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Ong SQ, Dawood MM, Rahman H, Alias MF, Moideen MA, Lee PC, Fiorenzano JM, Christy N, McGlynn T, Cote N, Letizia AG. A protocol and training guidelines for mosquito sampling in remote areas with limited power supply. MethodsX 2024; 12:102563. [PMID: 38328504 PMCID: PMC10847759 DOI: 10.1016/j.mex.2024.102563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 01/06/2024] [Indexed: 02/09/2024] Open
Abstract
Mosquito-borne diseases pose a significant threat in many Southeast Asian countries, particularly through the sylvatic cycle, which has a wildlife reservoir in forests and rural areas. Studying the composition and diversity of vectors and pathogen transmission is especially challenging in forests and rural areas due to their remoteness, limited accessibility, lack of power, and underdeveloped infrastructure. This study is based on the WHO mosquito sampling protocol, modifies technical details to support mosquito collection in difficult-to-access and resource-limited areas. Specifically, we describe the procedure for using rechargeable lithium batteries and solar panels to power the mosquito traps, demonstrate a workflow for processing and storing the mosquitoes in a -20 °C freezer, data management tools including microclimate data, and quality assurance processes to ensure the validity and reliability of the results. A pre- and post-test was utilized to measure participant knowledge levels. Additional research is needed to validate this protocol for monitoring vector-borne diseases in hard-to-reach areas within other countries and settings.
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Affiliation(s)
- Song-Quan Ong
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Malaysia
- Vysnova Partners, LLC, Alexandria, VA 22314, USA
| | | | - Homathevi Rahman
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Malaysia
| | | | | | - Ping-Chin Lee
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, Sabah 88400, Malaysia
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, Sabah 88400, Malaysia
- Vysnova Partners, LLC, Alexandria, VA 22314, USA
| | | | | | - Thomas McGlynn
- U.S. Naval Medical Research Unit INDO PACIFIC, Singapore
| | - Noel Cote
- U.S. Naval Medical Research Unit INDO PACIFIC, Singapore
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Sy Thau N, Nguyen TK, Truong NV, Chu TTH, Na SH, Moon RW, Lau YL, Nyunt MH, Park WS, Chun WJ, Lu F, Lee SK, Han JH, Han ET. Characterization of merozoite-specific thrombospondin-related anonymous protein (MTRAP) in Plasmodium vivax and P. knowlesi parasites. Front Cell Infect Microbiol 2024; 14:1354880. [PMID: 38465236 PMCID: PMC10920329 DOI: 10.3389/fcimb.2024.1354880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 02/08/2024] [Indexed: 03/12/2024] Open
Abstract
Plasmodium vivax, the most widespread human malaria parasite, and P. knowlesi, an emerging Plasmodium that infects humans, are the phylogenetically closest malarial species that infect humans, which may induce cross-species reactivity across most co-endemic areas in Southeast Asia. The thrombospondin-related anonymous protein (TRAP) family is indispensable for motility and host cell invasion in the growth and development of Plasmodium parasites. The merozoite-specific TRAP (MTRAP), expressed in blood-stage merozoites, is supposed to be essential for human erythrocyte invasion. We aimed to characterize MTRAPs in blood-stage P. vivax and P. knowlesi parasites and ascertain their cross-species immunoreactivity. Recombinant P. vivax and P. knowlesi MTRAPs of full-length ectodomains were expressed in a mammalian expression system. The MTRAP-specific immunoglobulin G, obtained from immune animals, was used in an immunofluorescence assay for subcellular localization and invasion inhibitory activity in blood-stage parasites was determined. The cross-species humoral immune responses were analyzed in the sera of patients with P. vivax or P. knowlesi infections. The MTRAPs of P. vivax (PvMTRAP) and P. knowlesi (PkMTRAP) were localized on the rhoptry body of merozoites in blood-stage parasites. Both anti-PvMTRAP and anti-PkMTRAP antibodies inhibited erythrocyte invasion of blood-stage P. knowlesi parasites. The humoral immune response to PvMTRAP showed high immunogenicity, longevity, and cross-species immunoreactivity with P. knowlesi. MTRAPs are promising candidates for development of vaccines and therapeutics against vivax and knowlesi malaria.
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Affiliation(s)
- Nguyen Sy Thau
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, Republic of Korea
| | - Tuyet-Kha Nguyen
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, Republic of Korea
| | - Nguyen Van Truong
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, Republic of Korea
| | - Thi-Thanh Hang Chu
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, Republic of Korea
| | - Sung-Hun Na
- Department of Obstetrics and Gynecology, Kangwon National University School of Medicine, Chuncheon, Gangwon-d, Republic of Korea
| | - Robert W. Moon
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | | | - Won-Sun Park
- Department of Physiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Wan-Joo Chun
- Department of Pharmacology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Feng Lu
- Department of Pathogen Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Seong-Kyun Lee
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, Republic of Korea
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, Republic of Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, Republic of Korea
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Gallalee S, Zarlinda I, Silaen MG, Cotter C, Cueto C, Elyazar IRF, Jacobson JO, Gosling R, Hsiang MS, Bennett A, Coutrier FN, Smith JL. Forest-goers as a heterogeneous population at high-risk for malaria: a case-control study in Aceh Province, Indonesia. Malar J 2024; 23:37. [PMID: 38291392 PMCID: PMC10826189 DOI: 10.1186/s12936-024-04856-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 01/20/2024] [Indexed: 02/01/2024] Open
Abstract
BACKGROUND A major challenge to malaria elimination is identifying and targeting populations that are harbouring residual infections and contributing to persistent transmission. In many near-elimination settings in Southeast Asia, it is known that forest-goers are at higher risk for malaria infection, but detailed information on their behaviours and exposures is not available. METHODS In Aceh Province, Indonesia, a near-elimination setting where a growing proportion of malaria is due to Plasmodium knowlesi, a case-control study was conducted to identify risk factors for symptomatic malaria, characteristics of forest-goers, and key intervention points. From April 2017 to September 2018, cases and controls were recruited and enrolled in a 1:3 ratio. Cases had confirmed malaria infection by rapid diagnostic test or microscopy detected at a health facility (HF). Gender-matched controls were recruited from passive case detection among individuals with suspected malaria who tested negative at a health facility (HF controls), and community-matched controls were recruited among those testing negative during active case detection. Multivariable logistic regression (unconditional for HF controls and conditional for community controls) was used to identify risk factors for symptomatic malaria infection. RESULTS There were 45 cases, of which 27 were P. knowlesi, 17 were Plasmodium vivax, and one was not determined. For controls, 509 and 599 participants were recruited from health facilities and the community, respectively. Forest exposures were associated with high odds of malaria; in particular, working and sleeping in the forest (HF controls: adjusted odds ratio (aOR) 21.66, 95% CI 5.09-92.26; community controls: aOR 16.78, 95% CI 2.19-128.7) and having a second residence in the forest (aOR 6.29, 95% CI 2.29-17.31 and 13.53, 95% CI 2.10-87.12). Male forest-goers were a diverse population employed in a variety of occupations including logging, farming, and mining, sleeping in settings, such as huts, tents, and barracks, and working in a wide range of group sizes. Reported use of protective measures, such as nets, hammock nets, mosquito coils, and repellents was low among forest-goers and interventions at forest residences were absent. CONCLUSIONS Second residences in the forest and gaps in use of protective measures point to key malaria interventions to improve coverage in forest-going populations at risk for P. knowlesi and P. vivax in Aceh, Indonesia. Intensified strategies tailored to specific sub-populations will be essential to achieve elimination.
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Affiliation(s)
- Sarah Gallalee
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA.
| | - Iska Zarlinda
- Malaria Pathogenesis Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Martha G Silaen
- Malaria Pathogenesis Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Chris Cotter
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Carmen Cueto
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Iqbal R F Elyazar
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Jerry O Jacobson
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Roly Gosling
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Michelle S Hsiang
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA
- Department of Pediatrics, University of California San Francisco, Benioff Children's Hospital, San Francisco, CA, USA
| | - Adam Bennett
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA
| | - Farah N Coutrier
- Malaria Pathogenesis Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
- Eijkman Research Center for Molecular Biology, National Research and Innovation Agency (BRIN), Jakarta, Indonesia
| | - Jennifer L Smith
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA
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Naserrudin NA, Adhikari B, Culleton R, Hod R, Jeffree MS, Ahmed K, Hassan MR. Knowledge, compliance, and challenges in anti-malarial products usage: a systematic review of at-risk communities for zoonotic malaria. BMC Public Health 2024; 24:317. [PMID: 38287308 PMCID: PMC10823597 DOI: 10.1186/s12889-024-17792-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/16/2024] [Indexed: 01/31/2024] Open
Abstract
BACKGROUND Zoonotic malaria is a growing public health threat in the WHO Southeast Asia (SEA) and Western Pacific (WP) regions. Despite vector-control measures, the distribution of Macaque fascicularis and M. nemestrina, and Anopheles mosquitoes carrying non-human simian malaria parasites poses challenges to malaria elimination. The systematic review assesses the literature on knowledge and malaria-preventive practices in zoonotic malaria-affected areas across the WHO SEA and WP, aiming to identify challenges for malaria control. METHODS Peer-reviewed articles published in English, Malay and Indonesian between January 2010 and December 2022 were searched in OVID Medline, Scopus, Web of Science, and Google Scholar. Studies of any design-excluding reviews, conference proceedings, and reports from all WHO SEA and WP countries vulnerable to zoonotic malaria-were included. Backwards-reference screening and thematic analysis were conducted. RESULTS Among 4,174 initially searched articles, 22 peer-reviewed articles met the inclusion criteria. An additional seven articles were identified through backwards-reference screening, resulting in a total of 29 articles for this review. Half of these studies were conducted in Cambodia, Myanmar, Malaysia, and Thailand, mainly in forests and remote communities. The review highlighted inconsistencies in the operationalization of knowledge, and five major themes were identified related to knowledge: causation and transmission, symptoms, treatment, severity and complications, and malaria prevention. While participants generally had some understanding of malaria causation/transmission, minority and indigenous ethnic groups demonstrated limited knowledge and held misconceptions, such as attributing malaria to drinking dirty water. Preventive practices included traditional and non-traditional or modern methods-with a preference for traditional approaches to avoid mosquito bites. Challenges to malaria control included feasibility, cost, and access to healthcare services. CONCLUSION This review provides insights into knowledge, local understandings, and preventive practices related to malaria in the WHO SEA and WP regions. The findings highlight the need for future research to explore the knowledge of at-risk communities regarding zoonotic malaria, their perceive threat of the disease and factors exposing them to zoonotic malaria. New strategies must be developed for zoonotic malaria programs tailored to local contexts, emphasizing the significance of community participation, health education, and socio-behavioural change initiatives. It is important to consider the interconnectedness of human health, environmental and non-human primates conservation. Socio-cultural nuances should also be carefully considered in the design and implementation of these programs to ensure their effect tailored to local contexts.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Institute for Health Systems Research, National Institutes of Health, Ministry of Health, Setia Alam, Shah alam, 40170, Malaysia
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, 56000, Malaysia
| | - Bipin Adhikari
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, 791-0295, Japan
| | - Rozita Hod
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, 56000, Malaysia
| | - Mohammad Saffree Jeffree
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, 88400, Kota Kinabalu, Malaysia
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, 88400, Malaysia
| | - Kamruddin Ahmed
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, 88400, Kota Kinabalu, Malaysia
| | - Mohd Rohaizat Hassan
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, 56000, Malaysia.
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, 88400, Kota Kinabalu, Malaysia.
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5
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Shears MJ, Reynolds RA, Duncombe CJ, Watson FN, Staubus WJ, Chavtur C, Seilie AM, Tran TM, Chakravarty S, Hoffman SL, Murphy SC. Plasmodium knowlesi in pig-tailed macaques: a potential new model for malaria vaccine research. Malar J 2023; 22:379. [PMID: 38093306 PMCID: PMC10720125 DOI: 10.1186/s12936-023-04788-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/11/2023] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND Plasmodium knowlesi is an established experimental model for basic and pre-clinical malaria vaccine research. Historically, rhesus macaques have been the most common host for malaria vaccine studies with P. knowlesi parasites. However, rhesus are not natural hosts for P. knowlesi, and there is interest in identifying alternative hosts for vaccine research. The study team previously reported that pig-tailed macaques (PTM), a natural host for P. knowlesi, could be challenged with cryopreserved P. knowlesi sporozoites (PkSPZ), with time to blood stage infection equivalent to in rhesus. Here, additional exploratory studies were performed to evaluate PTM as potential hosts for malaria vaccine studies. The aim was to further characterize the parasitological and veterinary health outcomes after PkSPZ challenge in this macaque species. METHODS Malaria-naïve PTM were intravenously challenged with 2.5 × 103 PkSPZ and monitored for blood stage infection by Plasmodium 18S rRNA RT-PCR and thin blood smears. Disease signs were evaluated by daily observations, complete blood counts, serum chemistry tests, and veterinary examinations. After anti-malarial drug treatment, a subset of animals was re-challenged and monitored as above. Whole blood gene expression analysis was performed on selected animals to assess host response to infection. RESULTS In naïve animals, the kinetics of P. knowlesi blood stage replication was reproducible, with parasite burden rising linearly during an initial acute phase of infection from 6 to 11 days post-challenge, before plateauing and transitioning into a chronic low-grade infection. After re-challenge, infections were again reproducible, but with lower blood stage parasite densities. Clinical signs of disease were absent or mild and anti-malarial treatment was not needed until the pre-defined study day. Whole blood gene expression analysis identified immunological changes associated with acute and chronic phases of infection, and further differences between initial challenge versus re-challenge. CONCLUSIONS The ability to challenge PTM with PkSPZ and achieve reliable blood stage infections indicate this model has significant potential for malaria vaccine studies. Blood stage P. knowlesi infection in PTM is characterized by low parasite burdens and a benign disease course, in contrast with the virulent P. knowlesi disease course commonly reported in rhesus macaques. These findings identify new opportunities for malaria vaccine research using this natural host-parasite combination.
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Affiliation(s)
- Melanie J Shears
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican Street, F870, Seattle, WA, 98109, USA
- Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, 750 Republican Street, Seattle, WA, 98109, USA
- Washington National Primate Research Center, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Rebekah A Reynolds
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican Street, F870, Seattle, WA, 98109, USA
- Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, 750 Republican Street, Seattle, WA, 98109, USA
| | - Caroline J Duncombe
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican Street, F870, Seattle, WA, 98109, USA
- Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, 750 Republican Street, Seattle, WA, 98109, USA
| | - Felicia N Watson
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican Street, F870, Seattle, WA, 98109, USA
- Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, 750 Republican Street, Seattle, WA, 98109, USA
| | - Weston J Staubus
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican Street, F870, Seattle, WA, 98109, USA
- Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, 750 Republican Street, Seattle, WA, 98109, USA
| | - Chris Chavtur
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican Street, F870, Seattle, WA, 98109, USA
- Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, 750 Republican Street, Seattle, WA, 98109, USA
| | - Annette M Seilie
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican Street, F870, Seattle, WA, 98109, USA
- Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, 750 Republican Street, Seattle, WA, 98109, USA
| | - Tuan M Tran
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Sumana Chakravarty
- Sanaria, Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Stephen L Hoffman
- Sanaria, Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Sean C Murphy
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican Street, F870, Seattle, WA, 98109, USA.
- Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, 750 Republican Street, Seattle, WA, 98109, USA.
- Washington National Primate Research Center, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA.
- Department of Microbiology, University of Washington, 750 Republican Street, F870, Seattle, WA, 98109, USA.
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Lee SK, Nguyen TK, Mohring F, Han JH, Firdaus ER, Na SH, Park WS, Moon RW, Han ET. Merozoite surface protein 1 paralog is involved in the human erythrocyte invasion of a zoonotic malaria, Plasmodium knowlesi. Front Cell Infect Microbiol 2023; 13:1314533. [PMID: 38111629 PMCID: PMC10726050 DOI: 10.3389/fcimb.2023.1314533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 11/15/2023] [Indexed: 12/20/2023] Open
Abstract
The zoonotic malaria parasite Plasmodium knowlesi is an important public health concern in Southeast Asia. Invasion of host erythrocytes is essential for parasite growth, and thus, understanding the repertoire of parasite proteins that enable this process is vital for identifying vaccine candidates and how some species are able to cause zoonotic infection. Merozoite surface protein 1 (MSP1) is found in all malaria parasite species and is perhaps the most well-studied as a potential vaccine candidate. While MSP1 is encoded by a single gene in P. falciparum, all other human infective species (P. vivax, P. knowlesi, P. ovale, and P. malariae) additionally encode a divergent paralogue known as MSP1P, and little is known about its role or potential functional redundancy with MSP1. We, therefore, studied the function of P. knowlesi merozoite surface protein 1 paralog (PkMSP1P), using both recombinant protein and CRISPR-Cas9 genome editing. The recombinant 19-kDa C-terminus of PkMSP1P (PkMSP1P-19) was shown to bind specifically to human reticulocytes. However, immunoblotting data suggested that PkMSP1P-19-induced antibodies can recognize PkMSP1-19 and vice versa, confounding our ability to separate the properties of these two proteins. Targeted disruption of the pkmsp1p gene profoundly impacts parasite growth, demonstrating for the first time that PkMSP1P is important in in vitro growth of P. knowlesi and likely plays a distinct role from PkMSP1. Importantly, the MSP1P KO also enabled functional characterization of the PkMSP1P-19 antibodies, revealing clear immune cross-reactivity between the two paralogues, highlighting the vital importance of genetic studies in contextualizing recombinant protein studies.
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Affiliation(s)
- Seong-Kyun Lee
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Tuyet Kha Nguyen
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Franziska Mohring
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Egy Rahman Firdaus
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Sung-Hun Na
- Department of Obstetrics and Gynecology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Won-Sun Park
- Department of Physiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Robert W. Moon
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
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Watson QD, Carias LL, Malachin A, Redinger KR, Bosch J, Bardelli M, Baldor L, Feufack-Donfack LB, Popovici J, Moon RW, Draper SJ, Zimmerman PA, King CL. Human monoclonal antibodies inhibit invasion of transgenic Plasmodium knowlesi expressing Plasmodium vivax Duffy binding protein. Malar J 2023; 22:369. [PMID: 38049801 PMCID: PMC10696754 DOI: 10.1186/s12936-023-04766-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 10/24/2023] [Indexed: 12/06/2023] Open
Abstract
BACKGROUND Plasmodium vivax has been more resistant to various control measures than Plasmodium falciparum malaria because of its greater transmissibility and ability to produce latent parasite forms. Therefore, developing P. vivax vaccines and therapeutic monoclonal antibodies (humAbs) remains a high priority. The Duffy antigen receptor for chemokines (DARC) expressed on erythrocytes is central to P. vivax invasion of reticulocytes. P. vivax expresses a Duffy binding protein (PvDBP) on merozoites, a DARC ligand, and the DARC: PvDBP interaction is critical for P. vivax blood stage malaria. Therefore, PvDBP is a leading vaccine candidate for P. vivax and a target for therapeutic human monoclonal antibodies (humAbs). METHODS Here, the functional activity of humAbs derived from naturally exposed and vaccinated individuals are compared for the first time using easily cultured Plasmodium knowlesi (P. knowlesi) that had been genetically modified to replace its endogenous PkDBP orthologue with PvDBP to create a transgenic parasite, PkPvDBPOR. This transgenic parasite requires DARC to invade human erythrocytes but is not reticulocyte restricted. This model was used to evaluate the invasion inhibition potential of 12 humAbs (9 naturally acquired; 3 vaccine-induced) targeting PvDBP individually and in combinations using growth inhibition assays (GIAs). RESULTS The PvDBP-specific humAbs demonstrated 70-100% inhibition of PkPvDBPOR invasion with the IC50 values ranging from 51 to 338 µg/mL for the 9 naturally acquired (NA) humAbs and 33 to 99 µg/ml for the 3 vaccine-induced (VI) humAbs. To evaluate antagonistic, additive, or synergistic effects, six pairwise combinations were performed using select humAbs. Of these combinations tested, one NA/NA (099100/094083) combination demonstrated relatively strong additive inhibition between 10 and 100 µg/mL; all combinations of NA and VI humAbs showed additive inhibition at concentrations below 25 µg/mL and antagonism at higher concentrations. None of the humAb combinations showed synergy. Invasion inhibition efficacy by some mAbs shown with PkPvDBPOR was closely replicated using P. vivax clinical isolates. CONCLUSION The PkPvDBPOR transgenic model is a robust surrogate of P. vivax to assess invasion and growth inhibition of human monoclonal Abs recognizing PvDBP individually and in combination. There was no synergistic interaction for growth inhibition with the humAbs tested here that target different epitopes or subdomains of PvDBP, suggesting little benefit in clinical trials using combinations of these humAbs.
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Affiliation(s)
- Quentin D Watson
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Lenore L Carias
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Alyssa Malachin
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Karli R Redinger
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Jürgen Bosch
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | | | - Lea Baldor
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | | | - Jean Popovici
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Robert W Moon
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Simon J Draper
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Peter A Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
| | - Christopher L King
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
- Veterans Affairs Medical Center, Cleveland, OH, USA.
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8
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Sangsri R, Choowongkomon K, Tuntipaiboontana R, Sugaram R, Boondej P, Sudathip P, Dondorp AM, Imwong M. Limited Polymorphism in the Dihydrofolate Reductase (dhfr) and dihydropteroate synthase genes (dhps) of Plasmodium knowlesi isolate from Thailand. Acta Trop 2023; 248:107016. [PMID: 37683820 PMCID: PMC10632683 DOI: 10.1016/j.actatropica.2023.107016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/27/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023]
Abstract
BACKGROUND The 2022 malaria WHO reported around 4000 P. knowlesi infections in the South-East Asia region. In the same period, 72 positive cases were reported by the Department of Disease Control in Thailand, suggesting a persistent infection. Little is known about dihydrofolate reductase (pkdhfr) and dihydropteroate synthase (pkdhps), putative antimalarial resistance markers for P. knowlesi. The relevant amplification and sequencing protocol are presently unavailable. In this study, we developed a protocol for amplifying and evaluating pkdhps mutations. The haplotype pattern of pkdhfr-pkdhps in Thai isolates was analyzed, and the effects of these pkdhps mutations were predicted by using a computer program. METHODS Pkdhps were amplified and sequenced from 28 P. knowlesi samples collected in 2008 and 2020 from nine provinces across Thailand. Combining pkdhfr sequencing data from previous work with pkdhps data to analyze polymorphisms of pkdhfr and pkdhps haplotype. Protein modeling and molecular docking were constructed using two inhibitors, sulfadoxine and sulfamethoxazole, and further details were obtained through analyses of protein-ligand interactions by using the Genetic Optimisation for Ligand Docking program. A phylogenetic tree cluster analysis was reconstructed to compare the P. knowlesi Malaysia isolates. RESULTS Five nonsynonymous mutations in the pkdhps were detected outside the equivalence of the binding pocket sites to sulfadoxine and sulfamethoxazole, which are at N391S, E421G, I425R, A449S, and N517S. Based on the modeling and molecular docking analyses, the N391S and N517S mutations located close to the enzyme-binding pocket demonstrated a different docking score and protein-ligand interaction in loop 2 of the enzyme. These findings indicated that it was less likely to induce drug resistance. Of the four haplotypes of pkdhfr-pkdhps, the most common one is the R34L pkdhfr mutation and the pkdhps quadruple mutation (GRSS) at E421G, I425R, A449S, and N517S, which were observed in P. knowlesi in southern Thailand (53.57%). Based on the results of neighbor-joining analysis for pkdhfr and pkdhps, the samples isolated from eastern Thailand displayed a close relationship with Cambodia isolates, while southern Thailand isolates showed a long branch separated from the Malaysian isolates. CONCLUSIONS A new PCR protocol amplification and evaluation of dihydropteroate synthase mutations in Knowlesi (pkdhps) has been developed. The most prevalent pkdhfr-pkdhps haplotypes (53.57%) in southern Thailand are R34L pkdhfr mutation and pkdhps quadruple mutation. Further investigation requires additional phenotypic data from clinical isolates, transgenic lines expressing mutant alleles, or recombinant proteins.
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Affiliation(s)
- Raweewan Sangsri
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Kiattawee Choowongkomon
- Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok 10903, Thailand
| | - Runch Tuntipaiboontana
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Rungniran Sugaram
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi 11000, Thailand
| | - Patcharida Boondej
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi 11000, Thailand
| | - Prayuth Sudathip
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi 11000, Thailand
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
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9
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Narapakdeesakul D, Pengsakul T, Kaewparuehaschai M, Thongsahuan S, Moonmake S, Lekcharoen P, Thanee S, Pattaradilokrat S, Kaewthamasorn M. Zoonotic simian malaria parasites in free-ranging Macaca fascicularis macaques and human malaria patients in Thailand, with a note on genetic characterization of recent isolates. Acta Trop 2023; 248:107030. [PMID: 37742788 DOI: 10.1016/j.actatropica.2023.107030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 09/26/2023]
Abstract
Despite the natural occurrences of human infections by Plasmodium knowlesi, P. cynomolgi, P. inui, and P. fieldi in Thailand, investigating the prevalence and genetic diversity of the zoonotic simian malaria parasites in macaque populations has been limited to certain areas. To address this gap, a total of 560 long-tailed macaques (Macaca fascicularis) and 20 southern pig-tailed macaques (M. nemestrina) were captured from 15 locations across 10 provinces throughout Thailand between 2018 and 2021 for investigation of malaria, as were 15 human samples residing in two simian-malaria endemic provinces, namely Songkhla and Satun, who exhibited malaria-like symptoms. Using PCR techniques targeting the mitochondrial cytb and cox1 genes coupled with DNA sequencing, 40 long-tailed macaques inhabiting five locations had mono-infections with one of the three simian malaria species. Most of the positive cases of macaque were infected with P. inui (32/40), while infections with P. cynomolgi (6/40) and P. knowlesi (2/40) were less common and confined to specific macaque populations. Interestingly, all 15 human cases were mono-infected with P. knowlesi, with one of them residing in an area with two P. knowlesi-infected macaques. Nucleotide sequence analysis showed a high level of genetic diversity in P. inui, while P. cynomolgi and P. knowlesi displayed limited genetic diversity. Phylogenetic and haplotype network analyses revealed that P. inui in this study was closely related to simian and Anopheles isolates from Peninsular Malaysia, while P. cynomolgi clustered with simian and human isolates from Asian countries. P. knowlesi, which was found in both macaques and humans in this study, was closely related to isolates from macaques, humans, and An. hackeri in Peninsular Malaysia, suggesting a sylvatic transmission cycle extending across these endemic regions. This study highlights the current hotspots for zoonotic simian malaria and sheds light on the genetic characteristics of recent isolates in both macaques and human residents in Thailand.
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Affiliation(s)
- Duriyang Narapakdeesakul
- Veterinary Pathobiology Graduate Program, Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand; Veterinary Parasitology Research Unit, Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Theerakamol Pengsakul
- Health and Environmental Research Center, Faculty of Environmental Management, Prince of Songkla University, Songkhla 90110, Thailand
| | - Mutchamon Kaewparuehaschai
- Department of National Parks, Wildlife and Plant Conservation, Ministry of Natural Resources and Environment, Bangkok 10900, Thailand
| | - Salintorn Thongsahuan
- Department of National Parks, Wildlife and Plant Conservation, Ministry of Natural Resources and Environment, Bangkok 10900, Thailand
| | - Sopavadee Moonmake
- The Office of Disease Prevention and Control Region 12 Songkhla, Department of Disease Control, Ministry of Public Health, Songkhla 90000, Thailand
| | - Paisin Lekcharoen
- Veterinary Public Health Graduate Program, Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Suchansa Thanee
- Veterinary Parasitology Research Unit, Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | | | - Morakot Kaewthamasorn
- Veterinary Parasitology Research Unit, Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand.
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D'Agostino I, Zara S, Carradori S, De Luca V, Capasso C, Kocken CHM, Zeeman AM, Angeli A, Carta F, Supuran CT. Antimalarial Agents Targeting Plasmodium falciparum Carbonic Anhydrase: Towards Artesunate Hybrid Compounds with Dual Mechanism of Action. ChemMedChem 2023; 18:e202300267. [PMID: 37697903 DOI: 10.1002/cmdc.202300267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 09/13/2023]
Abstract
Malaria continues to be a major public health challenge worldwide and, as part of the global effort toward malaria eradication, plasmodium carbonic anhydrases (CAs) have recently been proposed as potential targets for malaria treatment. In this study, a series of eight hybrid compounds combining the Artesunate core with a sulfonamide moiety were synthesized and evaluated for their inhibition potency against the widely expressed human (h) CAs I, II and the isoform from P. falciparum (PfCA). All derivatives demonstrated high inhibition potency against PfCA, achieving a KI value in the sub-nanomolar range (0.35 nM). Two Compounds showed a selectivity index of 4.1 and 3.1, respectively, against this protozoan isoform compared to hCA II. Three Derivatives showed no cytotoxic effects on human gingival fibroblasts at 50 μM with a high killing rate against both P. falciparum and P. knowlesi strains with IC50 in the sub-nanomolar range, providing a wide therapeutic window. Our findings suggest that these compounds may serve as promising leads for developing new antimalarial drugs and warrant further investigation, including activity against antimalarial-resistant strains, mode of action studies, and in vivo efficacy assessment in preclinical mouse models of malaria.
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Affiliation(s)
- Ilaria D'Agostino
- Department of Pharmacy "G. d'Annunzio", University of Chieti-Pescara, 66100, Chieti, Italy
| | - Susi Zara
- Department of Pharmacy "G. d'Annunzio", University of Chieti-Pescara, 66100, Chieti, Italy
| | - Simone Carradori
- Department of Pharmacy "G. d'Annunzio", University of Chieti-Pescara, 66100, Chieti, Italy
| | - Viviana De Luca
- Istituto di Bioscienze e Biorisorse CNR, 80131, Napoli, Italy
| | | | - Clemens H M Kocken
- Department of Parasitology, Biomedical Primate Research Center, 2288, Rijswijk, The Netherlands
| | - Anne-Marie Zeeman
- Department of Parasitology, Biomedical Primate Research Center, 2288, Rijswijk, The Netherlands
| | - Andrea Angeli
- Neurofarba Department, University of Florence, 50019, Sesto Fiorentino FL, Italy
| | - Fabrizio Carta
- Neurofarba Department, University of Florence, 50019, Sesto Fiorentino FL, Italy
| | - Claudiu T Supuran
- Neurofarba Department, University of Florence, 50019, Sesto Fiorentino FL, Italy
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11
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Jajosky RP, Wu SC, Jajosky PG, Stowell SR. Plasmodium knowlesi ( Pk) Malaria: A Review & Proposal of Therapeutically Rational Exchange (T-REX) of Pk-Resistant Red Blood Cells. Trop Med Infect Dis 2023; 8:478. [PMID: 37888606 PMCID: PMC10610852 DOI: 10.3390/tropicalmed8100478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/09/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023] Open
Abstract
Plasmodium knowlesi (Pk) causes zoonotic malaria and is known as the "fifth human malaria parasite". Pk malaria is an emerging threat because infections are increasing and can be fatal. While most infections are in Southeast Asia (SEA), especially Malaysia, travelers frequently visit this region and can present with Pk malaria around the world. So, clinicians need to know (1) patients who present with fever after recent travel to SEA might be infected with Pk and (2) Pk is often misdiagnosed as P. malariae (which typically causes less severe malaria). Here we review the history, pathophysiology, clinical features, diagnosis, and treatment of Pk malaria. Severe disease is most common in adults. Signs and symptoms can include fever, abdominal pain, jaundice, acute kidney injury, acute respiratory distress syndrome, hyponatremia, hyperparasitemia, and thrombocytopenia. Dengue is one of the diseases to be considered in the differential. Regarding pathophysiologic mechanisms, when Pk parasites invade mature red blood cells (RBCs, i.e., normocytes) and reticulocytes, changes in the red blood cell (RBC) surface can result in life-threatening cytoadherence, sequestration, and reduced RBC deformability. Since molecular mechanisms involving the erythrocytic stage are responsible for onset of severe disease and lethal outcomes, it is biologically plausible that manual exchange transfusion (ET) or automated RBC exchange (RBCX) could be highly beneficial by replacing "sticky" parasitized RBCs with uninfected, deformable, healthy donor RBCs. Here we suggest use of special Pk-resistant donor RBCs to optimize adjunctive manual ET/RBCX for malaria. "Therapeutically-rational exchange transfusion" (T-REX) is proposed in which Pk-resistant RBCs are transfused (instead of disease-promoting RBCs). Because expression of the Duffy antigen on the surface of human RBCs is essential for parasite invasion, T-REX of Duffy-negative RBCs-also known as Fy(a-b-) RBCs-could replace the majority of the patient's circulating normocytes with Pk invasion-resistant RBCs (in a single procedure lasting about 2 h). When sequestered or non-sequestered iRBCs rupture-in a 24 h Pk asexual life cycle-the released merozoites cannot invade Fy(a-b-) RBCs. When Fy(a-b-) RBC units are scarce (e.g., in Malaysia), clinicians can consider the risks and benefits of transfusing plausibly Pk-resistant RBCs, such as glucose-6-phosphate dehydrogenase deficient (G6PDd) RBCs and Southeast Asian ovalocytes (SAO). Patients typically require a very short recovery time (<1 h) after the procedure. Fy(a-b-) RBCs should have a normal lifespan, while SAO and G6PDd RBCs may have mildly reduced half-lives. Because SAO and G6PDd RBCs come from screened blood donors who are healthy and not anemic, these RBCs have a low-risk for hemolysis and do not need to be removed after the patient recovers from malaria. T-REX could be especially useful if (1) antimalarial medications are not readily available, (2) patients are likely to progress to severe disease, or (3) drug-resistant strains emerge. In conclusion, T-REX is a proposed optimization of manual ET/RBCX that has not yet been utilized but can be considered by physicians to treat Pk malaria patients.
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Affiliation(s)
- Ryan Philip Jajosky
- Joint Program in Transfusion Medicine, Brigham and Women’s Hospital, Harvard Medical School, 630E New Research Building, 77 Avenue Louis Pasteur, Boston, MA 02115, USA; (S.-C.W.)
- Biconcavity Inc., Lilburn, GA 30047, USA
| | - Shang-Chuen Wu
- Joint Program in Transfusion Medicine, Brigham and Women’s Hospital, Harvard Medical School, 630E New Research Building, 77 Avenue Louis Pasteur, Boston, MA 02115, USA; (S.-C.W.)
| | | | - Sean R. Stowell
- Joint Program in Transfusion Medicine, Brigham and Women’s Hospital, Harvard Medical School, 630E New Research Building, 77 Avenue Louis Pasteur, Boston, MA 02115, USA; (S.-C.W.)
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12
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Lo CKF, Plewes K, Sharma S, Low A, Su LD, Belga S, Salazar FV, Hajek J, Morshed M, Hogan CA. Plasmodium knowlesi Infection in Traveler Returning to Canada from the Philippines, 2023. Emerg Infect Dis 2023; 29:2177-2179. [PMID: 37735805 PMCID: PMC10521619 DOI: 10.3201/eid2910.230809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023] Open
Abstract
A 55-year-old man sought treatment for an uncomplicated febrile illness after returning to Canada from the Philippines. A suspected diagnosis of Plasmodium knowlesi infection was confirmed by PCR, and treatment with atovaquone/proguanil brought successful recovery. We review the evolving epidemiology of P. knowlesi malaria in the Philippines, specifically within Palawan Island.
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13
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Chang CY. Clinical characteristics and outcome of severe malaria in Kapit, Sarawak, Malaysian Borneo. J Vector Borne Dis 2023; 60:432-434. [PMID: 38174522 DOI: 10.4103/0972-9062.374238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024] Open
Abstract
Background & objectives Severe malaria is a medical emergency and can lead to severe complications and death if not treated promptly and appropriately. Along with Plasmodium falciparum, P. knowlesi is increasingly recognised as a significant cause of fatal and severe malaria. Methods We performed a retrospective review on 54 cases of severe malaria in a district hospital in Kapit, Sarawak, from January 2018 to May 2019. The patients' demographics, clinical features, complications based on organ involvement, and treatment outcomes were examined. Results There were 54 cases of severe malaria, with the majority being male (70%) and between the ages of 40 and 49 (26%). All patients with severe malaria were febrile or had a history of pyrexia except for one patient. P. knowlesi (81.5%) was the most common species causing severe malaria in our study, followed by P. falciparum (13%), and P. vivax (5.5%). There were no cases of severe malaria caused by P. ovale or P. malariae. Hyperparasitaemia was present in 76% of patients and the median parasitemia value at hospital admission was 33,944 parasites/μL (interquartile range: 19,920-113,285 parasites/μL). Circulatory shock was observed in 17 patients (31.5%). There were eight patients with acute renal failure and six patients with respiratory distress. One patient died as a result of severe malaria with multiorgan involvement (1.9% fatality rate). Interpretation & conclusion P. knowlesi is the most common cause of severe malaria in Kapit, Sarawak, Malaysia. Recognizing symptoms of severe malaria and prompt administration of antimalarial are critical for good clinical outcomes.
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Affiliation(s)
- Chee Yik Chang
- Medical Department, Hospital Kapit, Jalan Mamora, Kapit, Sarawak, Malaysia
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14
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Tan JH, Ding HX, Fong MY, Lau YL. Genetic diversity and in silico analysis of Plasmodium knowlesi Serine Repeat Antigen (SERA) 3 antigen 2 in Malaysia. Infect Genet Evol 2023; 114:105490. [PMID: 37595939 DOI: 10.1016/j.meegid.2023.105490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/29/2023] [Accepted: 08/15/2023] [Indexed: 08/20/2023]
Abstract
Plasmodium knowlesi is the leading cause of malaria in Malaysia. Serine Repeat Antigens (SERAs) have an essential role in the parasite life cycle. However, genetic characterization on P. knowlesi SERA3 Ag2 (PkSERA3 Ag2) is lacking. In the present study, nucleotide diversity, natural selection, and haplotypes of PkSERA3 Ag2 in clinical samples from Peninsular Malaysia and Malaysian Borneo were investigated. A total of 50 P. knowlesi clinical samples were collected from Peninsular Malaysia and Malaysian Borneo. The PkSERA3 Ag2 gene was amplified using PCR, and subsequently cloned and sequenced. Genetic diversity, haplotype, natural selection as well as genetic structure and differentiation of PkSERA3 Ag2 were analysed. In addition, in silico analyses were performed to identify repeat motifs, B-cell epitopes, and antigenicity indices of the protein. Analysis of 114 PkSERA3 Ag2 sequences revealed high nucleotide diversity of the gene in Malaysia. A codon-based Z-test indicated that the gene underwent purifying selection. Haplotype and population structure analyses identified two distinct PkSERA3 Ag2 clusters (K = 2, ΔK = 721.14) but no clear genetic distinction between PkSERA3 Ag2 from Peninsular Malaysia and Malaysian Borneo. FST index indicated moderate differentiation of the gene. In silico analyses revealed unique repeat motifs among PkSERA3 Ag2 isolates. Moreover, the amino acid sequence of PkSERA3 Ag2 exhibited potential B-cell epitopes and possessed high antigenicity indices. These findings enhance the understanding of PkSERA3 Ag2 gene as well as its antigenic properties. Further validation is necessary to ascertain the utility of PkSERA3 Ag2 as a serological marker for P. knowlesi infection.
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Affiliation(s)
- Jia Hui Tan
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Hans Xing Ding
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia.
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15
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Ahmed MA, Baruah P, Saif A, Han JH, Al-Zharani M, Wazid SW, Alkahtani S, Patgiri SJ, Al-Eissa MS, Quan FS. In Silico Analysis Reveals High Levels of Genetic Diversity of Plasmodium knowlesi Cell Traversal Protein for Ookinetes and Sporozoites ( PkCelTOS) in Clinical Samples. Trop Med Infect Dis 2023; 8:380. [PMID: 37624318 PMCID: PMC10458480 DOI: 10.3390/tropicalmed8080380] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 05/06/2023] [Revised: 07/05/2023] [Accepted: 07/20/2023] [Indexed: 08/26/2023] Open
Abstract
The cell-traversal protein for ookinetes and sporozoites (CelTOS), expressed on the surface of ookinetes and sporozoitesin Plasmodium species, is a promising malaria vaccine candidate. CelTOS is essential for parasite invasion into mosquito midgut and human hepatocytes, thereby contributing to malaria transmission and disease pathogenesis. This study explores the genetic diversity, polymorphisms, haplotypes, natural selection, phylogenetic analysis, and epitope prediction in the full-length Plasmodium knowlesi CelTOS gene in clinical samples from Sarawak, Malaysian Borneo, and long-term laboratory strains from Peninsular Malaysia and the Philippines. Our analysis revealed a high level of genetic variation in the PkCelTOS gene, with a nucleotide diversity of π ~ 0.021, which was skewed towards the 3' end of the gene. This level of diversity is double that observed in PfCelTOS and 20 times that observed in PvCelTOS from worldwide clinical samples. Tests of natural selection revealed evidence for positive selection within clinical samples. Phylogenetic analysis of the amino acid sequence of PkCelTOS revealed the presence of two distinct groups, although no geographical clustering was observed. Epitope prediction analysis identified two potential epitopes (96AQLKATA102 and 124TIKPPRIKED133) using the IEDB server and one epitope (125IKPPRIKED133) by Bcepred server on the C' terminal region of PkCelTOS protein. Both the servers predicted a common epitope region of nine amino acid length (IKPPRIKED) peptide, which can be studied in the future as a potential candidate for vaccine development. These findings shed light on the genetic diversity, polymorphism, haplotypes, and natural selection within PkCelTOS in clinical samples and provide insights about its future prospects as a potential candidate for P. knowlesi malaria vaccine development.
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Affiliation(s)
- Md Atique Ahmed
- ICMR-Regional Medical Research Centre, NE Region, Dibrugarh 786010, Assam, India (S.J.P.)
| | - Pratisthita Baruah
- ICMR-Regional Medical Research Centre, NE Region, Dibrugarh 786010, Assam, India (S.J.P.)
| | - Ahmed Saif
- Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, King Khalid University, Abha 61321, Saudi Arabia
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Mohammed Al-Zharani
- Biology Department, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSU), Riyadh 11623, Saudi Arabia (M.S.A.-E.)
| | - Syeda Wasfeea Wazid
- Arogyo Society of Health, Welfare and Support (ASHWAS), Guwahati 785640, Assam, India;
| | - Saad Alkahtani
- Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Saurav J. Patgiri
- ICMR-Regional Medical Research Centre, NE Region, Dibrugarh 786010, Assam, India (S.J.P.)
| | - Mohammed S. Al-Eissa
- Biology Department, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSU), Riyadh 11623, Saudi Arabia (M.S.A.-E.)
| | - Fu-Shi Quan
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, Core Research Institute (CRI), Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Medical Zoology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
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16
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Naserrudin NA, Lin PYP, Monroe A, Culleton R, Baumann SE, Sato S, Adhikari B, Fornace KM, Hod R, Jeffree MS, Ahmed K, Hassan MR. Exploring barriers to and facilitators of malaria prevention practices: a photovoice study with rural communities at risk to Plasmodium knowlesi malaria in Sabah, Malaysia. BMC Public Health 2023; 23:1316. [PMID: 37430300 DOI: 10.1186/s12889-023-16173-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 02/25/2023] [Accepted: 06/22/2023] [Indexed: 07/12/2023] Open
Abstract
BACKGROUND The control of Plasmodium knowlesi malaria remains challenging due to the presence of macaque monkeys and predominantly outdoor-biting Anopheles mosquitoes around human settlements. This study aims to explore the barriers and facilitators related to prevention of mosquito bites among rural communities living in Sabah, Malaysia using the participatory visual method, photovoice. METHODS From January through June 2022, 26 participants were recruited from four villages in Kudat, Sabah, using purposive sampling. Participants were male and female villagers, aged > 18 years old. After photovoice training in the villages, participants documented facilitators of and barriers related to avoiding mosquito bites using their own smartphone cameras, and provided narratives for their photos. Twelve Focus Group Discussions (FGDs) sessions in three rounds were held to share and discuss the photos, and to address challenges to the avoidance of mosquito bites. All discussions were conducted in the Sabah Malay dialect, and were video and audio recorded, transcribed, and analyzed using reflexive thematic analysis. The Ideation Model, a meta-theoretical model of behaviour change, underpinned this study. RESULTS The most common types of barriers identified by participants included (I) intrapersonal factors such as low perceived threat of malaria, (II) livelihood and lifestyle activities consisting of the local economy and socio-cultural activities, and (III) physical and social environment. The facilitators were categorized into (I) intrapersonal reasons, including having the opportunity to stay indoors, especially women who are housewives, (II) social support by the households, neaighbours and healthcare workers, and (III) support from healthcare services and malaria awareness program. Participants emphasized the importance of stakeholder's support in implementing feasible and affordable approaches to P. knowlesi malaria control. CONCLUSION Results provided insights regarding the challenges to preventing P. knowlesi malaria in rural Kudat, Sabah. The participation of communities in research was valuable in expanding knowledge of local challenges and highlighting possible ways to overcome barriers. These findings may be used to improve strategies for zoonotic malaria control, which is critical for advancing social change and minimizing health disparities in malaria prevention.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia
- Sabah State Health Department, Ministry of Health, 88590, Kota Kinabalu, Malaysia
| | - Pauline Yong Pau Lin
- Faculty of Social Sciences and Humanities, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - April Monroe
- Johns Hopkins Center for Communication Programs, Baltimore, MD, USA
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, 791-0295, Japan
| | - Sara Elizabeth Baumann
- Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Shigeharu Sato
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Bipin Adhikari
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kimberly M Fornace
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Rozita Hod
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia.
| | - Mohammad Saffree Jeffree
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Kamruddin Ahmed
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Mohd Rohaizat Hassan
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia.
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia.
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Mewara A, Sreenivasan P, Khurana S. Primate malaria of human importance. Trop Parasitol 2023; 13:73-83. [PMID: 37860614 PMCID: PMC10583777 DOI: 10.4103/tp.tp_79_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 06/10/2023] [Indexed: 10/21/2023] Open
Abstract
Nonhuman primate (NHP) malaria poses a major threat to the malaria control programs. The last two decades have witnessed a paradigm shift in our understanding of the malaria caused by species other than the traditionally known human Plasmodium species - Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale. The emergence of the malaria parasite of long-tailed macaque monkeys, Plasmodium knowlesi, as the fifth malaria species of humans has made the scientific community consider the risk of other zoonotic malaria, such as Plasmodium cynomolgi, Plasmodium simium, Plasmodium inui, and others, to humans. The development of knowledge about P. knowlesi as a pathogen which was earlier only known to experimentally cause malaria in humans and rarely cause natural infection, toward its acknowledgment as a significant cause of human malaria and a threat of malaria control programs has been made possible by the use of advanced molecular techniques such as polymerase chain reaction and gene sequencing. This review explores the various aspects of NHP malaria, and the association of various factors with their emergence and potential to cause human malaria which are important to understand to be able to control these emerging infections.
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Affiliation(s)
- Abhishek Mewara
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Priya Sreenivasan
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sumeeta Khurana
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Pramasivan S, Low VL, Jeyaprakasam NK, Liew JWK, Ngui R, Vythilingam I. Cryptic Diversity and Demographic Expansion of Plasmodium knowlesi Malaria Vectors in Malaysia. Genes (Basel) 2023; 14:1369. [PMID: 37510274 PMCID: PMC10378955 DOI: 10.3390/genes14071369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023] Open
Abstract
Although Malaysia is considered free of human malaria, there has been a growing number of Plasmodium knowlesi cases. This alarming trend highlighted the need for our understanding of this parasite and its associated vectors, especially considering the role of genetic diversity in the adaptation and evolution among vectors in endemic areas, which is currently a significant knowledge gap in their fundamental biology. Thus, this study aimed to investigate the genetic diversity of Anopheles balabacensis, Anopheles cracens, Anopheles introlatus, and Anopheles latens-the vectors for P. knowlesi malaria in Malaysia. Based on cytochrome c oxidase 1 (CO1) and internal transcribed spacer 2 (ITS2) markers, the genealogic networks of An. latens showed a separation of the haplotypes between Peninsular Malaysia and Malaysia Borneo, forming two distinct clusters. Additionally, the genetic distances between these clusters were high (2.3-5.2% for CO1) and (2.3-4.7% for ITS2), indicating the likely presence of two distinct species or cryptic species within An. latens. In contrast, no distinct clusters were observed in An. cracens, An. balabacensis, or An. introlatus, implying a lack of pronounced genetic differentiation among their populations. It is worth noting that there were varying levels of polymorphism observed across the different subpopulations, highlighting some levels of genetic variation within these mosquito species. Nevertheless, further analyses revealed that all four species have undergone demographic expansion, suggesting population growth and potential range expansion for these vectors in this region.
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Affiliation(s)
- Sandthya Pramasivan
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Van Lun Low
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Nantha Kumar Jeyaprakasam
- Biomedical Science Program, Center for Toxicology and Health Risk Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Jonathan Wee Kent Liew
- Environmental Health Institute, National Environment Agency, Singapore 569874, Singapore
| | - Romano Ngui
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Malaria Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak (UNIMAS), Kota Samarahan 94300, Sarawak, Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
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19
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Naserrudin NA, Yong PPL, Monroe A, Culleton R, Baumann SE, Sato S, Hod R, Jeffree MS, Ahmed K, Hassan MR. Seeing malaria through the eyes of affected communities: using photovoice to document local knowledge on zoonotic malaria causation and prevention practices among rural communities exposed to Plasmodium knowlesi malaria in Northern Borneo Island. Malar J 2023; 22:166. [PMID: 37237418 DOI: 10.1186/s12936-023-04603-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 05/22/2023] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND Many rural communities in Malaysian Borneo and Southeast Asia are at risk of Plasmodium knowlesi malaria. Multiple factors contribute to infection, however, a deep understanding of illness causation and prevention practices among at-risk communities remains limited. This study aims to document local knowledge on malaria causation and preventive practices of rural communities in Sabah, Malaysia, using photovoice-a participatory research method. METHODS From January to June 2022, a photovoice study was conducted with rural communities in Matunggong subdistrict, Malaysia, to explore their experiences with and local knowledge of non-human primate malaria and prevention practices. The study included (1) an introductory phase in which participants were introduced to the photovoice method; (2) a documentation phase in which participants captured and narrated photos from their communities; (3) a discussion phase in which participants discussed photos and relevant topics through a series of three focus group discussions (FGDs) per village; and (4) a dissemination phase where selected photos were shared with key stakeholders through a photo exhibition. A purposively selected sample of 26 participants (adults > 18 years old, male, and female) from four villages participated in all phases of the study. The study activities were conducted in Sabah Malay dialect. Participants and the research team contributed to data review and analyses. RESULTS Rural communities in Sabah, Malaysia possess local knowledge that attributes non-human primate malaria to natural factors related to the presence of mosquitoes that bite humans and which carry "kuman-malaria" or malaria parasite. Participants revealed various preventive practises ranging from traditional practises, including burning dried leaves and using plants that produce foul odours, to non-traditional approaches such as aerosols and mosquito repellents. By engaging with researchers and policymakers, the participants or termed as co-researchers in this study, showcased their ability to learn and appreciate new knowledge and perspectives and valued the opportunity to share their voices with policymakers. The study successfully fostered a balance of power dynamics between the co-researchers, research team members and policymakers. CONCLUSION There were no misconceptions about malaria causation among study participants. The insights from study participants are relevant because of their living experience with the non-human malaria. It is critical to incorporate rural community perspectives in designing locally effective and feasible malaria interventions in rural Sabah, Malaysia. Future research can consider adapting the photovoice methodology for further research with the community toward building locally tailored-malaria strategies.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, 88400, Kota Kinabalu, Malaysia
- Sabah State Health Department, Ministry of Health, 88590, Kota Kinabalu, Malaysia
| | - Pauline Pau Lin Yong
- Faculty of Social Sciences and Humanities, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - April Monroe
- Johns Hopkins Center for Communication Programs, Baltimore, MD, USA
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, 791-0295, Japan
| | - Sara Elizabeth Baumann
- Department of Behavioral and Community Health Sciences, University of Pittsburgh School of Public Health, Pittsburgh, PA, 15261, USA
| | - Shigeharu Sato
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, 88400, Kota Kinabalu, Malaysia
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Rozita Hod
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia
| | - Mohammad Saffree Jeffree
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, 88400, Kota Kinabalu, Malaysia
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Kamruddin Ahmed
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, 88400, Kota Kinabalu, Malaysia
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Mohd Rohaizat Hassan
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia.
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, 88400, Kota Kinabalu, Malaysia.
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20
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Noordin NR, Lau YL, Cheong FW, Fong MY. Inter-Population Genetic Diversity and Clustering of Merozoite Surface Protein-1 (pkmsp-1) of Plasmodium knowlesi Isolates from Malaysia and Thailand. Trop Med Infect Dis 2023; 8:tropicalmed8050285. [PMID: 37235333 DOI: 10.3390/tropicalmed8050285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/12/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
The genetic diversity of pkmsp-1 of Malaysian Plasmodium knowlesi isolates was studied recently. However, the study only included three relatively older strains from Peninsular Malaysia and focused mainly on the conserved blocks of this gene. In this study, the full-length pkmsp-1 sequence of recent P. knowlesi isolates from Peninsular Malaysia was characterized, along with Malaysian Borneo and Thailand pkmsp-1 sequences that were retrieved from GenBank. Genomic DNA of P. knowlesi was extracted from human blood specimens and the pkmsp-1 gene was PCR-amplified, cloned, and sequenced. The sequences were analysed for genetic diversity, departure from neutrality, and geographical clustering. The pkmsp-1 gene was found to be under purifying/negative selection and grouped into three clusters via a neighbour-joining tree and neighbour net inferences. Of the four polymorphic blocks in pkmsp-1, block IV, was most polymorphic, with the highest insertion-deletion (indel) sites. Two allelic families were identified in block IV, thereby highlighting the importance of this block as a promising genotyping marker for the multiplicity of infection study of P. knowlesi malaria. A single locus marker may provide an alternate, simpler method to type P. knowlesi in a population.
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Affiliation(s)
- Naqib Rafieqin Noordin
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Fei Wen Cheong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
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21
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Aftab H, Kemp M, Stensvold CR, Nielsen HV, Jakobsen MM, Porskrog A, Dessau RB. First molecular documented case of a rarely reported parasite: Plasmodium knowlesi infection in Denmark in a traveller returning from Malaysian Borneo. Travel Med Infect Dis 2023; 53:102580. [PMID: 37088361 DOI: 10.1016/j.tmaid.2023.102580] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 02/21/2023] [Revised: 04/03/2023] [Accepted: 04/19/2023] [Indexed: 04/25/2023]
Abstract
Plasmodium knowlesi has been reported as an emerging infection throughout the Southeast Asian region, especially in the Malaysian state of Sabah, where it accounts for the majority of the malaria cases reported. This is in contrast to Europe, where imported P. knowlesi is a rarely reported infection. We present a case of P. knowlesi infection in a Danish woman returning from a short trip to Malaysian Borneo. Microscopy of blood smears revealed 0.8% infected erythrocytes, but due to the atypical morphological presentation, a conclusive species identification was made by molecular methods. Plasmodium knowlesi is a potentially fatal infection and taking the increasing travel activity into consideration after the coronavirus disease 2019 (COVID-19) pandemic, P. knowlesi should be a differential diagnosis in patients with travel-associated illness returning from highly endemic Southeast Asian areas.
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Affiliation(s)
- Huma Aftab
- The Regional Department of Clinical Microbiology, Zealand University Hospital, Koege, Denmark.
| | - Michael Kemp
- The Regional Department of Clinical Microbiology, Zealand University Hospital, Koege, Denmark
| | - Christen R Stensvold
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institute, Copenhagen, Denmark
| | - Henrik V Nielsen
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institute, Copenhagen, Denmark
| | | | - Anders Porskrog
- Department of Infectious Diseases, Zealand University Hospital, Roskilde, Denmark
| | - Ram B Dessau
- The Regional Department of Clinical Microbiology, Zealand University Hospital, Koege, Denmark
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22
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T. Thurai Rathnam J, Grigg MJ, Dini S, William T, Sakam SS, Cooper DJ, Rajahram GS, Barber BE, Anstey NM, Haghiri A, Rajasekhar M, Simpson JA. Quantification of parasite clearance in Plasmodium knowlesi infections. Malar J 2023; 22:54. [PMID: 36782162 PMCID: PMC9926767 DOI: 10.1186/s12936-023-04483-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 02/04/2023] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND The incidence of zoonotic Plasmodium knowlesi infections in humans is rising in Southeast Asia, leading to clinical studies to monitor the efficacy of anti-malarial treatments for knowlesi malaria. One of the key outcomes of anti-malarial drug efficacy is parasite clearance. For Plasmodium falciparum, parasite clearance is typically estimated using a two-stage method, that involves estimating parasite clearance for individual patients followed by pooling of individual estimates to derive population estimates. An alternative approach is Bayesian hierarchical modelling which simultaneously analyses all parasite-time patient profiles to determine parasite clearance. This study compared these methods for estimating parasite clearance in P. knowlesi treatment efficacy studies, with typically fewer parasite measurements per patient due to high susceptibility to anti-malarials. METHODS Using parasite clearance data from 714 patients with knowlesi malaria and enrolled in three trials, the Worldwide Antimalarial Resistance Network (WWARN) Parasite Clearance Estimator (PCE) standard two-stage approach and Bayesian hierarchical modelling were compared. Both methods estimate the parasite clearance rate from a model that incorporates a lag phase, slope, and tail phase for the parasitaemia profiles. RESULTS The standard two-stage approach successfully estimated the parasite clearance rate for 678 patients, with 36 (5%) patients excluded due to an insufficient number of available parasitaemia measurements. The Bayesian hierarchical estimation method was applied to the parasitaemia data of all 714 patients. Overall, the Bayesian method estimated a faster population mean parasite clearance (0.36/h, 95% credible interval [0.18, 0.65]) compared to the standard two-stage method (0.26/h, 95% confidence interval [0.11, 0.46]), with better model fits (compared visually). Artemisinin-based combination therapy (ACT) is more effective in treating P. knowlesi than chloroquine, as confirmed by both methods, with a mean estimated parasite clearance half-life of 2.5 and 3.6 h, respectively using the standard two-stage method, and 1.8 and 2.9 h using the Bayesian method. CONCLUSION For clinical studies of P. knowlesi with frequent parasite measurements, the standard two-stage approach (WWARN's PCE) is recommended as this method is straightforward to implement. For studies with fewer parasite measurements per patient, the Bayesian approach should be considered. Regardless of method used, ACT is more efficacious than chloroquine, confirming the findings of the original trials.
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Affiliation(s)
- Jeyamalar T. Thurai Rathnam
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Matthew J. Grigg
- grid.1043.60000 0001 2157 559XMenzies School of Health Research and Charles Darwin University, Darwin, NT Australia ,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Saber Dini
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Sitti Saimah Sakam
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Daniel J. Cooper
- grid.1043.60000 0001 2157 559XMenzies School of Health Research and Charles Darwin University, Darwin, NT Australia ,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia ,grid.5335.00000000121885934Department of Medicine, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Giri S. Rajahram
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia ,grid.415759.b0000 0001 0690 5255Clinical Research Centre, Queen Elizabeth II Hospital, Ministry of Health, Kota Kinabalu, Sabah, Malaysia
| | - Bridget E. Barber
- grid.1043.60000 0001 2157 559XMenzies School of Health Research and Charles Darwin University, Darwin, NT Australia ,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia ,grid.1049.c0000 0001 2294 1395QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Nicholas M. Anstey
- grid.1043.60000 0001 2157 559XMenzies School of Health Research and Charles Darwin University, Darwin, NT Australia ,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Ali Haghiri
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Megha Rajasekhar
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Julie A. Simpson
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
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23
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Das R, Vashisht K, Pandey KC. A novel multiplex qPCR assay for clinical diagnosis of non-human malaria parasites- Plasmodium knowlesi and Plasmodium cynomolgi. Front Vet Sci 2023; 10:1127273. [PMID: 36777671 PMCID: PMC9909747 DOI: 10.3389/fvets.2023.1127273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 01/06/2023] [Indexed: 01/28/2023] Open
Abstract
Introduction The imminent risk of zoonoses of non-human malaria parasites is not far from reality in India, as has been observed in the case of Plasmodium knowlesi (Pk), and so is possible with P. cynomolgi (Pc), already reported from South East Asian countries. Therefore, a novel multiplex qPCR assay was developed and evaluated for detection of non-human malaria parasites- Pk and Pc in populations at risk. Methods The qPCR primers were designed in-house with fluorescence labeled probes (HEX for Pk and FAM for Pc). DNA samples of Pk and Pc were used as templates and further the qPCR assay was evaluated in 250 symptomatic and asymptomatic suspected human blood samples from malaria endemic areas of North Eastern states of India. Results The qPCR assay successfully amplified the target 18S rRNA gene segment from Pk and Pc and was highly specific for Pk and Pc parasites only, as no cross reactivity was observed with P. falciparum (Pf), P. vivax (Pv), P. malariae (Pm), and P. ovale (Po). Standard curves were generated to estimate the limit of detection (LOD) of Pk and Pc parasites DNA (0.00275 & 0.075 ng/μl, respectively). Due to COVID-19 pandemic situation during 2020-21, the sample accessibility was difficult, however, we managed to collect 250 samples. The samples were tested for Pf and Pv using conventional PCR- 14 Pf and 11 Pv infections were observed, but no Pk and Pc infections were detected. For Pk infections, previously reported conventional PCR was also performed, but no Pk infection was detected. Discussion The multiplex qPCR assay was observed to be robust, quick, cost-effective and highly sensitive as compared to the currently available conventional PCR methods. Further validation of the multiplex qPCR assay in field setting is desirable, especially from the high-risk populations. We anticipate that the multiplex qPCR assay would prove to be a useful tool in mass screening and surveillance programs for detection of non-human malaria parasites toward the control and elimination of malaria from India by 2030.
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Ng YL, Lee WC, Lau YL, Fong MY. The Impact of Geographical Variation in Plasmodium knowlesi Apical Membrane Protein 1 (PkAMA-1) on Invasion Dynamics of P. knowlesi. Trop Med Infect Dis 2023; 8:tropicalmed8010056. [PMID: 36668963 PMCID: PMC9863575 DOI: 10.3390/tropicalmed8010056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/16/2022] [Accepted: 01/08/2023] [Indexed: 01/12/2023] Open
Abstract
Plasmodium knowlesi has emerged as an important zoonotic parasite that causes persistent symptomatic malaria in humans. The signs and symptoms of malaria are attributed to the blood stages of the parasites, which start from the invasion of erythrocytes by the blood stage merozoites. The apical membrane protein 1 (AMA-1) plays an important role in the invasion. In this study, we constructed and expressed recombinant PkAMA-1 domain II (PkAMA-1-DII) representing the predominant haplotypes from Peninsular Malaysia and Malaysian Borneo and raised specific antibodies against the recombinant proteins in rabbits. Despite the minor amino acid sequence variation, antibodies raised against haplotypes from Peninsular Malaysia and Malaysian Borneo demonstrated different invasion inhibition (46.81% and 39.45%, respectively) to P. knowlesi A1-H.1, a reference strain derived from Peninsular Malaysia. Here, we demonstrated how a minor variation in a conserved parasite protein could cast a significant impact on parasite invasion biology, suggesting a complex host-switching of P. knowlesi from different locations. This may challenge the implementation of a standardized One Health approach against the transmission of knowlesi malaria.
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Affiliation(s)
- Yee Ling Ng
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Wenn-Chyau Lee
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A*STAR), Singapore 138648, Singapore
| | - Yee-Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Correspondence:
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25
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Phang WK, Hamid MHBA, Jelip J, Mudin RNB, Chuang TW, Lau YL, Fong MY. Predicting Plasmodium knowlesi transmission risk across Peninsular Malaysia using machine learning-based ecological niche modeling approaches. Front Microbiol 2023; 14:1126418. [PMID: 36876062 PMCID: PMC9977793 DOI: 10.3389/fmicb.2023.1126418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 01/30/2023] [Indexed: 02/18/2023] Open
Abstract
The emergence of potentially life-threatening zoonotic malaria caused by Plasmodium knowlesi nearly two decades ago has continued to challenge Malaysia healthcare. With a total of 376 P. knowlesi infections notified in 2008, the number increased to 2,609 cases in 2020 nationwide. Numerous studies have been conducted in Malaysian Borneo to determine the association between environmental factors and knowlesi malaria transmission. However, there is still a lack of understanding of the environmental influence on knowlesi malaria transmission in Peninsular Malaysia. Therefore, our study aimed to investigate the ecological distribution of human P. knowlesi malaria in relation to environmental factors in Peninsular Malaysia. A total of 2,873 records of human P. knowlesi infections in Peninsular Malaysia from 1st January 2011 to 31st December 2019 were collated from the Ministry of Health Malaysia and geolocated. Three machine learning-based models, maximum entropy (MaxEnt), extreme gradient boosting (XGBoost), and ensemble modeling approach, were applied to predict the spatial variation of P. knowlesi disease risk. Multiple environmental parameters including climate factors, landscape characteristics, and anthropogenic factors were included as predictors in both predictive models. Subsequently, an ensemble model was developed based on the output of both MaxEnt and XGBoost. Comparison between models indicated that the XGBoost has higher performance as compared to MaxEnt and ensemble model, with AUCROC values of 0.933 ± 0.002 and 0.854 ± 0.007 for train and test datasets, respectively. Key environmental covariates affecting human P. knowlesi occurrence were distance to the coastline, elevation, tree cover, annual precipitation, tree loss, and distance to the forest. Our models indicated that the disease risk areas were mainly distributed in low elevation (75-345 m above mean sea level) areas along the Titiwangsa mountain range and inland central-northern region of Peninsular Malaysia. The high-resolution risk map of human knowlesi malaria constructed in this study can be further utilized for multi-pronged interventions targeting community at-risk, macaque populations, and mosquito vectors.
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Affiliation(s)
- Wei Kit Phang
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | | | - Jenarun Jelip
- Disease Control Division, Ministry of Health Malaysia, Putrajaya, Malaysia
| | - Rose Nani Binti Mudin
- Sabah State Health Department, Ministry of Health Malaysia, Kota Kinabalu, Sabah, Malaysia
| | - Ting-Wu Chuang
- Department of Molecular Parasitology and Tropical Diseases, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
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Ng YL, Lau YL, Hamid MHA, Jelip J, Ooi CH, Mudin RN, Jaimin JJ, Fong MY. Genetic polymorphism of the thrombospondin-related apical merozoite protein (TRAMP) of Plasmodium knowlesi in Malaysia. Parasitol Res 2023; 122:195-200. [PMID: 36378331 DOI: 10.1007/s00436-022-07716-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 11/02/2022] [Indexed: 11/16/2022]
Abstract
Plasmodium knowlesi is a simian malaria parasite that causes significant zoonotic infections in Southeast Asia, particularly in Malaysia. The Plasmodium thrombospondin-related apical merozoite protein (TRAMP) plays an essential role in the invasion of the parasite into its host erythrocyte. The present study investigated the genetic polymorphism and natural selection of the full length PkTRAMP from P. knowlesi clinical isolates from Malaysia. Blood samples (n = 40) were collected from P. knowlesi malaria patients from Peninsular Malaysia and Malaysian Borneo. The PkTRAMP gene was amplified using PCR, followed by cloning into a plasmid vector and sequenced. Results showed that the nucleotide diversity of PkTRAMP was low (π: 0.009). Z-test results indicated negative (purifying) selection of PkTRAMP. The alignment of the deduced amino acid sequences of PkTRAMP of Peninsular Malaysia and Malaysian Borneo revealed 38 dimorphic sites. A total of 27 haplotypes were identified from the amino acid sequence alignment. Haplotype analysis revealed that there was no clustering of PkTRAMP from Peninsular Malaysia and Malaysian Borneo.
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Mohan K, Kumar M, Omar BJ. Knowlesi Malaria in Children. Curr Pediatr Rev 2023; 19:242-252. [PMID: 35366778 DOI: 10.2174/1573396318666220401110835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/28/2022] [Accepted: 02/15/2022] [Indexed: 02/08/2023]
Abstract
The fifth malaria parasite causing malaria- Plasmodium knowlesi (Pk), is not a novel emergent species but was an undiagnosed species before the availability of molecular methods as a tool from diagnostics and sometimes confused with morphologically similar human malaria parasite P. malariae or P. falciparum. Now it is well-distributed species in Southeast Asia, especially in Malaysia. Since 2004, cases of Pk malaria are continuously being reported in adults. Though adult age, forest-related activities and a recent visit to forested areas are well-known factors, childhood did not remain untouched by this disease. Few pieces of research and reports in the literature indicate that Infection in children is uncomplicated, but this may be attributed to the scarcity of data and research in this field. Pk malaria in pregnant females and infants are being well reported, so this indicates that the problem is not only restricted to known factors related to the disease, but we should think out of the box and take action before the disease takes the form of significant health burden on the human population as P. vivax and P. falciparum species did in the past. With the reports in literature of Pk malaria in pregnancy and early infancy, the possibility of congenital and neonatal malaria also cannot be denied. So more and more research is needed to understand Pk malaria in the pediatric population clearly. So this running review covers the problem status, demographic profile, clinical and haematological features, diagnosis, management and outcome of Pk malaria in paediatric group worldwide. This review also discusses the gaps in our present knowledge of the real problem status, prevention, control, diagnosis and management of Pk malaria, particularly in this age group.
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Affiliation(s)
- Kriti Mohan
- Department of Pediatrics, All India Institute of Medical Sciences, Gorakhpur, Uttar Pradesh, India
| | - Manish Kumar
- Department of Microbiology, All India Institute of Medical Science, Rishikesh, Uttarakhand, India
| | - Balram Ji Omar
- All India Institute of Medical Science, Gorakhpur, Uttar Pradesh, India
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Naserrudin NA, Hassan MR, Jeffree MS, Culleton R, Hod R, Ahmed K. A systematic review of asymptomatic Plasmodium knowlesi infection: an emerging challenge involving an emerging infectious disease. Malar J 2022; 21:373. [PMID: 36474243 PMCID: PMC9724390 DOI: 10.1186/s12936-022-04339-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 10/18/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND In the last decade Plasmodium knowlesi has been detected in humans throughout South East Asia. The highest risk groups for this infection are males, adults and those performing forest-related work. Furthermore, asymptomatic cases of P. knowlesi malaria have been reported including among women and children. METHODS Pubmed, Scopus and the Web of Science databases for literature describing asymptomatic P. knowlesi malaria published between 2010 and 2020 were searched. A systematic literature review was conducted to identify studies reporting the prevalence and incidence of laboratory confirmed asymptomatic P. knowlesi cases in humans, their clinical and demographic characteristics, and methods used to diagnose these cases. RESULTS By analysing over 102 papers, thirteen were eligible for this review. Asymptomatic P. knowlesi infections have been detected in 0.03%-4.0% of the population depending on region, and infections have been described in children as young as 2 years old. Various different diagnostic methods were used to detect P. knowlesi cases and there were differing definitions of asymptomatic cases in these studies. The literature indicates that regionally-differing immune-related mechanisms may play a part on the prevalence of asymptomatic P. knowlesi. CONCLUSION Differing epidemiological characteristics of asymptomatic P. knowlesi malaria in different regions reinforces the need to further investigate disease transmission mechanics. Effective public health responses to changes in P. knowlesi epidemiology require proactive intervention and multisectoral collaboration.
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Affiliation(s)
- Nurul Athirah Naserrudin
- grid.412113.40000 0004 1937 1557Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia ,grid.265727.30000 0001 0417 0814Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, Kota Kinabalu, Malaysia ,grid.415759.b0000 0001 0690 5255Sabah State Health Department, Ministry of Health, Kota Kinabalu, Malaysia
| | - Mohd Rohaizat Hassan
- grid.412113.40000 0004 1937 1557Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia ,grid.265727.30000 0001 0417 0814Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, Kota Kinabalu, Malaysia
| | - Mohammad Saffree Jeffree
- grid.265727.30000 0001 0417 0814Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, Kota Kinabalu, Malaysia ,grid.265727.30000 0001 0417 0814Department of Community and Family Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Richard Culleton
- grid.255464.40000 0001 1011 3808Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Japan
| | - Rozita Hod
- grid.412113.40000 0004 1937 1557Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Kamruddin Ahmed
- grid.265727.30000 0001 0417 0814Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Sabah, Kota Kinabalu, Malaysia ,grid.265727.30000 0001 0417 0814Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
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Azlan UW, Lau YL, Fong MY. Genetic Diversity and Clustering of the Rhoptry Associated Protein-1 of Plasmodium knowlesi from Peninsular Malaysia and Malaysian Borneo. Korean J Parasitol 2022; 60:393-400. [PMID: 36588415 PMCID: PMC9806503 DOI: 10.3347/kjp.2022.60.6.393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 11/22/2022] [Indexed: 12/29/2022]
Abstract
Human infection with simian malaria Plasmodium knowlesi is a cause for concern in Southeast Asian countries, especially in Malaysia. A previous study on Peninsular Malaysia P. knowlesi rhoptry associated protein-1 (PkRAP1) gene has discovered the existence of dimorphism. In this study, genetic analysis of PkRAP1 in a larger number of P. knowlesi samples from Malaysian Borneo was conducted. The PkRAP1 of these P. knowlesi isolates was PCR-amplified and sequenced. The newly obtained PkRAP1 gene sequences (n = 34) were combined with those from the previous study (n = 26) and analysed for polymorphism and natural selection. Sequence analysis revealed a higher genetic diversity of PkRAP1 compared to the previous study. Exon II of the gene had higher diversity (π = 0.0172) than exon I (π = 0.0128). The diversity of the total coding region (π = 0.0167) was much higher than those of RAP1 orthologues such as PfRAP-1 (π = 0.0041) and PvRAP1 (π = 0.00088). Z-test results indicated that the gene was under purifying selection. Phylogenetic tree and haplotype network showed distinct clustering of Peninsular Malaysia and Malaysian Borneo PkRAP1 haplotypes. This geographical-based clustering of PkRAP1 haplotypes provides further evidence of the dimorphism of the gene and possible existence of 2 distinct P. knowlesi lineages in Malaysia.
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Chaiphongpachara T, Laojun S, Changbunjong T, Sumruayphol S, Suwandittakul N, Chookaew S, Atta Y. Genetic Diversity, Haplotype Relationships, and kdr Mutation of Malaria Anopheles Vectors in the Most Plasmodium knowlesi-Endemic Area of Thailand. Trop Med Infect Dis 2022; 7. [PMID: 36548667 DOI: 10.3390/tropicalmed7120412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/25/2022] [Accepted: 11/26/2022] [Indexed: 12/04/2022] Open
Abstract
Plasmodium knowlesi, a malaria parasite that occurs naturally in long-tailed macaques, pig-tailed macaques, and banded leaf monkeys, is currently regarded as the fifth of the human malaria parasites. We aimed to investigate genetic diversity based on the cytochrome c oxidase subunit I (COI) gene, detect Plasmodium parasites, and screen for the voltage-gated sodium channel (VGSC)-mutation-mediated knockdown resistance (kdr) of Anopheles mosquitoes in Ranong province, which is the most P. knowlesi-endemic area in Thailand. One hundred and fourteen Anopheles females belonging to eight species, including An. baimaii (21.05%), An. minimus s.s. (20.17%), An. epiroticus (19.30%), An. jamesii (19.30%), An. maculatus s.s. (13.16%), An. barbirostris A3 (5.26%), An. sawadwongporni (0.88%), and An. aconitus (0.88%), were caught in three geographical regions of Ranong province. None of the Anopheles mosquitoes sampled in this study were infected with Plasmodium parasites. Based on the sequence analysis of COI sequences, An. epiroticus had the highest level of nucleotide diversity (0.012), followed by An. minimus (0.011). In contrast, An. maculatus (0.002) had the lowest level of nucleotide diversity. The Fu's Fs and Tajima's D values of the Anopheles species in Ranong were all negative, except the Tajima's D values of An. minimus (0.077). Screening of VGSC sequences showed no presence of the kdr mutation of Anopheles mosquitoes. Our results could be used to further select effective techniques for controlling Anopheles populations in Thailand's most P. knowlesi-endemic area.
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Naserrudin NA, Culleton R, Pau Lin PY, Baumann SE, Hod R, Jeffree MS, Ahmed K, Hassan MR. Generating Trust in Participatory Research on Plasmodium knowlesi Malaria: A Study with Rural Community Gatekeepers during the COVID-19 Pandemic. Int J Environ Res Public Health 2022; 19:ijerph192315764. [PMID: 36497837 PMCID: PMC9737837 DOI: 10.3390/ijerph192315764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/15/2022] [Accepted: 11/23/2022] [Indexed: 06/01/2023]
Abstract
BACKGROUND Plasmodium knowlesi malaria is a zoonotic infection that affects rural communities in South East Asia. Although the epidemiology of the disease has been extensively researched, the voices of individuals within affected communities often go unheard. Here, we describe a study that explores the importance of gatekeepers in conducting research among rural communities, their perspectives on the challenges encountered when attempting to avoid malaria infection, and their views on participatory research. METHODS Between 1 November 2021 and 28 February 2022, we conducted a study in Kudat district, Sabah, using a multi-method design. All participants consented to the study, which included health care workers (HCWs) (n = 5), community leaders (n = 8), and faith leaders (n = 1). We conducted interviews, transect walks, and observations with gatekeepers to ensure data trustworthiness. All interviews were conducted in the Sabah Malay dialect. The sessions were audio- and video-recorded, transcribed into English and analyzed using thematic analysis. RESULTS Between 2017 and 2021, the number of cases of P. knowlesi malaria detected in humans ranged from 35 to 87 in villages under the care of the Lotong primary health care clinic. The challenges in controlling malaria include social norms, lifestyles, socioeconomic factors, environmental factors, and limitations of basic resources. Critical discussions regarding participation with the gatekeepers identified that face-to-face interviews were preferable to online discussions, and influenced willingness to participate in future research. CONCLUSION This study was conducted among village gatekeepers during the COVID-19 pandemic and generated information to drive methodological changes, opening up new ideas by sharing perspectives on challenges in P. knowlesi malaria control among vulnerable communities. The study generated trust in the community and expanded knowledge regarding participation that is critical for future community-based studies.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
- Sabah State Health Department, Ministry of Health, Kota Kinabalu 88590, Malaysia
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Matsuyama 791-0295, Japan
| | - Pauline Yong Pau Lin
- Faculty of Social Sciences and Humanities, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Sara Elizabeth Baumann
- Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Rozita Hod
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Mohammad Saffree Jeffree
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Kamruddin Ahmed
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Mohd Rohaizat Hassan
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
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Chua TH, Manin BO, Fornace K. Life table analysis of Anopheles balabacensis, the primary vector of Plasmodium knowlesi in Sabah, Malaysia. Parasit Vectors 2022; 15:442. [PMID: 36434625 PMCID: PMC9701013 DOI: 10.1186/s13071-022-05552-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/07/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Plasmodium knowlesi has become a major public health concern in Sabah, Malaysian Borneo, where it is now the only cause of indigenous malaria. The importance of P. knowlesi has spurred on a series of studies on this parasite, as well as on the biology and ecology of its principal vector, Anopheles balabacensis. However, there remain critical knowledge gaps on the biology of An. balabacensis, such as life history data and life table parameters. To fill these gaps, we conducted a life table study of An. balabacensis in the laboratory. Characterising vector life cycles and survival rates can inform more accurate estimations of the serial interval, the time between two linked cases, which is crucial to understanding and monitoring potentially changing transmission patterns. METHODS Individuals of An. balabacensis were collected in the field in Ranau district, Sabah to establish a laboratory colony. Induced mating was used, and the life history parameters of the progeny were recorded. The age-stage, two-sex life table approach was used in the analysis. The culture conditions in the laboratory were 9 h light:15 h dark, mean temperature 25.7 °C ± 0.05 and relative humidity 75.8% ± 0.31. RESULTS The eggs hatched within 2 days, and the larval stage lasted for 10.5 days in total, with duration of instar stages I, II, III and IV of 2.3, 3.7, 2.3, 2.2 days, respectively. The maximum total fecundity was 729 for one particular female, while the maximum female age-specific mean fecundity (mx) was 142 at age 59 days. The gross reproductive rate or number of offspring per individual was about 102. On average, each female laid 1.81 ± 0.19 (range 1-7) batches of eggs, with 63% of the females producing only one batch; only one female laid six batches, while one other laid seven. Each batch comprised 159 ± 17.1 eggs (range 5-224) and the female ratio of offspring was 0.28 ± 0.06. The intrinsic rate of increase, finite rate of increase, net reproductive rate, mean generation time and doubling time were, respectively, 0.12 ± 0.01 day-1, 1.12 ± 0.01 day-1, 46.2 ± 14.97, 33.02 ± 1.85 and 5.97 days. CONCLUSIONS Both the net reproductive rate and intrinsic rate of increase of An. balabacensis are lower than those of other species in published studies. Our results can be used to improve models of P. knowlesi transmission and to set a baseline for assessing the impacts of environmental change on malaria dynamics. Furthermore, incorporating these population parameters of An. balabacensis into spatial and temporal models on the transmission of P. knowlesi would provide better insight and increase the accuracy of epidemiological forecasting.
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Affiliation(s)
- Tock H. Chua
- grid.265727.30000 0001 0417 0814Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Sabah, Malaysia
| | - Benny Obrain Manin
- grid.265727.30000 0001 0417 0814Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Sabah, Malaysia
| | - Kimberly Fornace
- grid.8756.c0000 0001 2193 314XSchool of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK ,grid.4280.e0000 0001 2180 6431Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
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Mohring F, van Schalkwyk DA, Henrici RC, Blasco B, Leroy D, Sutherland CJ, Moon RW. Cation ATPase (ATP4) Orthologue Replacement in the Malaria Parasite Plasmodium knowlesi Reveals Species-Specific Responses to ATP4-Targeting Drugs. mBio 2022; 13:e0117822. [PMID: 36190127 PMCID: PMC9600963 DOI: 10.1128/mbio.01178-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/31/2022] [Indexed: 11/30/2022] Open
Abstract
Several unrelated classes of antimalarial compounds developed against Plasmodium falciparum target a parasite-specific P-type ATP-dependent Na+ pump, PfATP4. We have previously shown that other malaria parasite species infecting humans are less susceptible to these compounds. Here, we generated a series of transgenic Plasmodium knowlesi orthologue replacement (OR) lines in which the endogenous pkatp4 locus was replaced by a recodonized P. knowlesi atp4 (pkatp4) coding region or the orthologous coding region from P. falciparum, Plasmodium malariae, Plasmodium ovale subsp. curtisi, or Plasmodium vivax. Each OR transgenic line displayed a similar growth pattern to the parental P. knowlesi line. We found significant orthologue-specific differences in parasite susceptibility to three chemically unrelated ATP4 inhibitors, but not to comparator drugs, among the P. knowlesi OR lines. The PfATP4OR transgenic line of P. knowlesi was significantly more susceptible than our control PkATP4OR line to three ATP4 inhibitors: cipargamin, PA21A092, and SJ733. The PvATP4OR and PmATP4OR lines were similarly susceptible to the control PkATP4OR line, but the PocATP4OR line was significantly less susceptible to all ATP4 inhibitors than the PkATP4OR line. Cipargamin-induced inhibition of Na+ efflux was also significantly greater with the P. falciparum orthologue of ATP4. This confirms that species-specific susceptibility differences previously observed in ex vivo studies of human isolates are partly or wholly enshrined in the primary amino acid sequences of the respective ATP4 orthologues and highlights the need to monitor efficacy of investigational malaria drugs against multiple species. P. knowlesi is now established as an important in vitro model for studying drug susceptibility in non-falciparum malaria parasites. IMPORTANCE Effective drugs are vital to minimize the illness and death caused by malaria. Development of new drugs becomes ever more urgent as drug resistance emerges. Among promising compounds now being developed to treat malaria are several unrelated molecules that each inhibit the same protein in the malaria parasite-ATP4. Here, we exploited the genetic tractability of P. knowlesi to replace its own ATP4 genes with orthologues from five human-infective species to understand the drug susceptibility differences among these parasites. We previously estimated the susceptibility to ATP4-targeting drugs of each species using clinical samples from malaria patients. These estimates closely matched those of the corresponding "hybrid" P. knowlesi parasites carrying introduced ATP4 genes. Thus, species-specific ATP4 inhibitor efficacy is directly determined by the sequence of the gene. Our novel approach to understanding cross-species susceptibility/resistance can strongly support the effort to develop antimalarials that effectively target all human malaria parasite species.
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Affiliation(s)
- Franziska Mohring
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Donelly A. van Schalkwyk
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ryan C. Henrici
- Center for Global Health, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Colin J. Sutherland
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- UK Health Security Agency Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Robert W. Moon
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Ahmed MA, Zaidi RH, Deshmukh GY, Saif A, Alshahrani MA, Salam SS, Elfaki MMA, Han JH, Patgiri SJ, Quan FS. Genetic Diversity and Population Genetic Structure Analysis of Plasmodium knowlesi Thrombospondin-Related Apical Merozoite Protein (TRAMP) in Clinical Samples. Genes (Basel) 2022; 13:1944. [PMID: 36360181 PMCID: PMC9689803 DOI: 10.3390/genes13111944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 10/12/2022] [Accepted: 10/19/2022] [Indexed: 08/20/2023] Open
Abstract
The simian malaria parasite Plasmodium knowlesi causes a high number of zoonotic infections in Malaysia. The thrombospondin-related apical merozoite protein (TRAMP) is an essential ligand for binding to the erythrocyte cell surface, whereby it facilitates the invasion. This study is the first attempt to determine the genetic diversity, phylogeography, natural selection and population structure from 97 full-length PkTRAMP gene sequences originating from Malaysia. We found low levels of nucleotide diversity (π~0.0065) for the full-length gene despite samples originating from geographically separated regions (i.e., Peninsular Malaysia and Malaysian Borneo). The rate of synonymous substitutions was significantly higher than that of non-synonymous substitutions, indicating a purifying selection for the full-length gene within the clinical samples. The population genetic analysis revealed that the parasite population is undergoing a significant population expansion. The analysis of the amino acid sequence alignment of 97 PkTRAMP sequences identified 15 haplotypes, of which a major shared haplotype was noted Hap 1 (n = 68, Sarawak; n = 34, Sabah; n = 12, Peninsular Malaysia; n = 22). The phylogenetic analysis using DNA sequences identified two clusters that separated due to geographical distance and three mixed clusters with samples from both Peninsular Malaysia and Malaysian Borneo. Population structure analyses indicated two distinct sub-populations (K = 2). Our findings point to the potential for independent parasite evolution, which could make zoonotic malaria control and elimination even more challenging.
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Affiliation(s)
- Md Atique Ahmed
- ICMR-Regional Medical Research Centre, NER, Dibrugarh, Assam, Bhubaneswar 786010, India
| | - Rehan Haider Zaidi
- Department of Biotechnology and Microbiology, National College, Tiruchirapalli 620001, India
| | | | - Ahmed Saif
- Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Najran University, Narjan 55461, Saudi Arabia
| | - Mohammed Abdulrahman Alshahrani
- Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Najran University, Narjan 55461, Saudi Arabia
| | - Syeda Sabiha Salam
- Department of Life Sciences, Dibrugarh University, Assam, Dibrugarh 786004, India
| | | | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon 24341, Korea
| | - Saurav Jyoti Patgiri
- ICMR-Regional Medical Research Centre, NER, Dibrugarh, Assam, Bhubaneswar 786010, India
| | - Fu-Shi Quan
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea
- Department of Medical Zoology, School of Medicine, Kyung Hee University, Seoul 02447, Korea
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Azlan UK, Cheong FW, Lau YL, Fong MY. Plasmodium knowlesi Duffy binding protein alpha region II (PkDBPαII) in clinical isolates from Peninsular Malaysia and Malaysian Borneo exhibit different immune responses in animal models. Parasitol Res 2022. [PMID: 36152079 DOI: 10.1007/s00436-022-07665-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 09/09/2022] [Indexed: 10/14/2022]
Abstract
Plasmodium knowlesi utilizes the Duffy binding protein alpha (PkDBPα) to facilitate its invasion into human erythrocytes. PkDBPα region II (PkDBPαII) from Peninsular Malaysia and Malaysian Borneo has been shown to occur as distinct haplotypes, and the predominant haplotypes from these geographical areas demonstrated differences in binding activity to human erythrocytes in erythrocyte binding assays. This study aimed to determine the effects of genetic polymorphisms in PkDBPαII to immune responses in animal models. The recombinant PkDBPαII (~ 45 kDa) of Peninsular Malaysia (PkDBPαII-H) and Malaysian Borneo (PkDBPαII-S) were expressed in a bacterial expression system, purified, and used in mice and rabbit immunization. The profile of cytokines IL-1ra, IL-2, IL-6, IL-10, TNF-α, and IFN-γ in immunized mice spleen was determined via ELISA. The titer and IgG subtype distribution of raised antibodies was characterized. Immunized rabbit sera were purified and used to perform an in vitro merozoite invasion inhibition assay. The PkDBPαII-immunized mice sera of both groups showed high antibody titer and a similar IgG subtype distribution pattern: IgG2b > IgG1 > IgG2a > IgG3. The PkDBPαII-H group was shown to have higher IL-1ra (P = 0.141) and IL-6 (P = 0.049) concentrations, with IL-6 levels significantly higher than that of the PkDBPαII-S group (P ≤ 0.05). Merozoite invasion inhibition assay using purified anti-PkDBPαII antibodies showed a significantly higher inhibition rate in the PkDBPαII-H group than the PkDBPαII-S group (P ≤ 0.05). Besides, anti-PkDBPαII-H antibodies were able to exhibit inhibition activity at a lower concentration than anti-PkDBPαII-S antibodies. PkDBPαII was shown to be immunogenic, and the PkDBPαII haplotype from Peninsular Malaysia exhibited higher responses in cytokines IL-1ra and IL-6, antibody IgM level, and merozoite invasion inhibition assay than the Malaysian Borneo haplotype. This suggests that polymorphisms in the PkDBPαII affect the level of immune responses in the host.
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Bin Said I, Kouakou YI, Omorou R, Bienvenu AL, Ahmed K, Culleton R, Picot S. Systematic review of Plasmodium knowlesi in Indonesia: a risk of emergence in the context of capital relocation to Borneo? Parasit Vectors 2022; 15:258. [PMID: 35850777 PMCID: PMC9290274 DOI: 10.1186/s13071-022-05375-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/23/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND The Indonesian Republic plans to relocate its capital from Jakarta to East Kalimantan, Borneo Island, in the next few years. This relocation may be associated with deforestation, decreased biodiversity, and an increased risk of emerging zoonotic infections, including Plasmodium knowlesi malaria. The Malaysian part of Borneo Island is one of the main hotspots of P. knowlesi malaria. METHODS Considering this risk, we evaluated the transmission dynamics of P. knowlesi in the Indonesian Archipelago based on a literature search and extensive review of data from the Indonesian Ministry of Health. RESULTS We report that 545 P. knowlesi cases were documented in Indonesia, mainly in the Aceh and North Sumatra provinces, with 95% of these occurring in the last 4 years. CONCLUSIONS The main P. knowlesi vectors are present in the area of the future capital, requiring strengthened surveillance to reduce the risk of emerging cases in a rapidly growing population.
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Affiliation(s)
- Ibrahim Bin Said
- Malaria Research Unit, UMR 5246 CNRS-INSA-CPE-University Lyon1, University Lyon, 69100 Villeurbanne, France
- Institut Agama Islam Negeri (IAIN) Kediri, Jawa Timur, 64127 Kota Kediri, Indonesia
| | - Yobouet Ines Kouakou
- Malaria Research Unit, UMR 5246 CNRS-INSA-CPE-University Lyon1, University Lyon, 69100 Villeurbanne, France
| | - Roukayatou Omorou
- Malaria Research Unit, UMR 5246 CNRS-INSA-CPE-University Lyon1, University Lyon, 69100 Villeurbanne, France
| | - Anne-Lise Bienvenu
- Malaria Research Unit, UMR 5246 CNRS-INSA-CPE-University Lyon1, University Lyon, 69100 Villeurbanne, France
- Service Pharmacie, Groupement Hospitalier Nord, Hospices Civils de Lyon, 69004 Lyon, France
| | - Kamruddin Ahmed
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Sabah Malaysia
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Stephane Picot
- Malaria Research Unit, UMR 5246 CNRS-INSA-CPE-University Lyon1, University Lyon, 69100 Villeurbanne, France
- Institute of Parasitology and Medical Mycology, Hôpital de La Croix-Rousse, Hospices Civils de Lyon, 69004 Lyon, France
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Longley RJ, Grigg MJ, Schoffer K, Obadia T, Hyslop S, Piera KA, Nekkab N, Mazhari R, Takashima E, Tsuboi T, Harbers M, Tetteh K, Drakeley C, Chitnis CE, Healer J, Tham WH, Sattabongkot J, White MT, Cooper DJ, Rajahram GS, Barber BE, William T, Anstey NM, Mueller I. Plasmodium vivax malaria serological exposure markers: Assessing the degree and implications of cross-reactivity with P. knowlesi. Cell Rep Med 2022; 3:100662. [PMID: 35732155 DOI: 10.1016/j.xcrm.2022.100662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/22/2022] [Accepted: 05/26/2022] [Indexed: 11/21/2022]
Abstract
Serological markers are a promising tool for surveillance and targeted interventions for Plasmodium vivax malaria. P. vivax is closely related to the zoonotic parasite P. knowlesi, which also infects humans. P. vivax and P. knowlesi are co-endemic across much of South East Asia, making it important to design serological markers that minimize cross-reactivity in this region. To determine the degree of IgG cross-reactivity against a panel of P. vivax serological markers, we assayed samples from human patients with P. knowlesi malaria. IgG antibody reactivity is high against P. vivax proteins with high sequence identity with their P. knowlesi ortholog. IgG reactivity peaks at 7 days post-P. knowlesi infection and is short-lived, with minimal responses 1 year post-infection. We designed a panel of eight P. vivax proteins with low levels of cross-reactivity with P. knowlesi. This panel can accurately classify recent P. vivax infections while reducing misclassification of recent P. knowlesi infections.
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Ooi CH, Phang WK, Liew JWK, Atroosh WM, Lau YL. Epidemiology of indigenous Plasmodium knowlesi infection in Sarawak, 2011-2019. Trop Med Int Health 2022; 27:705-718. [PMID: 35716113 DOI: 10.1111/tmi.13788] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Indexed: 12/01/2022]
Abstract
OBJECTIVES To characterize the state-wide epidemiology of indigenous knowlesi malaria in Sarawak from 2011-2019. METHODS Longitudinal retrospective study based on Sarawak knowlesi malaria surveillance data recorded 2011-2019. Only indigenous cases were included and information extracted for analysis comprised age, sex, occupation, ethnicity, case severity, hospital admission, and parasite density. RESULTS Over the 9 years 8473 indigenous knowlesi malaria cases were recorded. Age group 40 to 49 years, males, plantation workers, and Iban communities recorded the highest percentage of cases in each demographic variable. Most of the cases were uncomplicated (85.9%) and 89.5% of the total cases were reported with ≤20,000 parasites/μL of blood. Age group and ethnic group are associated with severity of knowlesi malaria in Sarawak. Multivariable logistic regression indicated that the age group 60+ years had the highest odds of developing severe knowlesi malaria compared to other age groups (AOR 2.48; 95% CI 1.22, 5.02; p=0.012). Bidayuh patients were more likely to develop severe knowlesi malaria than Ibans, the largest ethnic group among knowlesi malaria patients (AOR 1.97; 95% CI 1.31, 2.97; p=0.001). CONCLUSIONS Identification of risk groups is important for the implementation of prevention programs and treatments targeting at specific group to combat knowlesi malaria effectively.
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Affiliation(s)
- Choo Huck Ooi
- Vector Borne Disease Section, Sarawak Health Department, Ministry of Health Malaysia, Sarawak, Malaysia
| | - Wei Kit Phang
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Jonathan Wee Kent Liew
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.,Currenly Environmental Health Institute, National Environment Agency, Singapore
| | - Wahib M Atroosh
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.,Department of Microbiology and Parasitology, University of Aden, Aden, Yemen
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
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Budiman C, Razak RA, Unggit ARA, Razali R, Suzery M, Mokhtar RAM, Lee PC, Utomo DH. Catalytic Properties of Caseinolytic Protease Subunit of Plasmodium knowlesi and Its Inhibition by a Member of δ-Lactone, Hyptolide. Molecules 2022; 27:3787. [PMID: 35744912 DOI: 10.3390/molecules27123787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/05/2022] [Accepted: 06/08/2022] [Indexed: 11/17/2022]
Abstract
The caseinolytic protease (Clp) system plays an essential role in the protein homeostasis of the malaria parasite, particularly at the stage of apicoplast development. The inhibition of this protein is known to have a lethal effect on the parasite and is therefore considered an interesting avenue for antimalaria drugs discovery. The catalytic activity of the Clp system is modulated by its proteolytic subunit (ClpP), which belongs to the serine protease family member and is therefore extensively studied for further inhibitors development. Among many inhibitors, the group of β-lactone is known to be a specific inhibitor for ClpP. Nevertheless, other groups of lactones have never been studied. This study aims to characterize the catalytic properties of ClpP of Plasmodium knowlesi (Pk-ClpP) and the inhibition properties of a δ-lactone hyptolide against this protein. Accordingly, a codon-optimized synthetic gene encoding Pk-ClpP was expressed in Escherichia coli BL21(DE3) and purified under a single step of Ni2+-affinity chromatography, yielding a 2.20 mg from 1 L culture. Meanwhile, size-exclusion chromatography indicated that Pk-ClpP migrated primarily as homoheptameric with a size of 205 kDa. The specific activity of pure Pk-ClpP was 0.73 U µg-1, with a catalytic efficiency kcat/KM of 0.05 µM-1 s-1, with optimum temperature and pH of 50 °C and 7.0-7.5, respectively. Interestingly, hyptolide, a member of δ-lactone, was shown to inhibit Pk-ClpP with an IC50 value of 17.36 ± 1.44 nM. Structural homology modelling, secondary structure prediction, and far-UV CD spectra revealed that helical structures dominate this protein. In addition, the structural homology modeling showed that this protein forms a barrel-shaped homoheptamer. Docking simulation revealed that the inhibition was found to be a competitive inhibition in which hyptolide was able to dock into the catalytic site and block the substrate. The competitiveness of hyptolide is due to the higher binding affinity of this molecule than the substrate.
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40
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Brown R, Salgado-Lynn M, Jumail A, Jalius C, Chua TH, Vythilingam I, Ferguson HM. Exposure of Primate Reservoir Hosts to Mosquito Vectors in Malaysian Borneo. Ecohealth 2022; 19:233-245. [PMID: 35553290 PMCID: PMC9276546 DOI: 10.1007/s10393-022-01586-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 03/05/2022] [Accepted: 03/10/2022] [Indexed: 06/15/2023]
Abstract
Several vector-borne pathogens of primates have potential for human spillover. An example is the simian malaria Plasmodium knowlesi which is now a major public health problem in Malaysia. Characterization of exposure to mosquito vectors is essential for assessment of the force of infection within wild simian populations, however few methods exist to do so. Here we demonstrate the use of thermal imaging and mosquito magnet independence traps (MMIT) to assess the abundance, diversity and infection rates in mosquitoes host seeking near long-tailed macaque (Macaca fasicularis) sleeping sites in the Lower Kinabatangan Wildlife Sanctuary, Malaysian Borneo. The primary Plasmodium knowlesi vector, Anopheles balabacensis, was trapped at higher abundance near sleeping sites than control trees. Although none of the An. balabacensis collected (n = 15) were positive for P. knowlesi by PCR screening, two were infected with another simian malaria Plasmodium inui. Analysis of macaque stools from sleeping sites confirmed a high prevalence of Plasmodium infection, suspected to be P. inui. Recently, natural transmission of P. inui has been detected in humans and An. cracens in Peninsular Malaysia. The presence of P. inui in An. balabacensis here and previously in human-biting collections highlight its potential for spillover from macaques to humans in Sabah. We advocate the use of MMITs for non-invasive sampling of mosquito vectors that host seek on wild simian populations.
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Affiliation(s)
- Rebecca Brown
- Department of Vector Biology, Liverpool School of Tropical Medicine and Hygiene, Liverpool, L3 5QA, UK.
| | - Milena Salgado-Lynn
- Danau Girang Field Centre C/O Sabah Wildlife Department, Wisma Muis, Kota Kinabalu, Sabah, Malaysia
- School of Biosciences and Sustainable Places Research Institute, Cardiff University, Cardiff, UK
- Wildlife Health, Genetic and Forensic Laboratory, Kampung Potuki, Kota Kinabalu, Sabah, Malaysia
| | - Amaziasizamoria Jumail
- Danau Girang Field Centre C/O Sabah Wildlife Department, Wisma Muis, Kota Kinabalu, Sabah, Malaysia
| | - Cyrlen Jalius
- Wildlife Health, Genetic and Forensic Laboratory, Kampung Potuki, Kota Kinabalu, Sabah, Malaysia
| | - Tock-Hing Chua
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Heather M Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Graham Kerr Building, University Avenue, Glasgow, G12 8QQ, UK
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Oresegun DR, Thorpe P, Benavente ED, Campino S, Muh F, Moon RW, Clark TG, Cox-Singh J. De Novo Assembly of Plasmodium knowlesi Genomes From Clinical Samples Explains the Counterintuitive Intrachromosomal Organization of Variant SICAvar and kir Multiple Gene Family Members. Front Genet 2022; 13:855052. [PMID: 35677565 PMCID: PMC9169567 DOI: 10.3389/fgene.2022.855052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/15/2022] [Indexed: 12/31/2022] Open
Abstract
Plasmodium knowlesi, a malaria parasite of Old World macaque monkeys, is used extensively to model Plasmodium biology. Recently, P. knowlesi was found in the human population of Southeast Asia, particularly Malaysia. P. knowlesi causes uncomplicated to severe and fatal malaria in the human host with features in common with the more prevalent and virulent malaria caused by Plasmodium falciparum. As such, P. knowlesi presents a unique opportunity to develop experimental translational model systems for malaria pathophysiology informed by clinical data from same-species human infections. Experimental lines of P. knowlesi represent well-characterized genetically stable parasites, and to maximize their utility as a backdrop for understanding malaria pathophysiology, genetically diverse contemporary clinical isolates, essentially wild-type, require comparable characterization. The Oxford Nanopore PCR-free long-read sequencing platform was used to sequence and de novo assemble P. knowlesi genomes from frozen clinical samples. The sequencing platform and assembly pipelines were designed to facilitate capturing data and describing, for the first time, P. knowlesi schizont-infected cell agglutination (SICA) var and Knowlesi-Interspersed Repeats (kir) multiple gene families in parasites acquired from nature. The SICAvar gene family members code for antigenically variant proteins analogous to the virulence-associated P. falciparum erythrocyte membrane protein (PfEMP1) multiple var gene family. Evidence presented here suggests that the SICAvar family members have arisen through a process of gene duplication, selection pressure, and variation. Highly evolving genes including PfEMP1family members tend to be restricted to relatively unstable sub-telomeric regions that drive change with core genes protected in genetically stable intrachromosomal locations. The comparable SICAvar and kir gene family members are counter-intuitively located across chromosomes. Here, we demonstrate that, in contrast to conserved core genes, SICAvar and kir genes occupy otherwise gene-sparse chromosomal locations that accommodate rapid evolution and change. The novel methods presented here offer the malaria research community not only new tools to generate comprehensive genome sequence data from small clinical samples but also new insight into the complexity of clinically important real-world parasites.
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Affiliation(s)
- Damilola R. Oresegun
- Division of Infection and Global Health, School of Medicine, University of St Andrews, Scotland, United Kingdom
| | - Peter Thorpe
- Division of Infection and Global Health, School of Medicine, University of St Andrews, Scotland, United Kingdom
| | - Ernest Diez Benavente
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Susana Campino
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Fauzi Muh
- Division of Infection and Global Health, School of Medicine, University of St Andrews, Scotland, United Kingdom
| | - Robert William Moon
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Taane Gregory Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Janet Cox-Singh
- Division of Infection and Global Health, School of Medicine, University of St Andrews, Scotland, United Kingdom
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Khoo BY, Lim KGE, Chia JWZ, Chavatte JM, Ong KH, De PP, Vasoo S. Answer to May 2022 Photo Quiz. J Clin Microbiol 2022; 60:e0168621. [PMID: 35583365 DOI: 10.1128/jcm.01686-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Khoo BY, Lim KGE, Chia JWZ, Chavatte JM, Ong KH, De PP, Vasoo S. Photo Quiz: Fever in a Traveler Returning from West Malaysia. J Clin Microbiol 2022; 60:e0168521. [PMID: 35583366 DOI: 10.1128/jcm.01685-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Lee WC, Cheong FW, Amir A, Lai MY, Tan JH, Phang WK, Shahari S, Lau YL. Plasmodium knowlesi: the game changer for malaria eradication. Malar J 2022; 21:140. [PMID: 35505339 PMCID: PMC9066973 DOI: 10.1186/s12936-022-04131-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 03/18/2022] [Indexed: 11/12/2022] Open
Abstract
Plasmodium knowlesi is a zoonotic malaria parasite that has gained increasing medical interest over the past two decades. This zoonotic parasitic infection is prevalent in Southeast Asia and causes many cases with fulminant pathology. Despite several biogeographical restrictions that limit its distribution, knowlesi malaria cases have been reported in different parts of the world due to travelling and tourism activities. Here, breakthroughs and key information generated from recent (over the past five years, but not limited to) studies conducted on P. knowlesi were reviewed, and the knowledge gap in various research aspects that need to be filled was discussed. Besides, challenges and strategies required to control and eradicate human malaria with this emerging and potentially fatal zoonosis were described.
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Affiliation(s)
- Wenn-Chyau Lee
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Fei Wen Cheong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Amirah Amir
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Meng Yee Lai
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Jia Hui Tan
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Wei Kit Phang
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Shahhaziq Shahari
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Yee-Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.
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Abacha YZ, Forkuo AD, Gbedema SY, Mittal N, Ottilie S, Rocamora F, Winzeler EA, van Schalkwyk DA, Kelly JM, Taylor MC, Reader J, Birkholtz LM, Lisgarten DR, Cockcroft JK, Lisgarten JN, Palmer RA, Talbert RC, Shnyder SD, Wright CW. Semi-Synthetic Analogues of Cryptolepine as a Potential Source of Sustainable Drugs for the Treatment of Malaria, Human African Trypanosomiasis, and Cancer. Front Pharmacol 2022; 13:875647. [PMID: 35600849 PMCID: PMC9119314 DOI: 10.3389/fphar.2022.875647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/08/2022] [Indexed: 12/11/2022] Open
Abstract
The prospect of eradicating malaria continues to be challenging in the face of increasing parasite resistance to antimalarial drugs so that novel antimalarials active against asexual, sexual, and liver-stage malaria parasites are urgently needed. In addition, new antimalarials need to be affordable and available to those most in need and, bearing in mind climate change, should ideally be sustainable. The West African climbing shrub Cryptolepis sanguinolenta is used traditionally for the treatment of malaria; its principal alkaloid, cryptolepine (1), has been shown to have antimalarial properties, and the synthetic analogue 2,7-dibromocryptolepine (2) is of interest as a lead toward new antimalarial agents. Cryptolepine (1) was isolated using a two-step Soxhlet extraction of C. sanguinolenta roots, followed by crystallization (yield 0.8% calculated as a base with respect to the dried roots). Semi-synthetic 7-bromo- (3), 7, 9-dibromo- (4), 7-iodo- (5), and 7, 9-dibromocryptolepine (6) were obtained in excellent yields by reaction of 1 with N-bromo- or N-iodosuccinimide in trifluoroacetic acid as a solvent. All compounds were active against Plasmodia in vitro, but 6 showed the most selective profile with respect to Hep G2 cells: P. falciparum (chloroquine-resistant strain K1), IC50 = 0.25 µM, SI = 113; late stage, gametocytes, IC50 = 2.2 µM, SI = 13; liver stage, P. berghei sporozoites IC50 = 6.13 µM, SI = 4.6. Compounds 3-6 were also active against the emerging zoonotic species P. knowlesi with 5 being the most potent (IC50 = 0.11 µM). In addition, 3-6 potently inhibited T. brucei in vitro at nM concentrations and good selectivity with 6 again being the most selective (IC50 = 59 nM, SI = 478). These compounds were also cytotoxic to wild-type ovarian cancer cells as well as adriamycin-resistant and, except for 5, cisplatin-resistant ovarian cancer cells. In an acute oral toxicity test in mice, 3-6 did not exhibit toxic effects at doses of up to 100 mg/kg/dose × 3 consecutive days. This study demonstrates that C. sanguinolenta may be utilized as a sustainable source of novel compounds that may lead to the development of novel agents for the treatment of malaria, African trypanosomiasis, and cancer.
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Affiliation(s)
- Yabalu Z. Abacha
- School of Pharmacy and Medical Sciences, University of Bradford, Bradford, United Kingdom,Department of Pharmacognosy, Faculty of Pharmacy, University of Maiduguri, Maiduguri, Nigeria
| | - Arnold Donkor Forkuo
- Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Stephen Y. Gbedema
- Department of Pharmaceutics, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, KNUST, Kumasi, Ghana
| | - Nimisha Mittal
- Malaria Drug Accelerator (MalDA) Consortium, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Sabine Ottilie
- Malaria Drug Accelerator (MalDA) Consortium, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Frances Rocamora
- Malaria Drug Accelerator (MalDA) Consortium, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Elizabeth A. Winzeler
- Malaria Drug Accelerator (MalDA) Consortium, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Donelly A. van Schalkwyk
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - John M. Kelly
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Martin C. Taylor
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, South Africa
| | - David R. Lisgarten
- Biomolecular Research Group, School of Psychology and Life Sciences, Canterbury Christ Church University, Canterbury, United Kingdom
| | - Jeremy K. Cockcroft
- Department of Chemistry, Christopher Ingold Laboratories, University College London, London, United Kingdom
| | | | - Rex A. Palmer
- Department of Crystallography, Biochemical Sciences, Birkbeck College, University of London, London, United Kingdom
| | - Rosemary C. Talbert
- Biomolecular Research Group, School of Psychology and Life Sciences, Canterbury Christ Church University, Canterbury, United Kingdom
| | - Steven D. Shnyder
- School of Pharmacy and Medical Sciences, Institute of Cancer Therapeutics, University of Bradford, Bradford, United Kingdom
| | - Colin W. Wright
- School of Pharmacy and Medical Sciences, University of Bradford, Bradford, United Kingdom,*Correspondence: Colin W. Wright,
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Naserrudin NA, Monroe A, Culleton R, Hod R, Jeffree MS, Ahmed K, Hassan MR. Reimagining zoonotic malaria control in communities exposed to Plasmodium knowlesi infection. J Physiol Anthropol 2022; 41:14. [PMID: 35413881 PMCID: PMC9004057 DOI: 10.1186/s40101-022-00288-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 03/31/2022] [Indexed: 12/21/2022] Open
Abstract
Plasmodium knowlesi malaria infection in humans has been reported throughout southeast Asia. The communities at risk are those living in areas where Macaque monkeys and Anopheles mosquito are present. Zoonotic malaria control is challenging due to the presence of the reservoir host and the possibility of human-vector-human transmission. Current control measures, including insecticide-treated nets (ITNs) and indoor residual spraying (IRS), are insufficient to address this threat due to gaps in protection associated with outdoor and early evening vector biting and social and economic activities, such as agricultural and forest work. Understanding the challenges faced by affected communities in preventing mosquito bites is important for reducing disease transmission. This opinion paper discusses opportunities to improve P. knowlesi malaria control through understanding the challenges faced by communities at risk and increasing community engagement and ownership of control measures. The paper highlights this issue by describing how the concept of reimagining malaria can be adapted to zoonotic malaria control measures including identifying current gaps in vector control, understanding interactions between environmental, economic, and human behavioral factors, and increasing community participation in and ownership of control measures.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, Malaysia.,Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Kota Kinabalu, Sabah, Malaysia.,Sabah State Health Department, Ministry of Health, Kota Kinabalu, Malaysia
| | - April Monroe
- Johns Hopkins Center for Communication Programs, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - Richard Culleton
- Department of Molecular Parasitology, Proteo-Science Centre, Ehime University, Matsuyama, Japan
| | - Rozita Hod
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, Malaysia
| | - Muhammad Saffree Jeffree
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Kota Kinabalu, Sabah, Malaysia.,Department of Public Health, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Kamruddin Ahmed
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia, Kota Kinabalu, Sabah, Malaysia.,Department of Public Health, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Mohd Rohaizat Hassan
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, Malaysia.
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Naserrudin NA, Hod R, Jeffree MS, Ahmed K, Hassan MR. The Emerging Threat of Plasmodium knowlesi Malaria Infection: A Concept Paper on the Vulnerable Factors in Human. Int J Environ Res Public Health 2022; 19:ijerph19074419. [PMID: 35410098 PMCID: PMC8998343 DOI: 10.3390/ijerph19074419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 03/28/2022] [Accepted: 04/03/2022] [Indexed: 02/01/2023]
Abstract
In South-East Asia (SEA), there has been an increase in the trend of detected and reported cases of Plasmodium knowlesi malaria in the last few decades. This higher transmission rate within SEA countries is attributed to the distribution of the Macaque, banded leaf monkeys, and Anopheles mosquito in this region. This study aims to propose a concept that highlights the integration of vulnerability factors to P. knowlesi malaria infection. The relevant literature on the vulnerability factors of P. knowlesi was reviewed. Any theories and models that could be integrated to support the factors were also explored throughout this study. Exposure to P. knowlesi malaria was found to be influenced by sociodemographic, socioeconomic, environmental, social context, belief, and human behaviour factors. However, these factors were commonly discussed separately in existing studies. For better disease prevention and control, all these factors should be explored collectively, to facilitate research aimed at generating a deeper understanding of the vulnerability factors to P. knowlesi malaria from various perspectives, including the genetic, sociodemographic, socioeconomic, environmental, sociocultural beliefs, and human behaviour of the population.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia; (N.A.N.); (R.H.)
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia; (M.S.J.); (K.A.)
- Sabah State Health Department, Ministry of Health, Putrajaya 62590, Malaysia
| | - Rozita Hod
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia; (N.A.N.); (R.H.)
| | - Mohammad Saffree Jeffree
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia; (M.S.J.); (K.A.)
- Department of Public Health, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Kamruddin Ahmed
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia; (M.S.J.); (K.A.)
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Mohd Rohaizat Hassan
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia; (N.A.N.); (R.H.)
- Correspondence:
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van de Straat B, Sebayang B, Grigg MJ, Staunton K, Garjito TA, Vythilingam I, Russell TL, Burkot TR. Zoonotic malaria transmission and land use change in Southeast Asia: what is known about the vectors. Malar J 2022; 21:109. [PMID: 35361218 PMCID: PMC8974233 DOI: 10.1186/s12936-022-04129-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 03/18/2022] [Indexed: 11/28/2022] Open
Abstract
Zoonotic Plasmodium infections in humans in many Southeast Asian countries have been increasing, including in countries approaching elimination of human-only malaria transmission. Most simian malarias in humans are caused by Plasmodium knowlesi, but recent research shows that humans are at risk of many different simian Plasmodium species. In Southeast Asia, simian Plasmodium species are mainly transmitted by mosquitoes in the Anopheles leucosphyrus and Anopheles dirus complexes. Although there is some evidence of species outside the Leucosphyrus Group transmitting simian Plasmodium species, these await confirmation of transmission to humans. The vectors of monkey malarias are mostly found in forests and forest fringes, where they readily bite long-tailed and pig-tailed macaques (the natural reservoir hosts) and humans. How changing land-uses influence zoonotic malaria vectors is still poorly understood. Fragmentation of forests from logging, agriculture and other human activities is associated with increased zoonotic Plasmodium vector exposure. This is thought to occur through altered macaque and mosquito distributions and behaviours, and importantly, increased proximity of humans, macaques, and mosquito vectors. Underlying the increase in vector densities is the issue that the land-use change and human activities create more oviposition sites and, in correlation, increases availably of human blood hosts. The current understanding of zoonotic malaria vector species is largely based on a small number of studies in geographically restricted areas. What is known about the vectors is limited: the data is strongest for distribution and density with only weak evidence for a limited number of species in the Leucosphyrus Group for resting habits, insecticide resistance, blood feeding habits and larval habitats. More data are needed on vector diversity and bionomics in additional geographic areas to understand both the impacts on transmission of anthropogenic land-use change and how this significant disease in humans might be controlled.
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Affiliation(s)
- Bram van de Straat
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia.
| | - Boni Sebayang
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Matthew J Grigg
- Menzies School of Health Research & Charles Darwin University, Casuarina, Australia
| | - Kyran Staunton
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Triwibowo Ambar Garjito
- Institute for Vector and Reservoir Control Research and Development, National Institute of Health Research and Development (NIHRD), The Ministry of Health of Indonesia, Jakarta, Indonesia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Tanya L Russell
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Thomas R Burkot
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
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Naserrudin NA, Hod R, Jeffree MS, Ahmed K, Hassan MR. Expert Consensus on a Proposed Study Framework to Explore Factors Influencing Plasmodium knowlesi Malaria Preventive Behavior: A Modified Delphi Method Protocol. Int J Environ Res Public Health 2022; 19:ijerph19074141. [PMID: 35409824 PMCID: PMC8998657 DOI: 10.3390/ijerph19074141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 03/25/2022] [Accepted: 03/29/2022] [Indexed: 12/10/2022]
Abstract
The increasing incidence of P. knowlesi malaria infection among humans is a public health threat. This zoonotic disease is challenging to eliminate owing to the presence of animal reservoirs. Understanding the factors such as the community’s belief, social context, drivers, and barriers can provide insights into malaria preventive behavior. It is crucial to improve the current preventive measures. This study aims to achieve consensus among malaria experts based on evidence from literature reviews and experts’ opinions on possible factors influencing malaria preventive behavior among communities exposed to P. knowlesi malaria infection. A modified Delphi study protocol was developed to gather experts’ consensus on the study framework to explore the factors influencing preventive behavior among communities exposed to P. knowlesi malaria infection. The framework is adapted from the ideation model, and it is integrated with other relevant theories and extensive literature reviews. We will use the modified Delphi protocol to reach a consensus. The experts will respond to each questionnaire item and a related open-ended questionnaire. Consensus is predetermined at more than 70% agreement on the items. We will use descriptive statistics and thematic analysis to analyze the data. All experts will remain anonymous to maintain the characteristics of a traditional Delphi study.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia; (N.A.N.); (R.H.)
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia; (M.S.J.); (K.A.)
- Sabah State Health Department, Ministry of Health, Kota Kinabalu 88590, Malaysia
| | - Rozita Hod
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia; (N.A.N.); (R.H.)
| | - Mohammad Saffree Jeffree
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia; (M.S.J.); (K.A.)
- Department of Public Health Medicine, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Kamruddin Ahmed
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia; (M.S.J.); (K.A.)
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Mohd Rohaizat Hassan
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia; (N.A.N.); (R.H.)
- Correspondence:
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Naserrudin NA, Hod R, Jeffree MS, Ahmed K, Culleton R, Hassan MR. The Role of Human Behavior in Plasmodium knowlesi Malaria Infection: A Systematic Review. Int J Environ Res Public Health 2022; 19:3675. [PMID: 35329359 DOI: 10.3390/ijerph19063675] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 12/22/2022]
Abstract
Objectives: Plasmodium knowlesi is a non-human parasite that causes zoonotic disease in humans. This systematic review aims to highlight and summarize studies describing human behaviors and activities that expose humans to mosquito bites. Design: English entries in PubMed, Web of Science, and Science Direct from 2010 to 2020 were systematically perused, and the results were synthesized. Methodological quality was assessed using the Joanna Briggs Institute quality appraisal checklists. Setting: Studies that described malaria preventive measures were included. Laboratory, in vivo, in vitro, and animal studies were excluded. Primary and secondary outcome measures: The main outcome of the review was findings from studies describing the behavior that exposed a person or a group to P. knowlesi infection. Results: Twelve eligible studies were of good or medium quality. Attitude, disease misconceptions, perceived threat of disease, lack of motivation, and supernatural or traditional beliefs causing individuals to seek treatment from traditional healers influenced the exposure of individuals or communities to P. knowlesi malaria. Other factors were forestry activities (2.48, 1.45–4.23,95% CI, p = 0.0010) and sleeping outdoors (3.611, 1.48–8.85, 95% CI, p = 0.0049). Conclusions: Future studies must consider the importance of human behavior and community perspective on the infection to provide novel information to improve the current zoonotic malaria programs. Policymakers should concentrate on understanding human behavior and activities that expose individuals or communities to mosquito bites, in order to better design socially feasible interventions.
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