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Abagero BR, Rama R, Obeid A, Tolossa T, Legese F, Lo E, Yewhalaw D. Detection of Duffy Blood Group Genotypes and Submicroscopic Plasmodium Infections Using Molecular Diagnostic Assays in Febrile Malaria Patients. Res Sq 2023:rs.3.rs-3706814. [PMID: 38105972 PMCID: PMC10723540 DOI: 10.21203/rs.3.rs-3706814/v1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Background Malaria remains a severe parasitic disease, posing a significant threat to public health and hindering economic development in sub-Saharan Africa. Ethiopia, a malaria endemic country, is facing a resurgence of the disease with a steadily rising incidence. Conventional diagnostic methods, such asmicroscopy, have become less effective due to low parasite density, particularly among Duffy-negative human populations in Africa. To develop comprehensive control strategies, it is crucial to generate data on the distribution and clinical occurrence of Plasmodium vivax and P. falciparum infections in regions where the disease is prevalent. This study assessed Plasmodium infections and Duffy antigen genotypes in febrile patients in Ethiopia. Methods Three hundred febrile patients visiting four health facilities in Jimma town of southwestern Ethiopia were randomly selected during the malaria transmission season (Apr-Oct). Sociodemographic information was collected, and microscopic examination was performed for all study participants. Plasmodiumspecies and parasitemia as well as the Duffy genotype were assessed by quantitative polymerase chain reaction (qPCR) for all samples. Data were analyzed using Fisher's exact test and kappa statistics. Results The Plasmodium infection rate by qPCR was 16% (48/300) among febrile patients, of which 19 (39.6%) were P. vivax, 25 (52.1%) were P. falciparum, and 4 (8.3%) were mixed (P. vivax and P. falciparum) infections. Among the 48 qPCR-positive samples, 39 (13%) were negative by microscopy. The results of bivariate logistic regression analysis showed that agriculture-related occupation, relapse and recurrence were significantly associated withPlasmodium infection (P<0.001). Of the 300 febrile patients, 85 (28.3%) were Duffy negative, of whom two had P. vivax, six had P. falciparum, and one had mixed infections.Except for one patient with P. falciparum infection, Plasmodium infections in Duffy-negative individuals were all submicroscopic with low parasitemia. Conclusions The present study revealed a high prevalence of submicroscopic malaria infections. Plasmodium vivax infections in Duffy-negative individuals were not detected due to low parasitemia. Here, we recommend an improved molecular diagnostic tool to detect and characterize plasmodium infections, with the goal of quantifyingP. vivax infection in Duffy-negative individuals.
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Affiliation(s)
- Beka Raya Abagero
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA
| | - Rei Rama
- University of North Carolina at Charlotte
| | | | | | | | - Eugenia Lo
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
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Lo E, Russo G, Pestana K, Kepple D, Abagero BR, Dongho GBD, Gunalan K, Miller LH, Hamid MMA, Yewhalaw D, Paganotti GM. Contrasting epidemiology and genetic variation of Plasmodium vivax infecting Duffy-negative individuals across Africa. Int J Infect Dis 2021; 108:63-71. [PMID: 33991680 DOI: 10.1016/j.ijid.2021.05.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES Plasmodium vivax malaria was thought to be rare in Africans who lack the Duffy blood group antigen expression. However, recent studies indicate that P. vivax can infect Duffy-negative individuals and has spread into areas of high Duffy negativity across Africa. Our study compared epidemiological and genetic features of P. vivax between African regions. METHODS A standardized approach was used to identify and quantify P. vivax from Botswana, Ethiopia, and Sudan, where Duffy-positive and Duffy-negative individuals coexist. The study involved sequencing the Duffy binding protein (DBP) gene and inferring genetic relationships among P. vivax populations across Africa. RESULTS Among 1215 febrile patients, the proportions of Duffy negativity ranged from 20-36% in East Africa to 84% in southern Africa. Average P. vivax prevalence among Duffy-negative populations ranged from 9.2% in Sudan to 86% in Botswana. Parasite density in Duffy-negative infections was significantly lower than in Duffy-positive infections. P. vivax in Duffy-negative populations were not monophyletic, with P. vivax in Duffy-negative and Duffy-positive populations sharing similar DBP haplotypes and occurring in multiple, well-supported clades. CONCLUSIONS Duffy-negative Africans are not resistant to P. vivax, and the public health significance of this should not be neglected. Our study highlights the need for a standardized approach and more resources/training directed towards the diagnosis of vivax malaria in Africa.
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Affiliation(s)
- Eugenia Lo
- Biological Sciences, University of North Carolina at Charlotte, USA.
| | - Gianluca Russo
- Department of Public Health and Infectious Diseases, Sapienza University, Rome, Italy.
| | - Kareen Pestana
- Biological Sciences, University of North Carolina at Charlotte, USA
| | - Daniel Kepple
- Biological Sciences, University of North Carolina at Charlotte, USA
| | - Beka Raya Abagero
- Tropical Infectious Disease Research Center, Jimma University, Jimma, Ethiopia
| | - Ghyslaine Bruna Djeunang Dongho
- Department of Public Health and Infectious Diseases, Sapienza University, Rome, Italy; Evangelical University of Cameroon, Bandjoun, Cameroon
| | | | - Louis H Miller
- Laboratory of Malaria and Vector Research, NIAID/NIH, Bethesda, USA
| | - Muzamil Mahdi Abdel Hamid
- Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Delenasaw Yewhalaw
- Tropical Infectious Disease Research Center, Jimma University, Jimma, Ethiopia
| | - Giacomo Maria Paganotti
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana; Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Gaborone, Botswana
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Ford A, Kepple D, Abagero BR, Connors J, Pearson R, Auburn S, Getachew S, Ford C, Gunalan K, Miller LH, Janies DA, Rayner JC, Yan G, Yewhalaw D, Lo E. Whole genome sequencing of Plasmodium vivax isolates reveals frequent sequence and structural polymorphisms in erythrocyte binding genes. PLoS Negl Trop Dis 2020; 14:e0008234. [PMID: 33044985 PMCID: PMC7581005 DOI: 10.1371/journal.pntd.0008234] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [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: 03/17/2020] [Revised: 10/22/2020] [Accepted: 08/21/2020] [Indexed: 12/16/2022] Open
Abstract
Plasmodium vivax malaria is much less common in Africa than the rest of the world because the parasite relies primarily on the Duffy antigen/chemokine receptor (DARC) to invade human erythrocytes, and the majority of Africans are Duffy negative. Recently, there has been a dramatic increase in the reporting of P. vivax cases in Africa, with a high number of them being in Duffy negative individuals, potentially indicating P. vivax has evolved an alternative invasion mechanism that can overcome Duffy negativity. Here, we analyzed single nucleotide polymorphism (SNP) and copy number variation (CNV) in Whole Genome Sequence (WGS) data from 44 P. vivax samples isolated from symptomatic malaria patients in southwestern Ethiopia, where both Duffy positive and Duffy negative individuals are found. A total of 123,711 SNPs were detected, of which 22.7% were nonsynonymous and 77.3% were synonymous mutations. The largest number of SNPs were detected on chromosomes 9 (24,007 SNPs; 19.4% of total) and 10 (16,852 SNPs, 13.6% of total). There were particularly high levels of polymorphism in erythrocyte binding gene candidates including merozoite surface protein 1 (MSP1) and merozoite surface protein 3 (MSP3.5, MSP3.85 and MSP3.9). Two genes, MAEBL and MSP3.8 related to immunogenicity and erythrocyte binding function were detected with significant signals of positive selection. Variation in gene copy number was also concentrated in genes involved in host-parasite interactions, including the expansion of the Duffy binding protein gene (PvDBP) on chromosome 6 and MSP3.11 on chromosome 10. Based on the phylogeny constructed from the whole genome sequences, the expansion of these genes was an independent process among the P. vivax lineages in Ethiopia. We further inferred transmission patterns of P. vivax infections among study sites and showed various levels of gene flow at a small geographical scale. The genomic features of P. vivax provided baseline data for future comparison with those in Duffy-negative individuals and allowed us to develop a panel of informative Single Nucleotide Polymorphic markers diagnostic at a micro-geographical scale. Plasmodium vivax is the most geographically widespread parasite species that causes malaria in humans. Although it occurs in Africa as a member of a mix of Plasmodium species, P. vivax is dominant in other parts of the world outside of Africa (e.g., Brazil). It was previously thought that most African populations were immune to P. vivax infections due to the absence of Duffy antigen chemokine receptor (DARC) gene expression required for erythrocyte invasion. However, several recent reports have indicated the emergence and potential spread of P. vivax across human populations in Africa. Compared to Southeast Asia and South America where P. vivax is highly endemic, data on polymorphisms in erythrocyte binding gene candidates of P. vivax from Africa is limited. Filling this knowlege gap is critical for identifying functional genes in erythrocyte invasion, biomarkers for tracking the P. vivax isolates from Africa, as well as potential gene targets for vaccine development. This paper examined the level of genetic polymorphisms in a panel of 43 potential erythrocyte binding protein genes based on whole genome sequences and described transmission patterns of P. vivax infections from different study sites in Ethiopia based on the genetic variants. Our analyses showed that chromosomes 9 and 10 of the P. vivax genomes isolated in Ethiopia had the most high-quality genetic polymorphisms. Among all erythrocyte binding protein gene candidates, the merozoite surface proteins 1 and merozoite surface protein 3 showed high levels of polymorphism. MAEBL and MSP3.8 related to immunogenicity and erythrocyte binding function were detected with significant signals of positive selection. The expansion of the Duffy binding protein and merozoite surface protein 3 gene copies was an independent process among the P. vivax lineages in Ethiopia. Various levels of gene flow were observed even at a smaller geographical scale. Our study provided baseline data for future comparison with P. vivax in Duffy negative individuals and help develop a panel of genetic markers that are informative at a micro-geographical scale.
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Affiliation(s)
- Anthony Ford
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, United States of America
- Department of Biological Sciences, University of North Carolina at Charlotte, United States of America
- * E-mail: (AF); (GY); (EL)
| | - Daniel Kepple
- Department of Biological Sciences, University of North Carolina at Charlotte, United States of America
| | - Beka Raya Abagero
- Tropical Infectious Disease Research Center, Jimma University, Ethiopia
| | - Jordan Connors
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, United States of America
| | - Richard Pearson
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United States of America
| | - Sarah Auburn
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Sisay Getachew
- College of Natural Sciences, Addis Ababa University, Ethiopia
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Colby Ford
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, United States of America
| | - Karthigayan Gunalan
- Laboratory of Malaria and Vector Research, NIAID/NIH, Bethesda, United States of America
| | - Louis H. Miller
- Laboratory of Malaria and Vector Research, NIAID/NIH, Bethesda, United States of America
| | - Daniel A. Janies
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, United States of America
| | - Julian C. Rayner
- Department of Clinical Biochemistry, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 OXY, United Kingdom
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, United States of America
- * E-mail: (AF); (GY); (EL)
| | | | - Eugenia Lo
- Department of Biological Sciences, University of North Carolina at Charlotte, United States of America
- * E-mail: (AF); (GY); (EL)
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