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Setto JM, Libonati RMF, Ventura AMRDS, Chaves TDSS, Sequeira CG, Martins Filho AJ, Machado RLD, Franceschin SDCC, Barreto JTT. Association between vitamin D serum levels and clinical, laboratory, and parasitological parameters in patients with malaria from an endemic area of the Amazon. Rev Soc Bras Med Trop 2022; 55:e00772021. [PMID: 35416868 PMCID: PMC9009878 DOI: 10.1590/0037-8682-0077-2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 02/16/2022] [Indexed: 11/22/2022] Open
Abstract
Background: Some studies have suggested the importance of vitamin D [25(OH)D] in malaria clinical practice. The prevalence of 25(OH)D deficiency in the Amazon population is not well known, and there are few studies in patients with malaria. This study aimed to evaluate 25(OH)D serum levels in patients with malaria and determine their relationships with epidemiological, clinical, laboratory, and parasitemia data. Methods: An analytical cross-sectional study of 123 patients with malaria and 122 individuals without malaria was performed in Itaituba, Pará, Brazil, from January 2018 to October 2019, by evaluating sociodemographic, clinical-epidemiological, parasitological, and laboratory data and adopting a 5% significance level. Parametric tests (Student's t-test), non-parametric tests (Mann-Whitney U), and Spearman’s correlation ([rs], for non-parametric variables) were used according to the nature of the distribution of the variables. For the qualitative variables, Pearson's chi-square test, Fisher's exact test, and the G test were used. Spearman's correlation was used to compare the results of the 25(OH)D levels and blood counts performed among patients and the control group. Results: Malaria patients residing in a mining area had 25(OH)D serum levels that were significantly lower than those in the control group residing in the mining area, though both were within normal levels. Red blood cell counts had an inverse correlation with parasitemia (Plasmodium falciparum), and platelet levels had an inverse correlation with parasitemia (Plasmodium vivax). 25(OH)D deficiency was evidenced in Itaituba, in the state of Pará, which is an endemic area of malaria in the Amazon region.
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Affiliation(s)
- Janaina Maria Setto
- Marinha do Brasil, Centro de Instrução Almirante Braz de Aguiar, Belém, PA, Brasil.,Universidade Federal do Pará, Núcleo de Medicina Tropical, Programa de Pós-Graduação em Doenças Tropicais, Belém, PA, Brasil
| | - Rosana Maria Feio Libonati
- Universidade Federal do Pará, Núcleo de Medicina Tropical, Programa de Pós-Graduação em Doenças Tropicais, Belém, PA, Brasil
| | - Ana Maria Revoredo da Silva Ventura
- Instituto Evandro Chagas, Laboratório de Ensaios Clínicos em Malária, Ananindeua, PA, Brasil.,Universidade Estadual do Pará, Centro de Ciências Biológicas e da Saúde, Belém, PA, Brasil
| | - Tânia do Socorro Souza Chaves
- Instituto Evandro Chagas, Laboratório de Ensaios Clínicos em Malária, Ananindeua, PA, Brasil.,Universidade Federal do Pará, Centro Universitário do Estado do Pará, Belém, PA, Brasil
| | - Carina Guilhon Sequeira
- Universidade Estadual do Pará, Centro de Ciências Biológicas e da Saúde, Departamento de Saúde Integrada, Belém, PA, Brasil
| | | | - Ricardo Luiz Dantas Machado
- Universidade Federal Fluminense, Programa de Pós-Graduação em Microbiologia e Parasitologia, Rio de Janeiro, RJ, Brasil
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2
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Silva-Filho JL, Dos-Santos JC, Judice C, Beraldi D, Venugopal K, Lima D, Nakaya HI, De Paula EV, Lopes SC, Lacerda MV, Marti M, Costa FT. Total parasite biomass but not peripheral parasitaemia is associated with endothelial and haematological perturbations in Plasmodium vivax patients. eLife 2021; 10:71351. [PMID: 34585667 PMCID: PMC8536259 DOI: 10.7554/elife.71351] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/28/2021] [Indexed: 11/13/2022] Open
Abstract
Plasmodium vivax is the major cause of human malaria in the Americas. How P. vivax infection can lead to poor clinical outcomes, despite low peripheral parasitaemia, remains a matter of intense debate. Estimation of total P. vivax biomass based on circulating markers indicates existence of a predominant parasite population outside of circulation. In this study, we investigate associations between both peripheral and total parasite biomass and host response in vivax malaria. We analysed parasite and host signatures in a cohort of uncomplicated vivax malaria patients from Manaus, Brazil, combining clinical and parasite parameters, multiplexed analysis of host responses, and ex vivo assays. Patterns of clinical features, parasite burden, and host signatures measured in plasma across the patient cohort were highly heterogenous. Further data deconvolution revealed two patient clusters, here termed Vivaxlow and Vivaxhigh. These patient subgroups were defined based on differences in total parasite biomass but not peripheral parasitaemia. Overall Vivaxlow patients clustered with healthy donors and Vivaxhigh patients showed more profound alterations in haematological parameters, endothelial cell (EC) activation, and glycocalyx breakdown and levels of cytokines regulating different haematopoiesis pathways compared to Vivaxlow. Vivaxhigh patients presented more severe thrombocytopenia and lymphopenia, along with enrichment of neutrophils in the peripheral blood and increased neutrophil-to-lymphocyte ratio (NLCR). When patients' signatures were combined, high association of total parasite biomass with a subset of markers of EC activation, thrombocytopenia, and lymphopenia severity was observed. Finally, machine learning models defined a combination of host parameters measured in the circulation that could predict the extent of parasite infection outside of circulation. Altogether, our data show that total parasite biomass is a better predictor of perturbations in host homeostasis in P. vivax patients than peripheral parasitaemia. This supports the emerging paradigm of a P. vivax tissue reservoir, particularly in the haematopoietic niche of bone marrow and spleen.
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Affiliation(s)
- João L Silva-Filho
- Laboratory of Tropical Diseases - Prof. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas, Campinas, Brazil.,Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - João Ck Dos-Santos
- Laboratory of Tropical Diseases - Prof. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas, Campinas, Brazil.,Post-Graduation in Medical Pathophysiology, School of Medical Sciences, University of Campinas, Campinas, Brazil
| | - Carla Judice
- Laboratory of Tropical Diseases - Prof. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Dario Beraldi
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Kannan Venugopal
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Diogenes Lima
- School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Helder I Nakaya
- School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.,Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Erich V De Paula
- Department of Clinical Pathology, School of Medical Sciences, University of Campinas, Campinas, Brazil
| | - Stefanie Cp Lopes
- Department of Clinical Pathology, School of Medical Sciences, University of Campinas, Campinas, Brazil.,Institute Leônidas & Maria Deane, Fiocruz, Manaus, Brazil.,Tropical Medicine Foundation Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Marcus Vg Lacerda
- Institute Leônidas & Maria Deane, Fiocruz, Manaus, Brazil.,Tropical Medicine Foundation Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Matthias Marti
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Fabio Tm Costa
- Laboratory of Tropical Diseases - Prof. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas, Campinas, Brazil
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Punnath K, Dayanand KK, Chandrashekar VN, Achur RN, Kakkilaya SB, Ghosh SK, Mukhi B, Midya V, Kumari SN, Gowda DC. Clinical features and haematological parameters among malaria patients in Mangaluru city area in the southwestern coastal region of India. Parasitol Res 2019; 119:1043-1056. [PMID: 31754856 DOI: 10.1007/s00436-019-06540-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 11/05/2019] [Indexed: 12/15/2022]
Abstract
The aim of this study was to assess the clinical profile, severity and complications of patients suffering from malaria in Mangaluru, a southwestern coastal city in India. A total of 579 patients, who were treated at the District Wenlock Hospital, Mangaluru, and 168 healthy controls were recruited in this study. The clinical profile, haematological and biochemical parameters, and disease complications were assessed. The majority of patients were treated as outpatients and patients who had severe clinical conditions were admitted to the hospital for treatment and supportive care. Among the total 579 patients recruited in this study, the distribution of P. vivax, P. falciparum and mixed infections were 364 (62.9%), 150 (25.9%) and 65 (11.2%), respectively. Among these, 506 (87.4%) had mild malaria, whereas 73 (12.6%) had severe malaria. Overall, the clinical features and severity of malaria in P. vivax and mixed infection patients were comparable to P. falciparum patients, albeit with some significant differences. The clinical complications in severe malaria cases included thrombocytopenia (50.7%), metabolic acidosis (30.1%), severe anaemia (26.0%), jaundice (21.9%), hepatic dysfunction (15.1%), acute renal failure (6.8%), haematuria (8.2%), hypotension (9.6%), cerebral malaria (1.4%) and acute respiratory distress syndrome (1.4%). All the patients with severe malaria recruited in our study were successfully treated and discharged. Majority of patients had mild malaria, likely due to seeking treatment soon after experiencing symptoms and/or having preexisting immune protection. However, a significant number of patients had severe malaria and required hospital admission indicating that there is a substantial need for creating awareness among vulnerable immigrant population. Implementing effective surveillance and vector control measures in malaria hotspot locations in the city and educating people about preventive measures are likely to reduce the malaria burden in this endemic region.
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Affiliation(s)
- Kishore Punnath
- Department of Biochemistry, K.S. Hegde Medical Academy, NITTE (Deemed to be University), Mangaluru, India
- Department of Biochemistry, Kuvempu University, Shankaraghatta, Shivamogga District, Karnataka, India
| | - Kiran K Dayanand
- Department of Biochemistry, K.S. Hegde Medical Academy, NITTE (Deemed to be University), Mangaluru, India
- Department of Biochemistry, Kuvempu University, Shankaraghatta, Shivamogga District, Karnataka, India
| | - Valleesha N Chandrashekar
- Department of Biochemistry, K.S. Hegde Medical Academy, NITTE (Deemed to be University), Mangaluru, India
- Department of Biochemistry, Kuvempu University, Shankaraghatta, Shivamogga District, Karnataka, India
| | - Rajeshwara N Achur
- Department of Biochemistry, Kuvempu University, Shankaraghatta, Shivamogga District, Karnataka, India.
| | | | - Susanta K Ghosh
- Department of Molecular Parasitology, ICMR-National Institute of Malaria Research, Poojanahalli, Bangalore, India
| | - Benudhar Mukhi
- Department of Molecular Parasitology, ICMR-National Institute of Malaria Research, Poojanahalli, Bangalore, India
| | - Vishal Midya
- Department of Biostatistics and Bioinformatics, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA
| | - Suchetha N Kumari
- Department of Biochemistry, K.S. Hegde Medical Academy, NITTE (Deemed to be University), Mangaluru, India
| | - D Channe Gowda
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA.
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Prevalence of malarial recurrence and hematological alteration following the initial drug regimen: a retrospective study in Western Thailand. BMC Public Health 2019; 19:1294. [PMID: 31615478 PMCID: PMC6794853 DOI: 10.1186/s12889-019-7624-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 09/13/2019] [Indexed: 11/10/2022] Open
Abstract
Background The hematological changes following the initial drug regimen has been poorly understood in Thailand. This study was designed to determine the prevalence of malaria parasite recurrence and hematological alteration of patients during the initial drug regimen. Methods A retrospective study was conducted at Phop Phra Hospital, Tak Province, located in northwestern Thailand. All data from patients who were diagnosed with Plasmodium spp. infection – including types of Plasmodium spp., clinical characteristics, and hematological parameters – were retrieved and analyzed. Results The results demonstrated that during years 2012–2018, 95 out of 971 patients (9.78%) were infected with malaria two or more times. The gender, nationality, symptom of headache, type of Plasmodium spp., and career of each patient were associated with recurrence (P-value< 0.05). Among patients treated with malarial drug, the leukocyte count and red cell distribution width (RDW) were significantly changed when compared to untreated patients with recurrence (P-value< 0.05). Conclusion This study indicated the high prevalence of malarial recurrence in Tak Province, Western Thailand, and its relationship to certain characteristics of individuals. Patients who were treated with antimalarial drugs exhibited leukocyte and RDW changes following the initial drug regimen. This data could be useful for prompt detection, treatment, and prevention of malarial recurrence in endemic areas of Thailand.
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5
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Barton AJ, Hill J, Pollard AJ, Blohmke CJ. Transcriptomics in Human Challenge Models. Front Immunol 2017; 8:1839. [PMID: 29326715 PMCID: PMC5741696 DOI: 10.3389/fimmu.2017.01839] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/05/2017] [Indexed: 12/22/2022] Open
Abstract
Human challenge models, in which volunteers are experimentally infected with a pathogen of interest, provide the opportunity to directly identify both natural and vaccine-induced correlates of protection. In this review, we highlight how the application of transcriptomics to human challenge studies allows for the identification of novel correlates and gives insight into the immunological pathways required to develop functional immunity. In malaria challenge trials for example, innate immune pathways appear to play a previously underappreciated role in conferring protective immunity. Transcriptomic analyses of samples obtained in human challenge studies can also deepen our understanding of the immune responses preceding symptom onset, allowing characterization of innate immunity and early gene signatures, which may influence disease outcome. Influenza challenge studies demonstrate that these gene signatures have diagnostic potential in the context of pandemics, in which presymptomatic diagnosis of at-risk individuals could allow early initiation of antiviral treatment and help limit transmission. Furthermore, gene expression analysis facilitates the identification of host factors contributing to disease susceptibility, such as C4BPA expression in enterotoxigenic Escherichia coli infection. Overall, these studies highlight the exceptional value of transcriptional data generated in human challenge trials and illustrate the broad impact molecular data analysis may have on global health through rational vaccine design and biomarker discovery.
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Affiliation(s)
- Amber J Barton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Jennifer Hill
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Christoph J Blohmke
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
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6
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Chaves YO, da Costa AG, Pereira MLM, de Lacerda MVG, Coelho-Dos-Reis JG, Martins-Filho OA, Teixeira-Carvalho A, Malheiro A, Monteiro WM, Orlandi PP, Marinho CRF, Nogueira PA. Immune response pattern in recurrent Plasmodium vivax malaria. Malar J 2016; 15:445. [PMID: 27581163 PMCID: PMC5007810 DOI: 10.1186/s12936-016-1501-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 08/23/2016] [Indexed: 01/01/2023] Open
Abstract
Background Plasmodium vivax is the causative agent of human malaria of large geographic distribution, with 35 million cases annually. In Brazil, it is the most prevalent species, being responsible by around 70 % of the malaria cases. Methods A cross-sectional study was performed in Manaus (Amazonas, Brazil), including 36 adult patients with primary malaria, 19 with recurrent malaria, and 20 endemic controls. The ex vivo phenotypic features of circulating leukocyte subsets (CD4+ T-cells, CD8+ T-cells, NK, NKT, B, B1 and Treg cells) as well as the plasmatic cytokine profile (IL-2, IL-4, IL-6, IL-10, TNF and IFN-γ) were assessed, aiming at establishing patterns of immune response characteristic of primary malaria vs recurrent malaria as compared to endemic controls. Results The proportion of subjects with high levels of WBC was reduced in malaria patients as compared to the endemic control. Monocytes were diminished particularly in patients with primary malaria. The proportion of subjects with high levels of all lymphocyte subsets was decreased in all malaria groups, regardless their clinical status. Decreased proportion of subjects with high levels of CD4+ and CD8+ T-cells was found especially in the group of patients with recurrent malaria. Data analysis indicated significant increase in the proportion of the subjects with high plasmatic cytokine levels in both malaria groups, characterizing a typical cytokine storm. Recurrent malaria patients displayed the highest plasmatic IL-10 levels, that correlated directly with the CD4+/CD8+ T-cells ratio and the number of malaria episodes. Conclusion The findings confirm that the infection by the P. vivax causes a decrease in peripheral blood lymphocyte subsets, which is intensified in the cases of “recurrent malaria”. The unbalanced CD4+/CD8+ T-cells ratio, as well as increased IL-10 levels were correlated with the number of recurrent malaria episodes. These results suggest that the gradual remodelling of the immune response is dependent on the repeated exposure to the parasite, which involves a strict control of the immune response mediated by the CD4+/CD8+ T-cell unbalance and exacerbated IL-10 secretion. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1501-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yury Oliveira Chaves
- Instituto Leônidas e Maria Deane, Fundação Oswaldo Cruz (FIOCRUZ), Manaus, AM, Brazil
| | - Allyson Guimarães da Costa
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas (UEA), Manaus, AM, Brazil.,Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, AM, Brazil.,Departamento de Ensino e Pesquisa, Fundação Hospitalar de Hematologia e Hemoterapia do Amazonas (HEMOAM), Manaus, AM, Brazil
| | - Marcelo Luís Monteiro Pereira
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Marcus Vinícius Guimarães de Lacerda
- Instituto Leônidas e Maria Deane, Fundação Oswaldo Cruz (FIOCRUZ), Manaus, AM, Brazil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas (UEA), Manaus, AM, Brazil.,Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, AM, Brazil
| | - Jordana Grazziela Coelho-Dos-Reis
- Grupo Integrado de Pesquisas em Biomarcadores de Diagnóstico e Monitoração, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, MG, Brazil
| | - Olindo Assis Martins-Filho
- Grupo Integrado de Pesquisas em Biomarcadores de Diagnóstico e Monitoração, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, MG, Brazil
| | - Andréa Teixeira-Carvalho
- Grupo Integrado de Pesquisas em Biomarcadores de Diagnóstico e Monitoração, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, MG, Brazil
| | - Adriana Malheiro
- Departamento de Ensino e Pesquisa, Fundação Hospitalar de Hematologia e Hemoterapia do Amazonas (HEMOAM), Manaus, AM, Brazil.,Programa de Pós-Graduação em Imunologia Básica e Aplicada, Universidade Federal do Amazonas (UFAM), Manaus, AM, Brazil
| | - Wuelton Marcelo Monteiro
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas (UEA), Manaus, AM, Brazil.,Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, AM, Brazil
| | | | - Claudio Romero Farias Marinho
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Paulo Afonso Nogueira
- Instituto Leônidas e Maria Deane, Fundação Oswaldo Cruz (FIOCRUZ), Manaus, AM, Brazil.
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Liu H, Feng G, Zeng W, Li X, Bai Y, Deng S, Ruan Y, Morris J, Li S, Yang Z, Cui L. A more appropriate white blood cell count for estimating malaria parasite density in Plasmodium vivax patients in northeastern Myanmar. Acta Trop 2016; 156:152-6. [PMID: 26802490 DOI: 10.1016/j.actatropica.2016.01.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/15/2016] [Accepted: 01/18/2016] [Indexed: 10/22/2022]
Abstract
The conventional method of estimating parasite densities employ an assumption of 8000 white blood cells (WBCs)/μl. However, due to leucopenia in malaria patients, this number appears to overestimate parasite densities. In this study, we assessed the accuracy of parasite density estimated using this assumed WBC count in eastern Myanmar, where Plasmodium vivax has become increasingly prevalent. From 256 patients with uncomplicated P. vivax malaria, we estimated parasite density and counted WBCs by using an automated blood cell counter. It was found that WBC counts were not significantly different between patients of different gender, axillary temperature, and body mass index levels, whereas they were significantly different between age groups of patients and the time points of measurement. The median parasite densities calculated with the actual WBC counts (1903/μl) and the assumed WBC count of 8000/μl (2570/μl) were significantly different. We demonstrated that using the assumed WBC count of 8000 cells/μl to estimate parasite densities of P. vivax malaria patients in this area would lead to an overestimation. For P. vivax patients aged five years and older, an assumed WBC count of 5500/μl best estimated parasite densities. This study provides more realistic assumed WBC counts for estimating parasite densities in P. vivax patients from low-endemicity areas of Southeast Asia.
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8
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Medina-Morales DA, Montoya-Franco E, Sanchez-Aristizabal VD, Machado-Alba JE, Rodríguez-Morales AJ. Severe and benign Plasmodium vivax malaria in Emberá (Amerindian) children and adolescents from an endemic municipality in Western Colombia. J Infect Public Health 2016; 9:172-80. [DOI: 10.1016/j.jiph.2015.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/21/2015] [Accepted: 09/07/2015] [Indexed: 11/16/2022] Open
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9
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Laman M, Moore BR, Benjamin J, Padapu N, Tarongka N, Siba P, Betuela I, Mueller I, Robinson LJ, Davis TME. Comparison of an assumed versus measured leucocyte count in parasite density calculations in Papua New Guinean children with uncomplicated malaria. Malar J 2014; 13:145. [PMID: 24739250 PMCID: PMC3991873 DOI: 10.1186/1475-2875-13-145] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 04/02/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The accuracy of the World Health Organization method of estimating malaria parasite density from thick blood smears by assuming a white blood cell (WBC) count of 8,000/μL has been questioned in several studies. Since epidemiological investigations, anti-malarial efficacy trials and routine laboratory reporting in Papua New Guinea (PNG) have all relied on this approach, its validity was assessed as part of a trial of artemisinin-based combination therapy, which included blood smear microscopy and automated measurement of leucocyte densities on Days 0, 3 and 7. RESULTS 168 children with uncomplicated malaria (median (inter-quartile range) age 44 (39-47) months) were enrolled, 80.3% with Plasmodium falciparum monoinfection, 14.9% with Plasmodium vivax monoinfection, and 4.8% with mixed P. falciparum/P. vivax infection. All responded to allocated therapy and none had a malaria-positive slide on Day 3. Consistent with a median baseline WBC density of 7.3 (6.5-7.8) × 10(9)/L, there was no significant difference in baseline parasite density between the two methods regardless of Plasmodium species. Bland Altman plots showed that, for both species, the mean difference between paired parasite densities calculated from assumed and measured WBC densities was close to zero. At parasite densities <10,000/μL by measured WBC, almost all between-method differences were within the 95% limits of agreement. Above this range, there was increasing scatter but no systematic bias. CONCLUSIONS Diagnostic thresholds and parasite clearance assessment in most PNG children with uncomplicated malaria are relatively robust, but accurate estimates of a higher parasitaemia, as a prognostic index, requires formal WBC measurement.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Timothy M E Davis
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle 6959, Western Australia, Australia.
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10
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The Duffy-null state is associated with a survival advantage in leukopenic HIV-infected persons of African ancestry. Blood 2009; 114:2783-92. [PMID: 19620399 DOI: 10.1182/blood-2009-04-215186] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Persons of African ancestry, on average, have lower white blood cell (WBC) counts than those of European descent (ethnic leukopenia), but whether this impacts negatively on HIV-1 disease course remains unknown. Here, in a large natural history cohort of HIV-infected subjects, we show that, although leukopenia (< 4000 WBC/mm(3) during infection) was associated with an accelerated HIV disease course, this effect was more prominent in leukopenic subjects of European than African ancestry. The African-specific -46C/C genotype of Duffy Antigen Receptor for Chemokines (DARC) confers the malaria-resisting, Duffy-null phenotype, and we found that the recently described association of this genotype with ethnic leukopenia extends to HIV-infected African Americans (AAs). The association of Duffy-null status with HIV disease course differed according to WBC but not CD4(+) T-cell counts, such that leukopenic but not nonleukopenic HIV(+) AAs with DARC -46C/C had a survival advantage compared with all Duffy-positive subjects. This survival advantage became increasingly pronounced in those with progressively lower WBC counts. These data highlight that the interaction between DARC genotype and the cellular milieu defined by WBC counts may influence HIV disease course, and this may provide a partial explanation of why ethnic leukopenia remains benign in HIV-infected AAs, despite immunodeficiency.
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Rodriguez-Morales AJ, Ferrer MV, Barrera MA, Pacheco M, Daza V, Franco-Paredes C. Imported cases of malaria admitted to two hospitals of Margarita Island, Venezuela, 1998-2005. Travel Med Infect Dis 2008; 7:44-8. [PMID: 19174301 DOI: 10.1016/j.tmaid.2008.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 09/13/2008] [Accepted: 09/22/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Imported cases of malaria constitute an important public health problem in many countries, even in those with autochthonous cases, where disease could be acquired in these areas and then seen in non-endemic regions. Non-immune populations are susceptible to complications due to malaria infection, particularly in malaria caused by Plasmodium falciparum. However, Plasmodium vivax the predominant Plasmodium spp. in Venezuela can also lead to severe malaria. METHODS We reviewed retrospectively cases of malaria to identify the clinical features of those imported cases diagnosed at two institutions in Margarita Island (a non-endemic area), Venezuela, in an 8-year period. We conducted a retrospective observational study to identify the clinical and epidemiological features among hospitalized patients at Hospital Central and Hospital Agustin Hernández with malaria acquired at malaria-endemic locations. RESULTS We identified eighteen imported cases of malaria confirmed by thin and thick peripheral blood smears at these two institutions over an 8-year period. The mean age of diagnosis was 27 years. P. vivax was responsible for the majority of cases. All patients presented with fever, 89% with malaise, 78% with chills, and 67% with myalgia, among others symptoms. Mean haemoglobin levels on admission were 8.1g/dL (100% <12g/dL); platelets: 79,283cells/mm(3) (89% had platelets below 150,000); and a mean total leukocyte count: 3.4x10(3)cells/mm(3) (78% had leukopenia). Thirty nine percent of patients required blood transfusions. Two fatalities were identified (CFR=11%), one associated to severe malaria due to P. falciparum and the other due to a complicated case of P. vivax malaria. DISCUSSION Imported cases of malaria due to P. vivax and P. falciparum in the studied population are associated with significant hematological complications. These findings illustrate the importance of educating non-immune populations about the malaria risk and prevention strategies; and from a pubic health perspective, the need to develop further malaria prevention strategies at a national level.
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Rifakis PM, Hernandez O, Fernández CT, Rodriguez-Morales AJ, Von A, Franco-Paredes C. Atypical Plasmodium vivax malaria in a traveler: bilateral hydronephrosis, severe thrombocytopenia, and hypotension. J Travel Med 2008; 15:119-21. [PMID: 18346245 DOI: 10.1111/j.1708-8305.2007.00178.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a case of Plasmodium vivax infection manifested as severe thrombocytopenia, bilateral hydronephrosis, and hypotension in a returning traveler from a malaria-endemic area in Venezuela. While most of the efforts to prevent malaria in travelers focus on the life-threatening consequences of Plasmodium falciparum malaria, nonimmune travelers who encounter infection with P vivax may also develop serious complications. This case highlights the importance of preventing malaria cases among nonimmune or semi-immune individuals traveling to P vivax-endemic areas.
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Affiliation(s)
- Pedro M Rifakis
- Internal Medicine, Hosipital de Emergencia Pérez de León, Caracas, Venezuela
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Rodríguez-Morales AJ, Sánchez E, Arria M, Vargas M, Piccolo C, Colina R, Franco-Paredes C. Haemoglobin and haematocrit: the threefold conversion is also non valid for assessing anaemia in Plasmodium vivax malaria-endemic settings. Malar J 2007; 6:166. [PMID: 18086306 PMCID: PMC2222606 DOI: 10.1186/1475-2875-6-166] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 12/17/2007] [Indexed: 11/23/2022] Open
Abstract
It has been recently reported that the standard threefold conversion from haematocrit to haemoglobin underestimates the prevalence of anaemia and low levels of haemoglobin in children living in areas endemic for Plasmodium falciparum malaria. The data presented herein describes the experience in a malaria-endemic zone in northeastern Venezuela (state of Sucre), where a similar bias between haematocrit and haemoglobin in patients with Plasmodium vivax infection was found. In summary, the relationship between haematocrit and haemoglobin needs to be specifically evaluated according to each particular region or epidemiological setting.
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Rodríguez-Morales AJ, Benitez JA, Franco-Paredes C. Acute respiratory distress syndrome in Plasmodium vivax malaria in traveler returning from Venezuela. J Travel Med 2006; 13:325-6; author reply 326. [PMID: 16987135 DOI: 10.1111/j.1708-8305.2006.0064_1.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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McKenzie F, O’Meara W, Wongsrichanalai C. Reply to Rodríguez‐Morales et al. J Infect Dis 2005. [DOI: 10.1086/496995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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