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Kojom Foko LP, Hawadak J, Eboumbou Moukoko CE, Das A, Singh V. Genetic analysis of the circumsporozoite gene in Plasmodium falciparum isolates from Cameroon: Implications for efficacy and deployment of RTS,S/AS01 vaccine. Gene 2024; 927:148744. [PMID: 38964492 DOI: 10.1016/j.gene.2024.148744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 06/26/2024] [Accepted: 07/01/2024] [Indexed: 07/06/2024]
Abstract
Current understanding of genetic polymorphisms and natural selection in Plasmodium falciparum circumsporozoite (PfCSP), the leading malaria vaccine, is crucial for the development of next-generation vaccines, and such data is lacking in Africa. Blood samples were collected among Plasmodium-infected individuals living in four Cameroonian areas (Douala, Maroua, Mayo-Oulo, Pette). DNA samples were amplified using nested PCR protocols, sequenced, and BLASTed. Single nucleotide polymorphisms (SNPs) were analysed in each PfCSP region, and their impact on PfCSP function/structure was predicted in silico. The N-terminal region showed a limited polymorphism with four haplotypes, and three novel SNPs (N68Y, R87W, K93E) were found. Thirty-five haplotypes were identified in the central region, with several variants (e.g., NVNP and KANP). The C-terminal region was also highly diverse, with 25 haplotypes and eight novel SNPs (N290D, N308I, S312G, K317A, V344I, D356E, E357L, D359Y). Most polymorphic codon sites were mainly observed in the Th2R subregion in isolates from Douala and Pette. The codon site 321 was under episodic positive selection. One novel (E357L) and three known (K322I, G349D, D359Y) SNPs show an impact on function/structure. This study showed extensive genetic diversity with geographical patterns and evidence of the selection of Cameroonian PfCSP central and C-terminal regions.
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Affiliation(s)
| | - Joseph Hawadak
- Parasite & Host Biology Group, National Institute of Malaria Research, New-Delhi, India
| | - Carole Else Eboumbou Moukoko
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, Cameroon; Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé, Cameroon; Laboratory of Parasitology, Mycology and Virology, Postgraduate Training Unit for Health Sciences, Postgraduate School for Pure and Applied Sciences, The University of Douala, Cameroon
| | - Aparup Das
- Division of Vector Borne Diseases, National Institute of Research in Tribal Health, Madhya Pradesh, India
| | - Vineeta Singh
- Parasite & Host Biology Group, National Institute of Malaria Research, New-Delhi, India; Academy of Scientific and Innovative Research, Ghaziabad, India.
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Kojom Foko LP, Eboumbou Moukoko CE, Jakhan J, Narang G, Hawadak J, Kouemo Motse FD, Pande V, Singh V. Deletions of Histidine-Rich Protein 2/3 Genes in Natural Plasmodium falciparum Populations from Cameroon and India: Role of Asymptomatic and Submicroscopic Infections. Am J Trop Med Hyg 2024; 110:1100-1109. [PMID: 38688260 PMCID: PMC11154061 DOI: 10.4269/ajtmh.23-0896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/29/2024] [Indexed: 05/02/2024] Open
Abstract
The bulk of malaria rapid diagnostic tests (RDTs) target histidine-rich protein 2 of Plasmodium falciparum, the deadliest malaria species. The WHO considers pfhrp2/3 deletions as one of the main threats to successful malaria control and/or elimination; as such, parasites that lack part or all of the pfhrp2 gene are missed by pfHRP2-targeting RDTs. Such deletions have been reported in several African and Asian countries, but little is known in Cameroon and India. Blood samples were collected from individuals living in four areas of Cameroon (Douala, Maroua, Mayo-Oulo, Pette) and India (Mewat, Raipur, Ranchi, Rourkela). Deletions in pfhrp2/3 genes were confirmed if samples 1) had ≥100 parasites/µL by quantitative polymerase chain reaction (PCR), 2) PCR negative for pfhrp2/3, and 3) PCR positive for at least two single-copy genes. The overall proportion of pfhrp2 and pfhrp3 deletions in Cameroon was 13.5% and 3.1%. In India, the overall proportion was 8% for pfhrp2 and 4% for pfhrp3. The overall proportions of samples with both gene deletions (pfhrp2-/3-) were 3.1% in Cameroon and 1.3% in India. In Cameroon, pfhrp2-/3+ and pfhrp2-/3- deletions were common in Maroua (P = 0.02), in asymptomatic parasitemia (P = 0.006) and submicroscopic parasitemia (P <0.0001). In both countries, pfhrp2/3 deletions, including pfhrp2-/3- deletions, were mainly seen in monoclonal infections. This study outlines that double deletions that result in false negative RDTs are uncommon in our settings, and highlights the importance of active molecular surveillance for pfhrp2/3 deletions in Cameroon and India.
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Affiliation(s)
- Loick Pradel Kojom Foko
- National Institute of Malaria Research, New Delhi, India
- Department of Biotechnology, Kumaun University, Bhimtal, India
| | - Carole Else Eboumbou Moukoko
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, Douala, Cameroon
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé, Cameroon
- Laboratory of Parasitology, Mycology and Virology, Postgraduate Training Unit for Health Sciences, Postgraduate School for Pure and Applied Sciences, The University of Douala, Douala, Cameroon
| | - Jahnvi Jakhan
- National Institute of Malaria Research, New Delhi, India
| | - Geetika Narang
- National Institute of Malaria Research, New Delhi, India
| | - Joseph Hawadak
- National Institute of Malaria Research, New Delhi, India
- Department of Biotechnology, Kumaun University, Bhimtal, India
| | | | - Veena Pande
- Department of Biotechnology, Kumaun University, Bhimtal, India
| | - Vineeta Singh
- National Institute of Malaria Research, New Delhi, India
- Academy of Scientific and Innovative Research, Ghaziabad, India
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Kojom Foko LP, Moun A, Singh V. Addressing low-density malaria infections in India and other endemic part of the world-the opportune time? Crit Rev Microbiol 2024:1-17. [PMID: 38632931 DOI: 10.1080/1040841x.2024.2339267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 04/01/2024] [Indexed: 04/19/2024]
Abstract
Shifting from high- to low-malaria transmission accompanies a higher proportion of asymptomatic low-density malaria infections (LDMI). Currently, several endemic countries, such as India, are experiencing this shift as it is striving to eliminate malaria. LDMI is a complex concept for which there are several important questions yet unanswered on its natural history, infectiousness, epidemiology, and pathological and clinical impact. India is on the right path to eliminating malaria, but it is facing the LDMI problem. A brief discussion on the concept and definitions of LDMI is beforehand presented. Also, an exhaustive review and critical analysis of the existing literature on LDMI in malaria-endemic areas, including India, are included in this review. Finally, we opine that addressing LDMI in India is ethically and pragmatically achievable, and a pool of sine qua non conditions is required to efficiently and sustainably eliminate malaria.
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Affiliation(s)
- Loick P Kojom Foko
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, India
| | - Amit Moun
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, India
| | - Vineeta Singh
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India
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Fauziah N, Rinawan FR, Nugraha NF, Faridah L, Jati KM, Dakosta A, Santika MK, Zakiyyudin MY, Muhsin A, Rizkillah KF, Nisa MN, Ristandi RB. Malaria elimination in West Java, Indonesia: A descriptive-and-qualitative study. J Vector Borne Dis 2024; 61:183-194. [PMID: 38922652 DOI: 10.4103/jvbd.jvbd_113_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 09/05/2023] [Indexed: 06/27/2024] Open
Abstract
BACKGROUND OBJECTIVES Following World Health Organization (WHO) plans for thirty-five malaria-endemic countries, Indonesia will eliminate malaria by 2030. As one of the Indonesian provinces, West Java targeted subnational malaria elimination in 2022. This article aims to describe malaria surveillance data and elimination programs, including weaknesses in sustaining the program. METHODS This study used secondary data from malaria surveillance information system regencies/cities' case reports for 2019-2022 and achievement data of sub-national malaria elimination certification from each regency/city from 2014-2022. The data was confirmed from the evaluation study document, analysis of reported cases, and interviews. RESULTS Most cases were confirmed by microscopic examination (84.1% in 2021 and 94.4% in 2022) and rapid diagnostic tests (57% in 2019 and 58.1% in 2020). Malaria is more prevalent among men (93% in 2019, 95% in 2020, 96% in 2021, and 95.9% in 2022) and productive ages of 15-64 years (98.8% in 2019, 100% in 2020, 99.2% in 2021, and 98.8% in 2022), frequently occurs in the military (56.3% in 2019, 75.7% in 2020, 45.2% in 2021) and police (40.5% in 2022), often uses passive case detection for identifying cases (97.9% in 2019 and 2020, 95.2% in 2021, and 97.6% in 2022), and the majority undergo inpatient treatment (86.4% in 2019, 81.7% in 2021, and 82.6% in 2022). Most positive cases originated from imported cases, and last indigenous cases were still found in 2019. Plasmodium vivax dominated malaria cases and and relapses were high (55.0% in 2020, and 47.3% in 2022). INTERPRETATION CONCLUSION All regencies/cities have obtained sub-national malaria elimination certification in 2022. West Java has the potential to be verified for Java-Bali sub-national malaria elimination targeted in 2023, albeit cases of imported malaria still occur. It is imperative to address the issue of imported cases transitioning into locally transmitted cases (introduced) by effective coordination across all regencies/cities and inter-provincial efforts.
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Affiliation(s)
- Nisa Fauziah
- Division of Parasitology, Department of Biomedical Sciences, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
- Laboratory of Parasitology, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
- Research Center for Care and Control of Infectious Disease, Universitas Padjadjaran, West Java, Indonesia
| | - Fedri Ruluwedrata Rinawan
- Department of Public Health, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
- Center for Health System Study and Health Workforce Education Innovation, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
- Indonesian Society for Remote Sensing Branch West Java, Indoenesia
| | - Naufal Fakhri Nugraha
- Research Center for Care and Control of Infectious Disease, Universitas Padjadjaran, West Java, Indonesia
| | - Lia Faridah
- Division of Parasitology, Department of Biomedical Sciences, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
- Laboratory of Parasitology, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
- Research Center for Care and Control of Infectious Disease, Universitas Padjadjaran, West Java, Indonesia
| | - Karomahul Malaya Jati
- Undergraduate Medical Study Program, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
| | - Angelina Dakosta
- Undergraduate Medical Study Program, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
| | - Mahatyanta Kalya Santika
- Undergraduate Medical Study Program, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
| | - Muhammad Yusuf Zakiyyudin
- Undergraduate Medical Study Program, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
| | - Ahmad Muhsin
- Undergraduate Medical Study Program, Faculty of Medicine, Universitas Padjadjaran, West Java, Indonesia
| | | | - Miftahul Nurun Nisa
- Health Polytechnic of Health Ministry Yogyakarta, Yogyakarta, Indonesia
- World Health Organization (WHO) Country Office of Indonesia, Jakarta, Indonesia
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Nana RRD, Ngum NL, Makoge V, Amvongo-Adja N, Hawadak J, Singh V. Rapid diagnostic tests for malaria diagnosis in Cameroon: impact of histidine rich protein 2/3 deletions and lactate dehydrogenase gene polymorphism. Diagn Microbiol Infect Dis 2024; 108:116103. [PMID: 37944271 DOI: 10.1016/j.diagmicrobio.2023.116103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 09/20/2023] [Accepted: 10/09/2023] [Indexed: 11/12/2023]
Abstract
Malaria rapid diagnostic tests (mRDT) play a vital role in malaria control in endemic areas. In this study, histidine-rich protein (hrp) and lactate dehydrogenase (ldh) genes were genotyped in Plasmodium falciparum (Pf) and Plasmodium ovale (Po) spp. isolates. Deletions in P. falciparum hrp2/3 (pfhrp2/3) proteins and single nucleotide polymorphisms (SNPs) were analyzed. Twenty-four samples were analyzed for pfhrp2/3 gene deletions and 25 for SNPs in ldh gene (18 Pf and 7 Po spp.). Deletions in pfhrp2/3 genes were observed in 1.9% malaria positive isolates. The pfldh gene sequences showed one SNP at codon 272 (D272N) in 22.2% of samples while in Po spp., sequences were 100% similar to P. ovale curtisi but when compared to P. ovale wallikeri reference sequence, SNPs at positions 143 (P143S), 168 (K168N), 204 (V204I) were found. Findings suggest low prevalence in pfhrp2/3 genes and highlight the circulation of P. ovale curtisi in the studies areas.
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Affiliation(s)
- Rodrigue Roman Dongang Nana
- Institute of Medical Research and Medicinal Plants studies (IMPM), P.O Box 13033 Yaoundé, Cameroon; Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi 110077, India..
| | - Ngum Lesly Ngum
- Institute of Medical Research and Medicinal Plants studies (IMPM), P.O Box 13033 Yaoundé, Cameroon
| | - Valerie Makoge
- Institute of Medical Research and Medicinal Plants studies (IMPM), P.O Box 13033 Yaoundé, Cameroon
| | - Nathalie Amvongo-Adja
- Institute of Medical Research and Medicinal Plants studies (IMPM), P.O Box 13033 Yaoundé, Cameroon
| | - Joseph Hawadak
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi 110077, India
| | - Vineeta Singh
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi 110077, India..
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Adegbite G, Edeki S, Isewon I, Emmanuel J, Dokunmu T, Rotimi S, Oyelade J, Adebiyi E. Mathematical modeling of malaria transmission dynamics in humans with mobility and control states. Infect Dis Model 2023; 8:1015-1031. [PMID: 37649792 PMCID: PMC10463202 DOI: 10.1016/j.idm.2023.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 09/01/2023] Open
Abstract
Malaria importation is one of the hypothetical drivers of malaria transmission dynamics across the globe. Several studies on malaria importation focused on the effect of the use of conventional malaria control strategies as approved by the World Health Organization (WHO) on malaria transmission dynamics but did not capture the effect of the use of traditional malaria control strategies by vigilant humans. In order to handle the aforementioned situation, a novel system of Ordinary Differential Equations (ODEs) was developed comprising the human and the malaria vector compartments. Analysis of the system was carried out to assess its quantitative properties. The novel computational algorithm used to solve the developed system of ODEs was implemented and benchmarked with the existing Runge-Kutta numerical solution method. Furthermore, simulations of different vigilant conditions useful to control malaria were carried out. The novel system of malaria models was well-posed and epidemiologically meaningful based on its quantitative properties. The novel algorithm performed relatively better in terms of model simulation accuracy than Runge-Kutta. At the best model-fit condition of 98% vigilance to the use of conventional and traditional malaria control strategies, this study revealed that malaria importation has a persistent impact on malaria transmission dynamics. In lieu of this, this study opined that total vigilance to the use of the WHO-approved and traditional malaria management tools would be the most effective control strategy against malaria importation.
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Affiliation(s)
- Gbenga Adegbite
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Computer and Information Sciences, Covenant University, Ota, Nigeria
| | - Sunday Edeki
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Mathematics, Covenant University, Ota, Nigeria
| | - Itunuoluwa Isewon
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Computer and Information Sciences, Covenant University, Ota, Nigeria
- Covenant Applied Informatics and Communications-African Centre of Excellence, Covenant University, Ota, Ogun State, Nigeria
| | - Jerry Emmanuel
- Department of Computer and Information Sciences, Covenant University, Ota, Nigeria
- Covenant Applied Informatics and Communications-African Centre of Excellence, Covenant University, Ota, Ogun State, Nigeria
| | - Titilope Dokunmu
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Biochemistry, Covenant University, Ota, Nigeria
- Covenant Applied Informatics and Communications-African Centre of Excellence, Covenant University, Ota, Ogun State, Nigeria
| | - Solomon Rotimi
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Biochemistry, Covenant University, Ota, Nigeria
- Covenant Applied Informatics and Communications-African Centre of Excellence, Covenant University, Ota, Ogun State, Nigeria
| | - Jelili Oyelade
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Computer and Information Sciences, Covenant University, Ota, Nigeria
- Covenant Applied Informatics and Communications-African Centre of Excellence, Covenant University, Ota, Ogun State, Nigeria
| | - Ezekiel Adebiyi
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Computer and Information Sciences, Covenant University, Ota, Nigeria
- Covenant Applied Informatics and Communications-African Centre of Excellence, Covenant University, Ota, Ogun State, Nigeria
- Division of Applied Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Kojom Foko LP, Singh V. Malaria in pregnancy in India: a 50-year bird's eye. Front Public Health 2023; 11:1150466. [PMID: 37927870 PMCID: PMC10620810 DOI: 10.3389/fpubh.2023.1150466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 09/25/2023] [Indexed: 11/07/2023] Open
Abstract
Introduction In 2021, India contributed for ~79% of malaria cases and ~ 83% of deaths in the South East Asia region. Here, we systematically and critically analyzed data published on malaria in pregnancy (MiP) in India. Methods Epidemiological, clinical, parasitological, preventive and therapeutic aspects of MiP and its consequences on both mother and child were reviewed and critically analyzed. Knowledge gaps and solution ways are also presented and discussed. Several electronic databases including Google scholar, Google, PubMed, Scopus, Wiley Online library, the Malaria in Pregnancy Consortium library, the World Malaria Report, The WHO regional websites, and ClinicalTrials.gov were used to identify articles dealing with MiP in India. The archives of local scientific associations/journals and website of national programs were also consulted. Results Malaria in pregnancy is mainly due to Plasmodium falciparum (Pf) and P. vivax (Pv), and on rare occasions to P. ovale spp. and P. malariae too. The overall prevalence of MiP is ~0.1-57.7% for peripheral malaria and ~ 0-29.3% for placental malaria. Peripheral Pf infection at antenatal care (ANC) visits decreased from ~13% in 1991 to ~7% in 1995-1996 in Madhya Pradesh, while placental Pf infection at delivery unit slightly decreased from ~1.5% in 2006-2007 to ~1% in 2012-2015 in Jharkhand. In contrast, the prevalence of peripheral Pv infection at ANC increased from ~1% in 2006-2007 to ~5% in 2015 in Jharkhand, and from ~0.5% in 1984-1985 to ~1.5% in 2007-2008 in Chhattisgarh. Clinical presentation of MiP is diverse ranging from asymptomatic carriage of parasites to severe malaria, and associated with comorbidities and concurrent infections such as malnutrition, COVID-19, dengue, and cardiovascular disorders. Severe anemia, cerebral malaria, severe thrombocytopenia, and hypoglycemia are commonly seen in severe MiP, and are strongly associated with tragic consequences such as abortion and stillbirth. Congenital malaria is seen at prevalence of ~0-12.9%. Infected babies are generally small-for-gestational age, premature with low birthweight, and suffer mainly from anemia, thrombocytopenia, leucopenia and clinical jaundice. Main challenges and knowledge gaps to MiP control included diagnosis, relapsing malaria, mixed Plasmodium infection treatment, self-medication, low density infections and utility of artemisinin-based combination therapies. Conclusion All taken together, the findings could be immensely helpful to control MiP in malaria endemic areas.
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Kojom Foko LP, Jakhan J, Narang G, Singh V. Global polymorphism of Plasmodium falciparum histidine rich proteins 2/3 and impact on malaria rapid diagnostic test detection: a systematic review and meta-analysis. Expert Rev Mol Diagn 2023; 23:925-943. [PMID: 37698448 DOI: 10.1080/14737159.2023.2255136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/18/2023] [Accepted: 08/10/2023] [Indexed: 09/13/2023]
Abstract
BACKGROUND This review presents an overview of field findings on sequence variation of Plasmodium falciparum histidine-rich proteins 2/3 (PfHRP2/3) for which reference types (1-24) have been identified, and its critical impact on PfHRP2-based rapid diagnostic test (RDT) detection. RESEARCH DESIGN AND METHODS This systematic review and meta-analysis was registered with PROSPERO, CRD42022316027, and conducted as per the PRISMA guidelines, and the methodological quality of studies was assessed. RESULTS Of the 2184 records identified, 34 studies were included mostly from Africa (47.1%) and Asia (35.3%). The reference PfHRP2 types 1, 2, 3, 6, and 7 are invariably found at proportions ≥ 80-100% in all areas with the exception of The Americas where their proportion is very low. The proteins exhibited high diversity of variants/unknown types, especially for types 1, 2, 4, and 7. Eleven major PfHRP2 epitopes were found at pooled proportion > 90%. The existing models to predict RDT detection are greatly limited by the impact of factors such as low (very low) parasitemia, RDT brand, and PfHRP3 cross-reactivity. PfHRP2 length and presence/number of a given reference repeat type/variant did not seem to impact RDT detection. CONCLUSIONS PfHRP2/3 are highly polymorphic and current findings are insufficient, conflicting and not convincing enough to conclude on the role of PfHRP2/3 sequence polymorphism in PfHRP2-based RDT detection.
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Affiliation(s)
- Loick P Kojom Foko
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, Dwarka, India
| | - Jahnvi Jakhan
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, Dwarka, India
| | - Geetika Narang
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, Dwarka, India
| | - Vineeta Singh
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, Dwarka, India
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van Dijk NJ, Menting S, Wentink-Bonnema EMS, Broekhuizen-van Haaften PE, Withycombe E, Schallig HDFH, Mens PF. Laboratory evaluation of the miniature direct-on-blood PCR nucleic acid lateral flow immunoassay (mini-dbPCR-NALFIA), a simplified molecular diagnostic test for Plasmodium. Malar J 2023; 22:98. [PMID: 36932372 PMCID: PMC10024383 DOI: 10.1186/s12936-023-04496-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 02/13/2023] [Indexed: 03/19/2023] Open
Abstract
BACKGROUND Point-of-care diagnosis of malaria is currently based on microscopy and rapid diagnostic tests. However, both techniques have their constraints, including poor sensitivity for low parasitaemias. Hence, more accurate diagnostic tests for field use and routine clinical settings are warranted. The miniature direct-on-blood PCR nucleic acid lateral flow immunoassay (mini-dbPCR-NALFIA) is an innovative, easy-to-use molecular assay for diagnosis of malaria in resource-limited settings. Unlike traditional molecular methods, mini-dbPCR-NALFIA does not require DNA extraction and makes use of a handheld, portable thermal cycler that can run on a solar-charged power pack. Result read-out is done using a rapid lateral flow strip enabling differentiation of Plasmodium falciparum and non-falciparum malaria infections. A laboratory evaluation was performed to assess the performance of the mini-dbPCR-NALFIA for diagnosis of pan-Plasmodium and P. falciparum infections in whole blood. METHODS Diagnostic accuracy of the mini-dbPCR-NALFIA was determined by testing a set of Plasmodium-positive blood samples from returned travellers (n = 29), and Plasmodium-negative blood samples from travellers with suspected malaria (n = 23), the Dutch Blood Bank (n = 19) and intensive care patients at the Amsterdam University Medical Centers (n = 16). Alethia Malaria (LAMP) with microscopy for species differentiation were used as reference. Limit of detection for P. falciparum was determined by 23 measurements of a dilution series of a P. falciparum culture. A fixed sample set was tested three times by the same operator to evaluate the repeatability, and once by five different operators to assess the reproducibility. RESULTS Overall sensitivity and specificity of the mini-dbPCR-NALFIA were 96.6% (95% CI, 82.2%-99.9%) and 98.3% (95% CI, 90.8%-100%). Limit of detection for P. falciparum was 10 parasites per microlitre of blood. The repeatability of the assay was 93.7% (95% CI, 89.5%-97.8%) and reproducibility was 84.6% (95% CI, 79.5%-89.6%). CONCLUSIONS Mini-dbPCR-NALFIA is a sensitive, specific and robust method for molecular diagnosis of Plasmodium infections in whole blood and differentiation of P. falciparum. Incorporation of a miniature thermal cycler makes the assay well-adapted to resource-limited settings. A phase-3 field trial is currently being conducted to evaluate the potential implementation of this tool in different malaria transmission areas.
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Affiliation(s)
- Norbert J van Dijk
- Department of Medical Microbiology and Infection Prevention, Experimental Parasitology. Meibergdreef 9, Amsterdam University Medical Centres, Academic Medical Centre at the University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands.
- Amsterdam Institute for Infection and Immunity, Infectious Diseases Programme, Amsterdam, The Netherlands.
| | - Sandra Menting
- Department of Medical Microbiology and Infection Prevention, Experimental Parasitology. Meibergdreef 9, Amsterdam University Medical Centres, Academic Medical Centre at the University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Ellen M S Wentink-Bonnema
- Department of Medical Microbiology and Infection Prevention, Clinical Parasitology. Meibergdreef 9, Amsterdam University Medical Centres, Academic Medical Centre at the University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Patricia E Broekhuizen-van Haaften
- Department of Medical Microbiology and Infection Prevention, Clinical Parasitology. Meibergdreef 9, Amsterdam University Medical Centres, Academic Medical Centre at the University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Elen Withycombe
- Abingdon Health. York Biotech Campus, Sand Hutton, York, YO41 1LZ, UK
| | - Henk D F H Schallig
- Department of Medical Microbiology and Infection Prevention, Experimental Parasitology. Meibergdreef 9, Amsterdam University Medical Centres, Academic Medical Centre at the University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases Programme, Amsterdam, The Netherlands
| | - Petra F Mens
- Department of Medical Microbiology and Infection Prevention, Experimental Parasitology. Meibergdreef 9, Amsterdam University Medical Centres, Academic Medical Centre at the University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases Programme, Amsterdam, The Netherlands
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Foko LPK, Narang G, Tamang S, Hawadak J, Jakhan J, Sharma A, Singh V. The spectrum of clinical biomarkers in severe malaria and new avenues for exploration. Virulence 2022; 13:634-653. [PMID: 36036460 PMCID: PMC9427047 DOI: 10.1080/21505594.2022.2056966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Globally, malaria is a public health concern, with severe malaria (SM) contributing a major share of the disease burden in malaria endemic countries. In this context, identification and validation of SM biomarkers are essential in clinical practice. Some biomarkers (C-reactive protein, angiopoietin 2, angiopoietin-2/1 ratio, platelet count, histidine-rich protein 2) have yielded interesting results in the prognosis of Plasmodium falciparum severe malaria, but for severe P. vivax and P. knowlesi malaria, similar evidence is missing. The validation of these biomarkers is hindered by several factors such as low sample size, paucity of evidence-evaluating studies, suboptimal values of sensitivity/specificity, poor clinical practicality of measurement methods, mixed Plasmodium infections, and good clinical value of the biomarkers for concurrent infections (pneumonia and current COVID-19 pandemic). Most of these biomarkers are non-specific to pathogens as they are related to host response and hence should be regarded as prognostic/predictive biomarkers that complement but do not replace pathogen biomarkers for clinical evaluation of SM patients. This review highlights the importance of research on diagnostic/predictive/therapeutic biomarkers, neglected malaria species, and clinical practicality of measurement methods in future studies. Finally, the importance of omics technologies for faster identification/validation of SM biomarkers is also included.
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Affiliation(s)
- Loick Pradel Kojom Foko
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi, India
| | - Geetika Narang
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi, India
| | - Suman Tamang
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi, India
| | - Joseph Hawadak
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi, India
| | - Jahnvi Jakhan
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi, India
| | - Amit Sharma
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi, India.,Molecular Medicine Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Vineeta Singh
- Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, New Delhi, India
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11
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Feleke SM, Gidey B, Mohammed H, Nega D, Dillu D, Haile M, Solomon H, Parr JB, Tollera G, Tasew G, Mamo H, Petros B. Field performance of Plasmodium falciparum lactate dehydrogenase rapid diagnostic tests during a large histidine-rich protein 2 deletion survey in Ethiopia. Malar J 2022; 21:236. [PMID: 35971118 PMCID: PMC9377056 DOI: 10.1186/s12936-022-04257-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 08/05/2022] [Indexed: 11/10/2022] Open
Abstract
Background Malaria rapid diagnostic tests (RDTs) have expanded diagnostic service to remote endemic communities in Ethiopia, where 70% of malaria services per annum are reliant on them. However, diagnostic strategies are threatened by Plasmodium falciparum parasites with deletions of the histidine-rich protein 2 and/or 3 (pfhrp2/3) genes. Studies have reported pfhrp2/3 gene deletion prevalence in Ethiopia that exceeds the WHO recommended threshold to switch to non-HRP2 targeted RDTs for detection of P. falciparum. Therefore, RDTs that target alternative antigens, such as P. falciparum lactate dehydrogenase (PfLDH) are increasingly in programmatic use. Methods Malaria suspected patients visiting health facilities of Amhara, Tigray, Gambella, and Oromia regions of Ethiopia were screened by community health workers using Carestart Pf/Pv (HRP2/Pv-LDH) and SD-Bioline Pf (HRP2 for Pf/LDH for Pf) RDTs. Dried blood spot (DBS) samples were collected from selected patients for molecular and serological analysis. The clinical data and RDT results were recorded on standard forms, entered into EpiInfo, and analysed using STATA. The Pf-LDH detecting RDT results were compared with real-time PCR and bead-based immunoassay to determine their diagnostic performance. Results The 13,172 (56% male and 44% female, median age of 19 years ranging from 1 to 99 year) study participants were enrolled and tested with PfHRP2 and PfLDH detection RDTs; 20.6% (95% CI: 19.6 to 21.6) were P. falciparum RDT positive. A subset of samples (n = 820) were previously tested using P. falciparum lactate dehydrogenase (pfldh) quantitative real-time PCR, and 456 of these further characterized using bead-based immunoassay. The proportion of samples positive for P. falciparum by the PfHRP2 Carestart and SD-Bioline RDTs were 66% (539/820) and 59% (481/820), respectively; 68% (561/820) were positive for the PfLDH band on the SD-Bioline RDT. The sensitivity and specificity of the PfLDH RDT band were 69% and 38%, respectively, versus pfldh qPCR; and 72% and 36%, respectively, versus PfLDH detection by immunoassay. Among samples with results for RDT, qPCR, and immunoassay, higher proportions of P. falciparum were recorded by pfldh qPCR (90%, 411/456) and PfLDH immunoassay (88%, 363/413) compared to the PfLDH band on the SD-Bioline RDT (74.6%, 340/456). Conclusion and recommendation Both PfHRP2 RDTs detected fewer P. falciparum cases than PfLDH, and fewer cases than qPCR or immunoassay. The poor sensitivity and specificity of the PfLDH RDT compared to qPCR and to immunoassay in this study raises concern. Continuous operator training and RDTs quality assurance programme to ensure quality diagnostic services are recommended.
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Affiliation(s)
| | | | | | - Desalegn Nega
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | | | | | - Jonathan B Parr
- Institute for Global Health and Infectious Diseases and Department of Medicine, Division of Infectious Diseases, University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, USA
| | | | - Geremew Tasew
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Hassen Mamo
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Beyene Petros
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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12
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Eyong EM, Etutu SJM, Jerome FC, Nyasa RB, Kwenti TE, Moyeh MN. Plasmodium falciparum histidine-rich protein 2 and 3 gene deletion in the Mount Cameroon region. IJID REGIONS (ONLINE) 2022; 3:300-307. [PMID: 35755467 PMCID: PMC9216387 DOI: 10.1016/j.ijregi.2022.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 12/04/2022]
Abstract
pfhrp2/3 gene deletions occur in parasite populations in the Mount Cameroon region pfhrp2-negative parasites are the more common in the Mount Cameroon region pfhrp2/3-negative parasites negatively impact malaria rapid diagnostic test success
Objective Plasmodium falciparum produces histidine-rich protein 2/3 (Pfhrp2/3) genes that accumulate to high levels in the bloodstream and serve as a diagnostic and prognostic marker for falciparum malaria. Pfhrp2/3 gene deletions may lead to false-negative rapid diagnostic test (RDT) results. We aimed to determine the prevalence of pfhrp2/3 gene deletions in P. falciparum isolates and the implications for RDT use in the Mount Cameroon region. Methods A cross-sectional hospital-based study with malaria diagnosis performed using microscopy, RDT and nested polymerase chain reaction (nPCR). In total, 324 P. falciparum microscopy positive individuals were enrolled and their samples confirmed positive for P. falciparum using 18SrRNA PCR. Samples that gave false-negative RDT results were analyzed to detect pfhrp2/3 exon 2 deletions. Results Of 324 positive microscopic and nPCR samples, 16 gave RDT false-negative results. Among the 324 P. falciparum positive isolates, exon 2 deletions were observed in 2.2% (7 of 324); 3 were negative for pfhrp2 gene, 2 for pfhrp3, and 2 for both pfhrp2 and pfhrp3 (double deletions). Conclusion P. falciparum isolates with pfhrp2/3 gene deletion were present in the parasite populations and may contribute to the RDT false-negative results in the Mount Cameroon region.
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Affiliation(s)
- Esum Mathias Eyong
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, South West Region, Cameroon
| | - Sophie Jose Molua Etutu
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, South West Region, Cameroon
| | - Fru-Cho Jerome
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, South West Region, Cameroon
| | - Raymond Babila Nyasa
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, South West Region, Cameroon
| | - Tebit Emmanuel Kwenti
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Buea, P.O. Box 63, Buea, South West Region, Cameroon
| | - Marcel N Moyeh
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63, Buea, South West Region of Cameroon
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13
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Plasmodium falciparum histidine-rich protein 2 and 3 genes deletion in global settings (2010–2021): a systematic review and meta-analysis. Malar J 2022; 21:26. [PMID: 35093092 PMCID: PMC8800273 DOI: 10.1186/s12936-022-04051-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 01/17/2022] [Indexed: 01/10/2023] Open
Abstract
Background The usefulness of histidine-rich protein-2/3 (HRP2/3)-based rapid diagnostic tests of malaria due to Plasmodium falciparum has been threatened by the appearance of mutant PfHRP2/3 genes. This study was undertaken to determine the global pooled estimates of PfHRP2/3gene deletions. Methods Relevant publications were identified from electronic databases such as; PubMed, EMBASE, and MEDLINE online. Besides, all the relevant literatures were retrieved through Google and Google Scholar. STATA software was used for data analysis. The pooled estimates were calculated using random effect model. The summary estimates were presented using forest plots and tables. Results A total of 27 studies were included in the systematic review. However, only 24 and 17 studies were included for PfHRP2 and 3 gene deletion meta-analysis, respectively. The prevalence of PfHRP2 gene deletion across the individual studies ranged from the highest 100% to the lowest 0%. However, the meta-analysis result showed that the global pooled prevalence of PfHRP2 and PfHRP3 gene deletions were 21.30% and 34.50%, respectively. The pooled proportion of PfHRP2 gene deletion among false negative PfHRP2-based RDTs results was found to be 41.10%. The gene deletion status was higher in South America and followed by Africa. The pooled estimate of PfHRP2 gene deletion among studies, which did not follow the WHO PfHRP2/3 gene deletion analysis protocol was higher than their counter parts (21.3% vs 10.5%). Conclusions This review showed that there is a high pooled prevalence of PfHRP2/3 gene deletions in Plasmodium falciparum confirmed isolates and also a high proportion of their deletions among false-negative malaria cases using PfHRP2-based RDT results. Hence, malaria diagnosis based on PfHRP2-based rapid tests seems to be less sensitive and warrants further evaluation of PfHRP2/3 gene deletions.
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14
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Yerlikaya S, Owusu EDA, Frimpong A, DeLisle RK, Ding XC. A Dual, Systematic Approach to Malaria Diagnostic Biomarker Discovery. Clin Infect Dis 2021; 74:40-51. [PMID: 34718455 PMCID: PMC8752250 DOI: 10.1093/cid/ciab251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Indexed: 11/15/2022] Open
Abstract
Background The emergence and spread of Plasmodium falciparum parasites that lack HRP2/3 proteins and the resulting decreased utility of HRP2-based malaria rapid diagnostic tests (RDTs) prompted the World Health Organization and other global health stakeholders to prioritize the discovery of novel diagnostic biomarkers for malaria. Methods To address this pressing need, we adopted a dual, systematic approach by conducting a systematic review of the literature for publications on diagnostic biomarkers for uncomplicated malaria and a systematic in silico analysis of P. falciparum proteomics data for Plasmodium proteins with favorable diagnostic features. Results Our complementary analyses led us to 2 novel malaria diagnostic biomarkers compatible for use in an RDT format: glyceraldehyde 3-phosphate dehydrogenase and dihydrofolate reductase-thymidylate synthase. Conclusions Overall, our results pave the way for the development of next-generation malaria RDTs based on new antigens by identifying 2 lead candidates with favorable diagnostic features and partially de-risked product development prospects.
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Affiliation(s)
- Seda Yerlikaya
- Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - Ewurama D A Owusu
- Foundation for Innovative New Diagnostics, Geneva, Switzerland.,Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Augustina Frimpong
- West Africa Centre for Cell Biology of Infectious Pathogens (WACCBIP), Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana.,Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana.,African Institute for Mathematical Sciences, Accra, Ghana
| | | | - Xavier C Ding
- Foundation for Innovative New Diagnostics, Geneva, Switzerland
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15
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Alenou LD, Etang J. Airport Malaria in Non-Endemic Areas: New Insights into Mosquito Vectors, Case Management and Major Challenges. Microorganisms 2021; 9:2160. [PMID: 34683481 PMCID: PMC8540862 DOI: 10.3390/microorganisms9102160] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 11/16/2022] Open
Abstract
Despite the implementation of preventive measures in airports and aircrafts, the risk of importing Plasmodium spp. infected mosquitoes is still present in malaria-free countries. Evidence suggests that mosquitoes have found a new alliance with the globalization of trade and climate change, leading to an upsurge of malaria parasite transmission around airports. The resulting locally acquired form of malaria is called Airport malaria. However, piecemeal information is available, regarding its epidemiological and entomological patterns, as well as the challenges in the diagnosis, treatment, and prevention. Understanding these issues is a critical step towards a better implementation of control strategies. To cross reference this information, we conducted a systematic review on 135 research articles published between 1969 (when the first cases of malaria in airports were reported) and 2020 (i.e., 51 years later). It appears that the risk of malaria transmission by local mosquito vectors in so called malaria-free countries is not zero; this risk is more likely to be fostered by infected vectors coming from endemic countries by air or by sea. Furthermore, there is ample evidence that airport malaria is increasing in these countries. From 2010 to 2020, the number of cases in Europe was 7.4 times higher than that recorded during the 2000-2009 decade. This increase may be associated with climate change, increased international trade, the decline of aircraft disinsection, as well as delays in case diagnosis and treatment. More critically, current interventions are weakened by biological and operational challenges, such as drug resistance in malaria parasites and vector resistance to insecticides, and logistic constraints. Therefore, there is a need to strengthen malaria prevention and treatment for people at risk of airport malaria, and implement a rigorous routine entomological and epidemiological surveillance in and around airports.
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Affiliation(s)
- Leo Dilane Alenou
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases’ Control in Central Africa (OCEAC), Yaoundé P.O. Box 288, Cameroon;
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala P.O. Box 2701, Cameroon
| | - Josiane Etang
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases’ Control in Central Africa (OCEAC), Yaoundé P.O. Box 288, Cameroon;
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala P.O. Box 2701, Cameroon
- Department of Insect Biotechnology in Plant Protection, Institute for Insect Biotechnology, Faculty 09—Agricultural Sciences, Nutritional Sciences and Environmental Management, Justus-Liebig-University Gießen, Winchester Str. 2, 35394 Giessen, Germany
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16
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Oyedeji SI, Awobode HO, Ojurongbe O, Anumudu C, Bassi PU. Molecular Identification and Characterization of Plasmodium ovale curtisi in Field Isolates from Symptomatic Children in North-Central Nigeria. Acta Parasitol 2021; 66:915-924. [PMID: 33710479 DOI: 10.1007/s11686-021-00350-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 02/10/2021] [Indexed: 11/30/2022]
Abstract
PURPOSE Plasmodium ovale is not usually the focus of most malaria research or intervention programmes and has lately been termed the neglected human malaria parasites. The parasite exists as two genetically distinct sympatric species namely P. ovale curtisi and P. ovale wallikeri but information on the distribution of P. ovale sub-species is lacking in Nigeria. The objective of this study, therefore, was aimed at characterizing the P. ovale sub-species in isolates from symptomatic individuals in North-central Nigeria. METHODS Parasites were identified by light microscopy of Giemsa stained thick and thin blood films. Molecular characterization and confirmation of P. ovale sub-species were done by species-specific nested PCR and sequencing of the small subunit ribosomal RNA (SSUrRNA) gene. RESULTS A total of 412 children were enrolled into this study of which 88.6% (n = 365) were positive for Plasmodium species by nested PCR and P. falciparum was predominant. Of the 365 isolates, 4 (1.1%) had P. ovale infections and of these, 3 (0.8%) were mixed species infections of P. ovale with P. falciparum. DNA sequence analysis confirmed that all the four P. ovale parasites were P. ovale curtisi as their sequences were 99-100% identical to previously published P. ovale curtisi sequences in the GenBank and they cluster with the P. ovale curtisi sequences by phylogeny. CONCLUSION Our findings demonstrate the occurrence of P. ovale curtisi in the study area. This has implications for public health and malaria elimination programmes, since they also serve as potential risk to travellers from malaria-free regions.
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Affiliation(s)
- Segun Isaac Oyedeji
- Molecular Parasitology and Genetics Unit, Department of Animal and Environmental Biology, Federal University Oye-Ekiti, Oye-Ekiti, Nigeria.
| | | | - Olusola Ojurongbe
- Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria
| | - Chiaka Anumudu
- Parasitology Unit, Department of Zoology, University of Ibadan, Ibadan, Nigeria
| | - Peter Usman Bassi
- Department of Clinical Pharmacology and Therapeutics, University of Abuja, Abuja, Nigeria
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Molina-de la Fuente I, Pastor A, Herrador Z, Benito A, Berzosa P. Impact of Plasmodium falciparum pfhrp2 and pfhrp3 gene deletions on malaria control worldwide: a systematic review and meta-analysis. Malar J 2021; 20:276. [PMID: 34158065 PMCID: PMC8220794 DOI: 10.1186/s12936-021-03812-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/11/2021] [Indexed: 12/15/2022] Open
Abstract
Background Deletion of pfhrp2 and/or pfhrp3 genes cause false negatives in malaria rapid diagnostic test (RDT) and threating malaria control strategies. This systematic review aims to assess the main methodological aspects in the study of pfhrp2 and pfhrp3 gene deletions and its global epidemiological status, with special focus on their distribution in Africa; and its possible impact in RDT. Methods The systematic review was conducted by examining the principal issues of study design and methodological workflow of studies addressing pfhrp2 deletion. Meta-analysis was applied to represent reported prevalences of pfhrp2 and pfhrp3 single and double deletion in the World Health Organization (WHO) region. Pooled-prevalence of deletions was calculated using DerSimonnian-Laird random effect model. Then, in-deep analysis focused on Africa was performed to assess possible variables related with these deletions. Finally, the impact of these deletions in RDT results was analysed combining reported information about RDT sensitivity and deletion prevalences. Results 49 articles were included for the systematic review and 37 for the meta-analysis, 13 of them placed in Africa. Study design differs significantly, especially in terms of population sample and information reported, resulting in high heterogeneity between studies that difficulties comparisons and merged conclusions. Reported prevalences vary widely in all the WHO regions, significantly higher deletion were reported in South-Central America, following by Africa and Asia. Pfhrp3 deletion is more prevalent (43% in South-Central America; 3% in Africa; and 1% in Asia) than pfhrp2 deletion (18% in South-Central America; 4% in Africa; and 3% in Asia) worldwide. In Africa, there were not found differences in deletion prevalence by geographical or population origin of samples. The prevalence of deletion among false negatives ranged from 0 to 100% in Africa, but in Asia and South-Central America was only up to 90% and 48%, respectively, showing substantial relation between deletions and false negatives. Conclusion The concerning prevalence of pfhrp2, pfhrp3 and pfhrp2/3 gene deletions, as its possible implications in malaria control, highlights the importance of regular and systematic surveillance of these deletions. This review has also outlined that a standardized methodology could play a key role to ensure comparability between studies to get global conclusions. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03812-0.
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Affiliation(s)
- Irene Molina-de la Fuente
- Department of Biomedicine and Biotechnology, School of Pharmacy, University of Alcalá, Alcalá de Henares, Madrid, Spain. .,Malaria and Neglected Diseases Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, 28029, Madrid, Spain. .,Public Health and Epidemiology Research Group, School of Medicine, University of Alcalá, 28871, Alcalá de Henares, Madrid, Spain.
| | - Andrea Pastor
- Public Health and Epidemiology Research Group, School of Medicine, University of Alcalá, 28871, Alcalá de Henares, Madrid, Spain
| | - Zaida Herrador
- National Centre of Epidemiology, Institute of Health Carlos III, 28029, Madrid, Spain.,Network Biomedical Research on Tropical Diseases (RICET in Spanish), Madrid, Spain
| | - Agustín Benito
- Malaria and Neglected Diseases Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, 28029, Madrid, Spain.,Network Biomedical Research on Tropical Diseases (RICET in Spanish), Madrid, Spain
| | - Pedro Berzosa
- Malaria and Neglected Diseases Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, 28029, Madrid, Spain.,Network Biomedical Research on Tropical Diseases (RICET in Spanish), Madrid, Spain
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Epidemiology and clinical outcomes of severe Plasmodium vivax malaria in India. J Infect 2021; 82:231-246. [PMID: 33831459 DOI: 10.1016/j.jinf.2021.03.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/26/2021] [Accepted: 03/30/2021] [Indexed: 12/24/2022]
Abstract
OBJECTIVES A systematic review and meta-analysis (SR-MA) of the available Indian literature on severe vivax malaria (SVM) was undertaken. METHODS Relevant studies in eight electronic databases were retrieved and reviewed. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. The methodological quality of the studies included in the MA was assessed. RESULTS Overall, 162 studies were included in the work. The pooled proportion of SVM was 29.3%. The main severity signs/symptoms seen in SVM were jaundice, severe thrombocytopenia (ST), multi-organ dysfunction, and severe anaemia with pooled proportion of 37.4%, 37.2%, 24.2% and 20.4%, respectively. P. falciparum was inducing 6% less ST (RR = 0.94, 95% CI 0.5-1.5, I2 = 77.87%), 10% less thrombocytopenia (RR = 0.9, 95% CI 0.7-1.1, I2 = 91.68%) and 20% less DIC (RR = 0.8, 95% CI 0.3-1.9, I2 = 0%) than P. vivax. An atypical condition like myocarditis, was most commonly observed among the studied SVM cases. The mortality rate in SVM cases ranged from 0 to 12.9% among hospital patients with P. vivax mono-infections. CONCLUSIONS The present SR-MA provides evidence for P. vivax as the etiologic agent of severe malaria leading to deaths in few cases as seen recently in India. However, research gaps outlined here emphasise the need for further studies on SVM in pregnancy, SVM in drug resistance and correlations with cytoadherence in disease severity due to P. vivax.
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Kojom Foko LP, Pande V, Singh V. Field Performances of Rapid Diagnostic Tests Detecting Human Plasmodium Species: A Systematic Review and Meta-Analysis in India, 1990-2020. Diagnostics (Basel) 2021; 11:590. [PMID: 33806066 PMCID: PMC8064471 DOI: 10.3390/diagnostics11040590] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/19/2021] [Accepted: 03/21/2021] [Indexed: 11/29/2022] Open
Abstract
Rapid diagnostic tests (RDTs) have become a mainstay of malaria diagnosis in endemic countries since their implementation in the 1990s. We conducted a 30-year systematic review and meta-analysis on malaria RDTs performance in India. Outcomes of interest were sensitivity (Se), specificity (Sp), positive/negative likelihood ratio (PLR/NLR), and diagnostic odd ratio (DOR). Among the 75 studies included, most of the studies were cross-sectional (65.3%), hospital-based (77.3%), and targeted febrile patients (90.6%). Nearly half of RDTs were designed for detecting Plasmodium falciparum only (47.5%) while the rest were for P. falciparum and P. vivax (11.9%), and P. falciparum/Pan-Plasmodium except for P. knowlesi (32.3%). When compared to light microscopy (gold standard), pooled estimates of performances were: Se = 97.0%, Sp = 96.0%, PLR = 22.4, NLR = 0.02 and DOR = 1080. In comparison to polymerase chain reaction, the RDTs showed Se = 89.0% and Sp = 99.0%. Performance outcomes (Se and Sp) were similar for RDT targeting P. falciparum only, but decreased for mixed and non-falciparum infections. Performances of malaria RDTs are still high India. However, there is a need for developing RDTs with regard to targeting minor malarial species, individuals carrying only mature gametocytes, and pfhrp2-deleted parasites.
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Affiliation(s)
- Loick Pradel Kojom Foko
- Cell Biology Laboratory and Malaria Parasite Bank, ICMR-National Institute of Malaria Research, Sector 8, Dwarka, New Delhi 110077, India;
- Department of Biotechnology, Kumaun University, Bhimtal, Uttarakhand 263001, India;
| | - Veena Pande
- Department of Biotechnology, Kumaun University, Bhimtal, Uttarakhand 263001, India;
| | - Vineeta Singh
- Cell Biology Laboratory and Malaria Parasite Bank, ICMR-National Institute of Malaria Research, Sector 8, Dwarka, New Delhi 110077, India;
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Schlabe S, Reiter-Owona I, Nordmann T, Dolscheid-Pommerich R, Tannich E, Hoerauf A, Rockstroh J. Rapid diagnostic test negative Plasmodium falciparum malaria in a traveller returning from Ethiopia. Malar J 2021; 20:145. [PMID: 33712017 PMCID: PMC7952815 DOI: 10.1186/s12936-021-03678-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 03/01/2021] [Indexed: 12/23/2022] Open
Abstract
Background Plasmodium falciparum strains with mutations/deletions of the genes encoding the histidine-rich proteins 2/3 (pfhrp2/3) have emerged during the last 10 years leading to false-negative results in HRP2-based rapid diagnostic tests (RDTs). This can lead to unrecognized infections in individuals and to setbacks in malaria control in endemic countries where RDTs are the backbone of malaria diagnostics and control. Case description Here the detection of a pfhrp2/3-negative P. falciparum infection acquired in Ethiopia by a 63-year old female traveller is presented. After onset of symptoms during travel, she was first tested negative for malaria, most probably by RDT, at a local hospital in Harar, Ethiopia. Falciparum malaria was finally diagnosed microscopically upon her return to Germany, over 4 weeks after infection. At a parasite density of approximately 5387 parasites/µl, two different high-quality RDTs: Palutop + 4 OPTIMA, NADALRMalaria PF/pan Ag 4 Species, did not respond at their respective P. falciparum test lines. pfhrp2/3 deletion was confirmed by multiplex-PCR. The patient recovered after a complete course of atovaquone and proguanil. According to the travel route, malaria was acquired most likely in the Awash region, Central Ethiopia. This is the first case of imported P. falciparum with confirmed pfhrp2/3 deletion from Ethiopia. Conclusion HRP2-negative P. falciparum strains may not be recognized by the presently available HRP2-based RDTs. When malaria is suspected, confirmation by microscopy and/or qPCR is necessary in order to detect falciparum malaria, which requires immediate treatment. This case of imported P. falciparum, non-reactive to HRP2-based RDT, possibly underlines the necessity for standardized, nationwide investigations in Ethiopia and should alert clinicians from non-endemic countries to the possibility of false-negative RDT results which may increase in returning travellers with potentially life-threatening infections. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03678-2.
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Affiliation(s)
- Stefan Schlabe
- Department of Internal Medicine I, University Hospital of Bonn, Venusberg Campus 1, Building 26, 53127, Bonn, Germany. .,German Centre of Infection Research, Partner Site Bonn-Cologne, Bonn, Germany.
| | - Ingrid Reiter-Owona
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Tamara Nordmann
- Department of Internal Medicine I, University Hospital of Bonn, Venusberg Campus 1, Building 26, 53127, Bonn, Germany.,National Reference Centre for Tropical Pathogens, Bernhard Nocht-Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | | | - Egbert Tannich
- National Reference Centre for Tropical Pathogens, Bernhard Nocht-Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.,German Centre of Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Jürgen Rockstroh
- Department of Internal Medicine I, University Hospital of Bonn, Venusberg Campus 1, Building 26, 53127, Bonn, Germany.,German Centre of Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
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21
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Lê HG, Kang JM, Lee J, Yoo WG, Myint MK, Lin K, Kim TS, Na BK. Genetic variations in histidine-rich protein 2 and histidine-rich protein 3 of Myanmar Plasmodium falciparum isolates. Malar J 2020; 19:388. [PMID: 33138831 PMCID: PMC7607715 DOI: 10.1186/s12936-020-03456-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/18/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria rapid diagnostic tests (RDTs) are precious tools to diagnose malaria. Most RDTs used currently are based on the detection of Plasmodium falciparum histidine-rich protein 2 (PfHRP2) in a patient's blood. However, concern has been raised in recent years that deletion of pfhrp2 in the parasite could affect the accuracy of PfHRP2-based RDTs. In addition, genetic variation in pfhrp2 might influence the accuracy and sensitivity of RDTs. In this study, the genetic variation in pfhrp2 and pfhrp3 in Myanmar P. falciparum isolates was analysed. METHODS Blood samples were collected from malaria patients who were infected with P. falciparum in Mandalay, Naung Cho, Tha Beik Kyin, and Pyin Oo Lwin, Upper Myanmar between 2013 and 2015. The pfhrp2 and pfhrp3 were amplified by nested polymerase chain reaction (PCR), cloned and sequenced. Genetic variation in Myanmar pfhrp2 and pfhrp3 was analysed using the DNASTAR program. Comparative analysis of Myanmar and global pfhrp2 and pfhrp3 isolates was also performed. RESULTS One-hundred and two pfhrp2 and 89 pfhrp3 were amplified from 105 blood samples, of which 84 pfhrp2 and 56 pfhrp3 sequences were obtained successfully. Myanmar pfhrp2 and pfhrp3 showed high levels of genetic variation with different arrangements of distinct repeat types, which further classified Myanmar pfhrp2 and pfhrp3 into 76 and 47 haplotypes, respectively. Novel amino acid changes were also found in Myanmar pfhrp2 and pfhrp3, but their frequencies were very low. Similar structural organization was shared by Myanmar and global pfhrp2 and pfhrp3, and differences in frequencies of repeat types and lengths were also observed between and among global isolates. CONCLUSION Length polymorphisms and amino acid substitutions generated extensive genetic variation in Myanmar pfhrp2 and pfhrp3. Comparative analysis revealed that global pfhrp2 and pfhrp3 share similar structural features, as well as extensive length polymorphisms and distinct organizations of repeat types. These results provide a better understanding of the genetic structure of pfhrp2 and pfhrp3 in global P. falciparum populations and suggest useful information to develop RDTs with improved quality.
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Affiliation(s)
- Hương Giang Lê
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea.,Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea.,Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Jinyoung Lee
- Department of Tropical Medicine and Inha Research Institute for Medical Sciences, Inha University College of Medicine, Incheon, 22212, Republic of Korea
| | - Won Gi Yoo
- Korea Mouse Phenotyping Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Moe Kyaw Myint
- Department of Medical Research Pyin Oo Lwin Branch, Pyin Oo Lwin, Myanmar
| | - Khin Lin
- Department of Medical Research Pyin Oo Lwin Branch, Pyin Oo Lwin, Myanmar
| | - Tong-Soo Kim
- Department of Tropical Medicine and Inha Research Institute for Medical Sciences, Inha University College of Medicine, Incheon, 22212, Republic of Korea.
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea. .,Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea.
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22
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Varo R, Balanza N, Mayor A, Bassat Q. Diagnosis of clinical malaria in endemic settings. Expert Rev Anti Infect Ther 2020; 19:79-92. [PMID: 32772759 DOI: 10.1080/14787210.2020.1807940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Malaria continues to be a major global health problem, with over 228 million cases and 405,000 deaths estimated to occur annually. Rapid and accurate diagnosis of malaria is essential to decrease the burden and impact of this disease, particularly in children. We aimed to review the main available techniques for the diagnosis of clinical malaria in endemic settings and explore possible future options to improve its rapid recognition. AREAS COVERED literature relevant to malaria diagnosis was identified through electronic searches in Pubmed, with no language or date restrictions and limited to humans. EXPERT OPINION Light microscopy is still considered the gold standard method for malaria diagnosis and continues to be at the frontline of malaria diagnosis. However, technologies as rapid diagnostic tests, mainly those who detect histidine-rich protein-2, offer an accurate, rapid and affordable alternative for malaria diagnosis in endemic areas. They are now the technique most extended in endemic areas for parasitological confirmation. In these settings, PCR-based assays are usually restricted to research and they are not currently helpful in the management of clinical malaria. Other technologies, such as isothermal methods could be an interesting and alternative approach to PCR in the future.
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Affiliation(s)
- Rosauro Varo
- ISGlobal, Hospital Clínic - Universitat De Barcelona , Barcelona, Spain.,Centro De Investigação Em Saúde De Manhiça (CISM) , Maputo, Mozambique
| | - Núria Balanza
- ISGlobal, Hospital Clínic - Universitat De Barcelona , Barcelona, Spain
| | - Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat De Barcelona , Barcelona, Spain.,Centro De Investigação Em Saúde De Manhiça (CISM) , Maputo, Mozambique
| | - Quique Bassat
- ISGlobal, Hospital Clínic - Universitat De Barcelona , Barcelona, Spain.,Centro De Investigação Em Saúde De Manhiça (CISM) , Maputo, Mozambique.,ICREA, Pg. Lluís Companys 23 , Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan De Deu (University of Barcelona) , Barcelona, Spain.,Consorcio De Investigación Biomédica En Red De Epidemiología Y Salud Publica (CIBERESP) , Madrid, Spain
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23
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Boush MA, Djibrine MA, Mussa A, Talib M, Maki A, Mohammed A, Beshir KB, Mohamed Z, Hajissa K. Plasmodium falciparum isolate with histidine-rich protein 2 gene deletion from Nyala City, Western Sudan. Sci Rep 2020; 10:12822. [PMID: 32733079 PMCID: PMC7393171 DOI: 10.1038/s41598-020-69756-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 07/20/2020] [Indexed: 11/19/2022] Open
Abstract
In remote areas of malaria-endemic countries, rapid diagnostic tests (RDTs) have dramatically improved parasitological confirmation of suspected malaria cases, especially when skilled microscopists are not available. This study was designed to determine the frequency of Plasmodium falciparum isolates with histidine-rich protein 2 (pfhrp2) gene deletion as one of the possible factors contributing to the failure of PfHRP2-based RDTs in detecting malaria. A total of 300 blood samples were collected from several health centres in Nyala City, Western Sudan. The performance of PfHRP2-based RDTs in relation to microscopy was examined and the PCR-confirmed samples were investigated for the presence of pfhrp2 gene. A total of 113 out of 300 patients were P. falciparum positive by microscopy. Among them, 93.81% (106 out of 113) were positives by the PfHRP2 RDTs. Seven isolates were identified as false negative on the basis of the RDTs results. Only one isolate (0.9%; 1/113) potentially has pfhrp2 gene deletion. The sensitivity and specificity of PfHRP2-based RDTs were 93.81% and 100%, respectively. The results provide insights into the pfhrp2 gene deletion amongst P. falciparum population from Sudan. However, further studies with a large and systematic collection from different geographical settings across the country are needed.
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Affiliation(s)
- Mohammed A Boush
- Malaria, Centre for Disease Control, Malaria, Schistosomiasis and Leishmaniasis Control Program, State Ministry of Health, Nyala, Sudan
| | - Moussa A Djibrine
- Department of Biology, Faculty of Exact and Applied Sciences, University of N'djamena, N'djamena, Chad
| | - Ali Mussa
- Department of Biology, Faculty of Education, Omdurman Islamic University, Omdurman, Sudan.,Genetics and Molecular Biology Laboratory, Department of Zoology, Faculty of Science, University of Khartoum, Khartoum, Sudan.,Department of Zoology, Faculty of Science and Technology, Omdurman Islamic University, Omdurman, Sudan
| | - Mustafa Talib
- Genetics and Molecular Biology Laboratory, Department of Zoology, Faculty of Science, University of Khartoum, Khartoum, Sudan.,Department of Zoology, Faculty of Science and Technology, Omdurman Islamic University, Omdurman, Sudan
| | - A Maki
- Department of Molecular Genetics, Institute of Molecular Biology, University of Nyala, Nyala, Sudan
| | - Abdulrahman Mohammed
- National Public Health Reference Laboratory, Ministry of Health, Mogadishu, Somalia
| | - Khalid B Beshir
- Faculty of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Zeehaida Mohamed
- Department of Medical Microbiology & Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia.
| | - Khalid Hajissa
- Department of Zoology, Faculty of Science and Technology, Omdurman Islamic University, Omdurman, Sudan. .,Department of Medical Microbiology & Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia.
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