Department of Health, HIV Division, Port Moresby, Papua New Guinea
| | | | - Ragagalo Opina
- Heduru Clinic, Port Moresby General Hospital, Papua New Guinea
| | - Gola Sawiya
- Heduru Clinic, Port Moresby General Hospital, Papua New Guinea
| | - Joseph Kivavia
- Central Public Health Laboratory, HIV Section, Port Moresby, Papua New Guinea
| | - Albina Kalinoe
- Pathology Department, Port Moresby General Hospital, Port Moresby, Papua New Guinea
| | - Kathalina Nathaniel
- Pathology Department, Port Moresby General Hospital, Port Moresby, Papua New Guinea
| | - Oscillah Kaminiel
- Central Public Health Laboratory, Quality Assurance Section, Port Moresby, Papua New Guinea
| | - John Millan
- National Department of Health, Port Moresby, Papua New Guinea
| | - Andrea Carmone
- Clinton Health Access Initiative, Goroka, Papua New Guinea
- * E-mail:
| | - Mary Dini
- Pathology Department, Goroka General Hospital, Papua New Guinea
| | - Theresa Palou
- Pathology Department, Goroka General Hospital, Papua New Guinea
| | - Kum Topma
- Asaro District Health Centre, Eastern Highlands Province, Papua New Guinea
| | - Evelyn Lavu
- Central Public Health Laboratory, Papua New Guinea
| | - Jessica Markby
- Clinton Health Access Initiative, Goroka, Papua New Guinea
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Technical performance evaluation of the MyT4 point of care technology for CD4+ T cell enumeration. PLoS One 2014; 9:e107410. [PMID: 25229408 PMCID: PMC4167862 DOI: 10.1371/journal.pone.0107410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 08/09/2014] [Indexed: 12/27/2022] Open
Abstract
Objective Though absolute CD4+ T cell enumeration is the primary gateway to antiretroviral therapy initiation for HIV-positive patients in all developing countries, patient access to this critical diagnostic test is relatively poor. We technically evaluated the performance of a newly developed point-of-care CD4+ T cell technology, the MyT4, compared with conventional CD4+ T cell testing technologies. Design Over 250 HIV-positive patients were consecutively enrolled and their blood tested on the MyT4, BD FACSCalibur, and BD FACSCount. Results Compared with the BD FACSCount, the MyT4 had an r2 of 0.7269 and a mean bias of −23.37 cells/µl. Compared with the BD FACSCalibur, the MyT4 had an r2 of 0.5825 and a mean bias of −46.58 cells/µl. Kenya currently uses a CD4+ T cell test threshold of 350 cells/µl to determine patient eligibility for antiretroviral therapy. At this threshold, the MyT4 had a sensitivity of 95.3% (95% CI: 88.4–98.7%) and a specificity of 87.9% (95% CI: 82.3–92.3%) compared with the BD FACSCount and sensitivity and specificity of 88.2% (95% CI: 79.4–94.2%) and 84.2% (95% CI: 78.2–89.2%), respectively, compared with the BD FACSCalibur. Finally, the MyT4 had a coefficient of variation of 12.80% compared with 14.03% for the BD FACSCalibur. Conclusions We conclude that the MyT4 performed well at the current 350 cells/µl ART initiation eligibility threshold when used by lower cadres of health care facility staff in rural clinics compared to conventional CD4+ T cell technologies.
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The clinical and economic impact of point-of-care CD4 testing in mozambique and other resource-limited settings: a cost-effectiveness analysis. PLoS Med 2014; 11:e1001725. [PMID: 25225800 PMCID: PMC4165752 DOI: 10.1371/journal.pmed.1001725] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 07/30/2014] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Point-of-care CD4 tests at HIV diagnosis could improve linkage to care in resource-limited settings. Our objective is to evaluate the clinical and economic impact of point-of-care CD4 tests compared to laboratory-based tests in Mozambique. METHODS AND FINDINGS We use a validated model of HIV testing, linkage, and treatment (CEPAC-International) to examine two strategies of immunological staging in Mozambique: (1) laboratory-based CD4 testing (LAB-CD4) and (2) point-of-care CD4 testing (POC-CD4). Model outcomes include 5-y survival, life expectancy, lifetime costs, and incremental cost-effectiveness ratios (ICERs). Input parameters include linkage to care (LAB-CD4, 34%; POC-CD4, 61%), probability of correctly detecting antiretroviral therapy (ART) eligibility (sensitivity: LAB-CD4, 100%; POC-CD4, 90%) or ART ineligibility (specificity: LAB-CD4, 100%; POC-CD4, 85%), and test cost (LAB-CD4, US$10; POC-CD4, US$24). In sensitivity analyses, we vary POC-CD4-specific parameters, as well as cohort and setting parameters to reflect a range of scenarios in sub-Saharan Africa. We consider ICERs less than three times the per capita gross domestic product in Mozambique (US$570) to be cost-effective, and ICERs less than one times the per capita gross domestic product in Mozambique to be very cost-effective. Projected 5-y survival in HIV-infected persons with LAB-CD4 is 60.9% (95% CI, 60.9%-61.0%), increasing to 65.0% (95% CI, 64.9%-65.1%) with POC-CD4. Discounted life expectancy and per person lifetime costs with LAB-CD4 are 9.6 y (95% CI, 9.6-9.6 y) and US$2,440 (95% CI, US$2,440-US$2,450) and increase with POC-CD4 to 10.3 y (95% CI, 10.3-10.3 y) and US$2,800 (95% CI, US$2,790-US$2,800); the ICER of POC-CD4 compared to LAB-CD4 is US$500/year of life saved (YLS) (95% CI, US$480-US$520/YLS). POC-CD4 improves clinical outcomes and remains near the very cost-effective threshold in sensitivity analyses, even if point-of-care CD4 tests have lower sensitivity/specificity and higher cost than published values. In other resource-limited settings with fewer opportunities to access care, POC-CD4 has a greater impact on clinical outcomes and remains cost-effective compared to LAB-CD4. Limitations of the analysis include the uncertainty around input parameters, which is examined in sensitivity analyses. The potential added benefits due to decreased transmission are excluded; their inclusion would likely further increase the value of POC-CD4 compared to LAB-CD4. CONCLUSIONS POC-CD4 at the time of HIV diagnosis could improve survival and be cost-effective compared to LAB-CD4 in Mozambique, if it improves linkage to care. POC-CD4 could have the greatest impact on mortality in settings where resources for HIV testing and linkage are most limited. Please see later in the article for the Editors' Summary.
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Simple and rapid CD4 testing based on large-field imaging system composed of microcavity array and two-dimensional photosensor. Biosens Bioelectron 2014; 67:350-5. [PMID: 25192872 DOI: 10.1016/j.bios.2014.08.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 08/11/2014] [Accepted: 08/22/2014] [Indexed: 11/23/2022]
Abstract
This study presents a novel method for CD4 testing based on one-shot large-field imaging. The large-field imaging system was fabricated by a microcavity array and a two-dimensional (2D) photosensor within the desk-top-sized instrument. The microcavity array was employed to separate leukocytes from whole blood based on differences in the size of leukocytes and other blood cells. The large-field imaging system with lower side irradiation enabled acquisition of cell signatures with high signal-to-noise ratio, because the metallic substrate of the microcavity array obstructed excessive excitation light. In this setting, dual-color imaging of CD4(+) and CD8(+) T cells was achieved within the entire image area (64 mm(2)) in 2s. The practical performance of the large-field imaging system was demonstrated by determining the CD4/CD8 ratio in a few microliter of control whole blood as small as those obtained by a finger prick. The CD4/CD8 ratios measured using the large-field imaging system correlated well with those measured by microscopic analysis. These results indicate that our proposed system provides a simple and rapid CD4 testing for the application of HIV/AIDS treatment.
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WHO multicenter evaluation of FACSCount CD4 and Pima CD4 T-cell count systems: instrument performance and misclassification of HIV-infected patients. J Acquir Immune Defic Syndr 2014; 66:e98-107. [PMID: 24853304 PMCID: PMC4149645 DOI: 10.1097/qai.0000000000000214] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND CD4⁺ T-cell counts are used to screen and follow-up HIV-infected patients during treatment. As part of the World Health Organization prequalification program of diagnostics, we conducted an independent multicenter evaluation of the FACSCount CD4 and the Pima CD4, using the FACSCalibur as reference method. METHODS A total of 440 paired capillary and venous blood samples were collected from HIV-infected patients attending the HIV outpatient clinic in Antwerp, Belgium, and the HIV care and treatment center in Dar es Salam, Tanzania. Capillary blood was run on Pima analyzer, whereas venous blood was analyzed on FACSCount, Pima, and FACSCalibur instruments. Precision and agreement between methods were assessed. RESULTS The FACSCount CD4 results were in agreement with the FACSCalibur results with relative bias of 0.4% and 3.1% on absolute CD4 counts and an absolute bias of -0.6% and -1.1% on CD4% in Antwerp and Dar es Salam, respectively. The Pima CD4 results were in agreement with the FACSCalibur results with relative bias of -4.1% and -9.4% using venous blood and of -9.5% and -0.9% using capillary blood in Antwerp and Dar es Salam, respectively. At the threshold of 350 cells per microliter, the FACSCount CD4 and Pima CD4 using venous and capillary blood misclassified 7%, 9%, and 13% of patients, respectively. CONCLUSIONS The FACSCount CD4 provides reliable CD4 counts and CD4% and is suitable for monitoring adult and pediatric HIV patients in moderate-volume settings. The Pima CD4 is more suitable for screening eligible adult HIV patients for antiretroviral treatment initiation in low-volume laboratories.
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Watkins NN, Hassan U, Damhorst G, Ni H, Vaid A, Rodriguez W, Bashir R. Microfluidic CD4+ and CD8+ T lymphocyte counters for point-of-care HIV diagnostics using whole blood. Sci Transl Med 2014; 5:214ra170. [PMID: 24307694 DOI: 10.1126/scitranslmed.3006870] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Roughly 33 million people worldwide are infected with HIV; disease burden is highest in resource-limited settings. One important diagnostic in HIV disease management is the absolute count of lymphocytes expressing the CD4(+) and CD8(+) receptors. The current diagnostic instruments and procedures require expensive equipment and trained technicians. In response, we have developed microfluidic biochips that count CD4(+) and CD8(+) lymphocytes in whole blood samples, without the need for off-chip sample preparation. The device is based on differential electrical counting and relies on five on-chip modules that, in sequence, chemically lyses erythrocytes, quenches lysis to preserve leukocytes, enumerates cells electrically, depletes the target cells (CD4 or CD8) with antibodies, and enumerates the remaining cells electrically. We demonstrate application of this chip using blood from healthy and HIV-infected subjects. Erythrocyte lysis and quenching durations were optimized to create pure leukocyte populations in less than 1 min. Target cell depletion was accomplished through shear stress-based immunocapture, using antibody-coated microposts to increase the contact surface area and enhance depletion efficiency. With the differential electrical counting method, device-based CD4(+) and CD8(+) T cell counts closely matched control counts obtained from flow cytometry, over a dynamic range of 40 to 1000 cells/μl. By providing accurate cell counts in less than 20 min, from samples obtained from one drop of whole blood, this approach has the potential to be realized as a handheld, battery-powered instrument that would deliver simple HIV diagnostics to patients anywhere in the world, regardless of geography or socioeconomic status.
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Affiliation(s)
- Nicholas N Watkins
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, William L. Everett Laboratory, 1406 West Green Street, Urbana, IL 61801, USA
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Galiwango RM, Lubyayi L, Musoke R, Kalibbala S, Buwembo M, Kasule J, Serwadda D, Gray RH, Reynolds SJ, Chang LW. Field evaluation of PIMA point-of-care CD4 testing in Rakai, Uganda. PLoS One 2014; 9:e88928. [PMID: 24614083 PMCID: PMC3948619 DOI: 10.1371/journal.pone.0088928] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 01/16/2014] [Indexed: 11/18/2022] Open
Abstract
Objective To assess the accuracy of PIMA Point-of-Care (POC) CD4 testing in rural Rakai, Uganda. Methods 903 HIV positive persons attending field clinics provided a venous blood sample assessed on site using PIMA analyzers per manufacturer's specifications. The venous samples were then run on FACSCalibur flow cytometry at a central facility. The Bland–Altman method was used to estimate mean bias and 95% limits of agreement (LOA). Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated for a CD4 threshold of <350 and <500 cells/uL for antiretroviral eligibility. Results There was a high correlation between PIMA and FACSCalibur CD4 counts (r = 0.943, p<0.001). Relative to FACSCalibur, the PIMA POC CD4 had negative mean bias of −34.6 cells/uL (95% LOA: −219.8 to 150.6) overall. The dispersion at CD4<350 cells/uL was 5.1 cells/uL (95% LOA: −126.6 to 136.8). For a threshold of CD4<350 cells/uL, PIMA venous blood had a sensitivity of 88.6% (95%CI 84.8–92.4%), specificity of 87.5% (95%CI 84.9–90.1%), NPV of 94.9% (95%CI 93.1–96.7%), and PPV of 74.4% (95%CI 69.6–79.2%). PIMA sensitivity and PPV significantly increased to 96.1% and 88.3% respectively with increased threshold of 500 cells/uL. Conclusions Overall, PIMA POC CD4 counts demonstrated negative bias compared to FACSCalibur. PIMA POC sensitivity improved significantly at a higher CD4 threshold of 500 than a 350 cells/uL threshold.
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Affiliation(s)
| | | | | | | | | | | | - David Serwadda
- School of Public Health, Makerere University College of Health Sciences, Kampala, Uganda
| | - Ronald H. Gray
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Steven J. Reynolds
- Laboratory of Immunoregulation, Division of Intramural Research, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Larry W. Chang
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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Rathunde L, Kussen GMB, Beltrame MP, Dalla Costa LM, Raboni SM. Evaluation of the Alere Pima™ for CD4+ T lymphocytes counts in HIV-positive outpatients in Southern Brazil. Int J STD AIDS 2014; 25:956-9. [PMID: 24616116 DOI: 10.1177/0956462414526862] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
CD4 + lymphocyte counts are routinely ordered during the early phases of antiretroviral therapy and for prophylaxis of opportunistic infections in HIV-positive patients. Flow cytometry is the standard methodology for CD4 counts in Brazilian reference laboratories. However, these laboratories are located in large cities, frequently distant from patients, thus limiting patient access and delaying results. We compared a point-of-care test with flow cytometry determination of CD4(+) T lymphocyte counts in HIV patients. We analysed 107 consecutive samples by both methods. Overall, the point-of-care test performed well, with excellent agreement between it and the standard method. Test results were concordant for patients with CD4(+) T lymphocyte values above and below 200 cells/mm (3). The performance characteristics obtained were sensitivity 94% (95% CI 89.5-98.5%), specificity 93% (95% CI 88.2-97.8%), positive predictive value 86% (95% CI 79.4-92.6%), and negative predictive value 97% (95% CI 94-100%). The high sensitivity and specificity of the point-of-care test methodology suggest its utility as an alternative method for rapid measurement of CD4(+) T lymphocytes in patients with limited access to reference laboratories, enabling prompt therapeutic intervention for patients at risk of progression to AIDS.
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Affiliation(s)
- L Rathunde
- Medical School, Universidade Federal do Paraná, Curitiba, Brazil
| | - G M B Kussen
- Post-Graduate Program in Internal Medicine and Health Science, Universidade Federal do Paraná, Curitiba, Brazil Bacteriology Laboratory, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Brazil
| | - M P Beltrame
- Immunophenotyping Laboratory, Universidade Federal do Paraná, Curitiba, Brazil
| | - L M Dalla Costa
- Bacteriology Laboratory, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Brazil Faculdades e Instituto Pelé Pequeno Príncipe, Curitiba, Brazil
| | - S M Raboni
- Post-Graduate Program in Internal Medicine and Health Science, Universidade Federal do Paraná, Curitiba, Brazil
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Abstract
Effective prevention of HIV/AIDS requires early diagnosis, initiation of therapy, and regular plasma viral load monitoring of the infected individual. In addition, incidence estimation using accurate and sensitive assays is needed to facilitate HIV prevention efforts in the public health setting. Therefore, more affordable and accessible point-of-care (POC) technologies capable of providing early diagnosis, HIV viral load measurements, and CD4 counts in settings where HIV is most prevalent are needed to enable appropriate intervention strategies and ultimately stop transmission of the virus within these populations to achieve the future goal of an AIDS-free generation. This review discusses the available and emerging POC technologies for future application to these unmet public health needs.
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Feasibility of performing multiple point of care testing for HIV anti-retroviral treatment initiation and monitoring from multiple or single fingersticks. PLoS One 2013; 8:e85265. [PMID: 24376873 PMCID: PMC3869909 DOI: 10.1371/journal.pone.0085265] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 11/25/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Point of Care testing (POCT) provides on-site, rapid, accessible results. With current South African anti-retroviral treatment guidelines, up to 4 fingersticks /patient/clinic visit could be required if utilizing POC. We determined the feasibility and accuracy of a nurse performing multiple POCT on multiple fingersticks followed by simplification of the process by performance of multiple POC on a single fingerstick. METHOD AND FINDINGS Random HIV positive adult patients presenting at a HIV treatment clinic in South Africa, for ART initiation/ monitoring, were approached to participate in the study between April-June 2012. Phase I: n=150 patients approached for multiple POCT on multiple fingersticks. Phase II: n=150 patients approached for multiple POCT on a single fingerstick. The following POC tests were performed by a dedicated nurse: PIMA (CD4), HemoCue (hemoglobin), Reflotron (alanine aminotransferase, creatinine). A venepuncture specimen was taken for predicate laboratory methodology. Normal laboratory ranges and Royal College of Pathologists Australasia (RCPA) allowable differences were used as guidelines for comparison. In 67% of participants, ≥3 tests were requested per visit. All POCT were accurate but ranged in variability. Phase I: Hemoglobin was accurate (3.2%CV) while CD4, alanine aminotransferase and creatinine showed increased variability (16.3%CV; 9.3%CV; 12.9%CV respectively). PIMA generated a misclassification of 12.4%. Phase II: Hemoglobin, alanine aminotransferase and creatinine showed good accuracy (3.2%CV, 8.7%CV, 6.4%CV respectively) with increased variability on CD4 (12.4%CV) but low clinical misclassification (4.1%). No trends were observed for the sequence in which POC was performed on a single fingerstick. Overall, PIMA CD4 generated the highest error rate (16-19%). CONCLUSIONS Multiple POCT for ART initiation and/or monitoring can be performed practically by a dedicated nurse on multiple fingersticks. The process is as accurate as predicate methodology and can be simplified using a single fingerstick.
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Drain PK, Hyle EP, Noubary F, Freedberg KA, Wilson D, Bishai WR, Rodriguez W, Bassett IV. Diagnostic point-of-care tests in resource-limited settings. THE LANCET. INFECTIOUS DISEASES 2013; 14:239-49. [PMID: 24332389 DOI: 10.1016/s1473-3099(13)70250-0] [Citation(s) in RCA: 440] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The aim of diagnostic point-of-care testing is to minimise the time to obtain a test result, thereby allowing clinicians and patients to make a quick clinical decision. Because point-of-care tests are used in resource-limited settings, the benefits need to outweigh the costs. To optimise point-of-care testing in resource-limited settings, diagnostic tests need rigorous assessments focused on relevant clinical outcomes and operational costs, which differ from assessments of conventional diagnostic tests. We reviewed published studies on point-of-care testing in resource-limited settings, and found no clearly defined metric for the clinical usefulness of point-of-care testing. Therefore, we propose a framework for the assessment of point-of-care tests, and suggest and define the term test efficacy to describe the ability of a diagnostic test to support a clinical decision within its operational context. We also propose revised criteria for an ideal diagnostic point-of-care test in resource-limited settings. Through systematic assessments, comparisons between centralised testing and novel point-of-care technologies can be more formalised, and health officials can better establish which point-of-care technologies represent valuable additions to their clinical programmes.
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Affiliation(s)
- Paul K Drain
- Medical Practice Evaluation Center, Massachusetts General Hospital, Harvard Medical School, Boston, USA.
| | - Emily P Hyle
- Medical Practice Evaluation Center, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Farzad Noubary
- Medical Practice Evaluation Center, Massachusetts General Hospital, Harvard Medical School, Boston, USA; The Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA, USA; Tufts Clinical and Translational Science Institute, Tufts University, Boston, USA
| | - Kenneth A Freedberg
- Medical Practice Evaluation Center, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | | | - William R Bishai
- Johns Hopkins University, Baltimore, USA; KwaZulu-Natal Research Institute for Tuberculosis and HIV, Durban, South Africa
| | | | - Ingrid V Bassett
- Medical Practice Evaluation Center, Massachusetts General Hospital, Harvard Medical School, Boston, USA
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Mtapuri-Zinyowera S, Chiyaka ET, Mushayi W, Musuka G, Naluyinda-Kitabire F, Mushavi A, Chikwasha V. PIMA Point of Care CD4+ Cell Count Machines in Remote MNCH Settings: Lessons Learned from Seven Districts in Zimbabwe. Infect Dis (Lond) 2013; 6:51-60. [PMID: 24847177 PMCID: PMC3988624 DOI: 10.4137/idrt.s12801] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
An evaluation was commissioned to generate evidence on the impact of PIMA point-of-care CD4+ count machines in maternal and new-born child health settings in Zimbabwe; document best practices, lessons learned, challenges, and recommendations related to scale up of this new technology. A mixed methodology approach that included 31 in-depth interviews with stakeholders involved in procurement, distribution, and use of the POC machines was employed. Additionally, data was also abstracted from 207 patient records from 35 sites with the PIMA POC CD4+ count machines and 10 other comparative sites without the machine. A clearer training strategy was found to be necessary. The average time taken to initiate clients on antiretroviral treatment (ART) was substantially less, 15 days (IQR-1-149) for sites with a PIMA POC machine as compared to 32.7 days (IQR-1-192) at sites with no PIMA POC machine. There was general satisfaction because of the presence of the PIMA POC CD4+ count machine at sites that also initiated ART.
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Affiliation(s)
| | - Edward T. Chiyaka
- National University of Science and Technology, Department of Applied Mathematics, Bulawayo, Zimbabwe
| | | | | | | | | | - Vasco Chikwasha
- University of Zimbabwe, Department of Community Medicine, Harare, Zimbabwe
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Damhorst GL, Watkins NN, Bashir R. Micro- and nanotechnology for HIV/AIDS diagnostics in resource-limited settings. IEEE Trans Biomed Eng 2013; 60:715-26. [PMID: 23512111 DOI: 10.1109/tbme.2013.2244894] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Thirty-four million people are living with HIV worldwide, a disproportionate number of whom live in resource-limited settings. Proper clinical management of AIDS, the disease caused by HIV, requires regular monitoring of both the status of the host's immune system and levels of the virus in their blood. Therefore, more accessible technologies capable of performing a CD4+ T cell count and HIV viral load measurement in settings where HIV is most prevalent are desperately needed to enable better treatment strategies and ultimately quell the spread of the virus within populations. This review discusses micro- and nanotechnology solutions to performing these key clinical measurements in resource-limited settings.
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Affiliation(s)
- Gregory L Damhorst
- Department of Bioengineering and the Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Rowley CF. Developments in CD4 and viral load monitoring in resource-limited settings. Clin Infect Dis 2013; 58:407-12. [PMID: 24218101 DOI: 10.1093/cid/cit733] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
CD4 counts and human immunodeficiency virus (HIV) load testing are essential components of HIV care, and making these tests available in resource-limited settings is critical to the roll-out of HIV treatment globally. Until recently, the evidence supporting the importance of laboratory monitoring in resource-limited settings was lacking, but there is now a consensus emerging that testing should become routine to ensure the longevity of treatment programs. Low-cost, point-of-care testing offers the potential to fill this role as it potentially improves all aspects of HIV care, ranging from the diagnosis and staging of HIV infection in both infants and adults to monitoring for treatment failure once antiretroviral therapy has been initiated. It is imperative for low-cost solutions to become a reality, but it is equally imperative that close scrutiny be given to each new device that hits the market to ensure they perform optimally in all settings.
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Wade D, Diaw PA, Daneau G, Camara M, Dieye TN, Mboup S, Kestens L. CD4 T-cell enumeration in a field setting: evaluation of CyFlow counter using the CD4 easy count kit-dry and Pima CD4 systems. PLoS One 2013; 8:e75484. [PMID: 24066184 PMCID: PMC3774632 DOI: 10.1371/journal.pone.0075484] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Accepted: 08/20/2013] [Indexed: 12/02/2022] Open
Abstract
Background Flow Cytometry (FCM) is still considered to be the method of choice for accurate CD4 enumeration. However, the use of FCM in developing countries is problematic due to their cost and complexity. Lower-cost technologies have been introduced. We evaluated CyFlow Counter together with its lyophilized reagents, and Pima CD4 in high-temperature area, using FACSCount as reference. Materials and Methods Whole blood samples were consecutively collected by venipuncture from 111 HIV+ patients and 17 HIV-negative donors. CD4 T-cell enumeration was performed on CyFlow Counter, Pima CD4 and FACSCount. Results CyFlow Counter and Pima CD4 systems showed good correlation with FACSCount (slope of 0.82 and 0.90, and concordance ρc of 0.94 and 0.98, respectively). CyFlow Counter showed absolute or relative biases (LOA) of −63 cells/mm3 (−245 to 120) or −9.8% (−38.1 to 18.4) respectively, and Pima CD4 showed biases (LOA) of −30 cells/mm3 (−160 to 101) or −3.5% (−41.0 to 33.9%). CyFlow Counter and Pima CD4 showed respectively 106.7% and 105.9% of similarity with FACSCount. According to WHO-2010 ART initiation threshold of 350 cells/mm3, CyFlow Counter and Pima CD4 showed respectively sensibility of 100% and 97%, and specificity of 91% and 93%. CyFlow Counter and Pima CD4 were strongly correlated (slope of 1.09 and ρc of 0.95). These alternative systems showed good agreement with bias of 33 cells/mm3 (−132 to 203) or 6.3% (−31.2 to 43.8), and similarity of 104.3%. Conclusion CyFlow Counter using CD4 easy count kit-dry and Pima CD4 systems can accurately provide CD4 T-cell counts with acceptable agreement to those of FACSCount.
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Affiliation(s)
- Djibril Wade
- Immunology Unit, Laboratory of Bacteriology Virology, Le Dantec University Teaching Hospital, Dakar, Senegal ; Immunology Laboratory, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium ; Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
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Accuracy of pima point-of-care CD4 analyzer in routine use in public health clinics in Uganda. J Acquir Immune Defic Syndr 2013; 63:e113-5. [PMID: 23760094 DOI: 10.1097/qai.0b013e3182928f27] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Glynn MT, Kinahan DJ, Ducrée J. CD4 counting technologies for HIV therapy monitoring in resource-poor settings--state-of-the-art and emerging microtechnologies. LAB ON A CHIP 2013; 13:2731-2748. [PMID: 23670110 DOI: 10.1039/c3lc50213a] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Modern advancements in pharmaceuticals have provided individuals who have been infected with the human immunodeficiency virus (HIV) with the possibility of significantly extending their survival rates. When administered sufficiently soon after infection, antiretroviral therapy (ART) allows medical practitioners to control onset of the symptoms of the associated acquired immune deficiency syndrome (AIDS). Active monitoring of the immune system in both HIV patients and individuals who are regarded as "at-risk" is critical in the decision making process for when to start a patient on ART. A reliable and common method for such monitoring is to observe any decline in the number of CD4 expressing T-helper cells in the blood of a patient. However, the technology, expertise, infrastructure and costs to carry out such a diagnostic cannot be handled by medical services in resource-poor regions where HIV is endemic. Addressing this shortfall, commercialized point-of-care (POC) CD4 cell count systems are now available in such regions. A number of newer devices will also soon be on the market, some the result of recent maturing of charity-funded initiatives. Many of the current and imminent devices are enabled by microfluidic solutions, and this review will critically survey and analyze these POC technologies for CD4 counting, both on-market and near-to-market deployment. Additionally, promising technologies under development that may usher in a new generation of devices will be presented.
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Affiliation(s)
- Macdara T Glynn
- Biomedical Diagnostic Institute, National Centre for Sensor Research, School of Physical Sciences, Dublin City University, Dublin, Ireland.
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Optimizing PMTCT service delivery in rural North-Central Nigeria: protocol and design for a cluster randomized study. Contemp Clin Trials 2013; 36:187-97. [PMID: 23816493 DOI: 10.1016/j.cct.2013.06.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 06/15/2013] [Accepted: 06/20/2013] [Indexed: 11/24/2022]
Abstract
Nigeria has more HIV-infected women who do not receive needed services for the prevention of mother-to-child transmission of HIV (PMTCT) than any other nation in the world. To meet the UNAIDS/WHO goal of eliminating mother-to-child HIV transmission by 2015, multiple interventions will be required to scale up PMTCT services, especially to lower-level, rural health facilities. To address this, we are conducting a cluster-randomized controlled study to evaluate the impact and cost-effectiveness of a novel, family-focused integrated package of PMTCT services. A systematic re-assignment of patient care responsibilities coupled with the adoption of point-of-care CD4 + cell count testing could facilitate the ability of lower-cadre health providers to manage PMTCT care, including the provision and scale-up of antiretroviral therapy (ART) to pregnant women in rural settings. Additionally, as influential community members, male partners could support their partners' uptake of and adherence to PMTCT care. We describe an innovative approach to scaling up PMTCT service provision that incorporates considerations of where and from whom women can access services (task-shifting), ease of obtaining a CD4 + cell count result (point-of-care testing), the degree of HIV service integration for HIV-infected women and their infants, and the level of family and community involvement (specifically male partner involvement). This systematic approach, if proven feasible and effective, could be scaled up in Nigeria and similar resource-limited settings as a means to accelerate progress toward eliminating mother-to-child transmission of HIV and help women with HIV infection take ART and live long, healthy lives (Trial registration: NCT01805752).
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Point-of-care testing for sexually transmitted infections: recent advances and implications for disease control. Curr Opin Infect Dis 2013; 26:73-9. [PMID: 23242343 DOI: 10.1097/qco.0b013e32835c21b0] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Sexually transmitted infections (STIs) remain a major global public health issue, with more than 448 million incident bacterial infections each year. We review recent advances in STI point-of-care (POC) testing and implications for STI prevention and control. RECENT FINDINGS Accurate immunochromatographic assays to detect HIV, hepatitis C virus (HCV) and syphilis antibodies have made home or supervised self-testing possible. Several studies have demonstrated feasibility and excellent test characteristics for HIV, HCV and syphilis POC tests. Rapid oral HIV tests are now available for purchase at retail sites across the United States. Combined HIV and syphilis tests using a single finger prick blood sample are under evaluation. SUMMARY Oral POC STI tests with comparable performance to blood-based POC tests are available for self-testing. POC tests can expand screening, improve syndromic management and reduce loss to follow up. POC STI tests have the potential to facilitate prompt treatment and partner services. POC STI tests create opportunities for new social and financial models of community-based testing services. Increasing equity and access to testing will create challenges in linkage to care, quality assurance, partner services and surveillance. These important developments warrant research to understand appropriate contexts for implementation.
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Tucker JD, Bien CH, Peeling RW. Point-of-care testing for sexually transmitted infections: recent advances and implications for disease control. Curr Opin Infect Dis 2013; 26:73-79. [PMID: 23242343 DOI: 10.1097/qc0.0b013e32835c21b0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
PURPOSE OF REVIEW Sexually transmitted infections (STIs) remain a major global public health issue, with more than 448 million incident bacterial infections each year. We review recent advances in STI point-of-care (POC) testing and implications for STI prevention and control. RECENT FINDINGS Accurate immunochromatographic assays to detect HIV, hepatitis C virus (HCV) and syphilis antibodies have made home or supervised self-testing possible. Several studies have demonstrated feasibility and excellent test characteristics for HIV, HCV and syphilis POC tests. Rapid oral HIV tests are now available for purchase at retail sites across the United States. Combined HIV and syphilis tests using a single finger prick blood sample are under evaluation. SUMMARY Oral POC STI tests with comparable performance to blood-based POC tests are available for self-testing. POC tests can expand screening, improve syndromic management and reduce loss to follow up. POC STI tests have the potential to facilitate prompt treatment and partner services. POC STI tests create opportunities for new social and financial models of community-based testing services. Increasing equity and access to testing will create challenges in linkage to care, quality assurance, partner services and surveillance. These important developments warrant research to understand appropriate contexts for implementation.
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Affiliation(s)
- Joseph D Tucker
- UNC Project-China, Guangdong Provincial STD Control Center, Guangzhou, China
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Wu G, Zaman MH. Low-cost tools for diagnosing and monitoring HIV infection in low-resource settings. Bull World Health Organ 2012; 90:914-20. [PMID: 23284197 DOI: 10.2471/blt.12.102780] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Revised: 07/10/2012] [Accepted: 09/06/2012] [Indexed: 11/27/2022] Open
Abstract
Low-cost technologies to diagnose and monitor human immunodeficiency virus (HIV) infection in developing countries are a major subject of current research and health care in the developing world. With the great need to increase access to affordable HIV monitoring services in rural areas of developing countries, much work has been focus on the development of point-of-care technologies that are affordable, robust, easy to use, portable and of sufficient quantitative accuracy to enable clinical decision-making. For diagnosis of HIV infection, some low-cost tests, such as lateral flow tests and enzyme-linked immunosorbent assays, are already in place and well established. However, portable quantitative tests for rapid HIV monitoring at the point of care have only recently been introduced to the market. In this review, we discuss low-cost tests for HIV diagnosis and monitoring in low-resource settings, including promising technologies for use at the point of care, that are available or close to market.
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Affiliation(s)
- Grace Wu
- Department of Biomedical Engineering, Boston University, 44 Cummington Street, Boston, MA 02215, USA
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Logan C, Givens M, Ives JT, Delaney M, Lochhead MJ, Schooley RT, Benson CA. Performance evaluation of the MBio Diagnostics point-of-care CD4 counter. J Immunol Methods 2012; 387:107-13. [PMID: 23063690 DOI: 10.1016/j.jim.2012.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/28/2012] [Accepted: 10/04/2012] [Indexed: 10/27/2022]
Abstract
The measurement of the absolute CD4 T-cell count is critical in the initial evaluation and staging of HIV-infected persons, yet access to this technology remains limited in many low resource settings where disease burden is highest. Here we evaluate the performance of a prototype point-of-care device (POC) to quantify CD4 T cells from MBio Diagnostics, Inc. Whole blood samples, both venous and capillary (finger stick), were collected from known HIV-infected participants at the University of California, San Diego Antiviral Research Center, and tested using the MBio system and conventional flow cytometry. A total of 94 venipuncture and 52 capillary samples were processed and statistical analyses included comparison to flow cytometry results. For the venipuncture samples, Bland-Altman analysis resulted in a mean bias of -10 cells/μL (-23 to +3 cells/μL, 95% CI), and limits of agreement (LOA) of -132 and +112 cells/μL. For the capillary samples, Bland-Altman resulted in a mean bias of -4 cells/μL (-31 to +23 cells/μL, 95% CL), and LOA of -195 and +186 cells/μL. For the San Diego study cohort, the prototype MBio system showed negligible quantitative bias relative to flow cytometry. Higher variability was observed in the capillary samples relative to venipuncture, but system precision for both capillary and venipuncture samples was good. There was also close agreement between results from the same participant when tested with two different systems, different operators and different locations. This preliminary evaluation suggests that the MBio CD4 device holds promise as a POC system for quantitation of CD4 T cells in limited-resource settings.
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Affiliation(s)
- Cathy Logan
- Division of Infectious Diseases, University of California, 9500 Gilman Drive, MC 0711, San Diego, CA 92093, USA.
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Abstract
BACKGROUND Sub-Saharan Africa has the largest burden of pediatric HIV in the world. Global target has been set for eradication of pediatric HIV by 2015 but there are still so many complex issues facing HIV infected and affected children in the sub-continent. OBJECTIVE To review the current and emerging challenges facing pediatric HIV care in sub-Saharan Africa; and proffer solutions that could help in tackling these challenges. METHOD A Medline literature search of recent publications was performed to identify articles on "pediatric HIV", "HIV and children", "HIV and infants", "HIV and adolescents" in sub-Saharan Africa. RESULT There are a number of challenges and emerging complex issues facing children infected and affected by HIV in sub-Saharan Africa. These include late presentation, limited access to pediatric HIV services, delayed diagnosis, infant feeding choices, malnutrition, limited and complex drug regimen, disclosure, treatment failure and reproductive health concerns. A holistic cost effective preventive, diagnostic and treatment strategies are required in order to eliminate pediatric HIV in SSA. CONCLUSION HIV infected children and their families in sub-Saharan Africa face myriad of complex medical and psychosocial issues. A holistic health promotional approach is being advocated as the required step for eradication of pediatric HIV in Africa.
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Affiliation(s)
- A C Ubesie
- Department of Paediatrics, Faculty of Medical Sciences, University of Nigeria/University of Nigeria Teaching Hospital, Enugu, Nigeria.
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