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Ramli AH, Swain P, Mohd Fahmi MSA, Abas F, Leong SW, Tejo BA, Shaari K, Ali AH, Agustar HK, Awang R, Ng YL, Lau YL, Md Razali MA, Mastuki SN, Mohmad Misnan N, Mohd Faudzi SM, Kim CH. Preliminary insight on diarylpentanoids as potential antimalarials: In silico, in vitro pLDH and in vivo zebrafish toxicity assessment. Heliyon 2024; 10:e27462. [PMID: 38495201 PMCID: PMC10943399 DOI: 10.1016/j.heliyon.2024.e27462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 02/28/2024] [Accepted: 02/29/2024] [Indexed: 03/19/2024] Open
Abstract
Malaria remains a major public health problem worldwide, including in Southeast Asia. Chemotherapeutic agents such as chloroquine (CQ) are effective, but problems with drug resistance and toxicity have necessitated a continuous search for new effective antimalarial agents. Here we report on a virtual screening of ∼300 diarylpentanoids and derivatives, in search of potential Plasmodium falciparum lactate dehydrogenase (PfLDH) inhibitors with acceptable drug-like properties. Several molecules with binding affinities comparable to CQ were chosen for in vitro validation of antimalarial efficacy. Among them, MS33A, MS33C and MS34C are the most promising against CQ-sensitive (3D7) with EC50 values of 1.6, 2.5 and 3.1 μM, respectively. Meanwhile, MS87 (EC50 of 1.85 μM) shown the most active against the CQ-resistant Gombak A strain, and MS33A and MS33C the most effective P. knowlesi inhibitors (EC50 of 3.6 and 5.1 μM, respectively). The in vitro cytotoxicity of selected diarylpentanoids (MS33A, MS33C, MS34C and MS87) was tested on Vero mammalian cells to evaluate parasite selectivity (SI), showing moderate to low cytotoxicity (CC50 > 82 μM). In addition, MS87 exhibited a high SI and the lowest resistance index (RI), suggesting that MS87 may exert effective parasite inhibition with low resistance potential in the CQ-resistant P. falciparum strain. Furthermore, the in vivo toxicity of the molecules on early embryonic development, the cardiovascular system, heart rate, motor activity and apoptosis were assessed in a zebrafish animal model. The overall results indicate the preliminary potential of diarylpentanoids, which need further investigation for their development as new antimalarial agents.
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Affiliation(s)
- Amirah Hani Ramli
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang, 43400, Selangor, Malaysia
| | - Puspanjali Swain
- Department of Biology, Chungnam National University, Daejeon, 34134, South Korea
| | - Muhammad Syafiq Akmal Mohd Fahmi
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang, 43400, Selangor, Malaysia
| | - Faridah Abas
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang, 43400, Selangor, Malaysia
- Department of Food Science, Faculty of Food Science & Technology, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Sze Wei Leong
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Bimo Ario Tejo
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Khozirah Shaari
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang, 43400, Selangor, Malaysia
| | - Amatul Hamizah Ali
- Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, 43600, Selangor, Malaysia
| | - Hani Kartini Agustar
- Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, 43600, Selangor, Malaysia
| | - Rusdam Awang
- UPM - MAKNA Cancer Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Yee Ling Ng
- 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
| | | | - Siti Nurulhuda Mastuki
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang, 43400, Selangor, Malaysia
- Department of Biological Sciences and Biotechnology, Faculty of Science & Technology, Universiti Kebangsaan Malaysia, Bangi, 43600, Selangor, Malaysia
| | - Norazlan Mohmad Misnan
- Herbal Medicine Research Centre, Institute for Medical Research, National Institutes of Health, 40170, Shah Alam, Selangor Darul Ehsan, Malaysia
| | - Siti Munirah Mohd Faudzi
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang, 43400, Selangor, Malaysia
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon, 34134, South Korea
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Huber JH, Elliott M, Koepfli C, Perkins TA. The Impact of Emerging Plasmodium knowlesi on Accurate Diagnosis by Light Microscopy: A Systematic Review and Modeling Analysis. Am J Trop Med Hyg 2023; 108:61-68. [PMID: 36509046 PMCID: PMC9833074 DOI: 10.4269/ajtmh.21-1155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 07/05/2022] [Indexed: 12/14/2022] Open
Abstract
The five major Plasmodium spp. that cause human malaria appear similar under light microscopy, which raises the possibility that misdiagnosis could routinely occur in clinical settings. Assessing the extent of misdiagnosis is of particular importance for monitoring P. knowlesi, which cocirculates with the other Plasmodium spp. We performed a systematic review and meta-analysis of studies comparing the performance of microscopy and polymerase chain reaction (PCR) for diagnosing malaria in settings with co-circulation of the five Plasmodium spp. We assessed the extent to which co-circulation of Plasmodium parasites affects diagnostic outcomes. We fit a Bayesian hierarchical latent class model to estimate variation in microscopy sensitivity and specificity measured against PCR as the gold standard. Mean sensitivity of microscopy was low, yet highly variable across Plasmodium spp., ranging from 65.7% (95% confidence interval: 48.1-80.3%) for P. falciparum to 0.525% (95% confidence interval 0.0210-3.11%) for P. ovale. Observed PCR prevalence was positively correlated with estimated microscopic sensitivity and negatively correlated with estimated microscopic specificity, though the strength of the associations varied by species. Our analysis suggests that cocirculation of Plasmodium spp. undermines the accuracy of microscopy. Sensitivity was considerably lower for P. knowlesi, P. malariae, and P. ovale. The negative association between specificity and prevalence imply that less frequently encountered species may be misdiagnosed as more frequently encountered species. Together, these results suggest that the burden of P. knowlesi, P. malariae, and P. ovale may be underappreciated in a clinical setting.
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Affiliation(s)
- John H. Huber
- Address correspondence to John H. Huber, University of Notre Dame, 100 Galvin Life Sciences Center, Notre Dame, IN 46556. E-mail:
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Non-Human Primate Malaria Infections: A Review on the Epidemiology in Malaysia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19137888. [PMID: 35805545 PMCID: PMC9265734 DOI: 10.3390/ijerph19137888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 02/01/2023]
Abstract
Malaria remains a public health problem in many parts of the world, including Malaysia. Although Malaysia has been recognized as one of the countries free from indigenous human malaria since 2018, the rising trend of zoonotic malaria, particularly Plasmodium knowlesi cases, poses a threat to public health and is of great concern to the country’s healthcare system. We reviewed previously scattered information on zoonotic malaria infections in both Peninsular Malaysia and Malaysian Borneo to determine the epidemiology and distribution of emerging zoonotic malaria infections. Given the high prevalence of zoonotic malaria in Malaysia, efforts should be made to detect zoonotic malaria in humans, mosquito vectors, and natural hosts to ensure the success of the National Malaria Elimination Strategic Plan.
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Pramasivan S, Ngui R, Jeyaprakasam NK, Liew JWK, Low VL, Mohamed Hassan N, Wan Sulaiman WY, Jaraee R, Abdul Rahman R, Jelip J, Vythilingam I. Spatial distribution of Plasmodium knowlesi cases and their vectors in Johor, Malaysia: in light of human malaria elimination. Malar J 2021; 20:426. [PMID: 34715864 PMCID: PMC8555301 DOI: 10.1186/s12936-021-03963-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 10/21/2021] [Indexed: 12/03/2022] Open
Abstract
Background Plasmodium knowlesi, a simian malaria parasite infection, increases as Plasmodium falciparum and Plasmodium vivax infections decrease in Johor, Malaysia. Therefore, this study aimed to identify the distribution of vectors involved in knowlesi malaria transmission in Johor. This finding is vital in estimating hotspot areas for targeted control strategies. Methods Anopheles mosquitoes were collected from the location where P. knowlesi cases were reported. Cases of knowlesi malaria from 2011 to 2019 in Johor were analyzed. Internal transcribed spacers 2 (ITS2) and cytochrome c oxidase subunit I (COI) genes were used to identify the Leucosphyrus Group of Anopheles mosquitoes. In addition, spatial analysis was carried out on the knowlesi cases and vectors in Johor. Results One hundred and eighty-nine cases of P. knowlesi were reported in Johor over 10 years. Young adults between the ages of 20–39 years comprised 65% of the cases. Most infected individuals were involved in agriculture and army-related occupations (22% and 32%, respectively). Four hundred and eighteen Leucosphyrus Group Anopheles mosquitoes were captured during the study. Anopheles introlatus was the predominant species, followed by Anopheles latens. Spatial analysis by Kriging interpolation found that hotspot regions of P. knowlesi overlapped or were close to the areas where An. introlatus and An. latens were found. A significantly high number of vectors and P. knowlesi cases were found near the road within 0–5 km. Conclusions This study describes the distribution of P. knowlesi cases and Anopheles species in malaria-endemic transmission areas in Johor. Geospatial analysis is a valuable tool for studying the relationship between vectors and P. knowlesi cases. This study further supports that the Leucosphyrus Group of mosquitoes might be involved in transmitting knowlesi malaria cases in Johor. These findings may provide initial evidence to prioritize diseases and vector surveillance. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03963-0.
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Affiliation(s)
- Sandthya Pramasivan
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Romano Ngui
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.,Malaria Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak (UNIMAS), 94300, Kota Samarahan, Sarawak, Malaysia
| | | | - Jonathan Wee Kent Liew
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.,Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Van Lun Low
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Norzihan Mohamed Hassan
- Entomology & Pest Sector, Disease Control Division, Ministry of Health Malaysia, Putrajaya, Malaysia
| | | | - Ropiah Jaraee
- Entomology & Pest Unit, Johor State Health District Department, Johor, Malaysia
| | | | - Jenarun Jelip
- Disease Control Division, Ministry of Health Malaysia, Putrajaya, Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.
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Vythilingam I, Chua TH, Liew JWK, Manin BO, Ferguson HM. The vectors of Plasmodium knowlesi and other simian malarias Southeast Asia: challenges in malaria elimination. ADVANCES IN PARASITOLOGY 2021; 113:131-189. [PMID: 34620382 DOI: 10.1016/bs.apar.2021.08.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Plasmodium knowlesi, a simian malaria parasite of great public health concern has been reported from most countries in Southeast Asia and exported to various countries around the world. Currently P. knowlesi is the predominant species infecting humans in Malaysia. Besides this species, other simian malaria parasites such as P. cynomolgi and P. inui are also infecting humans in the region. The vectors of P. knowlesi and other Asian simian malarias belong to the Leucosphyrus Group of Anopheles mosquitoes which are generally forest dwelling species. Continual deforestation has resulted in these species moving into forest fringes, farms, plantations and human settlements along with their macaque hosts. Limited studies have shown that mosquito vectors are attracted to both humans and macaque hosts, preferring to bite outdoors and in the early part of the night. We here review the current status of simian malaria vectors and their parasites, knowledge of vector competence from experimental infections and discuss possible vector control measures. The challenges encountered in simian malaria elimination are also discussed. We highlight key knowledge gaps on vector distribution and ecology that may impede effective control strategies.
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Affiliation(s)
- Indra Vythilingam
- Department of Parasitology, University of Malaya, Kuala Lumpur, Malaysia.
| | - Tock Hing Chua
- Department of Pathobiology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Sabah Malaysia, Kota Kinabalu, Sabah, Malaysia.
| | - Jonathan Wee Kent Liew
- Department of Parasitology, University of Malaya, Kuala Lumpur, Malaysia; Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Benny O Manin
- Department of Pathobiology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Sabah Malaysia, Kota Kinabalu, Sabah, Malaysia
| | - Heather M Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, Scotland, United Kingdom
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Mahittikorn A, Masangkay FR, Kotepui KU, Milanez GDJ, Kotepui M. Quantification of the misidentification of Plasmodium knowlesi as Plasmodium malariae by microscopy: an analysis of 1569 P. knowlesi cases. Malar J 2021; 20:179. [PMID: 33836773 PMCID: PMC8033668 DOI: 10.1186/s12936-021-03714-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 03/26/2021] [Indexed: 02/26/2023] Open
Abstract
Background Plasmodium knowlesi is recognized as the fifth Plasmodium species causing malaria in humans. It is morphologically similar to the human malaria parasite Plasmodium malariae, so molecular detection should be used to clearly discriminate between these Plasmodium species. This study aimed to quantify the rate at which P. knowlesi is misidentified as P. malariae by microscopy in endemic and non-endemic areas. Methods The protocol of this systematic review was registered in the PROSPERO International Prospective Register of Systematic Reviews (ID = CRD42020204770). Studies reporting the misidentification of P. knowlesi as P. malariae by microscopy and confirmation of this by molecular methods in MEDLINE, Web of Science and Scopus were reviewed. The risk of bias in the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS). The pooled prevalence and 95% confidence interval (CI) of the misidentification of P. knowlesi as P. malariae by microscopy were estimated using a random effects model. Subgroup analysis of the study sites was performed to demonstrate any differences in the misidentification rates in different areas. Heterogeneity across the included studies was assessed and quantified using Cochran’s Q and I2 statistics, respectively. Publication bias in the included studies was assessed using the funnel plot, Egger’s test and contour-enhanced funnel plot. Results Among 375 reviewed studies, 11 studies with a total of 1569 confirmed P. knowlesi cases in humans were included. Overall, the pooled prevalence of the misidentification of P. knowlesi as P. malariae by microscopy was estimated at 57% (95% CI 37–77%, I2: 99.3%). Subgroup analysis demonstrated the highest rate of misidentification in Sawarak, Malaysia (87%, 95% CI 83–90%, I2: 95%), followed by Sabah, Malaysia (85%, 95% CI 79–92%, I2: 85.1%), Indonesia (16%, 95% CI 6–38%), and then Thailand (4%, 95% CI 2–9%, I2: 95%). Conclusion Although the World Health Organization (WHO) recommends that all P. malariae-positive diagnoses made by microscopy in P. knowlesi endemic areas be reported as P. malariae/P. knowlesi malaria, the possibility of microscopists misidentifying P. knowlesi as P. malariae is a diagnostic challenge. The use of molecular techniques in cases with malariae-like Plasmodium with high parasite density as determined by microscopy could help identify human P. knowlesi cases in non-endemic countries. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03714-1.
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Affiliation(s)
- Aongart Mahittikorn
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Frederick Ramirez Masangkay
- Department of Medical Technology, Institute of Arts and Sciences, Far Eastern University-Manila, Manila, Philippines
| | - Kwuntida Uthaisar Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Giovanni De Jesus Milanez
- Department of Medical Technology, Institute of Arts and Sciences, Far Eastern University-Manila, Manila, Philippines
| | - Manas Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand.
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Rahim MAFA, Munajat MB, Idris ZM. Malaria distribution and performance of malaria diagnostic methods in Malaysia (1980-2019): a systematic review. Malar J 2020; 19:395. [PMID: 33160393 PMCID: PMC7649001 DOI: 10.1186/s12936-020-03470-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 10/29/2020] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Malaysia has already achieved remarkable accomplishments in reaching zero indigenous human malaria cases in 2018. Prompt malaria diagnosis, surveillance and treatment played a key role in the country's elimination success. Looking at the dynamics of malaria distribution during the last decades might provide important information regarding the potential challenges of such an elimination strategy. This study was performed to gather all data available in term of prevalence or incidence on Plasmodium infections in Malaysia over the last four decades. METHODS A systematic review of the published English literature was conducted to identify malaria distribution from 1980 to June 2019 in Malaysia. Two investigators independently extracted data from PubMed, Scopus, Web of Science and Elsevier databases for original papers. RESULTS The review identified 46 epidemiological studies in Malaysia over the 39-year study period, on which sufficient information was available. The majority of studies were conducted in Malaysia Borneo (31/46; 67.4%), followed by Peninsular Malaysia (13/46; 28.3%) and in both areas (2/46; 4.3%). More than half of all studies (28/46; 60.9%) were assessed by both microscopy and PCR. Furthermore, there was a clear trend of decreases of all human malaria species with increasing Plasmodium knowlesi incidence rate throughout the year of sampling period. The summary estimates of sensitivity were higher for P. knowlesi than other Plasmodium species for both microscopy and PCR. Nevertheless, the specificities of summary estimates were similar for microscopy (40-43%), but varied for PCR (2-34%). CONCLUSIONS This study outlined the epidemiological changes in Plasmodium species distribution in Malaysia. Malaria cases shifted from predominantly caused by human malaria parasites to simian malaria parasites, which accounted for the majority of indigenous cases particularly in Malaysia Borneo. Therefore, malaria case notification and prompt malaria diagnosis in regions where health services are limited in Malaysia should be strengthened and reinforced to achieving the final goal of malaria elimination in the country.
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Affiliation(s)
- Mohd Amirul Fitri A Rahim
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia
| | - Mohd Bakhtiar Munajat
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia
| | - Zulkarnain Md Idris
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia.
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Chong ETJ, Neoh JWF, Lau TY, Lim YAL, Chai HC, Chua KH, Lee PC. Genetic diversity of circumsporozoite protein in Plasmodium knowlesi isolates from Malaysian Borneo and Peninsular Malaysia. Malar J 2020; 19:377. [PMID: 33092594 PMCID: PMC7579551 DOI: 10.1186/s12936-020-03451-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 10/16/2020] [Indexed: 11/25/2022] Open
Abstract
Background Understanding the genetic diversity of candidate genes for malaria vaccines such as circumsporozoite protein (csp) may enhance the development of vaccines for treating Plasmodium knowlesi. Hence, the aim of this study is to investigate the genetic diversity of non-repeat regions of csp in P. knowlesi from Malaysian Borneo and Peninsular Malaysia. Methods A total of 46 csp genes were subjected to polymerase chain reaction amplification. The genes were obtained from P. knowlesi isolates collected from different divisions of Sabah, Malaysian Borneo, and Peninsular Malaysia. The targeted gene fragments were cloned into a commercial vector and sequenced, and a phylogenetic tree was constructed while incorporating 168 csp sequences retrieved from the GenBank database. The genetic diversity and natural evolution of the csp sequences were analysed using MEGA6 and DnaSP ver. 5.10.01. A genealogical network of the csp haplotypes was generated using NETWORK ver. 4.6.1.3. Results The phylogenetic analysis revealed indistinguishable clusters of P. knowlesi isolates across different geographic regions, including Malaysian Borneo and Peninsular Malaysia. Nucleotide analysis showed that the csp non-repeat regions of zoonotic P. knowlesi isolates obtained in this study underwent purifying selection with population expansion, which was supported by extensive haplotype sharing observed between humans and macaques. Novel variations were observed in the C-terminal non-repeat region of csp. Conclusions The csp non-repeat regions are relatively conserved and there is no distinct cluster of P. knowlesi isolates from Malaysian Borneo and Peninsular Malaysia. Distinctive variation data obtained in the C-terminal non-repeat region of csp could be beneficial for the design and development of vaccines to treat P. knowlesi.
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Affiliation(s)
- Eric Tzyy Jiann Chong
- Biotechnology Programme, Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia
| | - Joveen Wan Fen Neoh
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia
| | - Tiek Ying Lau
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia
| | - Yvonne Ai-Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.,Centre of Excellence for Research in AIDS (CERiA), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Hwa Chia Chai
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Ping-Chin Lee
- Biotechnology Programme, Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia.
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Ramdzan AR, Ismail A, Mohd Zanib ZS. Prevalence of malaria and its risk factors in Sabah, Malaysia. Int J Infect Dis 2019; 91:68-72. [PMID: 31785400 DOI: 10.1016/j.ijid.2019.11.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/22/2019] [Accepted: 11/22/2019] [Indexed: 02/01/2023] Open
Abstract
OBJECTIVES The aim of this study was to determine the prevalence of malaria in Sabah and its potential risk factors. METHODS This cross-sectional study analysed secondary data obtained from the health clinics in Sabah, Malaysia from January to August 2016. The Pearson Chi-square test was used to analyse the relationships between malaria infection and socio-demographic characteristics. Multivariable logistic regression was performed in order to determine the risk factors for malaria in Sabah. RESULTS Out of 1222 patients, 410 (33.6%) had a laboratory-confirmed malaria infection. Infection by Plasmodium knowlesi accounted for the majority of malaria reports in Sabah (n=340, 82.9%). Multivariable analysis indicated that males (prevalence odds ratio 0.023, 95% confidence interval 0.012-0.047) and those living in a rural area (prevalence odds ratio 0.004, 95% confidence interval 0.002-0.009) were at higher risk 24.0-95.9) and those living in a rural area (adjusted odds ratio 212.6, 95% confidence interval 105.8-427.2) were at higher risk of acquiring a malaria infection. CONCLUSIONS Malaria infections in Sabah, Malaysia are common, with P. knowlesi being the most common malaria parasite. The infection was associated with several socio-demographic and geographical factors. Thus, mitigation measures should be considered to address modifiable risk factors for malaria infection.
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Affiliation(s)
- A R Ramdzan
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia; Department of Community and Family Medicine, Faculty of Medicine & Health Sciences, Universiti Malaysia Sabah, Sabah, Malaysia.
| | - A Ismail
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
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Chua TH, Manin BO, Vythilingam I, Fornace K, Drakeley CJ. Effect of different habitat types on abundance and biting times of Anopheles balabacensis Baisas (Diptera: Culicidae) in Kudat district of Sabah, Malaysia. Parasit Vectors 2019; 12:364. [PMID: 31345256 PMCID: PMC6659233 DOI: 10.1186/s13071-019-3627-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 07/19/2019] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND We investigated the effect of five common habitat types on the diversity and abundance of Anopheles spp. and on the biting rate and time of Anopheles balabacensis (currently the only known vector for Plasmodium knowlesi in Sabah) at Paradason village, Kudat, Sabah. The habitats were forest edge, playground area, longhouse, oil palm plantation and shrub-bushes area. Sampling of Anopheles was done monthly using the human landing catch method in all habitat types for 14 months (October 2013 to December 2014, excluding June 2014). The Anopheles species were morphologically identified and subjected to PCR assay for the detection of Plasmodium parasites. Generalised linear mixed models (GLMM) were applied to test the variation in abundance and biting rates of An. balabacensis in different habitat types. RESULTS A total of 1599 Anopheles specimens were collected in the village, of which about 90% were An. balabacensis. Anopheles balabacensis was present throughout the year and was the dominant Anopheles species in all habitat types. The shrub bushes habitat had the highest Anopheles species diversity while forest edge had the greatest number of Anopheles individuals caught. GLMM analysis indicated that An. balabacensis abundance was not affected by the type of habitats, and it was more active during the early and late night compared to predawn and dawn. PCR assay showed that 1.61% of the tested An. balabacensis were positive for malaria parasites, most of which were caught in oil palm estates and infected with one to two Plasmodium species. CONCLUSIONS The identification of infected vectors in a range of habitats, including agricultural and farming areas, illustrates the potential for humans to be exposed to P. knowlesi outside forested areas. This finding contributes to a growing body of evidence implicating environmental changes due to deforestation, expansion of agricultural and farming areas, and development of human settlements near to forest fringes in the emergence of P. knowlesi in Sabah.
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Affiliation(s)
- Tock H Chua
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia.
| | - Benny O Manin
- 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
| | - Kimberly Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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Chong ETJ, Neoh JWF, Lau TY, Lim YAL, Chua KH, Lee PC. Genetic and haplotype analyses targeting cytochrome b gene of Plasmodium knowlesi isolates of Malaysian Borneo and Peninsular Malaysia. Acta Trop 2018; 181:35-39. [PMID: 29409854 DOI: 10.1016/j.actatropica.2018.01.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 01/03/2018] [Accepted: 01/24/2018] [Indexed: 01/09/2023]
Abstract
Malaria is a notorious disease which causes major global morbidity and mortality. This study aims to investigate the genetic and haplotype differences of Plasmodium knowlesi (P. knowlesi) isolates in Malaysian Borneo and Peninsular Malaysia based on the molecular analysis of the cytochrome b (cyt b) gene. The cyt b gene of 49 P. knowlesi isolates collected from Sabah, Malaysian Borneo and Peninsular Malaysia was amplified using PCR, cloned into a commercialized vector and sequenced. In addition, 45 cyt b sequences were retrieved from humans and macaques bringing to a total of 94 cyt b gene nucleotide sequences for phylogenetic analysis. Genetic and haplotype analyses of the cyt b were analyzed using MEGA6 and DnaSP ver. 5.10.01. The haplotype genealogical linkage of cyt b was generated using NETWORK ver. 4.6.1.3. Our phylogenetic tree revealed the conservation of the cyt b coding sequences with no distinct cluster across different geographic regions. Nucleotide analysis of cyt b showed that the P. knowlesi isolates underwent purifying selection with population expansion, which was further supported by extensive haplotype sharing between the macaques and humans from Malaysian Borneo and Peninsular Malaysia in the median-joining network analysis. This study expands knowledge on conservation of the zoonotic P. knowlesi cyt b gene between Malaysian Borneo and Peninsular Malaysia.
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Affiliation(s)
- Eric Tzyy Jiann Chong
- Biotechnology Programme, Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Joveen Wan Fen Neoh
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Tiek Ying Lau
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Yvonne Ai-Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; Centre of Excellence for Research in AIDS (CERiA), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Ping-Chin Lee
- Biotechnology Programme, Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia; Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia.
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12
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Sarafraz S, Ghabouli Mehrabani N, Mirzaei Y, Jafari R, Ghabouli Mehrabani R, Rahnamaye Hayati V, Parsaei M, Fatollahzadeh M. Epidemiology of malaria in East Azerbaijan province, Iran, from 2001 to 2013. J Parasit Dis 2016; 40:813-7. [PMID: 27605789 PMCID: PMC4996197 DOI: 10.1007/s12639-014-0584-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 09/15/2014] [Indexed: 10/24/2022] Open
Abstract
Malaria is one of the most important parasitic diseases worldwide, which is characterized by high morbidity and mortality in tropical and subtropical regions. The aim of this study was to evaluate epidemiology of malaria in East Azerbaijan province, Iran, from 2001 to 2013. During 13 years, blood samples were taken from all suspected malaria cases using lancet and then peripheral blood smear was prepared using one blood drop. The smears were stained by Giemsa's stain and were examined under a light microscope with 1000X of magnification. All demographic variables and epidemiological recorded data were obtained from Health Center and were analyzed by SPSS v. 16 software using descriptive statistical tests. Total of 133 cases were fined to be infected by malaria in 13 years that the highest rate (54.13 %) was observed in Kaleybar county. One hundred and fifteen (86.46 %) and 18 (13.54 %) out of 133 infected individuals were male and female, respectively. Mean age of the infected people was 31.57 years. The most affected age group was 30-40 years. One hundred twenty seven (95.48 %) and 6 (4.52 %) cases were infected by Plasmodium vivax and Plasmodium falciparum, respectively. Based on the findings of this study, the incidence of malaria has been declined continuously over the past decade in East Azerbaijan province, Iran.
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Affiliation(s)
- Seddigheh Sarafraz
- Department of Medical Parasitology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
- East Azerbaijan Province Health Center, Tabriz Health Center, Tabriz, Iran
| | - Nader Ghabouli Mehrabani
- Department of Medical Parasitology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yaghoub Mirzaei
- East Azerbaijan Province Health Center, Tabriz Health Center, Tabriz, Iran
| | - Rasool Jafari
- Department of Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Vahid Rahnamaye Hayati
- Department of Medical Parasitology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahdi Parsaei
- East Azerbaijan Province Health Center, Tabriz Health Center, Tabriz, Iran
| | - Mohammad Fatollahzadeh
- Department of Medical Parasitology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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13
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Shearer FM, Huang Z, Weiss DJ, Wiebe A, Gibson HS, Battle KE, Pigott DM, Brady OJ, Putaporntip C, Jongwutiwes S, Lau YL, Manske M, Amato R, Elyazar IRF, Vythilingam I, Bhatt S, Gething PW, Singh B, Golding N, Hay SI, Moyes CL. Estimating Geographical Variation in the Risk of Zoonotic Plasmodium knowlesi Infection in Countries Eliminating Malaria. PLoS Negl Trop Dis 2016; 10:e0004915. [PMID: 27494405 PMCID: PMC4975412 DOI: 10.1371/journal.pntd.0004915] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/20/2016] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Infection by the simian malaria parasite, Plasmodium knowlesi, can lead to severe and fatal disease in humans, and is the most common cause of malaria in parts of Malaysia. Despite being a serious public health concern, the geographical distribution of P. knowlesi malaria risk is poorly understood because the parasite is often misidentified as one of the human malarias. Human cases have been confirmed in at least nine Southeast Asian countries, many of which are making progress towards eliminating the human malarias. Understanding the geographical distribution of P. knowlesi is important for identifying areas where malaria transmission will continue after the human malarias have been eliminated. METHODOLOGY/PRINCIPAL FINDINGS A total of 439 records of P. knowlesi infections in humans, macaque reservoir and vector species were collated. To predict spatial variation in disease risk, a model was fitted using records from countries where the infection data coverage is high. Predictions were then made throughout Southeast Asia, including regions where infection data are sparse. The resulting map predicts areas of high risk for P. knowlesi infection in a number of countries that are forecast to be malaria-free by 2025 (Malaysia, Cambodia, Thailand and Vietnam) as well as countries projected to be eliminating malaria (Myanmar, Laos, Indonesia and the Philippines). CONCLUSIONS/SIGNIFICANCE We have produced the first map of P. knowlesi malaria risk, at a fine-scale resolution, to identify priority areas for surveillance based on regions with sparse data and high estimated risk. Our map provides an initial evidence base to better understand the spatial distribution of this disease and its potential wider contribution to malaria incidence. Considering malaria elimination goals, areas for prioritised surveillance are identified.
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Affiliation(s)
- Freya M. Shearer
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Zhi Huang
- Malaria Atlas Project, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Daniel J. Weiss
- Malaria Atlas Project, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Antoinette Wiebe
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Harry S. Gibson
- Malaria Atlas Project, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Katherine E. Battle
- Malaria Atlas Project, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - David M. Pigott
- Institute of Health Metrics and Evaluation, University of Washington, Seattle, Washington, United States of America
| | - Oliver J. Brady
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Chaturong Putaporntip
- Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Somchai Jongwutiwes
- Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Magnus Manske
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, United Kingdom
| | - Roberto Amato
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, United Kingdom
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | | | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Samir Bhatt
- Malaria Atlas Project, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Peter W. Gething
- Malaria Atlas Project, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Balbir Singh
- Malaria Research Centre, Universiti Malaysia Sarawak, Kuching, Sarawak, Malaysia
| | - Nick Golding
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
- Department of BioSciences, University of Melbourne, Parkville, Victoria, Australia
| | - Simon I. Hay
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
- Institute of Health Metrics and Evaluation, University of Washington, Seattle, Washington, United States of America
| | - Catherine L. Moyes
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
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Fattahi Bafghi A, Hashemi A, Abolhasanizadeh S. Comparison of hematological aspects among children with Malaria and healthy children. IRANIAN JOURNAL OF PEDIATRIC HEMATOLOGY AND ONCOLOGY 2015; 5:89-92. [PMID: 26131347 PMCID: PMC4475629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Accepted: 04/10/2015] [Indexed: 10/28/2022]
Abstract
BACKGROUND Malaria is an acute and chronic illness characterized by paroxysms of fever, chills, sweating, fatigue, anemia, and splenomegaly. Most malarial deaths occur in infants and young children.Anemia in malaria has diverse pathophysiologic mechanisms such as direct invasion of Red cells, In the following, we presented comparison of hematological aspects: children with Malaria and healthy children. MATERIALS AND METHODS This was a lab trial study. Patients were referred and admitted to the pathobiology laboratory along with physical examination. Then, they underwent a complete blood count and the result of complete blood count was compared with healthy person in the same age. Out of 30 patients, with equally falciparum, vivax, and healthy .The hematological examination was performed. Finally, the data was analyzed using SPSS version 19 software. RESULTS The levels of HGB (P=0.001), HCT (P=0.001), MCV (P= 0.001), MCH (P=0.001), WBC (P=0.001), and Plt (P= 0.02) decreased significantly in children with falciparum and vivax malaria compared to healthy controls. The levels of RBC (P=0.49) increased significantly in children with falciparum and vivax malaria compared to controls. Blood culture at two times. To investigate malaria; blood smears taken after microscopic study of Plasmodium falciparum ring was observed. CONCLUSION Malaria is a multisystem disorder which can lead to many diseases. Physicians, especially those in endemic areas, should be aware of the varied manifestations and maintain in a high index of suspicion for the disease in order to that diagnose and treat timely and, morbidity and mortality.
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Affiliation(s)
- A Fattahi Bafghi
- 1.Associate Professor, Medical Parasitology and Mycology Department, school of Medicine, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran
| | - A Hashemi
- 2.Associate professor, Pediatric Hematology & Oncology Department and Editor in chief Iranian Journal of Pediatric Hematology & Oncology Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - S Abolhasanizadeh
- Msc Microbiology Student, microbiology Department, The international campus, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran
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15
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Human infections with Plasmodium knowlesi--zoonotic malaria. Clin Microbiol Infect 2015; 21:640-8. [PMID: 25843504 DOI: 10.1016/j.cmi.2015.03.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 03/09/2015] [Accepted: 03/19/2015] [Indexed: 11/21/2022]
Abstract
In 2004 a large focus of Plasmodium knowlesi malaria was reported in the human population in Sarawak, Malaysian Borneo. Plasmodium knowlesi, a parasite of the South-East Asian macaques (Macaca fascicularis and Macaca nemestrina), had entered the human population. Plasmodium knowlesi is transmitted by the leucosphyrus group of Anopheline mosquitoes and transmission is largely zoonotic and restricted to the jungle setting. Humans entering jungle transmission sites are at risk. Since 2004, human cases of P. knowlesi have been continuously reported in local communities and in travellers returning from South East Asia. Plasmodium knowlesi is the most common type of indigenous malaria reported in Malaysia. Infections are most often uncomplicated but at least 10% of patients report with severe malaria and 1-2% of cases have a fatal outcome. Parasitaemia is positively associated with the clinical and laboratory markers of severe malaria. The current literature on P. knowlesi, including epidemiology, natural hosts and vectors, pathogenesis, clinical descriptions, treatment and diagnosis, is reviewed. There are many gaps in our understanding of this disease that are highlighted here with suggestions for further research to inform pre-emptive control measures that would be required to prevent a full emergence of this parasite into the human population.
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16
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Cramer JP. Plasmodium knowlesi malaria: Overview Focussing on Travel-Associated Infections. Curr Infect Dis Rep 2015; 17:469. [PMID: 25821192 DOI: 10.1007/s11908-015-0469-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In 2004, Plasmodium knowlesi was first recognised as a relevant cause of human malaria in Southeast Asia. Since then, P. knowlesi has been described from all Southeast Asian countries except Laos and has become well-established as the fifth human malaria parasite and the first significant zoonotic Plasmodium species. As countries endemic for P. knowlesi malaria are among the most popular and most highly visited international destinations, travel medicine experts should be aware about disease and risks including prophylactic and therapeutic measures. Between 2005 and 2012, 15 cases of P. knowlesi malaria have been recognised and published in international travellers. Male gender and travel to rural/forested areas with contact to wild monkeys are risk factors for P. knowlesi infection. The present review gives an overview on current literature on the P. knowlesi parasite and summarises recent findings related to epidemiology, diagnostics, treatment and prophylaxis focussing on travellers.
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Affiliation(s)
- Jakob P Cramer
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Strasse 74, 20359, Hamburg, Germany,
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17
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Lee PC, Chong ETJ, Anderios F, Al Lim Y, Chew CH, Chua KH. Molecular detection of human Plasmodium species in Sabah using PlasmoNex™ multiplex PCR and hydrolysis probes real-time PCR. Malar J 2015; 14:28. [PMID: 25651852 PMCID: PMC4318434 DOI: 10.1186/s12936-015-0542-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 01/05/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria is a vector borne-parasitic disease transmitted through the bite of the infective female Anopheles mosquitoes. Five Plasmodium species have been recognized by World Health Organization (WHO) as the causative agents of human malaria. Generally, microscopic examination is the gold standard for routine malaria diagnosis. However, molecular PCR assays in many cases have shown improvement on the sensitivity and specificity over microscopic or other immunochromatographic assays. METHODS The present study attempts to screen 207 suspected malaria samples from patients seeking treatment in clinics around Sabah state, Malaysia, using two panels of multiplex PCRs, conventional PCR system (PlasmoNex™) and real-time PCR based on hydrolysis probe technology. Discordance results between two PCR assays were further confirmed by sequencing using 18S ssu rRNA species-specific primers. RESULTS Of the 207 malaria samples, Plasmodium knowlesi (73.4% vs 72.0%) was the most prevalent species based on two PCR assays, followed by Plasmodium falciparum (15.9% vs 17.9%), and Plasmodium vivax (9.7% vs 7.7%), respectively. Neither Plasmodium malariae nor Plasmodium ovale was detected in this study. Nine discrepant species identification based on both the PCR assays were further confirmed through DNA sequencing. Species-specific real-time PCR only accurately diagnosed 198 of 207 (95.7%) malaria samples up to species level in contrast to PlasmoNex™ assay which had 100% sensitivity and specificity based on sequencing results. CONCLUSIONS Multiplex PCR accelerate the speed in the diagnosis of malaria. The PlasmoNex™ PCR assay seems to be more accurate than real-time PCR in the speciation of all five human malaria parasites. The present study also showed a significant increase of the potential fatal P. knowlesi infection in Sabah state as revealed by molecular PCR assays.
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Affiliation(s)
| | | | | | | | | | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia.
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Abba K, Kirkham AJ, Olliaro PL, Deeks JJ, Donegan S, Garner P, Takwoingi Y. Rapid diagnostic tests for diagnosing uncomplicated non-falciparum or Plasmodium vivax malaria in endemic countries. Cochrane Database Syst Rev 2014; 2014:CD011431. [PMID: 25519857 PMCID: PMC4453861 DOI: 10.1002/14651858.cd011431] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND In settings where both Plasmodium vivax and Plasmodium falciparum infection cause malaria, rapid diagnostic tests (RDTs) need to distinguish which species is causing the patients' symptoms, as different treatments are required. Older RDTs incorporated two test lines to distinguish malaria due to P. falciparum, from malaria due to any other Plasmodium species (non-falciparum). These RDTs can be classified according to which antibodies they use: Type 2 RDTs use HRP-2 (for P. falciparum) and aldolase (all species); Type 3 RDTs use HRP-2 (for P. falciparum) and pLDH (all species); Type 4 use pLDH (fromP. falciparum) and pLDH (all species).More recently, RDTs have been developed to distinguish P. vivax parasitaemia by utilizing a pLDH antibody specific to P. vivax. OBJECTIVES To assess the diagnostic accuracy of RDTs for detecting non-falciparum or P. vivax parasitaemia in people living in malaria-endemic areas who present to ambulatory healthcare facilities with symptoms suggestive of malaria, and to identify which types and brands of commercial test best detect non-falciparum and P. vivax malaria. SEARCH METHODS We undertook a comprehensive search of the following databases up to 31 December 2013: Cochrane Infectious Diseases Group Specialized Register; MEDLINE; EMBASE; MEDION; Science Citation Index; Web of Knowledge; African Index Medicus; LILACS; and IndMED. SELECTION CRITERIA Studies comparing RDTs with a reference standard (microscopy or polymerase chain reaction) in blood samples from a random or consecutive series of patients attending ambulatory health facilities with symptoms suggestive of malaria in non-falciparum endemic areas. DATA COLLECTION AND ANALYSIS For each study, two review authors independently extracted a standard set of data using a tailored data extraction form. We grouped comparisons by type of RDT (defined by the combinations of antibodies used), and combined in meta-analysis where appropriate. Average sensitivities and specificities are presented alongside 95% confidence intervals (95% CI). MAIN RESULTS We included 47 studies enrolling 22,862 participants. Patient characteristics, sampling methods and reference standard methods were poorly reported in most studies. RDTs detecting 'non-falciparum' parasitaemiaEleven studies evaluated Type 2 tests compared with microscopy, 25 evaluated Type 3 tests, and 11 evaluated Type 4 tests. In meta-analyses, average sensitivities and specificities were 78% (95% CI 73% to 82%) and 99% (95% CI 97% to 99%) for Type 2 tests, 78% (95% CI 69% to 84%) and 99% (95% CI 98% to 99%) for Type 3 tests, and 89% (95% CI 79% to 95%) and 98% (95% CI 97% to 99%) for Type 4 tests, respectively. Type 4 tests were more sensitive than both Type 2 (P = 0.01) and Type 3 tests (P = 0.03).Five studies compared Type 3 tests with PCR; in meta-analysis, the average sensitivity and specificity were 81% (95% CI 72% to 88%) and 99% (95% CI 97% to 99%) respectively. RDTs detecting P.vivax parasitaemiaEight studies compared pLDH tests to microscopy; the average sensitivity and specificity were 95% (95% CI 86% to 99%) and 99% (95% CI 99% to 100%), respectively. AUTHORS' CONCLUSIONS RDTs designed to detect P. vivax specifically, whether alone or as part of a mixed infection, appear to be more accurate than older tests designed to distinguish P. falciparum malaria from non-falciparum malaria. Compared to microscopy, these tests fail to detect around 5% ofP. vivax cases. This Cochrane Review, in combination with other published information about in vitro test performance and stability in the field, can assist policy-makers to choose between the available RDTs.
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Affiliation(s)
- Katharine Abba
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK.
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Yusof R, Lau YL, Mahmud R, Fong MY, Jelip J, Ngian HU, Mustakim S, Hussin HM, Marzuki N, Mohd Ali M. High proportion of knowlesi malaria in recent malaria cases in Malaysia. Malar J 2014; 13:168. [PMID: 24886266 PMCID: PMC4016780 DOI: 10.1186/1475-2875-13-168] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 04/28/2014] [Indexed: 01/04/2023] Open
Abstract
Background Plasmodium knowlesi is a simian parasite that has been recognized as the fifth species causing human malaria. Naturally-acquired P. knowlesi infection is widespread among human populations in Southeast Asia. The aim of this epidemiological study was to determine the incidence and distribution of malaria parasites, with a particular focus on human P. knowlesi infection in Malaysia. Methods A total of 457 microscopically confirmed, malaria-positive blood samples were collected from 22 state and main district hospitals in Malaysia between September 2012 and December 2013. Nested PCR assay targeting the 18S rRNA gene was used to determine the infecting Plasmodium species. Results A total of 453 samples were positive for Plasmodium species by using nested PCR assay. Plasmodium knowlesi was identified in 256 (56.5%) samples, followed by 133 (29.4%) cases of Plasmodium vivax, 49 (10.8%) cases of Plasmodium falciparum, two (0.4%) cases of Plasmodium ovale and one (0.2%) case of Plasmodium malariae. Twelve mixed infections were detected, including P. knowlesi/P. vivax (n = 10), P. knowlesi/P. falciparum (n = 1), and P. falciparum/P. vivax (n = 1). Notably, P. knowlesi (Included mixed infections involving P. knowlesi (P. knowlesi/P. vivax and P. knowlesi /P. falciparum)) showed the highest proportion in Sabah (84/115 cases, prevalence of 73.0%), Sarawak (83/120, 69.2%), Kelantan (42/56, 75.0%), Pahang (24/25, 96.0%), Johor (7/9, 77.8%), and Terengganu (4/5, 80.0%,). In contrast, the rates of P. knowlesi infection in Selangor and Negeri Sembilan were found to be 16.2% (18/111 cases) and 50.0% (5/10 cases), respectively. Sample of P. knowlesi was not obtained from Kuala Lumpur, Melaka, Perak, Pulau Pinang, and Perlis during the study period, while a microscopically-positive sample from Kedah was negative by PCR. Conclusion In addition to Sabah and Sarawak, which have been known for high prevalence of P. knowlesi infection, the findings from this study highlight the widespread distribution of P. knowlesi in many Peninsular Malaysia states.
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Affiliation(s)
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, Tropical Infectious Disease Research and Education Center (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia.
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Jeremiah S, Janagond AB, Parija SC. Challenges in diagnosis of Plasmodium knowlesi infections. Trop Parasitol 2014; 4:25-30. [PMID: 24754023 PMCID: PMC3992798 DOI: 10.4103/2229-5070.129156] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 03/20/2014] [Indexed: 11/15/2022] Open
Abstract
Plasmodium knowlesi is the fifth species of Plasmodium recently identified to cause human malaria. Infections with P. knowlesi are currently being reported from South-East Asian countries and the incidence is on the rise with a possibility of spread to the geographically contiguous countries. P. knowlesi infections can result in a high degree of parasitemia causing severe malaria in a larger proportion of infected individuals. If detected early and treated with appropriate antimicrobials, these infections show a significant clinical improvement. The widely used microscopic methods usually misidentify P. knowlesi as the less pathogenic Plasmodium malariae leading to inadequate therapy and adverse clinical outcomes. The currently popular rapid immuno-chromatographic card tests have a very low sensitivity in diagnosing knowlesi malaria and can erroneously report P. knowlesi as other Plasmodia and vice-versa. At present molecular methods are the most efficacious in diagnosing P. knowlesi infections, but these tests can produce a false positive report in Plasmodium vivax infections and require expensive equipment and trained personnel. An ideal diagnostic test for P. knowlesi infections, which is potent, cost-effective and practically feasible in the resource limited setting is yet to be developed.
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Affiliation(s)
- Ss Jeremiah
- Department of Microbiology, Velammal Medical College Hospital and Research Institute, Madurai, Tamil Nadu, India
| | - Anand B Janagond
- Department of Microbiology, Velammal Medical College Hospital and Research Institute, Madurai, Tamil Nadu, India
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Hakimi H, Kawai S, Kawazu SI. Molecular epidemiology of the emerging human malaria parasite "Plasmodium knowlesi". Trop Parasitol 2014; 4:20-4. [PMID: 24754022 PMCID: PMC3992797 DOI: 10.4103/2229-5070.129154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 03/20/2014] [Indexed: 12/02/2022] Open
Abstract
Malaria is the most important parasitic disease with global concern. Plasmodium knowlesi recently has emerged from its natural simian host as a significant cause of human malaria, particularly in Malaysian Borneo. Therefore, it has been added as the fifth human Plasmodium specie which is widely distributed in Southeast Asia. Recent developments of new molecular tools enhanced our understanding about the key features of this malaria parasite. Here, we review some of the ways in which molecular approaches might be used for epidemiology of P. knowlesi and finally lead to an efficient control of malaria.
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Affiliation(s)
- Hassan Hakimi
- Department of Disease Control, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Satoru Kawai
- Laboratory of Tropical Medicine and Parasitology, Institute of International Education and Research, Dokkyo Medical University, Mibu, Tochigi, Japan
| | - Shin-Ichiro Kawazu
- Department of Disease Control, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
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Plasmodium knowlesi in travellers, update 2014. Int J Infect Dis 2014; 22:55-64. [PMID: 24631521 DOI: 10.1016/j.ijid.2013.12.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 12/16/2013] [Accepted: 12/19/2013] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES Since the initial discovery of Plasmodium knowlesi in Malaysia, cases have been reported from several neighbouring countries. Tourism has also resulted in an increasing number of cases diagnosed in Europe, America, and Oceania. In this review we focus on the risk of the travel-associated acquisition of P. knowlesi malaria. METHODS A search of the literature in PubMed was carried out to identify articles and literature on the distribution of P. knowlesi infections in Southeast Asia and details of its acquisition and importation by travellers to other continents. The cut-off date for the search was December 1, 2013. Search words used were: "Plasmodium knowlesi", "Plasmodium knowlesi infections", "Plasmodium knowlesi travellers", "Plasmodium knowlesi prevalence", "Plasmodium knowlesi host", "Plasmodium knowlesi vector" "Plasmodium knowlesi RDT", and "Plasmodium knowlesi Malaysia". Traveller numbers to Malaysia were obtained from the Tourism Malaysia website. RESULTS A total of 103 articles were found. Using a selection of these and others identified from the reference lists of the papers, we based our review on a total of 66 articles. RESULTS P. knowlesi malaria appears to be the most common malaria species in Malaysian Borneo and is also widely distributed on the Malaysian mainland. Furthermore, locally transmitted cases of P. knowlesi malaria have been reported in Thailand, the Philippines, Vietnam, Singapore, Myanmar, Indonesian Borneo, and Cambodia. Two cases have been reported from non-endemic countries in Asia (Japan and Taiwan) in people with a history of travel to Malaysia and the Philippines. Twelve cases were imported to their home countries by travellers from other continents: two from the USA, two from the Netherlands, two from Germany, and one each from Spain, France, Sweden, Finland, Australia, and New Zealand. In most cases, the infection was associated with a trip to or near forested areas. The symptoms were fever (n=12), headache (n=6), chills (n=6), nausea (n=4), myalgia (n=3), back pain (n=3), abdominal problems (n=1), anorexia (n=2), fatigue (n=2), malaise (n=1), arthralgia (n=1), sore throat (n=1) vomiting (n=2), and jaundice (n=1). All patients were treated successfully with currently available antimalaria treatments. The identification of the pathogen by microscopy can be problematic due to the morphological similarity of P. knowlesi to Plasmodium malariae. CONCLUSION P. knowlesi appears to be a threat not only to the local population in Malaysia, but also to the estimated 25 million annual tourists and occupational travellers to Malaysia, especially those who visit rural, forested areas of the country. The P. knowlesi risk is not limited to Malaysia, and travellers from Southeast Asia presenting with possible malaria should be considered for a diagnostic work-up that includes P. knowlesi.
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Abstract
ODCase is a highly proficient enzyme responsible for the decarboxylation of orotidine monophosphate to generate uridine monophosphate. ODCase has attracted early attention due to its interesting mechanism of catalysis. In order to exploit therapeutic advantages due to the inhibition of ODCase, one must have selective inhibitors of this enzyme from the pathogen, or a dysregulated molecular mechanism involving ODCase. ODCase inhibitors have potential applications as anticancer agents, antiviral agents, antimalarial agents and potentially act against other parasitic diseases. A variety of C6-substituted uridine monophosphate derivatives have shown excellent inhibition of ODCase. 6-iodouridine is a potent inhibitor of the malaria parasite, and its monophosphate form covalently inhibits ODCase. A variety of inhibitors of ODCase with potential applications as therapeutic agents are discussed in this review.
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Calderaro A, Piccolo G, Gorrini C, Rossi S, Montecchini S, Dell'Anna ML, De Conto F, Medici MC, Chezzi C, Arcangeletti MC. Accurate identification of the six human Plasmodium spp. causing imported malaria, including Plasmodium ovale wallikeri and Plasmodium knowlesi. Malar J 2013; 12:321. [PMID: 24034175 PMCID: PMC3847200 DOI: 10.1186/1475-2875-12-321] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 09/09/2013] [Indexed: 11/20/2022] Open
Abstract
Background Accurate identification of Plasmodium infections in non-endemic countries is of critical importance with regard to the administration of a targeted therapy having a positive impact on patient health and management and allowing the prevention of the risk of re-introduction of endemic malaria in such countries. Malaria is no longer endemic in Italy where it is the most commonly imported disease, with one of the highest rates of imported malaria among European non-endemic countries including France, the UK and Germany, and with a prevalence of 24.3% at the University Hospital of Parma. Molecular methods showed high sensitivity and specificity and changed the epidemiology of imported malaria in several non-endemic countries, highlighted a higher prevalence of Plasmodium ovale, Plasmodium vivax and Plasmodium malariae underestimated by microscopy and, not least, brought to light both the existence of two species of P. ovale (Plasmodium ovale curtisi and Plasmodium ovale wallikeri) and the infection in humans by Plasmodium knowlesi, otherwise not detectable by microscopy. Methods In this retrospective study an evaluation of two real-time PCR assays able to identify P. ovale wallikeri, distinguishing it from P. ovale curtisi, and to detect P. knowlesi, respectively, was performed applying them on a subset of 398 blood samples belonging to patients with the clinical suspicion of malaria. Results These assays revealed an excellent analytical sensitivity and no cross-reactivity versus other Plasmodium spp. infecting humans, suggesting their usefulness for an accurate and complete diagnosis of imported malaria. Among the 128 patients with malaria, eight P. ovale curtisi and four P. ovale wallikeri infections were detected, while no cases of P. knowlesi infection were observed. Discussion and conclusions Real-time PCR assays specific for P. ovale wallikeri and P. knowlesi were included in the panel currently used in the University Hospital of Parma for the diagnosis of imported malaria, accomplishing the goal of adhering to the recommendations of the World Health Organization to countries that are malaria-free to include the improvement of the early diagnosis of all cases of imported malaria.
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Affiliation(s)
- Adriana Calderaro
- Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Surgery, University of Parma, Viale A, Gramsci 14, Parma, Italy.
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