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Kimathi D, Juan-Giner A, Orindi B, Grantz KH, Bob NS, Cheruiyot S, Hamaluba M, Kamau N, Fall G, Dia M, Mosobo M, Moki F, Kiogora K, Chirro O, Thiong'o A, Mwendwa J, Guantai A, Karanja HK, Gitonga J, Mugo D, Ramko K, Faye O, Sanders EJ, Grais RF, Bejon P, Warimwe GM. Immunogenicity and safety of fractional doses of 17D-213 yellow fever vaccine in HIV-infected people in Kenya (YEFE): a randomised, double-blind, non-inferiority substudy of a phase 4 trial. Lancet Infect Dis 2023; 23:974-982. [PMID: 37127045 PMCID: PMC10371873 DOI: 10.1016/s1473-3099(23)00114-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 05/03/2023]
Abstract
BACKGROUND Evidence indicates that fractional doses of yellow fever vaccine are safe and sufficiently immunogenic for use during yellow fever outbreaks. However, there are no data on the generalisability of this observation to populations living with HIV. Therefore, we aimed to evaluate the immunogenicity of fractional and standard doses of yellow fever vaccine in HIV-positive adults. METHODS We conducted a randomised, double-blind, non-inferiority substudy in Kilifi, coastal Kenya to compare the immunogenicity and safety of a fractional dose (one-fifth of the standard dose) versus the standard dose of 17D-213 yellow fever vaccine among HIV-positive volunteers. HIV-positive participants aged 18-59 years, with baseline CD4+ T-cell count of at least 200 cells per mL, and who were not pregnant, had no previous history of yellow fever vaccination or infection, and had no contraindication for yellow fever vaccination were recruited from the community. Participants were randomly assigned 1:1 in blocks (variable block sizes) to either a fractional dose or a standard dose of the 17D-213 yellow fever vaccine. Vaccines were administered subcutaneously by an unblinded nurse and pharmacist; all other study personnel were blinded to the vaccine allocation. The primary outcome of the study was the proportion of participants who seroconverted by the plaque reduction neutralisation test (PRNT50) 28 days after vaccination for the fractional dose versus the standard dose in the per-protocol population. Secondary outcomes were assessment of adverse events and immunogenicity during the 1-year follow-up period. Participants were considered to have seroconverted if the post-vaccination antibody titre was at least 4 times greater than the pre-vaccination titre. We set a non-inferiority margin of not less than a 17% decrease in seroconversion in the fractional dose compared with the standard dose. This study is registered with ClinicalTrials.gov, NCT02991495. FINDINGS Between Jan 29, 2019, and May 17, 2019, 303 participants were screened, and 250 participants were included and vaccinated; 126 participants were assigned to the fractional dose and 124 to the standard dose. 28 days after vaccination, 112 (96%, 95% CI 90-99) of 117 participants in the fractional dose group and 115 (98%, 94-100) of 117 in the standard dose group seroconverted by PRNT50. The difference in seroconversion between the fractional dose and the standard dose was -3% (95% CI -7 to 2). Fractional dosing therefore met the non-inferiority criterion, and non-inferiority was maintained for 1 year. The most common adverse events were headache (n=31 [12%]), fatigue (n=23 [9%]), myalgia (n=23 [9%]), and cough (n=14 [6%]). Reported adverse events were either mild (182 [97%] of 187 adverse events) or moderate (5 [3%]) and were self-limiting. INTERPRETATION Fractional doses of the 17D-213 yellow fever vaccine were sufficiently immunogenic and safe demonstrating non-inferiority to the standard vaccine dose in HIV-infected individuals with CD4+ T cell counts of at least 200 cells per mL. These results provide confidence that fractional dose recommendations are applicable to populations with high HIV prevalence. FUNDING Wellcome Trust, Médecins Sans Frontières Foundation, and the UK Department for International Development.
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Affiliation(s)
- Derick Kimathi
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | | | - Benedict Orindi
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kyra H Grantz
- Department of Biology and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Stanley Cheruiyot
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Mainga Hamaluba
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | - Naomi Kamau
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | | | - Moses Mosobo
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Felix Moki
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kenneth Kiogora
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Oscar Chirro
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Alexander Thiong'o
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Jane Mwendwa
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Andrew Guantai
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Henry K Karanja
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - John Gitonga
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Daisy Mugo
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kelly Ramko
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Eduard J Sanders
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | | | - Philip Bejon
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | - George M Warimwe
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK.
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Odera DO, Tuju J, Mwai K, Nkumama IN, Fürle K, Chege T, Kimathi R, Diehl S, Musasia FK, Rosenkranz M, Njuguna P, Hamaluba M, Kapulu MC, Frank R, Osier FHA, Abdi AI, Chi PC, de Laurent Z, Jao I, Kamuya D, Kamuyu G, Makale J, Murungi L, Musyoki J, Muthui M, Mwacharo J, Kariuki S, Mwanga D, Mwongeli J, Ndungu F, Njue M, Nyangweso G, Kimani D, Ngoi JM, Musembi J, Ngoto O, Otieno E, Ooko M, Shangala J, Wambua J, Mohammed KS, Omuoyo D, Mosobo M, Kibinge N, Kinyanjui S, Bejon P, Lowe B, Marsh K, Marsh V, Abebe Y, Billingsley PF, Sim BKL, Hoffman SL, James ER, Richie TL, Audi A, Olewe F, Oloo J, Ongecha J, Ongas MO, Koskei N, Bull PC, Hodgson SH, Kivisi C, Imwong M, Murphy SC, Ogutu B, Tarning J, Winterberg M, Williams TN. Anti-merozoite antibodies induce natural killer cell effector function and are associated with immunity against malaria. Sci Transl Med 2023; 15:eabn5993. [PMID: 36753561 DOI: 10.1126/scitranslmed.abn5993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Natural killer (NK) cells are potent immune effectors that can be activated via antibody-mediated Fc receptor engagement. Using multiparameter flow cytometry, we found that NK cells degranulate and release IFN-γ upon stimulation with antibody-opsonized Plasmodium falciparum merozoites. Antibody-dependent NK (Ab-NK) activity was largely strain transcending and enhanced invasion inhibition into erythrocytes. Ab-NK was associated with the successful control of parasitemia after experimental malaria challenge in African adults. In an independent cohort study in children, Ab-NK increased with age, was boosted by concurrent P. falciparum infections, and was associated with a lower risk of clinical episodes of malaria. Nine of the 14 vaccine candidates tested induced Ab-NK, including some less well-characterized antigens: P41, P113, MSP11, RHOPH3, and Pf_11363200. These data highlight an important role of Ab-NK activity in immunity against malaria and provide a potential mechanism for evaluating vaccine candidates.
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Affiliation(s)
- Dennis O Odera
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany.,Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - James Tuju
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kennedy Mwai
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.,Epidemiology and Biostatistics Division, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - Irene N Nkumama
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Kristin Fürle
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Timothy Chege
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Rinter Kimathi
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Stefan Diehl
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Fauzia K Musasia
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Micha Rosenkranz
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Patricia Njuguna
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Mainga Hamaluba
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Melissa C Kapulu
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Roland Frank
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Faith H A Osier
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany.,Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.,Department of Life Sciences, Imperial College London, UK
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Gumba H, Opiyo M, Musyoki J, Mutunga M, Ngetsa C, Mwarumba S, Mosobo M, Njuguna S, Kai O, Lambisia AW, Kimani D, Cheruiyot R, Kiyuka P, Lewa C, Gicheru E, Tendwa M, Said Mohammed K, Osoti V, Makale J, Tawa B, Odundo C, Cheruiyot W, Nyamu W, Gumbi W, Mwacharo J, Nyamako L, Otieno E, Amadi D, Ouma N, Karia B, Thoya J, Karani A, Mugo D, Gichuki BM, Riako D, Mutua S, Gitonga JN, Ominde K, Wanjiku P, Mutiso A, Mwanzu A, Sein Y, Bartilol B, Mwangi S, Omuoyo DO, Morobe JM, de Laurent ZR, Mitsanze F, Mwakubia A, Rono M, Nyaguara A, Tsofa B, Bejon P, Agoti CN, Ochola-Oyier LI. Maintaining laboratory quality assurance and safety in a pandemic: Experiences from the KEMRI-Wellcome Trust Research Programme laboratory’s COVID-19 response. Wellcome Open Res 2022. [DOI: 10.12688/wellcomeopenres.16704.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Laboratory diagnosis plays a critical role in the containment of a pandemic. Strong laboratory quality management systems (QMS) are essential for laboratory diagnostic services. However, low laboratory capacities in resource-limited countries has made the maintenance of laboratory quality assurance, especially during a pandemic, a daunting task. In this paper, we describe our experience of how we went about providing diagnostic testing services for SARS-CoV-2 through laboratory reorganization, redefining of the laboratory workflow, and training and development of COVID-19 documented procedures, all while maintaining the quality assurance processes during the COVID-19 pandemic at the Kenya Medical Research Institute (KEMRI) Wellcome Trust Research Programme (KWTRP) laboratory. The KWTRP laboratory managed to respond to the COVID-19 outbreak in Kenya by providing diagnostic testing for the coastal region of the country, while maintaining its research standard quality assurance processes. A COVID-19 team comprising of seven sub-teams with assigned specific responsibilities and an organizational chart with established reporting lines were developed. Additionally, a total of four training sessions were conducted for county Rapid Response Teams (RRTs) and laboratory personnel. A total of 11 documented procedures were developed to support the COVID-19 testing processes, with three for the pre-analytical phases, seven for the analytical phase, and one for the post-analytical phase. With the workflow re-organization, the development of appropriate standard operating procedures, and training, research laboratories can effectively respond to pandemic outbreaks while maintaining research standard QMS procedures.
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Kapulu MC, Kimani D, Njuguna P, Hamaluba M, Otieno E, Kimathi R, Tuju J, Sim BKL, Abdi AI, Abebe Y, Bejon P, Billingsley PF, Bull PC, de Laurent Z, Hoffman SL, James ER, Kariuki S, Kinyanjui S, Kivisi C, Makale J, Marsh K, Mohammed KS, Mosobo M, Musembi J, Musyoki J, Muthui M, Mwacharo J, Mwai K, Ngoi JM, Ngoto O, Nkumama I, Ndungu F, Odera D, Ogutu B, Olewe F, Omuoyo D, Ong’echa J, Osier F, Richie TL, Shangala J, Wambua J, Williams TN. Controlled human malaria infection (CHMI) outcomes in Kenyan adults is associated with prior history of malaria exposure and anti-schizont antibody response. BMC Infect Dis 2022; 22:86. [PMID: 35073864 PMCID: PMC8785382 DOI: 10.1186/s12879-022-07044-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 01/11/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Individuals living in endemic areas acquire immunity to malaria following repeated parasite exposure. We sought to assess the controlled human malaria infection (CHMI) model as a means of studying naturally acquired immunity in Kenyan adults with varying malaria exposure.
Methods
We analysed data from 142 Kenyan adults from three locations representing distinct areas of malaria endemicity (Ahero, Kilifi North and Kilifi South) enrolled in a CHMI study with Plasmodium falciparum sporozoites NF54 strain (Sanaria® PfSPZ Challenge). To identify the in vivo outcomes that most closely reflected naturally acquired immunity, parameters based on qPCR measurements were compared with anti-schizont antibody levels and residence as proxy markers of naturally acquired immunity.
Results
Time to endpoint correlated more closely with anti-schizont antibodies and location of residence than other parasite parameters such as growth rate or mean parasite density. Compared to observational field-based studies in children where 0.8% of the variability in malaria outcome was observed to be explained by anti-schizont antibodies, in the CHMI model the dichotomized anti-schizont antibodies explained 17% of the variability.
Conclusions
The CHMI model is highly effective in studying markers of naturally acquired immunity to malaria.
Trial registration Clinicaltrials.gov number NCT02739763. Registered 15 April 2016
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Gilchrist JJ, Kariuki SN, Watson JA, Band G, Uyoga S, Ndila CM, Mturi N, Mwarumba S, Mohammed S, Mosobo M, Alasoo K, Rockett KA, Mentzer AJ, Kwiatkowski DP, Hill AVS, Maitland K, Scott JAG, Williams TN. BIRC6 modifies risk of invasive bacterial infection in Kenyan children. eLife 2022; 11:77461. [PMID: 35866869 PMCID: PMC9391038 DOI: 10.7554/elife.77461] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 07/22/2022] [Indexed: 11/23/2022] Open
Abstract
Invasive bacterial disease is a major cause of morbidity and mortality in African children. Despite being caused by diverse pathogens, children with sepsis are clinically indistinguishable from one another. In spite of this, most genetic susceptibility loci for invasive infection that have been discovered to date are pathogen specific and are not therefore suggestive of a shared genetic architecture of bacterial sepsis. Here, we utilise probabilistic diagnostic models to identify children with a high probability of invasive bacterial disease among critically unwell Kenyan children with Plasmodium falciparum parasitaemia. We construct a joint dataset including 1445 bacteraemia cases and 1143 severe malaria cases, and population controls, among critically unwell Kenyan children that have previously been genotyped for human genetic variation. Using these data, we perform a cross-trait genome-wide association study of invasive bacterial infection, weighting cases according to their probability of bacterial disease. In doing so, we identify and validate a novel risk locus for invasive infection secondary to multiple bacterial pathogens, that has no apparent effect on malaria risk. The locus identified modifies splicing of BIRC6 in stimulated monocytes, implicating regulation of apoptosis and autophagy in the pathogenesis of sepsis in Kenyan children.
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Affiliation(s)
- James J Gilchrist
- Department of Paediatrics, University of OxfordOxfordUnited Kingdom,MRC–Weatherall Institute of Molecular Medicine, University of OxfordOxfordUnited Kingdom,Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom
| | - Silvia N Kariuki
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya
| | - James A Watson
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of OxfordOxfordUnited Kingdom,Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Gavin Band
- Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom
| | - Sophie Uyoga
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya
| | - Carolyne M Ndila
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya
| | - Neema Mturi
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya
| | - Salim Mwarumba
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya
| | - Shebe Mohammed
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya
| | - Moses Mosobo
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya
| | - Kaur Alasoo
- Institute of Computer Science, University of TartuTartuEstonia
| | - Kirk A Rockett
- Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom
| | - Alexander J Mentzer
- Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom
| | - Dominic P Kwiatkowski
- Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom,Wellcome Sanger InstituteCambridgeUnited Kingdom
| | - Adrian VS Hill
- Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom,The Jenner Institute, University of OxfordOxfordUnited Kingdom
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya,Division of Medicine, Imperial CollegeLondonUnited Kingdom
| | - J Anthony G Scott
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya,Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical MedicineLondonUnited Kingdom
| | - Thomas N Williams
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-CoastKilifiKenya,Institute for Global Health Innovation, Department of Surgery and Cancer, Imperial CollegeLondonUnited Kingdom
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Gumba H, Opiyo M, Musyoki J, Mutunga M, Ngetsa C, Mwarumba S, Mosobo M, Njuguna S, Kai O, Lambisia AW, Kimani D, Cheruiyot R, Kiyuka P, Lewa C, Gicheru E, Tendwa M, Said Mohammed K, Osoti V, Makale J, Tawa B, Odundo C, Cheruiyot W, Nyamu W, Gumbi W, Mwacharo J, Nyamako L, Otieno E, Amadi D, Ouma N, Karia B, Thoya J, Karani A, Mugo D, Gichuki BM, Riako D, Mutua S, Gitonga JN, Ominde K, Wanjiku P, Mutiso A, Mwanzu A, Sein Y, Bartilol B, Mwangi S, Omuoyo DO, Morobe JM, de Laurent ZR, Mitsanze F, Mwakubia A, Rono M, Nyaguara A, Tsofa B, Bejon P, Agoti CN, Ochola-Oyier LI. Maintaining laboratory quality assurance and safety in a pandemic: Experiences from the KEMRI-Wellcome Trust Research Programme laboratory’s COVID-19 response. Wellcome Open Res 2021. [DOI: 10.12688/wellcomeopenres.16704.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Laboratory diagnosis plays a critical role in the containment of a pandemic. Strong laboratory quality management systems (QMS) are essential for laboratory diagnostic services. However, low laboratory capacities in resource-limited countries has made the maintenance of laboratory quality assurance, especially during a pandemic, a daunting task. In this paper, we describe our experience of how we went about providing diagnostic testing services for SARS-CoV-2 through laboratory reorganization, redefining of the laboratory workflow, and training and development of COVID-19 documented procedures, all while maintaining the quality assurance processes during the COVID-19 pandemic at the Kenya Medical Research Institute (KEMRI) Wellcome Trust Research Programme (KWTRP) laboratory. The KWTRP laboratory managed to respond to the COVID-19 outbreak in Kenya by providing diagnostic testing for the coastal region of the country, while maintaining its research standard quality assurance processes. A COVID-19 team comprising of seven sub-teams with assigned specific responsibilities and an organizational chart with established reporting lines were developed. Additionally, a total of four training sessions were conducted for county Rapid Response Teams (RRTs) and laboratory personnel. A total of 11 documented procedures were developed to support the COVID-19 testing processes, with three for the pre-analytical phases, seven for the analytical phase, and one for the post-analytical phase. With the workflow re-organization, the development of appropriate standard operating procedures, and training, research laboratories can effectively respond to pandemic outbreaks while maintaining research standard QMS procedures.
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Gumba H, Musyoki J, Mosobo M, Lowe B. Implementation of Good Clinical Laboratory Practice in an Immunology Basic Research Laboratory: The KEMRI-Wellcome Trust Research Laboratories Experience. Am J Clin Pathol 2019; 151:270-274. [PMID: 30339188 PMCID: PMC6360634 DOI: 10.1093/ajcp/aqy138] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Objectives Good Clinical Laboratory Practice (GCLP) is a standard that ensures quality and reliability of research data by adopting the principles of Good Laboratory Practice and Good Clinical Practice. Even though implementing a quality system in a basic research laboratory is still a contentious issue, it ensures that the research data are accurate, valid, and reliable. GCLP implementation requires proper documented procedures and safety precautions to achieve this objective. Methods This article describes the Kenya Medical Research Institute (KEMRI)–Wellcome Trust Research Laboratories experience in the implementation of GCLP guidelines in a laboratory conducting basic research. Results The laboratory managed to implement GCLP elements that could be applied to a basic research laboratory, such as standard operating procedures, equipment management, laboratory analytical plans, organization, and personnel. The laboratory achieved GCLP accreditation in October 2015. Conclusions The methodology, suggestions, and comments that arose from our experience in implementing GCLP guidelines can be used by other laboratories to develop a quality system using GCLP guidelines to support medical research conducted to ensure the research data are reliable and can be easily reconstructed in other research settings.
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Affiliation(s)
- Horace Gumba
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Moses Mosobo
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Brett Lowe
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
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Borrmann S, Sasi P, Mwai L, Bashraheil M, Abdallah A, Muriithi S, Frühauf H, Schaub B, Pfeil J, Peshu J, Hanpithakpong W, Rippert A, Juma E, Tsofa B, Mosobo M, Lowe B, Osier F, Fegan G, Lindegårdh N, Nzila A, Peshu N, Mackinnon M, Marsh K. Declining responsiveness of Plasmodium falciparum infections to artemisinin-based combination treatments on the Kenyan coast. PLoS One 2011; 6:e26005. [PMID: 22102856 PMCID: PMC3213089 DOI: 10.1371/journal.pone.0026005] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 09/15/2011] [Indexed: 12/30/2022] Open
Abstract
Background The emergence of artemisinin-resistant P. falciparum malaria in South-East Asia highlights the need for continued global surveillance of the efficacy of artemisinin-based combination therapies. Methods On the Kenyan coast we studied the treatment responses in 474 children 6–59 months old with uncomplicated P. falciparum malaria in a randomized controlled trial of dihydroartemisinin-piperaquine vs. artemether-lumefantrine from 2005 to 2008. (ISRCTN88705995) Results The proportion of patients with residual parasitemia on day 1 rose from 55% in 2005–2006 to 87% in 2007–2008 (odds ratio, 5.4, 95%CI, 2.7–11.1; P<0.001) and from 81% to 95% (OR, 4.1, 95%CI, 1.7–9.9; P = 0.002) in the DHA-PPQ and AM-LM groups, respectively. In parallel, Kaplan-Meier estimated risks of apparent recrudescent infection by day 84 increased from 7% to 14% (P = 0.1) and from 6% to 15% (P = 0.05) with DHA-PPQ and AM-LM, respectively. Coinciding with decreasing transmission in the study area, clinical tolerance to parasitemia (defined as absence of fever) declined between 2005–2006 and 2007–2008 (OR body temperature >37.5°C, 2.8, 1.9–4.1; P<0.001). Neither in vitro sensitivity of parasites to DHA nor levels of antibodies against parasite extract accounted for parasite clearance rates or changes thereof. Conclusions The significant, albeit small, decline through time of parasitological response rates to treatment with ACTs may be due to the emergence of parasites with reduced drug sensitivity, to the coincident reduction in population-level clinical immunity, or both. Maintaining the efficacy of artemisinin-based therapy in Africa would benefit from a better understanding of the mechanisms underlying reduced parasite clearance rates. Trial Registration Controlled-Trials.com ISRCTN88705995
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Affiliation(s)
- Steffen Borrmann
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Kilifi, Kenya.
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Mackintosh CL, Mwangi T, Kinyanjui SM, Mosobo M, Pinches R, Williams TN, Newbold CI, Marsh K. Failure to respond to the surface of Plasmodium falciparum infected erythrocytes predicts susceptibility to clinical malaria amongst African children. Int J Parasitol 2008; 38:1445-54. [PMID: 18534600 PMCID: PMC2697313 DOI: 10.1016/j.ijpara.2008.03.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 03/07/2008] [Accepted: 03/17/2008] [Indexed: 11/15/2022]
Abstract
Following infection with Plasmodium falciparum malaria, children in endemic areas develop antibodies specific to antigens on the parasite-infected red cell surface of the infecting isolate, antibodies associated with protection against subsequent infection with that isolate. In some circumstances induction of antibodies to heterologous parasite isolates also occurs and this has been suggested as evidence for cross-reactivity of responses against the erythrocyte surface. The role of these relatively cross-reactive antibodies in protection from clinical malaria is currently unknown. We studied the incidence of clinical malaria amongst children living on the coast of Kenya through one high transmission season. By categorising individuals according to their pre-season parasite status and antibody response to the surface of erythrocytes infected with four parasite isolates we were able to identify a group of children, those who failed to make a concomitant antibody response in the presence of an asymptomatic parasitaemia, at increased susceptibility to clinical malaria in the subsequent 6 months. The fact that this susceptible group was identified regardless of the parasite isolate tested infers a cross-reactive or conserved target is present on the surface of infected erythrocytes. Identification of this target will significantly aid understanding of naturally acquired immunity to clinical malaria amongst children in endemic areas.
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Affiliation(s)
- C L Mackintosh
- Kenya Medical Research Institute, Centre for Geographic Medicine Research Coast, Kilifi District Hospital, Kilifi, Kenya.
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Sasi P, Burns SP, Waruiru C, English M, Hobson CL, King CG, Mosobo M, Beech JS, Iles RA, Boucher BJ, Cohen RD. Metabolic acidosis and other determinants of hemoglobin-oxygen dissociation in severe childhood Plasmodium falciparum malaria. Am J Trop Med Hyg 2007; 77:256-60. [PMID: 17690396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023] Open
Abstract
Metabolic acidosis is a common complication of severe malaria caused by Plasmodium falciparum. The factors contributing to the acidosis were assessed in 62 children with severe falciparum malaria (cases) and in 29 control children who had recently recovered from mild or moderate malaria. The acidosis was largely caused by the accumulation of both lactic and 3-hydroxybutyric acids. The determinants of oxygen release to the tissues were also examined; although there was no difference between cases and controls in respect of 2,3-bisphosphoglycerate and mean corpuscular hemoglobin concentration, there was a marked increase in P(50) in the cases, caused by pyrexia, low pH, and base deficit. There was substantial relative or actual hypoglycemia in many cases. The relationship of these observations to therapeutic strategy is discussed.
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Affiliation(s)
- Philip Sasi
- KEMRI/Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya.
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Sasi P, Burns SP, English M, Iles RA, Waruiru C, Beech JS, King CG, Hobson CL, Cohen RD, Mosobo M, Boucher BJ. Metabolic Acidosis and Other Determinants of Hemoglobin-Oxygen Dissociation in Severe Childhood Plasmodium falciparum Malaria. Am J Trop Med Hyg 2007. [DOI: 10.4269/ajtmh.2007.77.256] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Nery S, Deans AM, Mosobo M, Marsh K, Rowe JA, Conway DJ. Expression of Plasmodium falciparum genes involved in erythrocyte invasion varies among isolates cultured directly from patients. Mol Biochem Parasitol 2006; 149:208-15. [PMID: 16837080 PMCID: PMC2877258 DOI: 10.1016/j.molbiopara.2006.05.014] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 05/22/2006] [Accepted: 05/31/2006] [Indexed: 11/19/2022]
Abstract
Plasmodium falciparum merozoites invade erythrocytes using a range of alternative ligands that includes erythrocyte binding antigenic proteins (EBAs) and reticulocyte binding protein homologues (Rh). Variation in the expression of some of these genes among culture-adapted parasite lines correlates with the use of different erythrocyte receptors. Here, expression profiles of four Rh genes and eba175 are analysed in a sample of 42 isolates cultured from malaria patients in Kenya. The profiles cluster into distinct groups, largely because of very strong negative correlations between the levels of expression of particular gene pairs (Rh1 versus Rh2b, eba175 versus Rh2b, and eba175 versus Rh4), previously associated with alternative invasion pathways in culture-adapted parasite lines. High levels of eba175 are seen in isolates in expression profile group I, and may be associated with sialic acid-dependent invasion. Groups II and III are, respectively, characterized by high levels of Rh2b and Rh4, and are more likely to be associated with sialic acid-independent invasion.
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Affiliation(s)
- Susana Nery
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Anne-Marie Deans
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, United Kingdom
| | - Moses Mosobo
- Wellcome Trust Research Laboratories, Kenya Medical Research Institute, Kilifi, Kenya
| | - Kevin Marsh
- Wellcome Trust Research Laboratories, Kenya Medical Research Institute, Kilifi, Kenya
| | - J. Alexandra Rowe
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, United Kingdom
| | - David J. Conway
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
- Medical Research Council Laboratories, Fajara, P.O. Box 273, Banjul, Gambia
- Corresponding author. Tel.: +220 449 5917; fax: +220 449 6513. (D.J. Conway)
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Urban BC, Mwangi T, Ross A, Kinyanjui S, Mosobo M, Kai O, Lowe B, Marsh K, Roberts DJ. Peripheral blood dendritic cells in children with acute Plasmodium falciparum malaria. Blood 2001; 98:2859-61. [PMID: 11675362 DOI: 10.1182/blood.v98.9.2859] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The importance of dendritic cells (DCs) for the initiation and regulation of immune responses not only to foreign organisms but also to the self has raised considerable interest in the qualitative and quantitative analysis of these cells in various human diseases. Plasmodium falciparum malaria is characterized by the poor induction of long-lasting protective immune responses. This study, therefore, investigated the percentage of peripheral blood DCs as lineage marker-negative and HLA-DR(+) or CD83(+) cells in healthy children and in children suffering from acute malaria in Kilifi, Kenya. Comparable percentages of CD83(+) DCs were found in peripheral blood of healthy children and children with malaria. However, the percentage of HLA-DR(+) peripheral blood DCs was significantly reduced in children with malaria. The results suggest that a proportion of peripheral blood DCs may be functionally impaired due to the low expression of HLA-DR on their surface.
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Affiliation(s)
- B C Urban
- Weatherall Institute of Molecular Medicine, Nuffield Department of Clinical Medicine, and National Blood Service, John Radcliffe Hospital, University of Oxford, United Kingdom.
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Brooker S, Peshu N, Warn PA, Mosobo M, Guyatt HL, Marsh K, Snow RW. The epidemiology of hookworm infection and its contribution to anaemia among pre-school children on the Kenyan coast. Trans R Soc Trop Med Hyg 1999; 93:240-6. [PMID: 10492749 DOI: 10.1016/s0035-9203(99)90007-x] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Intestinal nematode infections are recognized as a major public health problem, and helminth control is currently being directed towards school-aged children who are known to harbour the heaviest infections and are most likely to suffer from associated morbidity. However, few data are available for the epidemiology of intestinal nematodes in pre-school children in Africa, and the contribution of hookworm infection to the aetiology and severity of anaemia among pre-school children remains poorly understood. This paper investigates the epidemiology of parasitic infections in 460 pre-school children who were part of a larger case-control study of severe malaria in Kilifi on the Kenyan coast. Almost one-third (28.7%) were infected with hookworm, 20.2% with Ascaris lumbricoides and 15.0% with Trichuris trichiura. Infection prevalence of each species rose with age, and the prevalence of heavy infection with hookworm and mean intensity of hookworm were markedly age-dependent. One-third (34.3%) of children had malaria. Overall, 76.3% of children were anaemic (haemoglobin < 110 g/L), with the prevalence decreasing with age. Anaemia was significantly worst in children with heavy hookworm infection (> 200 eggs per gram). This relationship held for all ages, both sexes, and was independent of socioeconomic factors. The application of attributable morbidity methods confirmed the contribution of hookworm infection to anaemia.
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Affiliation(s)
- S Brooker
- Wellcome Trust Centre for the Epidemiology of Infectious Disease, University of Oxford, UK.
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Affiliation(s)
- B S Lowe
- Kenya Medical Research Institute, Clinical Research Centre, Kilifi Unit, Kenya
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Amukoye E, Winstanley PA, Watkins WM, Snow RW, Hatcher J, Mosobo M, Ngumbao E, Lowe B, Ton M, Minyiri G, Marsh K. Chlorproguanil-dapsone: effective treatment for uncomplicated falciparum malaria. Antimicrob Agents Chemother 1997; 41:2261-4. [PMID: 9333058 PMCID: PMC164103 DOI: 10.1128/aac.41.10.2261] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Pyrimethamine-sulfadoxine, the first choice for uncomplicated falciparum malaria in Africa, exerts strong selection pressure for resistance because of its slow elimination. It is likely that resistance will emerge rapidly, and there is no widely affordable replacement. Chlorproguanil-dapsone is cheap, rapidly eliminated, more potent than pyrimethamine-sulfadoxine, and could be introduced in the near future to delay the onset of antifolate resistance and as "salvage therapy" for pyrimethamine-sulfadoxine failure. A total of 448 children were randomly allocated (double blind) to either a single dose of pyrimethamine-sulfadoxine or to one of two chlorproguanil-dapsone regimens: a single dose or three doses at 24-h intervals. Reinfections are clinically indistinguishable from recrudescence and are more likely after treatment with rapidly eliminated drugs; we measured the incidence of parasitemia in 205 initially aparasitemic children to allow comparison with the three treatment groups. The patients and a community surveillance group were followed up for 28 days. At the study end point, 31.2% (95% confidence interval, 24.9-38.0) of the community surveillance group subjects were parasitemic, compared with subjects in the treatment groups, whose rates of parasitemia were 40.8% (32.9-49.0; relative risk [RR], 1.31 [0.99-1.73]) after triple-dose chlorproguanil-dapsone, 19.7% (13.5-27.2; RR, 0.63 [0.43-0.93]) after pyrimethamine-sulfadoxine, and 65.6% (57.5-73.0; RR, 2.10 [1.66-2.65]) after single-dose chlorproguanil-dapsone. Pyrimethamine-sulfadoxine and triple-dose chlorproguanil-dapsone were effective treatments. Pyrimethamine-sulfadoxine provided chemoprophylaxis during follow-up because of its slow elimination. Triple-dose chlorproguanil-dapsone should now be developed in an attempt to reduce the rate of emergence of antifolate resistance in Africa and for affordable salvage therapy in cases of pyrimethamine-sulfadoxine failure.
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Affiliation(s)
- E Amukoye
- Kilifi Research Unit, Kenya Medical Research Institute
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Abstract
Data were prospectively collected on 306 Kenyan children, including blood gases in 258 (75%). Severe malaria caused a predominantly high-anion-gap metabolic acidosis in at least 43% of children. Children with coma and respiratory distress (CM + RD) had greater evidence of renal dysfunction, lower mean pH and higher mean plasma osmolality than those with respiratory distress (RD) or coma (CM) as isolated findings (mean urea 10.7 vs. 6.0 vs. 4.3 mmol/l; mean creatinine 97 vs. 74 vs. 58 mumol/l; mean osmolality 301 vs. 288 vs. 283 mosmol/l; and mean pH 7.16 vs. 7.29 vs. 7.39, respectively, p < 0.001 for each comparison of CM + RD vs. RD or CM). In addition, children with CM + RD had a higher mean blood lactate (6.7 vs. 3.3 mmol/l, p < 0.001), a lower mean haemoglobin (5.5 vs. 7.0 g/dl, p = 0.002) and a lower mean age (26.4 vs. 41.9 months, p < 0.001) than children with CM and accounted for 15/24 (63%) of all deaths. These and previous data implicate hypovolaemia and renal impairment in the pathogenesis of metabolic acidosis in severe childhood malaria. In children who are acidotic, anaemia is strongly associated with lactic acidaemia and may therefore contribute to its pathogenesis. These data also imply that coma in acidotic children (CM + RD) and those with an isolated encephalopathy (CM) may result from quite different pathophysiological mechanisms.
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Watkins WM, Mosobo M. Treatment of Plasmodium falciparum malaria with pyrimethamine-sulfadoxine: selective pressure for resistance is a function of long elimination half-life. Trans R Soc Trop Med Hyg 1993; 87:75-8. [PMID: 8465404 DOI: 10.1016/0035-9203(93)90431-o] [Citation(s) in RCA: 138] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In an area of continuing transmission of Plasmodium falciparum on the Kenya coast, children treated with pyrimethamine-sulfadoxine experienced rapid parasite clearance, although a high proportion became reinfected within a short time. The frequency of pyrimethamine resistance in vitro in new infections was higher during the elimination phase of drug from a previous treatment. In infections which occurred at times when predicted residual drug concentrations were no longer inhibitory, incidence of pyrimethamine resistance was no different from the natural or background frequency. These results are discussed in terms of the selective pressure for resistance which is exerted by drugs with long elimination half-lives and a consideration of possible ways by which the problem might be addressed.
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Affiliation(s)
- W M Watkins
- Kenya Medical Research Institute Coast Research Unit, Kilifi
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