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Lo E, Nguyen J, Oo W, Hemming-Schroeder E, Zhou G, Yang Z, Cui L, Yan G. Examining Plasmodium falciparum and P. vivax clearance subsequent to antimalarial drug treatment in the Myanmar-China border area based on quantitative real-time polymerase chain reaction. BMC Infect Dis 2016; 16:154. [PMID: 27084511 PMCID: PMC4833920 DOI: 10.1186/s12879-016-1482-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 03/25/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recent emergence of artemisinin-resistant P. falciparum has posed a serious hindrance to the elimination of malaria in the Greater Mekong Subregion. Parasite clearance time, a measure of change in peripheral parasitaemia in a sequence of samples taken after treatment, can be used to reflect the susceptibility of parasites or the efficiency of antimalarials. The association of genetic polymorphisms and artemisinin resistance has been documented. This study aims to examine clearance time of P. falciparum and P. vivax parasitemia as well as putative gene mutations associated with residual or recurred parasitemia in Myanmar. METHODS A total of 63 P. falciparum and 130 P. vivax samples collected from two internally-displaced populations and one surrounding village were examined for parasitemia changes. At least four samples were taken from each patient, at the first day of diagnosis up to 3 months following the initial treatment. The amount of parasite gene copy number was estimated using quantitative real-time PCR based on a species-specific region of the 18S rRNA gene. For samples that showed residual or recurred parasitemia after treatment, microsatellites were used to identify the 'post-treatment' parasite genotype and compared such with the 'pre-treatment' genotype. Mutations in genes pfcrt, pfmdr1, pfatp6, pfmrp1 and pfK13 that are potentially associated with ACT resistance were examined to identify if mutation is a factor for residual or persistent parasitemia. RESULTS Over 30% of the P. falciprium infections showed delayed clearance of parasitemia after 2-3 days of treatment and 9.5% showed recurred parasitemia. Mutations in codon 876 of the pfmrp1 corroborated significance association with slow clearance time. However, no association was observed in the variation in pfmdr1 gene copy number as well as mutations of various codonsinpfatp6, pfcrt, and pfK13 with clearance time. For P. vivax, over 95% of the infections indicated cleared parasitemia at days 2-3 of treatment. Four samples were found to be re-infected with new parasite strains based on microsatellite genotypes after initial treatment. CONCLUSION The appearance of P.falciparum infected samples showing delayed clearance or recurred parasitemia after treatment raises concerns on current treatment and ACT drug resistance.
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Affiliation(s)
- Eugenia Lo
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
| | - Jennifer Nguyen
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
| | - Winny Oo
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
| | | | - Guofa Zhou
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
| | - Zhaoqing Yang
- />Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Liwang Cui
- />Department of Entomology, Pennsylvania State University, University Park, PA USA
| | - Guiyun Yan
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
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Novotny J, Singh A, Dysoley L, Sovannaroth S, Rekol H. Evidence of successful malaria case management policy implementation in Cambodia: results from national ACTwatch outlet surveys. Malar J 2016; 15:194. [PMID: 27059952 PMCID: PMC4826540 DOI: 10.1186/s12936-016-1200-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 03/01/2016] [Indexed: 01/11/2023] Open
Abstract
Background For over a decade, Cambodia has implemented a number of policies and innovative strategies to increase access to quality malaria case management services and address the drivers of multi-drug resistance. This paper utilizes outlet survey trend data collected by the ACTwatch project to demonstrate how changes in Cambodian policy and strategies have led to shifts in anti-malarial markets. Methods Anti-malarial ACTwatch outlet surveys were conducted in Cambodia in 2009 (June–July), 2011 (June–August) and 2013 (September–October). A census of all outlets with the potential to sell or distribute anti-malarials was conducted within a nationally representative sample of communes. Drug information, sales/distribution in the previous week, and retail price were collected for each anti-malarial in stock. Information on availability of malaria blood testing was also collected. Results A total of 7833 outlets were enumerated in 2009, 18,584 in 2011, and 16,153 in 2013. The percentage of public health facilities with at least one anti-malarial in stock on the day of the survey increased between 2009 (65.8 %) and 2011 (90.0 %) and remained high in 2013 (82.0 %). Similar trends were found for village malaria workers (VMW). Overall, private sector availability of anti-malarials declined over time and varied by outlet type. By 2013 most anti-malarial stocking public health facilities (81.5 %), VMW (95.4 %), private for-profit health facilities (64.8 %), and pharmacies (71.9 %) had the countries first-line artemisinin-based combination therapy (ACT) treatment in stock. In 2013, 60 % of anti-malarials were delivered through the private sector, 40 % through the public sector, and the most common anti-malarial to be sold or distributed was the first-line ACT, comprising 62.8 % of the national market share. Oral artemisinin monotherapy, which had accounted for 6 % of total anti-malarial market share in 2009, was no longer reportedly sold/distributed in 2013. Malaria blood testing availability remained high over time among public facilities and VMW, with availability over 90 % in 2011 and 2013. Moderate availability was observed in the private sector. Conclusions Continued implementation of successful public and private sector strategies in support of evolving malaria drug treatment policies will be important to protect the efficacy of anti-malarial medicines and ultimately facilitate malaria elimination in Cambodia by 2025. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1200-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Joe Novotny
- Clinton Health Access Initiative, #7B, Str. 81 and corner Str. 109, Sangkat Boeung Raing, Khan Don Penh, Phnom Penh, Cambodia
| | - Amandeep Singh
- Clinton Health Access Initiative, #7B, Str. 81 and corner Str. 109, Sangkat Boeung Raing, Khan Don Penh, Phnom Penh, Cambodia
| | - Lek Dysoley
- Cambodia National Centre of Entomology, Parasitological and Malaria control, House 372, St Monivong Vong, Boeung Keng Kang I, Chamcar Mon, Phnom Penh, Cambodia.,School of Public Health, National Institute of Public Health, Phnom Penh, Cambodia
| | - Siv Sovannaroth
- Cambodia National Centre of Entomology, Parasitological and Malaria control, House 372, St Monivong Vong, Boeung Keng Kang I, Chamcar Mon, Phnom Penh, Cambodia
| | - Huy Rekol
- Cambodia National Centre of Entomology, Parasitological and Malaria control, House 372, St Monivong Vong, Boeung Keng Kang I, Chamcar Mon, Phnom Penh, Cambodia
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103
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Tun KM, Jeeyapant A, Imwong M, Thein M, Aung SSM, Hlaing TM, Yuentrakul P, Promnarate C, Dhorda M, Woodrow CJ, Dondorp AM, Ashley EA, Smithuis FM, White NJ, Day NPJ. Parasite clearance rates in Upper Myanmar indicate a distinctive artemisinin resistance phenotype: a therapeutic efficacy study. Malar J 2016; 15:185. [PMID: 27036739 PMCID: PMC4815199 DOI: 10.1186/s12936-016-1240-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/16/2016] [Indexed: 01/23/2023] Open
Abstract
Background Artemisinin resistance in Plasmodium falciparum extends across Southeast Asia where it is associated with worsening partner drug resistance and a decline in the efficacy of frontline artemisinin-based combination therapy. Dihydroartemisinin-piperaquine (DP) is an essential component of preventive and curative treatment in the region, but its therapeutic efficacy has fallen in Cambodia. Methods A prospective clinical and parasitological evaluation of DP was conducted at two sites in Upper Myanmar between August 2013 and December 2014, enrolling 116 patients with acute uncomplicated falciparum malaria. Patients received DP orally for 3 days together with primaquine 0.25 mg/kg on admission. Parasite clearance half-lives based on 6 hourly blood smears, and day 42 therapeutic responses were assessed as well as parasite K13 genotypes. Results Median parasite clearance half-life was prolonged, and clearance half-life was greater than 5 h in 21 % of patients. Delayed parasite clearance was significantly associated with mutations in the propeller region of the parasite k13 gene. The k13 F446I mutation was found in 25.4 % of infections and was associated with a median clearance half-life of 4.7 h compared with 2.7 h for infections without k13 mutations (p < 0.001). There were no failures after 42 days of follow-up, although 18 % of patients had persistent parasitaemia on day 3. Conclusion The dominant k13 mutation observed in Upper Myanmar, F446I, appears to be associated with an intermediate rate of parasite clearance compared to other common mutations described elsewhere in the Greater Mekong Subregion. Discerning this phenotype requires relatively detailed clearance measurements, highlighting the importance of methodology in assessing artemisinin resistance. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1240-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kyaw Myo Tun
- Defence Services Medical Research Centre, Naypyitaw, Myanmar.,Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
| | - Atthanee Jeeyapant
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Min Thein
- Defence Services Medical Research Centre, Naypyitaw, Myanmar
| | | | | | - Prayoon Yuentrakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand
| | | | - Mehul Dhorda
- Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.,Worldwide Antimalarial Resistance Network (WWARN), Bangkok, Thailand
| | - Charles J Woodrow
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Elizabeth A Ashley
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand
| | - Frank M Smithuis
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.,Medical Action Myanmar, Yangon, Myanmar
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand. .,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.
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Abstract
The current epidemic of artemisinin resistant Plasmodium falciparum in Southeast Asia is the result of a soft selective sweep involving at least 20 independent kelch13 mutations. In a large global survey, we find that kelch13 mutations which cause resistance in Southeast Asia are present at low frequency in Africa. We show that African kelch13 mutations have originated locally, and that kelch13 shows a normal variation pattern relative to other genes in Africa, whereas in Southeast Asia there is a great excess of non-synonymous mutations, many of which cause radical amino-acid changes. Thus, kelch13 is not currently undergoing strong selection in Africa, despite a deep reservoir of variations that could potentially allow resistance to emerge rapidly. The practical implications are that public health surveillance for artemisinin resistance should not rely on kelch13 data alone, and interventions to prevent resistance must account for local evolutionary conditions, shown by genomic epidemiology to differ greatly between geographical regions. DOI:http://dx.doi.org/10.7554/eLife.08714.001 Malaria is an infectious disease caused by a microscopic parasite called Plasmodium, which is transferred between humans by mosquitos. One species of malaria parasite called Plasmodium falciparum can cause particularly severe and life-threatening forms of the disease. Currently, the most widely used treatment for P. falciparum infections is artemisinin combination therapy, a treatment that combines the drug artemisinin (or a closely related molecule) with another antimalarial drug. However, resistance to artemisinin has started to spread throughout Southeast Asia. Artemisinin resistance is caused by mutations in a parasite gene called kelch13, and researchers have identified over 20 different mutations in P. falciparum that confer artemisinin resistance. The diversity of mutations involved, and the fact that the same mutation can arise independently in different locations, make it difficult to track the spread of resistance using conventional molecular marker approaches. Here, Amato, Miotto et al. sequenced the entire genomes of more than 3,000 clinical samples of P. falciparum from Southeast Asia and Africa, collected as part of a global network of research groups called the MalariaGEN Plasmodium falciparum Community Project. Amato, Miotto et al. found that African parasites had independently acquired many of the same kelch13 mutations that are known to cause resistance to artemisinin in Southeast Asia. However the kelch13 mutations seen in Africa remained at low levels in the parasite population, and appeared to be under much less pressure for evolutionary selection than those found in Southeast Asia. These findings demonstrate that the emergence and spread of resistance to antimalarial drugs does not depend solely on the mutational process, but also on other factors that influence whether the mutations will spread in the population. Understanding how this is affected by different patterns of drug treatments and other environmental conditions will be important in developing more effective strategies for combating malaria. DOI:http://dx.doi.org/10.7554/eLife.08714.002
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105
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Win AA, Imwong M, Kyaw MP, Woodrow CJ, Chotivanich K, Hanboonkunupakarn B, Pukrittayakamee S. K13 mutations and pfmdr1 copy number variation in Plasmodium falciparum malaria in Myanmar. Malar J 2016; 15:110. [PMID: 26911145 PMCID: PMC4765153 DOI: 10.1186/s12936-016-1147-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 02/04/2016] [Indexed: 11/11/2022] Open
Abstract
Background Artemisinin-based combination therapy has been first-line treatment for falciparum malaria in Myanmar since 2005. The wide extent of artemisinin resistance in the Greater Mekong sub-region and the presence of mefloquine resistance at the Myanmar-Thailand border raise concerns over resistance patterns in Myanmar. The availability of molecular markers for resistance to both drugs enables assessment even in remote malaria-endemic areas. Methods A total of 250 dried blood spot samples collected from patients with Plasmodium falciparum malarial infection in five malaria-endemic areas across Myanmar were analysed for kelch 13 sequence (k13) and pfmdr1 copy number variation. K13 mutations in the region corresponding to amino acids 210–726 (including the propeller region of the protein) were detected by nested PCR amplification and sequencing, and pfmdr1 copy number variation by real-time PCR. In two sites, a sub-set of patients were prospectively followed up for assessment of day-3 parasite clearance rates after a standard course of artemether-lumefantrine. Results K13 mutations and pfmdr1 amplification were successfully analysed in 206 and 218 samples, respectively. Sixty-nine isolates (33.5 %) had mutations within the k13 propeller region with 53 of these (76.8 %) having mutations already known to be associated with artemisinin resistance. F446I (32 isolates) and P574L (15 isolates) were the most common examples. K13 mutation was less common in sites in western border regions (29 of 155 isolates) compared to samples from the east and north (40 of 51 isolates; p < 0.0001). The overall proportion of parasites with multiple pfmdr1 copies (greater than 1.5) was 5.5 %. Seven samples showed both k13 mutation and multiple copies of pfmdr1. Only one of 36 patients followed up after artemether-lumefantrine treatment still had parasites at day 3; molecular analysis indicated wild-type k13 and single copy pfmdr1. Conclusion The proportion of P. falciparum isolates with mutations in the propeller region of k13 indicates that artemisinin resistance extends across much of Myanmar. There is a low prevalence of parasites with multiple pfmdr1 copies across the country. The efficacy of artemisinin-based combination therapy containing mefloquine and lumefantrine is, therefore, expected to be high, although regular monitoring of efficacy will be important. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1147-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aye A Win
- Department of Medicine, Institute of Medicine 1, Yangon, Myanmar.
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Mahidol University, Bangkok, Thailand. .,Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand.
| | - Myat P Kyaw
- Department of Medical Research (Lower Myanmar), Yangon, Myanmar.
| | - Charles J Woodrow
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand. .,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK.
| | - Kesinee Chotivanich
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand. .,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Borimas Hanboonkunupakarn
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand. .,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Sasithon Pukrittayakamee
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand. .,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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106
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Abstract
PURPOSE OF REVIEW The emergence of artemisinin resistance in Southeast Asia (SEA), where artemisinin combination therapies (ACTs) are beginning to fail, threatens global endeavors to control and eliminate Plasmodium falciparum malaria. Future efforts to prevent the spread of this calamity to Africa will benefit from last year's tremendous progress in understanding artemisinin resistance. RECENT FINDINGS Multiple international collaborations have established that artemisinin resistance is associated with slow parasite clearance in patients, increased survival of early-ring-stage parasites in vitro, single-nucleotide polymorphisms (SNPs) in the parasite's kelch protein gene (K13), parasite 'founder' populations sharing a genetic background of four additional SNPs, parasite transcriptional profiles reflecting an 'unfolded protein response' and decelerated parasite development, and elevated parasite phosphatidylinositol-3-kinase activity. In Western Cambodia, where the K13 C580Y mutation is approaching fixation, the frontline ACT is failing to cure nearly half of patients, likely due to partner drug resistance. In Africa, where dozens of K13 mutations have been detected at low frequency, there is no evidence yet of artemisinin resistance. SUMMARY In SEA, clinical and epidemiological investigations are urgently needed to stop the further spread of artemisinin resistance, monitor the efficacy of ACTs where K13 mutations are prevalent, identify currently-available drug regimens that cure ACT failures, and rapidly advance new antimalarial compounds through preclinical studies and clinical trials.
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107
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Gonçalves D, Hunziker P. Transmission-blocking strategies: the roadmap from laboratory bench to the community. Malar J 2016; 15:95. [PMID: 26888537 PMCID: PMC4758146 DOI: 10.1186/s12936-016-1163-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 02/11/2016] [Indexed: 11/10/2022] Open
Abstract
Malaria remains one of the most prevalent tropical and infectious diseases in the world, with an estimated more than 200 million clinical cases every year. In recent years, the mosquito stages of the parasite life cycle have received renewed attention with some progress being made in the development of transmission-blocking strategies. From gametocytes to late ookinetes, some attractive antigenic targets have been found and tested in order to develop a transmission blocking vaccine, and drugs are being currently screened for gametocytocidal activity, and also some new and less conventional approaches are drawing increased attention, such as genetically modified and fungus-infected mosquitoes that become refractory to Plasmodium infection. In this review some of those strategies focusing on the progress made so far will be summarized, but also, the challenges that come from the translation of early promising benchwork resulting in successful applications in the field. To do this, the available literature will be screened and all the pieces of the puzzle must be combined: from molecular biology to epidemiologic and clinical data.
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Affiliation(s)
- Daniel Gonçalves
- CLINAM Foundation for Nanomedicine, University of Basel, Basel, Switzerland.
| | - Patrick Hunziker
- CLINAM Foundation for Nanomedicine, University of Basel, Basel, Switzerland.
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108
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Ye R, Hu D, Zhang Y, Huang Y, Sun X, Wang J, Chen X, Zhou H, Zhang D, Mungthin M, Pan W. Distinctive origin of artemisinin-resistant Plasmodium falciparum on the China-Myanmar border. Sci Rep 2016; 6:20100. [PMID: 26831371 PMCID: PMC4735722 DOI: 10.1038/srep20100] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/22/2015] [Indexed: 02/06/2023] Open
Abstract
The artemisinin (ART), discovered in China, has been widely used against malaria in China over the last 30 years. Understanding the emergence and origin of ART resistance in China is therefore of great interest. We analyzed 111 culture-adapted isolates of P. falciparum from China-Myanmar (CM) border for their susceptibility to dihydroartemisinin using the ring stage survival assay (RSA0−3h) and genotyped their K13 genes. Of the isolates, 59 had a wild type of the K13 marker and a median ring survival rate of 0.26% (P95 = 1.005%). Among the remaining isolates harboring single mutations in the K13 marker, 26 survived at >P95(median survival rate = 2.95%). Further, we genotyped the K13 gene of 693 isolates collected from different regions in China and China-Myanmar/Thai-Cambodia/Thai-Myanmar (CM/TC/TM) borders, 308 (44.4%) had K13 mutations and marked differences in the patterns of K13 mutations were observed between the CM and the TC/TM borders. A network diagram showed that majority of the K13 mutant alleles from the CM border clustered together including those harboring the high resistant-associated R539T mutations. The resistant parasites carrying distinct halplotypes suggested the multiple indigenous origins of the resistant alleles, which highlight the importance of surveillance of resistance in all malaria endemic areas where ART has been introduced.
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Affiliation(s)
- Run Ye
- Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai 200433, China
| | - Dongwei Hu
- Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai 200433, China
| | - Yilong Zhang
- Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai 200433, China
| | - Yufu Huang
- Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai 200433, China
| | - Xiaodong Sun
- Yunnan Institute of Parasitic Diseases, Puer 665000, China
| | - Jian Wang
- Yunnan Institute of Parasitic Diseases, Puer 665000, China
| | - Xuedi Chen
- Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai 200433, China
| | - Hongning Zhou
- Yunnan Institute of Parasitic Diseases, Puer 665000, China
| | - Dongmei Zhang
- Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai 200433, China
| | - Mathirut Mungthin
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok 10400, Thailand
| | - Weiqing Pan
- Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai 200433, China
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109
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Rahul CN, Shiva Krishna K, Pawar AP, Rajesh V. In silico approach to ascertain the calcium dependent role of Plasmodium falciparum SERA5. J Biomol Struct Dyn 2016; 35:17-25. [PMID: 26725489 DOI: 10.1080/07391102.2015.1129988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The P. falciparum serine repeat antigen (PfSERA5) is the most abundantly expressed protein in the parasitophorous vacuole during the asexual blood stage and serves as both drug and vaccine target. The processed central fragment (56 KDa) of PfSERA5 is implicated to play an important role in parasite exit (egress) during schizont rupture from erythrocytes. Structural characterization of its enzymatic domain supports protease-like function for this central domain. The understanding of exact functional role of PfSERA5 in parasite egress remains unconfirmed as recent studies also indicate an indispensable non-catalytic role for PfSERA5 putative enzyme domain in the blood stage. No structural insight into PfSERA5 prodomain is available. Structure prediction of PfSERA5 prodomain using in silico approach in our study, showed it to have structural similarity with calcium-binding proteins. An earlier observation of steep rise in intracellular calcium concentration as an important factor in egress makes the prodomain calcium-binding role significant. The implication of calcium on structure and activity of PfSERA5 putative enzyme domain is also unknown, and such information would aid to substantiating any calcium-dependent effects on PfSERA5. To understand this, we performed molecular dynamic (MD) simulation both in the presence and absence of calcium. MD results show secondary structure conformational differences in local regions of protein structure. Our results support calcium to be an important parameter for stability and function of PfSERA5. This computational assessment suggest a need to design future experiments like calcium-dependent inhibition studies to reveal exact functional role of PfSERA5 in parasite egress.
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Affiliation(s)
- C N Rahul
- a Department of Biological Sciences, Birla Institute of Technology and Science, Pilani , Hyderabad Campus , Andhra Pradesh , India
| | - K Shiva Krishna
- a Department of Biological Sciences, Birla Institute of Technology and Science, Pilani , Hyderabad Campus , Andhra Pradesh , India
| | - Atul P Pawar
- a Department of Biological Sciences, Birla Institute of Technology and Science, Pilani , Hyderabad Campus , Andhra Pradesh , India
| | - Vidya Rajesh
- a Department of Biological Sciences, Birla Institute of Technology and Science, Pilani , Hyderabad Campus , Andhra Pradesh , India
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Wilson BA, Garud NR, Feder AF, Assaf ZJ, Pennings PS. The population genetics of drug resistance evolution in natural populations of viral, bacterial and eukaryotic pathogens. Mol Ecol 2016; 25:42-66. [PMID: 26578204 PMCID: PMC4943078 DOI: 10.1111/mec.13474] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/28/2015] [Accepted: 10/08/2015] [Indexed: 01/09/2023]
Abstract
Drug resistance is a costly consequence of pathogen evolution and a major concern in public health. In this review, we show how population genetics can be used to study the evolution of drug resistance and also how drug resistance evolution is informative as an evolutionary model system. We highlight five examples from diverse organisms with particular focus on: (i) identifying drug resistance loci in the malaria parasite Plasmodium falciparum using the genomic signatures of selective sweeps, (ii) determining the role of epistasis in drug resistance evolution in influenza, (iii) quantifying the role of standing genetic variation in the evolution of drug resistance in HIV, (iv) using drug resistance mutations to study clonal interference dynamics in tuberculosis and (v) analysing the population structure of the core and accessory genome of Staphylococcus aureus to understand the spread of methicillin resistance. Throughout this review, we discuss the uses of sequence data and population genetic theory in studying the evolution of drug resistance.
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Affiliation(s)
| | | | | | - Zoe J. Assaf
- Department of GeneticsStanford UniversityStanfordCA94305USA
| | - Pleuni S. Pennings
- Department of BiologySan Francisco State UniversityRoom 520Hensill Hall1600 Holloway AveSan FranciscoCA94132USA
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Nyunt MH, Aye KM, Kyaw MP, Wai KT, Oo T, Than A, Oo HW, Phway HP, Han SS, Htun T, San KK. Evaluation of the behaviour change communication and community mobilization activities in Myanmar artemisinin resistance containment zones. Malar J 2015; 14:522. [PMID: 26697850 PMCID: PMC4690302 DOI: 10.1186/s12936-015-1047-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 12/11/2015] [Indexed: 11/10/2022] Open
Abstract
Background Behaviour change communication (BCC) can improve malaria prevention and treatment behaviour. As a one of the activities under Myanmar Artemisinin Resistance Containment (MARC) programme, BCC have been conducting. This study aimed to evaluate the effectiveness of the behaviour change communication and community mobilization activities in MARC zones in Myanmar. Methods A cross sectional descriptive survey was conducted in randomly selected 16 townships in Tier I and II areas of MARC zones by quantitative and qualitative approaches. Results In 832 households resided by 4664 people, there were 3797 bed nets. Around 54 % were untreated while 45.6 % were insecticide-treated nets (ITN) and 36.2 % were long-lasting insecticide-treated nets (LLINs). Proportion of households with at least one ITN was 625 (75.12 %), proportion of households with at least one ITN for every two peoples was 487 (58.53 %), and proportion of existing ITNs used in previous night was 1225 (70.65 %) respectively. Nearly 23 % of households had old nets while 52 % had new and unused extra bed nets reflecting the adequacy. Interestingly, 38 % could not mention the benefit of the use of ITN/LLINs. Although 88.2 % knew the disease “malaria”, 11.9 % could not be able to mention the symptoms. More than 80 % provided correct responses that mosquito bite can cause malaria while only 36.9 % could mention the blood test for malaria diagnosis. Only 36.6 % received malaria information within previous year but nearly 15 % could not recognize it. Mostly, 80 % of fever episodes were treated at rural health centers (38.24 %) followed by drug shops (17.65 %) and private clinics (16.18 %) respectively. Conclusions Efforts should focus on correcting misconceptions about malaria transmission, prevention and universal use of ITN/LLINs. Although BCC activities have been documented, it is still necessary to intensify community mobilization through all accessible multiple channels in MARC areas.
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Affiliation(s)
- Myat Htut Nyunt
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Khin Myo Aye
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Myat Phone Kyaw
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Khin Thet Wai
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Tin Oo
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Aye Than
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Htet Wai Oo
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Hnin Phyu Phway
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Soe Soe Han
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Thurein Htun
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Kyaw Kyaw San
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
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Duru V, Khim N, Leang R, Kim S, Domergue A, Kloeung N, Ke S, Chy S, Eam R, Khean C, Loch K, Ken M, Lek D, Beghain J, Ariey F, Guerin PJ, Huy R, Mercereau-Puijalon O, Witkowski B, Menard D. Plasmodium falciparum dihydroartemisinin-piperaquine failures in Cambodia are associated with mutant K13 parasites presenting high survival rates in novel piperaquine in vitro assays: retrospective and prospective investigations. BMC Med 2015; 13:305. [PMID: 26695060 PMCID: PMC4688949 DOI: 10.1186/s12916-015-0539-5] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 11/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The declining efficacy of dihydroartemisinin-piperaquine against Plasmodium falciparum in Cambodia, along with increasing numbers of recrudescent cases, suggests resistance to both artemisinin and piperaquine. Available in vitro piperaquine susceptibility assays do not correlate with treatment outcome. A novel assay using a pharmacologically relevant piperaquine dose/time exposure was designed and its relevance explored in retrospective and prospective studies. METHODS The piperaquine survival assay (PSA) exposed parasites to 200 nM piperaquine for 48 hours and monitored survival 24 hours later. The retrospective study tested 32 culture-adapted, C580Y-K13 mutant parasites collected at enrolment from patients treated with a 3-day course of dihydroartemisinin-piperaquine and having presented or not with a recrudescence at day 42 (registered ACTRN12615000793516). The prospective study assessed ex vivo PSA survival rate alongside K13 polymorphism of isolates collected from patients enrolled in an open-label study with dihydroartemisinin-piperaquine for uncomplicated P. falciparum malaria in Cambodia (registered ACTRN12615000696594). RESULTS All parasites from recrudescent cases had in vitro or ex vivo PSA survival rates ≥10%, a relevant cut-off value for piperaquine-resistance. Ex vivo PSA survival rates were higher for recrudescent than non-recrudescent cases (39.2% vs. 0.17%, P <1 × 10(-7)). Artemisinin-resistant K13 mutants with ex vivo PSA survival rates ≥10% were associated with 32-fold higher risk of recrudescence (95% CI, 4.5-224; P = 0.0005). CONCLUSION PSA adequately captures the piperaquine resistance/recrudescence phenotype, a mainstay to identify molecular marker(s) and evaluate efficacy of alternative drugs. Combined ex vivo PSA and K13 genotyping provides a convenient monitor for both artemisinin and piperaquine resistance where dihydroartemisinin-piperaquine is used.
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Affiliation(s)
- Valentine Duru
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Nimol Khim
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Rithea Leang
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia.
| | - Saorin Kim
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Anais Domergue
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Nimol Kloeung
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Sopheakvatey Ke
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Sophy Chy
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Rotha Eam
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Chanra Khean
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Kaknika Loch
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Malen Ken
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Dysoley Lek
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia.
| | - Johann Beghain
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France.
| | - Frédéric Ariey
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France.
| | - Philippe J Guerin
- WorldWide Antimalarial Resistance Network, Oxford, UK. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK.
| | - Rekol Huy
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia.
| | | | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
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No Polymorphism in Plasmodium falciparum K13 Propeller Gene in Clinical Isolates from Kolkata, India. J Pathog 2015; 2015:374354. [PMID: 26688755 PMCID: PMC4673352 DOI: 10.1155/2015/374354] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/11/2015] [Indexed: 01/25/2023] Open
Abstract
Molecular markers associated with artemisinin resistance in Plasmodium falciparum are yet to be well defined. Recent studies showed that polymorphisms in K13 gene are associated with artemisinin resistance. The present study was designed to know the pattern of polymorphisms in propeller region of K13 gene among the clinical isolates collected from urban Kolkata after five years of ACT implementation. We collected 59 clinical isolates from urban Kolkata and sequenced propeller region of K13 gene in 51 isolates successfully. We did not find any mutation in any isolate. All patients responded to the ACT, a combination of artesunate + sulphadoxine-pyrimethamine. The drug regimen is still effective in the study area and there is no sign of emergence of resistance against artemisinin as evidenced by wild genotype of K13 gene in all isolates studied.
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Abdulla S, Ashley EA, Bassat Q, Bethell D, Björkman A, Borrmann S, D'Alessandro U, Dahal P, Day NP, Diakite M, Djimde AA, Dondorp AM, Duong S, Edstein MD, Fairhurst RM, Faiz MA, Falade C, Flegg JA, Fogg C, Gonzalez R, Greenwood B, Guérin PJ, Guthmann JP, Hamed K, Hien TT, Htut Y, Juma E, Lim P, Mårtensson A, Mayxay M, Mokuolu OA, Moreira C, Newton P, Noedl H, Nosten F, Ogutu BR, Onyamboko MA, Owusu-Agyei S, Phyo AP, Premji Z, Price RN, Pukrittayakamee S, Ramharter M, Sagara I, Se Y, Suon S, Stepniewska K, Ward SA, White NJ, Winstanley PA. Baseline data of parasite clearance in patients with falciparum malaria treated with an artemisinin derivative: an individual patient data meta-analysis. Malar J 2015; 14:359. [PMID: 26390866 PMCID: PMC4578675 DOI: 10.1186/s12936-015-0874-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 08/26/2015] [Indexed: 11/15/2022] Open
Abstract
Background Artemisinin resistance in Plasmodium falciparum manifests as slow parasite clearance but this measure is also influenced by host immunity, initial parasite biomass and partner drug efficacy. This study collated data from clinical trials of artemisinin derivatives in falciparum malaria with frequent
parasite counts to provide reference parasite clearance estimates stratified by location, treatment and time, to examine host factors affecting parasite clearance, and to assess the relationships between parasite clearance and risk of recrudescence during follow-up. Methods Data from 24 studies, conducted from 1996 to 2013, with frequent parasite counts were pooled. Parasite clearance half-life (PC1/2) was estimated using the WWARN Parasite Clearance Estimator. Random effects regression models accounting for study and site heterogeneity were used to explore factors affecting PC1/2 and risk of recrudescence within areas with reported delayed parasite clearance (western Cambodia, western Thailand after 2000, southern Vietnam, southern Myanmar) and in all other areas where parasite populations are artemisinin sensitive. Results PC1/2 was estimated in 6975 patients, 3288 of whom also had treatment outcomes evaluate d during 28–63 days follow-up, with 93 (2.8 %) PCR-confirmed recrudescences. In areas with artemisinin-sensitive parasites, the median PC1/2 following three-day artesunate treatment (4 mg/kg/day) ranged from 1.8 to 3.0 h and the proportion of patients with PC1/2 >5 h from 0 to 10 %. Artesunate doses of 4 mg/kg/day decreased PC1/2 by 8.1 % (95 % CI 3.2–12.6) compared to 2 mg/kg/day, except in populations with delayed parasite clearance. PC1/2 was longer in children and in patients with fever or anaemia at enrolment. Long PC1/2 (HR = 2.91, 95 % CI 1.95–4.34 for twofold increase, p < 0.001) and high initial parasitaemia (HR = 2.23, 95 % CI 1.44–3.45 for tenfold increase, p < 0.001) were associated independently with an increased risk of recrudescence. In western Cambodia, the region with the highest prevalence of artemisinin resistance, there was no evidence for increasing PC1/2 since 2007. Conclusions Several factors affect PC1/2. As substantial heterogeneity in parasite clearance exists between locations, early detection of artemisinin resistance requires reference PC1/2 data. Studies with frequent parasite count measurements to characterize PC1/2 should be encouraged. In western Cambodia, where PC1/2 values are longest, there is no evidence for recent emergence of higher levels of artemisinin resistance. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0874-1) contains supplementary material, which is available to authorized users.
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115
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Mvumbi DM, Kayembe JM, Situakibanza H, Bobanga TL, Nsibu CN, Mvumbi GL, Melin P, De Mol P, Hayette MP. Falciparum malaria molecular drug resistance in the Democratic Republic of Congo: a systematic review. Malar J 2015; 14:354. [PMID: 26376639 PMCID: PMC4574228 DOI: 10.1186/s12936-015-0892-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 09/04/2015] [Indexed: 01/22/2023] Open
Abstract
Background Malaria cases were estimated to 207 million in 2013. One of the problems of malaria control is the emergence and spread of Plasmodium falciparum strains that become resistant to almost all drugs available. Monitoring drug resistance is essential for early detection and subsequent prevention of the spread of drug resistance by timely changes of treatment policy. This review was performed to gather all data available on P. falciparum molecular resistance in DR Congo, as baseline for future assessments. Methods The search for this review was undertaken using the electronic databases PubMed and Google Scholar using the terms “malaria”, “Congo”, “resistance”, “molecular”, “antimalarial”, “efficacy”. Articles were classified based on year of collecting, year of publication, sample size and characteristics, molecular markers analysed and polymorphisms detected. Results Thirteen articles were included and five genes have been analysed in these studies: pfcrt, pfdhps, pfdhfr, pfmdr1 and K13-propeller. The majority of studies included were not representative of the whole country. Conclusion This systematic review demonstrates the lack of molecular resistance studies in DRC. Only 13 studies were identified in almost 15 years. The MOH must implement a national surveillance system for monitoring malaria drug resistance and this surveillance should be conducted frequently and country-representative.
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Affiliation(s)
- Dieudonné Makaba Mvumbi
- Biochemistry and Molecular Biology Unit, Department of Basic Sciences, School of Medicine, University of Kinshasa, Kinshasa, DR Congo.
| | - Jean-Marie Kayembe
- Department of Internal Medicine, School of Medicine, University of Kinshasa, Kinshasa, DR Congo.
| | - Hippolyte Situakibanza
- Department of Tropical Medicine and Infectious Disease, School of Medicine, University of Kinshasa, Kinshasa, DR Congo.
| | - Thierry L Bobanga
- Department of Tropical Medicine and Infectious Disease, School of Medicine, University of Kinshasa, Kinshasa, DR Congo.
| | - Célestin N Nsibu
- Department of Paediatric, School of Medicine, University of Kinshasa, Kinshasa, DR Congo.
| | - Georges L Mvumbi
- Biochemistry and Molecular Biology Unit, Department of Basic Sciences, School of Medicine, University of Kinshasa, Kinshasa, DR Congo.
| | - Pierrette Melin
- Department of Clinical Microbiology, University Hospital of Liège, Liège, Belgium.
| | - Patrick De Mol
- Department of Clinical Microbiology, University Hospital of Liège, Liège, Belgium.
| | - Marie-Pierre Hayette
- Department of Clinical Microbiology, University Hospital of Liège, Liège, Belgium.
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Hlaing T, Wai KT, Oo T, Sint N, Min T, Myar S, Lon KN, Naing MM, Tun TT, Maung NLY, Galappaththy GNL, Thimarsan K, Wai TT, Thaung LNN. Mobility dynamics of migrant workers and their socio-behavioral parameters related to malaria in Tier II, Artemisinin Resistance Containment Zone, Myanmar. BMC Public Health 2015; 15:886. [PMID: 26370297 PMCID: PMC4570258 DOI: 10.1186/s12889-015-2241-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 09/07/2015] [Indexed: 11/29/2022] Open
Abstract
Background Areas with dynamic population movements are likely to be associated with higher levels of drug-resistant malaria. Myanmar Artemisinin Resistance Containment (MARC) Project has been launching since 2012. One of its components includes enhancing strategic approaches for mobile/migrant populations. We aimed to ascertain the estimated population of mobile migrant workers and their families in terms of stability in work setting in townships classified as tier II (areas with significant inflows of people from areas with credible evidence of artemisinin resistance) for Artemisinin resistance; to identify knowledge, attitudes and practices related to prevention and control of malaria and to recommend cost-effective strategies in planning for prevention and control of malaria. Methods A prospective cross-sectional study conducted between June to December 2013 that covered 1,899 migrant groups from 16 tier II townships of Bago Region, and Kayin and Kayah States. Trained data collectors used a pre-tested and subsequently modified questionnaire and interviewed 2,381 respondents. Data of migrant groups were analyzed and compared by category depending upon the stability of their work setting. Results The estimated population of the 1,899 migrant groups categorized into three on the nature of their work setting was 56,030. Bago region was the commonest reported source of origin of migrant groups as well as their transit. Malaria volunteers were mostly within the reach of category 1 migrant groups (43/66, 65.2 %). Less stable migrant groups in category 3 had limited access to malaria information (14.7 %) and malaria care providers (22.1 %), low level of awareness and use of long-lasting insecticide-treated nets (46.6 and 38.8 %). Also, they had poor knowledge on malaria prevention on confirming suspected malaria and on using artemisinin combined therapy (ACT). Within two weeks prior to the survey, only 16.5 % of respondents in all categories combined reported acute undifferentiated fever. Discussion and Conclusions Mobility dynamics of migrant groups was complex and increased their vulnerability to malaria. This phenomenon was accentuated in less stable areas. Even though migrant workers were familiar with rapid diagnostic tests for malaria, ACT still needed wide recognition to improve practices supportive of MARC including the use of appropriate personal protection. High mobility calls for re-designation of tier II townships to optimize ACT resistance containment. Electronic supplementary material The online version of this article (doi:10.1186/s12889-015-2241-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Khin Thet Wai
- Department of Medical Research, No. 5 Ziwaka Road, Dagon Township, Yangon, 11191, Myanmar.
| | - Tin Oo
- Department of Medical Research, No. 5 Ziwaka Road, Dagon Township, Yangon, 11191, Myanmar.
| | - Nyan Sint
- Department of Public Health, Naypyitaw, Myanmar.
| | - Tun Min
- Department of Public Health, Naypyitaw, Myanmar.
| | - Shwe Myar
- Department of Public Health, Naypyitaw, Myanmar.
| | - Khin Nan Lon
- Department of Public Health, Naypyitaw, Myanmar.
| | | | - Tet Toe Tun
- Malaria Unit, WHO Country Office, Yangon, Myanmar.
| | | | | | | | - Tin Tin Wai
- Department of Medical Research, No. 5 Ziwaka Road, Dagon Township, Yangon, 11191, Myanmar.
| | - Lwin Ni Ni Thaung
- Department of Medical Research, No. 5 Ziwaka Road, Dagon Township, Yangon, 11191, Myanmar.
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Dahal P, d'Alessandro U, Dorsey G, Guerin PJ, Nsanzabana C, Price RN, Sibley CH, Stepniewska K, Talisuna AO. Clinical determinants of early parasitological response to ACTs in African patients with uncomplicated falciparum malaria: a literature review and meta-analysis of individual patient data. BMC Med 2015; 13:212. [PMID: 26343145 PMCID: PMC4561425 DOI: 10.1186/s12916-015-0445-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/11/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Artemisinin-resistant Plasmodium falciparum has emerged in the Greater Mekong sub-region and poses a major global public health threat. Slow parasite clearance is a key clinical manifestation of reduced susceptibility to artemisinin. This study was designed to establish the baseline values for clearance in patients from Sub-Saharan African countries with uncomplicated malaria treated with artemisinin-based combination therapies (ACTs). METHODS A literature review in PubMed was conducted in March 2013 to identify all prospective clinical trials (uncontrolled trials, controlled trials and randomized controlled trials), including ACTs conducted in Sub-Saharan Africa, between 1960 and 2012. Individual patient data from these studies were shared with the WorldWide Antimalarial Resistance Network (WWARN) and pooled using an a priori statistical analytical plan. Factors affecting early parasitological response were investigated using logistic regression with study sites fitted as a random effect. The risk of bias in included studies was evaluated based on study design, methodology and missing data. RESULTS In total, 29,493 patients from 84 clinical trials were included in the analysis, treated with artemether-lumefantrine (n = 13,664), artesunate-amodiaquine (n = 11,337) and dihydroartemisinin-piperaquine (n = 4,492). The overall parasite clearance rate was rapid. The parasite positivity rate (PPR) decreased from 59.7 % (95 % CI: 54.5-64.9) on day 1 to 6.7 % (95 % CI: 4.8-8.7) on day 2 and 0.9 % (95 % CI: 0.5-1.2) on day 3. The 95th percentile of observed day 3 PPR was 5.3 %. Independent risk factors predictive of day 3 positivity were: high baseline parasitaemia (adjusted odds ratio (AOR) = 1.16 (95 % CI: 1.08-1.25); per 2-fold increase in parasite density, P <0.001); fever (>37.5 °C) (AOR = 1.50 (95 % CI: 1.06-2.13), P = 0.022); severe anaemia (AOR = 2.04 (95 % CI: 1.21-3.44), P = 0.008); areas of low/moderate transmission setting (AOR = 2.71 (95 % CI: 1.38-5.36), P = 0.004); and treatment with the loose formulation of artesunate-amodiaquine (AOR = 2.27 (95 % CI: 1.14-4.51), P = 0.020, compared to dihydroartemisinin-piperaquine). CONCLUSIONS The three ACTs assessed in this analysis continue to achieve rapid early parasitological clearance across the sites assessed in Sub-Saharan Africa. A threshold of 5 % day 3 parasite positivity from a minimum sample size of 50 patients provides a more sensitive benchmark in Sub-Saharan Africa compared to the current recommended threshold of 10 % to trigger further investigation of artemisinin susceptibility.
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Affiliation(s)
| | - Prabin Dahal
- WorldWide Antimalarial Resistance Network (WWARN); Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, UK
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Shibi I, Aswathy L, Jisha R, Masand V, Divyachandran A, Gajbhiye J. Molecular docking and QSAR analyses for understanding the antimalarial activity of some 7-substituted-4-aminoquinoline derivatives. Eur J Pharm Sci 2015; 77:9-23. [DOI: 10.1016/j.ejps.2015.05.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/02/2015] [Accepted: 05/21/2015] [Indexed: 12/28/2022]
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119
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Artemisinin resistance at the China-Myanmar border and association with mutations in the K13 propeller gene. Antimicrob Agents Chemother 2015; 59:6952-9. [PMID: 26324266 DOI: 10.1128/aac.01255-15] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/18/2015] [Indexed: 02/07/2023] Open
Abstract
Artemisinin resistance in Plasmodium falciparum parasites in Southeast Asia is a major concern for malaria control. Its emergence at the China-Myanmar border, where there have been more than 3 decades of artemisinin use, has yet to be investigated. Here, we comprehensively evaluated the potential emergence of artemisinin resistance and antimalarial drug resistance status in P. falciparum using data and parasites from three previous efficacy studies in this region. These efficacy studies of dihydroartemisinin-piperaquine combination and artesunate monotherapy of uncomplicated falciparum malaria in 248 P. falciparum patients showed an overall 28-day adequate clinical and parasitological response of >95% and day 3 parasite-positive rates of 6.3 to 23.1%. Comparison of the 57 K13 sequences (24 and 33 from day 3 parasite-positive and -negative cases, respectively) identified nine point mutations in 38 (66.7%) samples, of which F446I (49.1%) and an N-terminal NN insertion (86.0%) were predominant. K13 propeller mutations collectively, the F446I mutation alone, and the NN insertion all were significantly associated with day 3 parasite positivity. Increased ring-stage survival determined using the ring-stage survival assay (RSA) was highly associated with the K13 mutant genotype. Day 3 parasite-positive isolates had ∼10 times higher ring survival rates than day 3 parasite-negative isolates. Divergent K13 mutations suggested independent evolution of artemisinin resistance. Taken together, this study confirmed multidrug resistance and emergence of artemisinin resistance in P. falciparum at the China-Myanmar border. RSA and K13 mutations are useful phenotypic and molecular markers for monitoring artemisinin resistance.
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McConville M, Fernández J, Angulo-Barturen Í, Bahamontes-Rosa N, Ballell-Pages L, Castañeda P, de Cózar C, Crespo B, Guijarro L, Jiménez-Díaz MB, Martínez-Martínez MS, de Mercado J, Santos-Villarejo Á, Sanz LM, Frigerio M, Washbourn G, Ward SA, Nixon GL, Biagini GA, Berry NG, Blackman MJ, Calderón F, O'Neill PM. Carbamoyl Triazoles, Known Serine Protease Inhibitors, Are a Potent New Class of Antimalarials. J Med Chem 2015. [PMID: 26222445 DOI: 10.1021/acs.jmedchem.5b00434] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Screening of the GSK corporate collection, some 1.9 million compounds, against Plasmodium falciparum (Pf), revealed almost 14000 active hits that are now known as the Tres Cantos Antimalarial Set (TCAMS). Followup work by Calderon et al. clustered and computationally filtered the TCAMS through a variety of criteria and reported 47 series containing a total of 522 compounds. From this enhanced set, we identified the carbamoyl triazole TCMDC-134379 (1), a known serine protease inhibitor, as an excellent starting point for SAR profiling. Lead optimization of 1 led to several molecules with improved antimalarial potency, metabolic stabilities in mouse and human liver microsomes, along with acceptable cytotoxicity profiles. Analogue 44 displayed potent in vitro activity (IC50 = 10 nM) and oral activity in a SCID mouse model of Pf infection with an ED50 of 100 and ED90 of between 100 and 150 mg kg(-1), respectively. The results presented encourage further investigations to identify the target of these highly active compounds.
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Affiliation(s)
- Matthew McConville
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Jorge Fernández
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Íñigo Angulo-Barturen
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Noemi Bahamontes-Rosa
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Lluis Ballell-Pages
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Pablo Castañeda
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Cristina de Cózar
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Benigno Crespo
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Laura Guijarro
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - María Belén Jiménez-Díaz
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Maria S Martínez-Martínez
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Jaime de Mercado
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Ángel Santos-Villarejo
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Laura M Sanz
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Micol Frigerio
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Gina Washbourn
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Stephen A Ward
- Liverpool School of Tropical Medicine , Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Gemma L Nixon
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Giancarlo A Biagini
- Liverpool School of Tropical Medicine , Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Neil G Berry
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Michael J Blackman
- Division of Parasitology, MRC National Institute for Medical Research , Mill Hill, London NW7 1AA, United Kingdom
| | - Félix Calderón
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Paul M O'Neill
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
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How Robust Are Malaria Parasite Clearance Rates as Indicators of Drug Effectiveness and Resistance? Antimicrob Agents Chemother 2015; 59:6428-36. [PMID: 26239987 DOI: 10.1128/aac.00481-15] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 07/22/2015] [Indexed: 11/20/2022] Open
Abstract
Artemisinin-based combination therapies (ACTs) are currently the first-line drugs for treating uncomplicated falciparum malaria, the most deadly of the human malarias. Malaria parasite clearance rates estimated from patients' blood following ACT treatment have been widely adopted as a measure of drug effectiveness and as surveillance tools for detecting the presence of potential artemisinin resistance. This metric has not been investigated in detail, nor have its properties or potential shortcomings been identified. Herein, the pharmacology of drug treatment, parasite biology, and human immunity are combined to investigate the dynamics of parasite clearance following ACT. This approach parsimoniously recovers the principal clinical features and dynamics of clearance. Human immunity is the primary determinant of clearance rates, unless or until artemisinin killing has fallen to near-ineffective levels. Clearance rates are therefore highly insensitive metrics for surveillance that may lead to overconfidence, as even quite substantial reductions in drug sensitivity may not be detected as lower clearance rates. Equally serious is the use of clearance rates to quantify the impact of ACT regimen changes, as this strategy will plausibly miss even very substantial increases in drug effectiveness. In particular, the malaria community may be missing the opportunity to dramatically increase ACT effectiveness through regimen changes, particularly through a switch to twice-daily regimens and/or increases in artemisinin dosing levels. The malaria community therefore appears overreliant on a single metric of drug effectiveness, the parasite clearance rate, that has significant and serious shortcomings.
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Cravo P, Napolitano H, Culleton R. How genomics is contributing to the fight against artemisinin-resistant malaria parasites. Acta Trop 2015; 148:1-7. [PMID: 25910626 DOI: 10.1016/j.actatropica.2015.04.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 04/06/2015] [Accepted: 04/11/2015] [Indexed: 11/30/2022]
Abstract
Plasmodium falciparum, the malignant malaria parasite, has developed resistance to artemisinin, the most important and widely used antimalarial drug at present. Currently confined to Southeast Asia, the spread of resistant parasites to Africa would constitute a public health catastrophe. In this review we highlight the recent contributions of genomics to our understanding how the parasite develops resistance to artemisinin and its derivatives, and how resistant parasites may be monitored and tracked in real-time, using molecular approaches.
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Affiliation(s)
- Pedro Cravo
- Laboratory of Genomics and Biotechnology (GenoBio), IPTSP, Universidade Federal de Goiás, Goiânia 74605050, GO, Brazil; PPSTMA, Centro Universitário de Anápolis (UniEVANGÉLICA), Anápolis 75083515, GO, Brazil; Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon 1349-008, Portugal.
| | - Hamilton Napolitano
- PPSTMA, Centro Universitário de Anápolis (UniEVANGÉLICA), Anápolis 75083515, GO, Brazil; Ciências Exatas e Tecnológicas, Universidade Estadual de Goiás. 459, 75001970 Anápolis, GO, Brazil
| | - Richard Culleton
- Malaria Unit, Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523, Japan
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123
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Golassa L, Kamugisha E, Ishengoma DS, Baraka V, Shayo A, Baliraine FN, Enweji N, Erko B, Aseffa A, Choy A, Swedberg G. Identification of large variation in pfcrt, pfmdr-1 and pfubp-1 markers in Plasmodium falciparum isolates from Ethiopia and Tanzania. Malar J 2015; 14:264. [PMID: 26152336 PMCID: PMC4495614 DOI: 10.1186/s12936-015-0783-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 06/27/2015] [Indexed: 01/15/2023] Open
Abstract
Background Plasmodium falciparum resistance to anti-malarials is a major drawback in effective malaria control and elimination globally. Artemisinin-combination therapy (ACT) is currently the key first-line treatment for uncomplicated falciparum malaria. Plasmodium falciparum genetic signatures at pfmdr-1, pfcrt, and pfubp-1 loci are known to modulate in vivo and in vitro parasite response to ACT. The objective of this study was to assess the distribution of these resistance gene markers in isolates collected from different malaria transmission intensity in Ethiopia and Tanzania. Methods Plasmodium falciparum clinical isolates were collected from different regions of Ethiopia and Tanzania. Genetic polymorphisms in the genes pfcrt, pfmdr-1 and pfubp-1 were analysed by PCR and sequencing. Frequencies of the different alleles in the three genes were compared within and between regions, and between the two countries. Results The majority of the isolates from Ethiopia were mutant for the pfcrt 76 and wild-type for pfmdr-1 86. In contrast, the majority of the Tanzanian samples were wild-type for both pfcrt and pfmdr-1 loci. Analysis of a variable linker region in pfmdr-1 showed substantial variation in isolates from Tanzania as compared to Ethiopian isolates that had minimal variation. Direct sequencing of the pfubp-1 region showed that 92.8% (26/28) of the Ethiopian isolates had identical genome sequence with the wild type reference P. falciparum strain 3D7. Of 42 isolates from Tanzania, only 13 (30.9%) had identical genome sequences with 3D7. In the Tanzanian samples, 10 variant haplotypes were identified. Conclusion The majority of Ethiopian isolates carried the main marker for chloroquine (CQ) resistance, while the majority of the samples from Tanzania carried markers for CQ susceptibility. Polymorphic genes showed substantially more variation in Tanzanian isolates. The low variability in the polymorphic region of pfmdr-1 in Ethiopia may be a consequence of low transmission intensity as compared to high transmission intensity and large variations in Tanzania.
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Affiliation(s)
- Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia. .,Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
| | - Erasmus Kamugisha
- Department of Biochemistry, Catholic University of Health and Allied Sciences-Bugando, Mwanza, Tanzania.
| | | | - Vito Baraka
- National Institute for Medical Research, Tanga, Tanzania. .,International Health Unit, Department of Epidemiology, University of Antwerp, Antwerp, Belgium.
| | - Alex Shayo
- The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
| | | | - Nizar Enweji
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
| | - Berhanu Erko
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
| | - Angel Choy
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
| | - Göte Swedberg
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
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124
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Takala-Harrison S, Laufer MK. Antimalarial drug resistance in Africa: key lessons for the future. Ann N Y Acad Sci 2015; 1342:62-7. [PMID: 25891142 DOI: 10.1111/nyas.12766] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Drug-resistant parasites repeatedly arise as a result of widespread use of antimalarial drugs and have contributed significantly to the failure to control and eradicate malaria throughout the world. In this review, we describe the spread of resistance to chloroquine and sulfadoxine-pyrimethamine, two old drugs that are no longer used owing to high rates of resistance, and examine the effect of the removal of drug pressure on the survival of resistant parasites. Artemisinin-resistant malaria is now emerging in Southeast Asia in a unique and unexpected pattern. We will review the most recent genomic and clinical data to help predict the behavior of resistance to new antimalarial medications and inform strategies to prevent the spread of drug-resistant malaria in Africa in the future.
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Affiliation(s)
- Shannon Takala-Harrison
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland
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125
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Huang F, Takala-Harrison S, Jacob CG, Liu H, Sun X, Yang H, Nyunt MM, Adams M, Zhou S, Xia Z, Ringwald P, Bustos MD, Tang L, Plowe CV. A Single Mutation in K13 Predominates in Southern China and Is Associated With Delayed Clearance of Plasmodium falciparum Following Artemisinin Treatment. J Infect Dis 2015; 212:1629-35. [PMID: 25910630 DOI: 10.1093/infdis/jiv249] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 04/16/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Artemisinin resistance in Plasmodium falciparum has emerged in Southeast Asia and poses a threat to malaria control and elimination. Mutations in a P. falciparum gene encoding a kelch protein on chromosome 13 have been associated with delayed parasite clearance following artemisinin treatment elsewhere in the region, but not yet in China. METHODS Therapeutic efficacy studies of artesunate and dihydroartemisinin-piperaquine were conducted from 2009 to 2012 in the Yunnan Province of China near the border with Myanmar. K13 mutations were genotyped by capillary sequencing of DNA extracted from dried blood spots collected in these clinical trials and in routine surveillance. Associations between K13 mutations and delayed parasite clearance were tested using regression models. RESULTS Parasite clearance half-lives were prolonged after artemisinin treatment, with 44% of infections having half-lives >5 hours (n = 109). Fourteen mutations in K13 were observed, with an overall prevalence of 47.7% (n = 329). A single mutation, F446I, predominated, with a prevalence of 36.5%. Infections with F446I were significantly associated with parasitemia on day 3 following artemisinin treatment and with longer clearance half-lives. CONCLUSIONS Plasmodium falciparum infections in southern China displayed markedly delayed clearance following artemisinin treatment. F446I was the predominant K13 mutation and was associated with delayed parasite clearance.
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Affiliation(s)
- Fang Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, World Health Organization Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, PR China Center for Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore
| | - Shannon Takala-Harrison
- Center for Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore
| | - Christopher G Jacob
- Center for Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore
| | - Hui Liu
- Yunnan Institute of Parasitic Diseases, Puer, PR China
| | - Xiaodong Sun
- Yunnan Institute of Parasitic Diseases, Puer, PR China
| | - Henglin Yang
- Yunnan Institute of Parasitic Diseases, Puer, PR China
| | - Myaing M Nyunt
- Center for Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore
| | - Matthew Adams
- Center for Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore
| | - Shuisen Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, World Health Organization Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, PR China
| | - Zhigui Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, World Health Organization Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, PR China
| | - Pascal Ringwald
- Drug Resistance and Containment Unit, Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | | | - Linhua Tang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, World Health Organization Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, PR China
| | - Christopher V Plowe
- Center for Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore
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126
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Talundzic E, Okoth SA, Congpuong K, Plucinski MM, Morton L, Goldman IF, Kachur PS, Wongsrichanalai C, Satimai W, Barnwell JW, Udhayakumar V. Selection and spread of artemisinin-resistant alleles in Thailand prior to the global artemisinin resistance containment campaign. PLoS Pathog 2015; 11:e1004789. [PMID: 25836766 PMCID: PMC4383523 DOI: 10.1371/journal.ppat.1004789] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 03/06/2015] [Indexed: 11/18/2022] Open
Abstract
The recent emergence of artemisinin resistance in the Greater Mekong Subregion poses a major threat to the global effort to control malaria. Tracking the spread and evolution of artemisinin-resistant parasites is critical in aiding efforts to contain the spread of resistance. A total of 417 patient samples from the year 2007, collected during malaria surveillance studies across ten provinces in Thailand, were genotyped for the candidate Plasmodium falciparum molecular marker of artemisinin resistance K13. Parasite genotypes were examined for K13 propeller mutations associated with artemisinin resistance, signatures of positive selection, and for evidence of whether artemisinin-resistant alleles arose independently across Thailand. A total of seven K13 mutant alleles were found (N458Y, R539T, E556D, P574L, R575K, C580Y, S621F). Notably, the R575K and S621F mutations have previously not been reported in Thailand. The most prevalent artemisinin resistance-associated K13 mutation, C580Y, carried two distinct haplotype profiles that were separated based on geography, along the Thai-Cambodia and Thai-Myanmar borders. It appears these two haplotypes may have independent evolutionary origins. In summary, parasites with K13 propeller mutations associated with artemisinin resistance were widely present along the Thai-Cambodia and Thai-Myanmar borders prior to the implementation of the artemisinin resistance containment project in the region. The Plasmodium falciparum parasites that cause malaria are evolving resistance to our most effective and potent anti-malarial drugs available, called artemisinins. Currently, artemisinin resistance is emerging in a number of countries in the Greater Mekong Subregion, including Cambodia, Thailand, Myanmar, and Vietnam. Historically, the Thai-Cambodia border region has been an epicenter of resistance to several anti-malarial drugs. To prevent the spread of artemisinin resistant parasites from the Greater Mekong Subregion, a global artemisinin resistance project was initiated in 2009. Here, we show that artemisinin resistance associated mutation in the K13 gene were widely present throughout Thailand, as early as 2007, primarily along the Thai-Cambodia and Thai-Myanmar border regions. Additional data based on microsatellite markers suggests that the most commonly found K13 C580Y allele may have two recent independent origins in Thailand, on the borders of Cambodia and Myanmar.
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Affiliation(s)
- Eldin Talundzic
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
- Atlanta Research and Education Foundation, Atlanta VA Medical Center, Atlanta, Georgia, United States of America
- * E-mail:
| | - Sheila Akinyi Okoth
- Atlanta Research and Education Foundation, Atlanta VA Medical Center, Atlanta, Georgia, United States of America
| | - Kanungnit Congpuong
- Bureau of Vector Borne Diseases, Ministry of Public Health, Nonthaburi, Thailand
- Bansomdej-chaopraya Rajabhat University, Bangkok, Thailand
| | - Mateusz M. Plucinski
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Lindsay Morton
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Ira F. Goldman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Patrick S. Kachur
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | | | - Wichai Satimai
- Bureau of Vector Borne Diseases, Ministry of Public Health, Nonthaburi, Thailand
| | - John W. Barnwell
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Venkatachalam Udhayakumar
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
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127
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Sibley CH. Observing in real time the evolution of artemisinin resistance in Plasmodium falciparum. BMC Med 2015; 13:67. [PMID: 25889405 PMCID: PMC4379603 DOI: 10.1186/s12916-015-0316-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 03/10/2015] [Indexed: 01/25/2023] Open
Abstract
Simple genetic changes that correlate with drug resistance are used routinely to identify resistant pathogens. These "molecular markers" have usually been defined long after the phenotype of resistance was noted. The molecular changes at the "end game" reflect a long and complex evolution of genetic changes, but once a solidly resistant set of changes assembles under drug selection, that genotype is likely to become fixed, and resistant pathogens will spread widely. Artemisinins are currently used worldwide to treat malaria caused by Plasmodium falciparum, but parasite response has diminished rapidly in the Mekong region of Southeast Asia. Should artemisinins lose potency completely and this effect spread worldwide, effective malaria treatment would be almost impossible. The full range of modern methods has been applied to define rapidly the genetic changes responsible. Changes associated with artemisinin resistance are complex and seem to be evolving rapidly, especially in Southeast Asia. This is a rare chance to observe the early stages in evolution of resistance, and to develop strategies to reverse or mitigate the trend and to protect these key medicines.
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Affiliation(s)
- Carol Hopkins Sibley
- Worldwide Antimalarial Resistance Network, Department of Genome Sciences, University of Washington, Seattle, WA, USA.
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128
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Miotto O, Amato R, Ashley EA, MacInnis B, Almagro-Garcia J, Amaratunga C, Lim P, Mead D, Oyola SO, Dhorda M, Imwong M, Woodrow C, Manske M, Stalker J, Drury E, Campino S, Amenga-Etego L, Thanh TNN, Tran HT, Ringwald P, Bethell D, Nosten F, Phyo AP, Pukrittayakamee S, Chotivanich K, Chuor CM, Nguon C, Suon S, Sreng S, Newton PN, Mayxay M, Khanthavong M, Hongvanthong B, Htut Y, Han KT, Kyaw MP, Faiz MA, Fanello CI, Onyamboko M, Mokuolu OA, Jacob CG, Takala-Harrison S, Plowe CV, Day NP, Dondorp AM, Spencer CCA, McVean G, Fairhurst RM, White NJ, Kwiatkowski DP. Genetic architecture of artemisinin-resistant Plasmodium falciparum. Nat Genet 2015; 47:226-34. [PMID: 25599401 PMCID: PMC4545236 DOI: 10.1038/ng.3189] [Citation(s) in RCA: 416] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 12/15/2014] [Indexed: 01/31/2023]
Abstract
We report a large multicenter genome-wide association study of Plasmodium falciparum resistance to artemisinin, the frontline antimalarial drug. Across 15 locations in Southeast Asia, we identified at least 20 mutations in kelch13 (PF3D7_1343700) affecting the encoded propeller and BTB/POZ domains, which were associated with a slow parasite clearance rate after treatment with artemisinin derivatives. Nonsynonymous polymorphisms in fd (ferredoxin), arps10 (apicoplast ribosomal protein S10), mdr2 (multidrug resistance protein 2) and crt (chloroquine resistance transporter) also showed strong associations with artemisinin resistance. Analysis of the fine structure of the parasite population showed that the fd, arps10, mdr2 and crt polymorphisms are markers of a genetic background on which kelch13 mutations are particularly likely to arise and that they correlate with the contemporary geographical boundaries and population frequencies of artemisinin resistance. These findings indicate that the risk of new resistance-causing mutations emerging is determined by specific predisposing genetic factors in the underlying parasite population.
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Affiliation(s)
- Olivo Miotto
- 1] Wellcome Trust Sanger Institute, Hinxton, UK. [2] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK. [3] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Roberto Amato
- 1] Wellcome Trust Sanger Institute, Hinxton, UK. [2] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK. [3] Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Elizabeth A Ashley
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Bronwyn MacInnis
- 1] Wellcome Trust Sanger Institute, Hinxton, UK. [2] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Jacob Almagro-Garcia
- 1] Wellcome Trust Sanger Institute, Hinxton, UK. [2] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK. [3] Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Chanaki Amaratunga
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Pharath Lim
- 1] Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA. [2] National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Daniel Mead
- Wellcome Trust Sanger Institute, Hinxton, UK
| | | | - Mehul Dhorda
- 1] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK. [2] Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, USA. [3] WorldWide Antimalarial Resistance Network (WWARN), Asia Regional Centre, Mahidol University, Bangkok, Thailand
| | - Mallika Imwong
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Charles Woodrow
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Magnus Manske
- 1] Wellcome Trust Sanger Institute, Hinxton, UK. [2] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Jim Stalker
- 1] Wellcome Trust Sanger Institute, Hinxton, UK. [2] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | | | - Susana Campino
- 1] Wellcome Trust Sanger Institute, Hinxton, UK. [2] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Lucas Amenga-Etego
- 1] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK. [2] Navrongo Health Research Centre, Navrongo, Ghana
| | - Thuy-Nhien Nguyen Thanh
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Hien Tinh Tran
- 1] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK. [2] Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Pascal Ringwald
- Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | - Delia Bethell
- Department of Immunology and Medicine, US Army Medical Component, Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Francois Nosten
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK. [3] Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Aung Pyae Phyo
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK. [3] Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | | | | | - Char Meng Chuor
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Chea Nguon
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Seila Suon
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Sokunthea Sreng
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Paul N Newton
- 1] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK. [2] Lao Oxford Mahosot Wellcome Trust Research Unit (LOMWRU), Mahosot Hospital, Vientiane, Laos
| | - Mayfong Mayxay
- 1] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK. [2] Lao Oxford Mahosot Wellcome Trust Research Unit (LOMWRU), Mahosot Hospital, Vientiane, Laos. [3] Faculty of Postgraduate Studies, University of Health Sciences, Vientiane, Laos
| | - Maniphone Khanthavong
- Center of Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Laos
| | - Bouasy Hongvanthong
- Center of Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Laos
| | - Ye Htut
- Department of Medical Research, Lower Myanmar, Yangon, Myanmar
| | - Kay Thwe Han
- Department of Medical Research, Lower Myanmar, Yangon, Myanmar
| | - Myat Phone Kyaw
- Department of Medical Research, Lower Myanmar, Yangon, Myanmar
| | - Md Abul Faiz
- Malaria Research Group and Dev Care Foundation, Dhaka, Bangladesh
| | - Caterina I Fanello
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Marie Onyamboko
- 1] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK. [2] Kinshasa School of Public Health, Kinshasa, Democratic Republic of the Congo
| | - Olugbenga A Mokuolu
- Department of Paediatrics and Child Health, University of Ilorin, Ilorin, Nigeria
| | - Christopher G Jacob
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Shannon Takala-Harrison
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Christopher V Plowe
- 1] Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, USA. [2] Howard Hughes Medical Institute, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Nicholas P Day
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chris C A Spencer
- 1] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK. [2] Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Gilean McVean
- 1] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK. [2] Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK. [3] Department of Statistics, University of Oxford, Oxford, UK
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Nicholas J White
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Dominic P Kwiatkowski
- 1] Wellcome Trust Sanger Institute, Hinxton, UK. [2] Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK. [3] Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
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129
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Canier L, Khim N, Kim S, Eam R, Khean C, Loch K, Ken M, Pannus P, Bosman P, Stassijns J, Nackers F, Alipon S, Char MC, Chea N, Etienne W, De Smet M, Kindermans JM, Ménard D. Malaria PCR detection in Cambodian low-transmission settings: dried blood spots versus venous blood samples. Am J Trop Med Hyg 2015; 92:573-7. [PMID: 25561570 PMCID: PMC4350552 DOI: 10.4269/ajtmh.14-0614] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 11/09/2014] [Indexed: 11/07/2022] Open
Abstract
In the context of malaria elimination, novel strategies for detecting very low malaria parasite densities in asymptomatic individuals are needed. One of the major limitations of the malaria parasite detection methods is the volume of blood samples being analyzed. The objective of the study was to compare the diagnostic accuracy of a malaria polymerase chain reaction assay, from dried blood spots (DBS, 5 μL) and different volumes of venous blood (50 μL, 200 μL, and 1 mL). The limit of detection of the polymerase chain reaction assay, using calibrated Plasmodium falciparum blood dilutions, showed that venous blood samples (50 μL, 200 μL, 1 mL) combined with Qiagen extraction methods gave a similar threshold of 100 parasites/mL, ∼100-fold lower than 5 μL DBS/Instagene method. On a set of 521 field samples, collected in two different transmission areas in northern Cambodia, no significant difference in the proportion of parasite carriers, regardless of the methods used was found. The 5 μL DBS method missed 27% of the samples detected by the 1 mL venous blood method, but most of the missed parasites carriers were infected by Plasmodium vivax (84%). The remaining missed P. falciparum parasite carriers (N = 3) were only detected in high-transmission areas.
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Affiliation(s)
- Lydie Canier
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Nimol Khim
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Saorin Kim
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Rotha Eam
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Chanra Khean
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Kaknika Loch
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Malen Ken
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Pieter Pannus
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Philippe Bosman
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Jorgen Stassijns
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Fabienne Nackers
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - SweetC Alipon
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Meng Chuor Char
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Nguon Chea
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - William Etienne
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Martin De Smet
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Jean-Marie Kindermans
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Didier Ménard
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia; Médecins Sans Frontières, Brussels, Belgium; Epicentre, Paris, France; Médecins Sans Frontières, Tuol Svay Prey I, Chamkarmon, Phnom Penh, Cambodia; National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
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130
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Tun KM, Imwong M, Lwin KM, Win AA, Hlaing TM, Hlaing T, Lin K, Kyaw MP, Plewes K, Faiz MA, Dhorda M, Cheah PY, Pukrittayakamee S, Ashley EA, Anderson TJC, Nair S, McDew-White M, Flegg JA, Grist EPM, Guerin P, Maude RJ, Smithuis F, Dondorp AM, Day NPJ, Nosten F, White NJ, Woodrow CJ. Spread of artemisinin-resistant Plasmodium falciparum in Myanmar: a cross-sectional survey of the K13 molecular marker. THE LANCET. INFECTIOUS DISEASES 2015; 15:415-21. [PMID: 25704894 PMCID: PMC4374103 DOI: 10.1016/s1473-3099(15)70032-0] [Citation(s) in RCA: 315] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/30/2022]
Abstract
BACKGROUND Emergence of artemisinin resistance in southeast Asia poses a serious threat to the global control of Plasmodium falciparum malaria. Discovery of the K13 marker has transformed approaches to the monitoring of artemisinin resistance, allowing introduction of molecular surveillance in remote areas through analysis of DNA. We aimed to assess the spread of artemisinin-resistant P falciparum in Myanmar by determining the relative prevalence of P falciparum parasites carrying K13-propeller mutations. METHODS We did this cross-sectional survey at malaria treatment centres at 55 sites in ten administrative regions in Myanmar, and in relevant border regions in Thailand and Bangladesh, between January, 2013, and September, 2014. K13 sequences from P falciparum infections were obtained mainly by passive case detection. We entered data into two geostatistical models to produce predictive maps of the estimated prevalence of mutations of the K13 propeller region across Myanmar. FINDINGS Overall, 371 (39%) of 940 samples carried a K13-propeller mutation. We recorded 26 different mutations, including nine mutations not described previously in southeast Asia. In seven (70%) of the ten administrative regions of Myanmar, the combined K13-mutation prevalence was more than 20%. Geospatial mapping showed that the overall prevalence of K13 mutations exceeded 10% in much of the east and north of the country. In Homalin, Sagaing Region, 25 km from the Indian border, 21 (47%) of 45 parasite samples carried K13-propeller mutations. INTERPRETATION Artemisinin resistance extends across much of Myanmar. We recorded P falciparum parasites carrying K13-propeller mutations at high prevalence next to the northwestern border with India. Appropriate therapeutic regimens should be tested urgently and implemented comprehensively if spread of artemisinin resistance to other regions is to be avoided. FUNDING Wellcome Trust-Mahidol University-Oxford Tropical Medicine Research Programme and the Bill & Melinda Gates Foundation.
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Affiliation(s)
- Kyaw M Tun
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar; Defence Services Medical Research Centre, Naypyitaw, Myanmar
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Mahidol University, Bangkok, Thailand; Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.
| | - Khin M Lwin
- Shoklo Malaria Research Unit, Mae Sot, Thailand
| | - Aye A Win
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Institute of Medicine 1, Yangon, Myanmar
| | - Tin M Hlaing
- Defence Services Medical Research Centre, Naypyitaw, Myanmar
| | - Thaung Hlaing
- Defence Services Medical Research Centre, Naypyitaw, Myanmar; Department of Health, Ministry of Health, Naypyitaw, Myanmar
| | - Khin Lin
- Department of Medical Research, Upper Myanmar, Myanmar
| | - Myat P Kyaw
- Department of Medical Research, Lower Myanmar, Myanmar
| | - Katherine Plewes
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - M Abul Faiz
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Dev Care Foundation, Dhaka, Bangladesh
| | - Mehul Dhorda
- WorldWide Antimalarial Resistance Network, Oxford, UK; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Phaik Yeong Cheah
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Elizabeth A Ashley
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Tim J C Anderson
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Shalini Nair
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Marina McDew-White
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Jennifer A Flegg
- WorldWide Antimalarial Resistance Network, Oxford, UK; School of Mathematical Sciences, Monash University, Melbourne, Australia
| | | | | | - Richard J Maude
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Frank Smithuis
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Medical Action Myanmar, Yangon, Myanmar
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - François Nosten
- Shoklo Malaria Research Unit, Mae Sot, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Charles J Woodrow
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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131
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Liu H, Yang HL, Tang LH, Li XL, Huang F, Wang JZ, Li CF, Wang HY, Nie RH, Guo XR, Lin YX, Li M, Wang J, Xu JW. In vivo monitoring of dihydroartemisinin-piperaquine sensitivity in Plasmodium falciparum along the China-Myanmar border of Yunnan Province, China from 2007 to 2013. Malar J 2015; 14:47. [PMID: 25652213 PMCID: PMC4333884 DOI: 10.1186/s12936-015-0584-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 01/25/2015] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Artemisinin-based combination therapy (ACT) is the recommended first-line treatment of falciparum malaria in all endemic countries. Artemisinin resistance in Plasmodium falciparum has been confirmed in the Greater Mekong subregion (GMS). Dihydroartemisinin-piperaquine (DAPQ) is the most commonly used ACT in China. To understand the DAPQ sensitivity of P. falciparum, DAPQ resistance was monitored in vivo along the China-Myanmar border from 2007 to 2013. METHODS Eligible patients with mono-infections of P. falciparum were recruited to this study after obtaining full informed consent. DAPQ tablets for different categories of kg body weight ranges were given once a day for three days. Patients were followed up for 42 days. Polymerase chain reaction (PCR) was conducted to distinguish between re-infection and recrudescence, to confirm the Plasmodium species. The data were entered and analysed by the Kaplan-Meier method. Treatment outcome was assessed according to the WHO recommended standards. RESULTS 243 patients were completed valid follow-up. The fever clearance time (FCT) and asexual parasite clearance times (APCT) were, respectively, 36.5 ± 10.9 and 43.5 ± 11.8 hours, and there was an increasing trend of both FCT (F = 268.41, P < 0.0001) and APCT (F = 88.6, P < 0.0001) from 2007 to 2013. Eight (3.3%, 95% confidence interval, 1.4-6.4%) patients present parasitaemia on day three after medication; however they were spontaneous cure on day four. 241 (99.2%; 95% CI, 97.1-99.9%) of the patients were adequate clinical and parasitological response (ACPR) and the proportions of ACPR had not changed significantly from 2007 to 2013 (X(2) = 2.81, P = 0.7288). CONCLUSION In terms of efficacy, DAPQ is still an effective treatment for falciparum malaria. DAPQ sensitivity in P. falciparum had not significantly changed along the China-Myanmar border of Yunnan Province, China. However more attentions should be given to becoming slower fever and parasite clearance.
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Affiliation(s)
- Hui Liu
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-borne Diseases Control and Research, Puer, 665000, China.
| | - Heng-lin Yang
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-borne Diseases Control and Research, Puer, 665000, China.
| | - Lin-hua Tang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, PR China.
| | - Xing-liang Li
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-borne Diseases Control and Research, Puer, 665000, China.
| | - Fang Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, PR China.
| | - Jia-zhi Wang
- Tengchong County Center for Disease Control and Prevention, Tengchong, 679100, China.
| | - Chun-fu Li
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-borne Diseases Control and Research, Puer, 665000, China.
| | - Heng-ye Wang
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-borne Diseases Control and Research, Puer, 665000, China.
| | - Ren-hua Nie
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-borne Diseases Control and Research, Puer, 665000, China.
| | - Xiang-rui Guo
- Yangjiang County Center for Disease Control and Prevention, Yingjiang, 679300, China.
| | - Ying-xue Lin
- Yangjiang County Center for Disease Control and Prevention, Yingjiang, 679300, China.
| | - Mei Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, PR China.
| | - Jian Wang
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-borne Diseases Control and Research, Puer, 665000, China.
| | - Jian-wei Xu
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-borne Diseases Control and Research, Puer, 665000, China.
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Carter TE, Boulter A, Existe A, Romain JR, St Victor JY, Mulligan CJ, Okech BA. Artemisinin resistance-associated polymorphisms at the K13-propeller locus are absent in Plasmodium falciparum isolates from Haiti. Am J Trop Med Hyg 2015; 92:552-4. [PMID: 25646258 DOI: 10.4269/ajtmh.14-0664] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Antimalarial drugs are a key tool in malaria elimination programs. With the emergence of artemisinin resistance in southeast Asia, an effort to identify molecular markers for surveillance of resistant malaria parasites is underway. Non-synonymous mutations in the kelch propeller domain (K13-propeller) in Plasmodium falciparum have been associated with artemisinin resistance in samples from southeast Asia, but additional studies are needed to characterize this locus in other P. falciparum populations with different levels of artemisinin use. Here, we sequenced the K13-propeller locus in 82 samples from Haiti, where limited government oversight of non-governmental organizations may have resulted in low-level use of artemisinin-based combination therapies. We detected a single-nucleotide polymorphism (SNP) at nucleotide 1,359 in a single isolate. Our results contribute to our understanding of the global genomic diversity of the K13-propeller locus in P. falciparum populations.
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Affiliation(s)
- Tamar E Carter
- Genetics and Genomics Program, University of Florida, Gainesville, Florida; Department of Anthropology, University of Florida, Gainesville, Florida; Genetics Institute, University of Florida, Gainesville, Florida; National Public Health Laboratory, Ministry of Public Health and the Population, Port-au-Prince, Haiti; Hospital Saint Croix, Leogane, Haiti; Blanchard Clinic, Terre Noire, Haiti; Emerging Pathogens Institute, University of Florida, Gainesville, Florida; Department of Environmental and Global Health, University of Florida, Gainesville, Florida
| | - Alexis Boulter
- Genetics and Genomics Program, University of Florida, Gainesville, Florida; Department of Anthropology, University of Florida, Gainesville, Florida; Genetics Institute, University of Florida, Gainesville, Florida; National Public Health Laboratory, Ministry of Public Health and the Population, Port-au-Prince, Haiti; Hospital Saint Croix, Leogane, Haiti; Blanchard Clinic, Terre Noire, Haiti; Emerging Pathogens Institute, University of Florida, Gainesville, Florida; Department of Environmental and Global Health, University of Florida, Gainesville, Florida
| | - Alexandre Existe
- Genetics and Genomics Program, University of Florida, Gainesville, Florida; Department of Anthropology, University of Florida, Gainesville, Florida; Genetics Institute, University of Florida, Gainesville, Florida; National Public Health Laboratory, Ministry of Public Health and the Population, Port-au-Prince, Haiti; Hospital Saint Croix, Leogane, Haiti; Blanchard Clinic, Terre Noire, Haiti; Emerging Pathogens Institute, University of Florida, Gainesville, Florida; Department of Environmental and Global Health, University of Florida, Gainesville, Florida
| | - Jean R Romain
- Genetics and Genomics Program, University of Florida, Gainesville, Florida; Department of Anthropology, University of Florida, Gainesville, Florida; Genetics Institute, University of Florida, Gainesville, Florida; National Public Health Laboratory, Ministry of Public Health and the Population, Port-au-Prince, Haiti; Hospital Saint Croix, Leogane, Haiti; Blanchard Clinic, Terre Noire, Haiti; Emerging Pathogens Institute, University of Florida, Gainesville, Florida; Department of Environmental and Global Health, University of Florida, Gainesville, Florida
| | - Jean Yves St Victor
- Genetics and Genomics Program, University of Florida, Gainesville, Florida; Department of Anthropology, University of Florida, Gainesville, Florida; Genetics Institute, University of Florida, Gainesville, Florida; National Public Health Laboratory, Ministry of Public Health and the Population, Port-au-Prince, Haiti; Hospital Saint Croix, Leogane, Haiti; Blanchard Clinic, Terre Noire, Haiti; Emerging Pathogens Institute, University of Florida, Gainesville, Florida; Department of Environmental and Global Health, University of Florida, Gainesville, Florida
| | - Connie J Mulligan
- Genetics and Genomics Program, University of Florida, Gainesville, Florida; Department of Anthropology, University of Florida, Gainesville, Florida; Genetics Institute, University of Florida, Gainesville, Florida; National Public Health Laboratory, Ministry of Public Health and the Population, Port-au-Prince, Haiti; Hospital Saint Croix, Leogane, Haiti; Blanchard Clinic, Terre Noire, Haiti; Emerging Pathogens Institute, University of Florida, Gainesville, Florida; Department of Environmental and Global Health, University of Florida, Gainesville, Florida
| | - Bernard A Okech
- Genetics and Genomics Program, University of Florida, Gainesville, Florida; Department of Anthropology, University of Florida, Gainesville, Florida; Genetics Institute, University of Florida, Gainesville, Florida; National Public Health Laboratory, Ministry of Public Health and the Population, Port-au-Prince, Haiti; Hospital Saint Croix, Leogane, Haiti; Blanchard Clinic, Terre Noire, Haiti; Emerging Pathogens Institute, University of Florida, Gainesville, Florida; Department of Environmental and Global Health, University of Florida, Gainesville, Florida
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Peatey CL, Chavchich M, Chen N, Gresty KJ, Gray KA, Gatton ML, Waters NC, Cheng Q. Mitochondrial Membrane Potential in a Small Subset of Artemisinin-Induced Dormant Plasmodium falciparum Parasites In Vitro. J Infect Dis 2015; 212:426-34. [PMID: 25635122 DOI: 10.1093/infdis/jiv048] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/20/2015] [Indexed: 11/12/2022] Open
Abstract
Artemisinin-induced dormancy is a proposed mechanism for failures of monotherapy and is linked with artemisinin resistance in Plasmodium falciparum. The biological characterization and dynamics of dormant parasites are not well understood. Here we report that after dihydroartemisinin treatment in vitro, a small subset of morphologically dormant parasites was stained with rhodamine 123 (RH), a mitochondrial membrane potential marker, and persisted to recovery. RH-positive parasites sorted with fluorescence-activated cell sorting resumed growth at 10,000/well whereas RH-negative parasites failed to recover at 5 million/well. Furthermore, transcriptional activity for mitochondrial enzymes was detected only in RH-positive dormant parasites. Importantly, after treatment of dormant parasites with different concentrations of atovaquone, a mitochondrial inhibitor, the recovery of dormant parasites was delayed or stopped. This demonstrates that mitochondrial activity is critical for survival and regrowth of dormant parasites and that RH staining provides a means of identifying these parasites. These findings provide novel paths for studying and eradicating this dormant stage.
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Affiliation(s)
- Christopher L Peatey
- Drug Resistance and Diagnostics, Australian Army Malaria Institute Clinical Tropical Medicine, QIMR Berghofer Medical Research Institute
| | - Marina Chavchich
- Drug Resistance and Diagnostics, Australian Army Malaria Institute
| | - Nanhua Chen
- Drug Resistance and Diagnostics, Australian Army Malaria Institute
| | - Karryn J Gresty
- Drug Resistance and Diagnostics, Australian Army Malaria Institute Clinical Tropical Medicine, QIMR Berghofer Medical Research Institute
| | - Karen-Ann Gray
- Drug Resistance and Diagnostics, Australian Army Malaria Institute Clinical Tropical Medicine, QIMR Berghofer Medical Research Institute
| | - Michelle L Gatton
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia
| | - Norman C Waters
- Walter Reed Army Institute of Research, Malaria Vaccine Branch, Military Malaria Research Program, Silver Spring, Maryland
| | - Qin Cheng
- Drug Resistance and Diagnostics, Australian Army Malaria Institute Clinical Tropical Medicine, QIMR Berghofer Medical Research Institute
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Nyunt MH, Hlaing T, Oo HW, Tin-Oo LLK, Phway HP, Wang B, Zaw NN, Han SS, Tun T, San KK, Kyaw MP, Han ET. Molecular assessment of artemisinin resistance markers, polymorphisms in the k13 propeller, and a multidrug-resistance gene in the eastern and western border areas of Myanmar. Clin Infect Dis 2014; 60:1208-15. [PMID: 25537878 DOI: 10.1093/cid/ciu1160] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND As K13 propeller mutations have been recently reported to serve as molecular markers, assessment of K13 propeller polymorphisms in multidrug-resistant gene in isolates from Myanmar, especially the eastern and western border areas, is crucial if we are to understand the spread of artemisinin resistance. METHODS A 3-day surveillance study was conducted in the eastern and western border areas in Myanmar, and K13 propeller and Plasmodium falciparum multidrug resistance-associated protein 1 (pfmrp1) mutations were analyzed. RESULTS Among the 1761 suspected malaria cases screened, a total of 42 uncomplicated falciparum cases from the eastern border and 49 from the western border were subjected to 3 days of surveillance after artemether-lumefantrine treatment. No parasitemic case showing positivity on day 3 was noted from the western border, but 26.2% (11/42) of cases were positive in the eastern border. Although we found no marked difference in the prevalence of the pfmrp1 mutation in the eastern and western borders (36% vs 31%, respectively), K13 mutations were more frequent in the eastern border area (where the 3-day persistent cases were detected; 48% vs 14%). C580Y, M476I, A481V, N458Y, R539T, and R516Y accounted for 68.9% of all K13 mutations significantly associated with day 3 parasitaemia. CONCLUSIONS The K13 mutations were significantly associated with day 3 parasitaemia, emphasizing the importance of K13 surveillance. The low prevalence of K13 mutations and the absence of day 3 parasitaemic cases indicate that artemisinin resistance may not have spread to the western Myanmar border region. Although analysis of multiple K13 mutations is challenging, it should be done at various sentinel sites in Myanmar.
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Affiliation(s)
- Myat Htut Nyunt
- Department of Medical Research (Lower Myanmar), Yangon, Republic of the Union of Myanmar Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Thaung Hlaing
- Department of Health, Nay Pyi Taw, Republic of the Union of Myanmar
| | - Htet Wai Oo
- Department of Medical Research (Lower Myanmar), Yangon, Republic of the Union of Myanmar
| | - Lu-Lu Kyaw Tin-Oo
- Department of Medical Research (Lower Myanmar), Yangon, Republic of the Union of Myanmar
| | - Hnin Phyu Phway
- Department of Medical Research (Lower Myanmar), Yangon, Republic of the Union of Myanmar
| | - Bo Wang
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Ni Ni Zaw
- Department of Medical Research (Lower Myanmar), Yangon, Republic of the Union of Myanmar
| | - Soe Soe Han
- Department of Medical Research (Lower Myanmar), Yangon, Republic of the Union of Myanmar
| | - Thurein Tun
- Department of Medical Research (Lower Myanmar), Yangon, Republic of the Union of Myanmar
| | - Kyaw Kyaw San
- Department of Medical Research (Lower Myanmar), Yangon, Republic of the Union of Myanmar
| | - Myat Phone Kyaw
- Department of Medical Research (Lower Myanmar), Yangon, Republic of the Union of Myanmar
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
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Abstract
Across the globe, over 200 million annual malaria infections result in up to 660,000 deaths, 77% of which occur in children under the age of five years. Although prevention is important, malaria deaths are typically prevented by using antimalarial drugs that eliminate symptoms and clear parasites from the blood. Artemisinins are one of the few remaining compound classes that can be used to cure multidrug-resistant Plasmodium falciparum infections. Unfortunately, clinical trials from Southeast Asia are showing that artemisinin-based treatments are beginning to lose their effectiveness, adding renewed urgency to the search for the genetic determinants of parasite resistance to this important drug class. We review the genetic and genomic approaches that have led to an improved understanding of artemisinin resistance, including the identification of resistance-conferring mutations in the P. falciparum kelch13 gene.
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136
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Histone methyltransferase inhibitors are orally bioavailable, fast-acting molecules with activity against different species causing malaria in humans. Antimicrob Agents Chemother 2014; 59:950-9. [PMID: 25421480 DOI: 10.1128/aac.04419-14] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Current antimalarials are under continuous threat due to the relentless development of drug resistance by malaria parasites. We previously reported promising in vitro parasite-killing activity with the histone methyltransferase inhibitor BIX-01294 and its analogue TM2-115. Here, we further characterize these diaminoquinazolines for in vitro and in vivo efficacy and pharmacokinetic properties to prioritize and direct compound development. BIX-01294 and TM2-115 displayed potent in vitro activity, with 50% inhibitory concentrations (IC50s) of <50 nM against drug-sensitive laboratory strains and multidrug-resistant field isolates, including artemisinin-refractory Plasmodium falciparum isolates. Activities against ex vivo clinical isolates of both P. falciparum and Plasmodium vivax were similar, with potencies of 300 to 400 nM. Sexual-stage gametocyte inhibition occurs at micromolar levels; however, mature gametocyte progression to gamete formation is inhibited at submicromolar concentrations. Parasite reduction ratio analysis confirms a high asexual-stage rate of killing. Both compounds examined displayed oral efficacy in in vivo mouse models of Plasmodium berghei and P. falciparum infection. The discovery of a rapid and broadly acting antimalarial compound class targeting blood stage infection, including transmission stage parasites, and effective against multiple malaria-causing species reveals the diaminoquinazoline scaffold to be a very promising lead for development into greatly needed novel therapies to control malaria.
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137
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Mohon AN, Alam MS, Bayih AG, Folefoc A, Shahinas D, Haque R, Pillai DR. Mutations in Plasmodium falciparum K13 propeller gene from Bangladesh (2009-2013). Malar J 2014; 13:431. [PMID: 25404021 PMCID: PMC4240861 DOI: 10.1186/1475-2875-13-431] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 11/03/2014] [Indexed: 12/22/2022] Open
Abstract
Background Bangladesh is a malaria hypo-endemic country sharing borders with India and Myanmar. Artemisinin combination therapy (ACT) remains successful in Bangladesh. An increase of artemisinin-resistant malaria parasites on the Thai-Cambodia and Thai-Myanmar borders is worrisome. K13 propeller gene (PF3D7_1343700 or PF13_0238) mutations have been linked to both in vitro artemisinin resistance and in vivo slow parasite clearance rates. This group undertook to evaluate if mutations seen in Cambodia have emerged in Bangladesh where ACT use is now standard for a decade. Methods Samples were obtained from Plasmodium falciparum-infected malaria patients from Upazila health complexes (UHC) between 2009 and 2013 in seven endemic districts of Bangladesh. These districts included Khagrachari (Matiranga UHC), Rangamati (Rajasthali UHC), Cox’s Bazar (Ramu and Ukhia UHC), Bandarban (Lama UHC), Mymensingh (Haluaghat UHC), Netrokona (Durgapur and Kalmakanda UHC), and Moulvibazar (Sreemangal and Kamalganj UHC). Results Out of 296 microscopically positive P. falciparum samples, 271 (91.6%) were confirmed as mono-infections by both real-time PCR and nested PCR. The K13 propeller gene from 253 (93.4%) samples was sequenced bi-directionally. One non-synonymous mutation (A578S) was found in Bangladeshi clinical isolates. The A578S mutation was confirmed and lies adjacent to the C580Y mutation, the major mutation causing delayed parasite clearance in Cambodia. Based on computational modeling A578S should have a significant effect on tertiary structure of the protein. Conclusion The data suggest that P. falciparum in Bangladesh remains free of the C580Y mutation linked to delayed parasite clearance. However, the mutation A578S is present and based on structural analysis could affect K13 gene function. Further in vivo clinical studies are required to validate the effect of this mutation.
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Affiliation(s)
| | | | | | | | | | | | - Dylan R Pillai
- Department of Microbiology, Immunology and Infectious Diseases, Faculty of Medicine, University of Calgary, Diagnostic and Scientific Centre, Room 1 W-416, 9-3535 Research Road NW, Calgary, AB T2L 2 K8, Canada.
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138
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Reduced polymorphism in the Kelch propeller domain in Plasmodium vivax isolates from Cambodia. Antimicrob Agents Chemother 2014; 59:730-3. [PMID: 25385109 DOI: 10.1128/aac.03908-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Polymorphism in the ortholog gene of the Plasmodium falciparum K13 gene was investigated in Plasmodium vivax isolates collected in Cambodia. All of them were Sal-1 wild-type alleles except two (2/284, 0.7%), and P. vivax K12 polymorphism was reduced compared to that of the P. falciparum K13 gene. Both mutant allele isolates had the same nonsynonymous mutation at codon 552 (V552I) and were from Ratanak Kiri province. These preliminary data should encourage additional studies for associating artemisinin or chloroquine resistance and K12 polymorphism.
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139
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Maude RJ, Nguon C, Ly P, Bunkea T, Ngor P, Canavati de la Torre SE, White NJ, Dondorp AM, Day NPJ, White LJ, Chuor CM. Spatial and temporal epidemiology of clinical malaria in Cambodia 2004-2013. Malar J 2014; 13:385. [PMID: 25266007 PMCID: PMC4531392 DOI: 10.1186/1475-2875-13-385] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 09/26/2014] [Indexed: 11/10/2022] Open
Abstract
Background Artemisinin-resistant Plasmodium falciparum malaria has recently been identified on the Thailand-Cambodia border and more recently in parts of Thailand, Myanmar and Vietnam. There is concern that if this resistance were to spread, it would severely hamper malaria control and elimination efforts worldwide. Efforts are currently underway to intensify malaria control activities and ultimately eliminate malaria from Cambodia. To support these efforts, it is crucial to have a detailed picture of disease burden and its major determinants over time. Methods An analysis of spatial and temporal data on clinical malaria in Cambodia collected by the National Centre for Parasitology, Entomology and Malaria Control (CNM) and the Department of Planning and Health Information, Ministry of Health Cambodia from 2004 to 2013 is presented. Results There has been a marked decrease of 81% in annual cases due to P. falciparum since 2009 coinciding with a rapid scale-up in village malaria workers (VMWs) and insecticide-treated bed nets (ITNs). Concurrently, the number of cases with Plasmodium vivax has greatly increased. It is estimated that there were around 112,000 total cases in 2012, 2.8 times greater than the WHO estimate for that year, and 68,000 in 2013 (an annual parasite incidence (API) of 4.6/1000). With the scale-up of VMWs, numbers of patients presenting to government facilities did not fall and it appears likely that those who saw VMWs had previously accessed healthcare in the private sector. Malaria mortality has decreased, particularly in areas with VMWs. There has been a marked decrease in cases in parts of western Cambodia, especially in Pailin and Battambang Provinces. In the northeast, the fall in malaria burden has been more modest, this area having the highest API in 2013. Conclusion The clinical burden of falciparum malaria in most areas of Cambodia has greatly decreased from 2009 to 2013, associated with roll-out of ITNs and VMWs. Numbers of cases with P. vivax have increased. Possible reasons for these trends are discussed and areas requiring further study are highlighted. Although malaria surveillance data are prone to collection bias and tend to underestimate disease burden, the finding of similar trends in two independent datasets in this study greatly increased the robustness of the findings. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-385) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Richard J Maude
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Maude RJ, Nguon C, Dondorp AM, White LJ, White NJ. The diminishing returns of atovaquone-proguanil for elimination of Plasmodium falciparum malaria: modelling mass drug administration and treatment. Malar J 2014; 13:380. [PMID: 25249272 PMCID: PMC4192368 DOI: 10.1186/1475-2875-13-380] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 09/18/2014] [Indexed: 11/26/2022] Open
Abstract
Background Artemisinin resistance is a major threat to current efforts to eliminate Plasmodium falciparum malaria which rely heavily on the continuing efficacy of artemisinin combination therapy (ACT). It has been suggested that ACT should not be used in mass drug administration (MDA) in areas where artemisinin-resistant P. falciparum is prevalent, and that atovaquone-proguanil (A-P) might be a preferable alternative. However, a single point mutation in the cytochrome b gene confers high level resistance to atovaquone, and such mutant parasites arise frequently during treatment making A-P a vulnerable tool for elimination. Methods A deterministic, population level, mathematical model was developed based on data from Cambodia to explore the possible effects of large-scale use of A-P compared to dihydroartemisinin-piperaquine ACT for mass drug administration and/or treatment of P. falciparum malaria, with and without adjunctive primaquine (PQ) and long-lasting insecticide-treated bed nets (LLIN). The aim was local elimination. Results The model showed the initial efficacy of ACT and A-P for MDA to be similar. However, each round of A-P MDA resulted in rapid acquisition and spread of atovaquone resistance. Even a single round of MDA could compromise efficacy sufficient to preclude its use for treatment or prophylaxis. A switch to A-P for treatment of symptomatic episodes resulted in a complete loss of efficacy in the population within four to five years of its introduction. The impact of MDA was temporary and a combination of maintained high coverage with ACT treatment for symptomatic individuals and LLIN was necessary for elimination. Conclusion For malaria elimination, A-P for MDA or treatment of symptomatic cases should be avoided. A combined strategy of high coverage with ACT for treatment of symptomatic episodes, LLIN and ACT + P MDA would be preferable. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-380) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Richard J Maude
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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141
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Ulrich P, Gipson GR, Clark MA, Tripathi A, Sullivan DJ, Cerami C. In vitro and in vivo antimalarial activity of amphiphilic naphthothiazolium salts with amine-bearing side chains. Am J Trop Med Hyg 2014; 91:824-32. [PMID: 25184829 DOI: 10.4269/ajtmh.13-0565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Because of emerging resistance to existing drugs, new chemical classes of antimalarial drugs are urgently needed. We have rationally designed a library of compounds that were predicted to accumulate in the digestive vacuole and then decrystallize hemozoin by breaking the iron carboxylate bond in hemozoin. We report the synthesis of 16 naphthothiazolium salts with amine-bearing side chains and their activities against the erythrocytic stage of Plasmodium falciparum in vitro. KSWI-855, the compound with the highest efficacy against the asexual stages of P. falciparum in vitro, also had in vitro activity against P. falciparum gametocytes and in vivo activity against P. berghei in a murine malaria model.
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Affiliation(s)
- Peter Ulrich
- The Kenneth S. Warren Institute, Ossining, New York; University of North Carolina, Chapel Hill, North Carolina; Johns Hopkins Malaria Institute, Baltimore, Maryland
| | - Gregory R Gipson
- The Kenneth S. Warren Institute, Ossining, New York; University of North Carolina, Chapel Hill, North Carolina; Johns Hopkins Malaria Institute, Baltimore, Maryland
| | - Martha A Clark
- The Kenneth S. Warren Institute, Ossining, New York; University of North Carolina, Chapel Hill, North Carolina; Johns Hopkins Malaria Institute, Baltimore, Maryland
| | - Abhai Tripathi
- The Kenneth S. Warren Institute, Ossining, New York; University of North Carolina, Chapel Hill, North Carolina; Johns Hopkins Malaria Institute, Baltimore, Maryland
| | - David J Sullivan
- The Kenneth S. Warren Institute, Ossining, New York; University of North Carolina, Chapel Hill, North Carolina; Johns Hopkins Malaria Institute, Baltimore, Maryland
| | - Carla Cerami
- The Kenneth S. Warren Institute, Ossining, New York; University of North Carolina, Chapel Hill, North Carolina; Johns Hopkins Malaria Institute, Baltimore, Maryland
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142
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Ndour PA, Lopera-Mesa TM, Diakité SAS, Chiang S, Mouri O, Roussel C, Jauréguiberry S, Biligui S, Kendjo E, Claessens A, Ciceron L, Mazier D, Thellier M, Diakité M, Fairhurst RM, Buffet PA. Plasmodium falciparum clearance is rapid and pitting independent in immune Malian children treated with artesunate for malaria. J Infect Dis 2014; 211:290-7. [PMID: 25183768 DOI: 10.1093/infdis/jiu427] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND In Plasmodium falciparum-infected patients treated with artemisinins, parasitemia declines through so-called pitting, an innate splenic process that transforms infected red blood cells (iRBCs) into once-infected RBCs (O-iRBCs). METHODS We measured pitting in 83 French travelers and 42 Malian children treated for malaria with artesunate. RESULTS In travelers, O-iRBCs peaked at 107.7% initial parasitemia. In Malian children aged 1.5-4 years, O-iRBCs peaked at higher concentrations than in children aged 9-13 years (91.60% vs 31.95%; P = .0097). The parasite clearance time in older children was shorter than in younger children (P = .0001), and the decline in parasitemia in children aged 1.5-4 years often started 6 hours after treatment initiation, a lag phase generally absent in infants and older children. A 6-hour lag phase in artificial pitting of artesunate-exposed iRBCs was also observed in vitro. The proportion of iRBCs recognized by autologous immunoglobulin G (IgG) correlated with the parasite clearance time (r = -0.501; P = .0006) and peak O-iRBC concentration (r = -0.420; P = .0033). CONCLUSIONS Antimalarial immunity correlates with fast artemisinin-induced parasite clearance and low pitting rates. In nonimmune populations, artemisinin-induced P. falciparum clearance is related to pitting and starts after a 6-hour lag phase. In immune populations, passively and naturally acquired immune mechanisms operating faster than pitting may exist. This mechanism may mitigate the emergence of artemisinin-resistant P. falciparum in Africa.
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Affiliation(s)
- Papa Alioune Ndour
- Centre d'Immunologie et des Maladies Infectieuses de Paris, INSERM U1135, UPMC CR7, CNRS ERL 8255 Centre National de Référence du Paludisme site Pitié-Salpêtrière Laboratory of Excellence GR-Ex
| | - Tatiana M Lopera-Mesa
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Seidina A S Diakité
- Malaria Research and Training Center, Faculty of Medicine, Pharmacy and Odonto-stomatology, University of Bamako, Mali
| | - Serena Chiang
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Oussama Mouri
- AP-HP, Hôpital Pitié-Salpêtrière, Service de Parasitologie-Mycologie et Service des Maladies Infectieuses et Tropicales, Paris, France
| | - Camille Roussel
- Centre d'Immunologie et des Maladies Infectieuses de Paris, INSERM U1135, UPMC CR7, CNRS ERL 8255
| | - Stéphane Jauréguiberry
- Centre National de Référence du Paludisme site Pitié-Salpêtrière AP-HP, Hôpital Pitié-Salpêtrière, Service de Parasitologie-Mycologie et Service des Maladies Infectieuses et Tropicales, Paris, France
| | - Sylvestre Biligui
- Centre d'Immunologie et des Maladies Infectieuses de Paris, INSERM U1135, UPMC CR7, CNRS ERL 8255 Centre National de Référence du Paludisme site Pitié-Salpêtrière
| | - Eric Kendjo
- Centre d'Immunologie et des Maladies Infectieuses de Paris, INSERM U1135, UPMC CR7, CNRS ERL 8255 Centre National de Référence du Paludisme site Pitié-Salpêtrière
| | - Antoine Claessens
- Centre for Immunity, Infection and Evolution, University of Edinburgh, United Kingdom
| | - Liliane Ciceron
- Centre d'Immunologie et des Maladies Infectieuses de Paris, INSERM U1135, UPMC CR7, CNRS ERL 8255 Centre National de Référence du Paludisme site Pitié-Salpêtrière
| | - Dominique Mazier
- Centre d'Immunologie et des Maladies Infectieuses de Paris, INSERM U1135, UPMC CR7, CNRS ERL 8255 Centre National de Référence du Paludisme site Pitié-Salpêtrière AP-HP, Hôpital Pitié-Salpêtrière, Service de Parasitologie-Mycologie et Service des Maladies Infectieuses et Tropicales, Paris, France
| | - Marc Thellier
- Centre d'Immunologie et des Maladies Infectieuses de Paris, INSERM U1135, UPMC CR7, CNRS ERL 8255 Centre National de Référence du Paludisme site Pitié-Salpêtrière AP-HP, Hôpital Pitié-Salpêtrière, Service de Parasitologie-Mycologie et Service des Maladies Infectieuses et Tropicales, Paris, France
| | - Mahamadou Diakité
- Malaria Research and Training Center, Faculty of Medicine, Pharmacy and Odonto-stomatology, University of Bamako, Mali
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Pierre A Buffet
- Centre d'Immunologie et des Maladies Infectieuses de Paris, INSERM U1135, UPMC CR7, CNRS ERL 8255 Centre National de Référence du Paludisme site Pitié-Salpêtrière Laboratory of Excellence GR-Ex AP-HP, Hôpital Pitié-Salpêtrière, Service de Parasitologie-Mycologie et Service des Maladies Infectieuses et Tropicales, Paris, France
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Takala-Harrison S, Jacob CG, Arze C, Cummings MP, Silva JC, Dondorp AM, Fukuda MM, Hien TT, Mayxay M, Noedl H, Nosten F, Kyaw MP, Nhien NTT, Imwong M, Bethell D, Se Y, Lon C, Tyner SD, Saunders DL, Ariey F, Mercereau-Puijalon O, Menard D, Newton PN, Khanthavong M, Hongvanthong B, Starzengruber P, Fuehrer HP, Swoboda P, Khan WA, Phyo AP, Nyunt MM, Nyunt MH, Brown TS, Adams M, Pepin CS, Bailey J, Tan JC, Ferdig MT, Clark TG, Miotto O, MacInnis B, Kwiatkowski DP, White NJ, Ringwald P, Plowe CV. Independent emergence of artemisinin resistance mutations among Plasmodium falciparum in Southeast Asia. J Infect Dis 2014; 211:670-9. [PMID: 25180241 DOI: 10.1093/infdis/jiu491] [Citation(s) in RCA: 327] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The emergence of artemisinin-resistant Plasmodium falciparum in Southeast Asia threatens malaria treatment efficacy. Mutations in a kelch protein encoded on P. falciparum chromosome 13 (K13) have been associated with resistance in vitro and in field samples from Cambodia. METHODS P. falciparum infections from artesunate efficacy trials in Bangladesh, Cambodia, Laos, Myanmar, and Vietnam were genotyped at 33 716 genome-wide single-nucleotide polymorphisms (SNPs). Linear mixed models were used to test associations between parasite genotypes and parasite clearance half-lives following artesunate treatment. K13 mutations were tested for association with artemisinin resistance, and extended haplotypes on chromosome 13 were examined to determine whether mutations arose focally and spread or whether they emerged independently. RESULTS The presence of nonreference K13 alleles was associated with prolonged parasite clearance half-life (P = 1.97 × 10(-12)). Parasites with a mutation in any of the K13 kelch domains displayed longer parasite clearance half-lives than parasites with wild-type alleles. Haplotype analysis revealed both population-specific emergence of mutations and independent emergence of the same mutation in different geographic areas. CONCLUSIONS K13 appears to be a major determinant of artemisinin resistance throughout Southeast Asia. While we found some evidence of spreading resistance, there was no evidence of resistance moving westward from Cambodia into Myanmar.
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Affiliation(s)
| | | | - Cesar Arze
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore
| | - Michael P Cummings
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore
| | | | - Mark M Fukuda
- Armed Forces Research Institute of Medical Sciences, Bangkok
| | - Tran Tinh Hien
- Center for Tropical Medicine, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital Faculty of Postgraduate Studies, University of Health Sciences Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford
| | - Harald Noedl
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Austria
| | - Francois Nosten
- Mahidol-Oxford Tropical Medicine Research Unit Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford
| | - Myat P Kyaw
- Department of Medical Research (Lower Myanmar), Yangon
| | - Nguyen Thanh Thuy Nhien
- Center for Tropical Medicine, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University
| | - Delia Bethell
- Armed Forces Research Institute of Medical Sciences, Bangkok
| | - Youry Se
- Armed Forces Research Institute of Medical Sciences
| | - Chanthap Lon
- Armed Forces Research Institute of Medical Sciences
| | - Stuart D Tyner
- Armed Forces Research Institute of Medical Sciences, Bangkok
| | | | | | | | - Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Paul N Newton
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford
| | | | | | - Peter Starzengruber
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Austria
| | - Hans-Peter Fuehrer
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Austria
| | - Paul Swoboda
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Austria
| | - Wasif A Khan
- International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Aung Pyae Phyo
- Mahidol-Oxford Tropical Medicine Research Unit Shoklo Malaria Research Unit Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Myaing M Nyunt
- Howard Hughes Medical Institute/Center for Vaccine Development
| | - Myat H Nyunt
- Department of Medical Research (Lower Myanmar), Yangon
| | - Tyler S Brown
- Howard Hughes Medical Institute/Center for Vaccine Development
| | - Matthew Adams
- Howard Hughes Medical Institute/Center for Vaccine Development
| | | | - Jason Bailey
- Howard Hughes Medical Institute/Center for Vaccine Development
| | - John C Tan
- Research and Development, Roche NimbleGen, Madison, Wisconsin
| | - Michael T Ferdig
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Indiana
| | - Taane G Clark
- Faculty of Epidemiology and Population Health Faculty Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine
| | - Olivo Miotto
- Mahidol-Oxford Tropical Medicine Research Unit MRC Centre for Genomics and Global Health, Oxford University and Wellcome Trust Sanger Institute Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Bronwyn MacInnis
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Dominic P Kwiatkowski
- MRC Centre for Genomics and Global Health, Oxford University and Wellcome Trust Sanger Institute Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | | | - Pascal Ringwald
- Drug Resistance and Containment Unit, Global Malaria Programme, World Health Organization, Geneva, Switzerland
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144
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Hopkins Sibley C. Artemisinin resistance: the more we know, the more complicated it appears. J Infect Dis 2014; 211:667-9. [PMID: 25180242 DOI: 10.1093/infdis/jiu469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Carol Hopkins Sibley
- WorldWide Antimalarial Resistance Network (WWARN), Department of Genome Sciences, University of Washington, Seattle
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145
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Leroy D, Campo B, Ding XC, Burrows JN, Cherbuin S. Defining the biology component of the drug discovery strategy for malaria eradication. Trends Parasitol 2014; 30:478-90. [PMID: 25131411 DOI: 10.1016/j.pt.2014.07.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 10/24/2022]
Abstract
Malaria is still considered a deadly scourge in Africa, Asia, and South America despite improved vector control and curative treatments with new antimalarial combinations. The next challenge is to work towards disease eradication. To achieve this goal it is crucial to develop, validate, and integrate biological assays into test cascades that align with the key target product profiles. For anti-relapse, a parent molecule should kill hypnozoites or cause activation of Plasmodium vivax liver stages. For transmission blocking, dual equal-activity antimalarials killing both the asexual and the sexual parasite stages in human blood are favored. Finally, by assessing cross resistance and generating drug resistance in the laboratory, it is expected that new medicines with acceptable resistance profiles will be forthcoming.
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Affiliation(s)
- Didier Leroy
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland.
| | - Brice Campo
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland
| | - Xavier C Ding
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland
| | - Jeremy N Burrows
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland
| | - Stéphanie Cherbuin
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland
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146
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Pollitt LC, Sim D, Salathé R, Read AF. Understanding genetic variation in in vivo tolerance to artesunate: implications for treatment efficacy and resistance monitoring. Evol Appl 2014; 8:296-304. [PMID: 25861387 PMCID: PMC4380923 DOI: 10.1111/eva.12194] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 05/20/2014] [Indexed: 01/10/2023] Open
Abstract
Artemisinin-based drugs are the front-line weapon in the treatment of human malaria cases, but there is concern that recent reports of slow clearing infections may signal developing resistance to treatment. In the absence of molecular markers for resistance, current efforts to monitor drug efficacy are based on the rate at which parasites are cleared from infections. However, some knowledge of the standing variation in parasite susceptibility is needed to identify a meaningful increase in infection half-life. Here, we show that five previously unexposed genotypes of the rodent malaria parasite Plasmodium chabaudi differ substantially in their in vivo response to treatment. Slower clearance rates were not linked to parasite virulence or growth rate, going against the suggestion that drug treatment will drive the evolution of virulence in this system. The level of variation observed here in a relatively small number of genotypes suggests existing ‘resistant’ parasites could be present in the population and therefore, increased parasite clearance rates could represent selection on pre-existing variation rather than de novo resistance events. This has implications for resistance monitoring as susceptibility may depend on evolved traits unrelated to drug exposure.
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Affiliation(s)
- Laura C Pollitt
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University University Park, PA, USA ; Centre for Immunity, Infection and Evolution, University of Edinburgh Edinburgh, UK
| | - Derek Sim
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University University Park, PA, USA
| | - Rahel Salathé
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University University Park, PA, USA
| | - Andrew F Read
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University University Park, PA, USA ; Department of Entomology, The Pennsylvania State University University Park, PA, USA ; Fogarty International Center, National Institutes of Health Bethesda, MD, USA
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147
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Omotuyi OI. Methyl-methoxylpyrrolinone and flavinium nucleus binding signatures on falcipain-2 active site. J Mol Model 2014; 20:2386. [PMID: 25096811 DOI: 10.1007/s00894-014-2386-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/17/2014] [Indexed: 01/18/2023]
Abstract
Following the increasing reports of human toxicity and plasmodium resistance to artemisinin and its derivatives, falcipain-2 (FP-2) is now emerging as the choice antimalarial drug target. Coincidentally, FP-2 is the in vivo target of naturally occurring, therapeutically safe flavonoids (stenopalustroside, myricetin, and fisetin) and symplostatin (symplostatin 4) compounds known to exhibit potent in vitro and in vivo antiplasmodial actions. Here, the structural bases for their inhibitory actions have been studied using molecular dynamics simulation. Myricetin and fisetin act as proton transfer tunnel breakers by inserting between His174 and Cys42, which are key active site residues of FP-2, stenopalustroside inhibits the polarization of His174 by Asn173; a major preparatory step for Cys42/His174 proton transfer process. The roles of flavonoids are favored by T-shaped pi-pi interactions with His174. Symplostatin 4 inserts its methyl-methoxylpyrrolinone moiety into the active site where its proton acceptor function prepares Cys42 for nucleophilic attack on the Michael α,β-unsaturated bonds on its 4(S)-amino-2(E)-pentenoate moiety. Further analyses of the structures identified a unique bridge formed on FP-2 active site groove by stenopalustroside and symplostatin 4 during interaction with the sub-site I of FP-2, whereas fisetin preferentially interacts with sub-site II and myricetin interacts with sub-site III residues. Ultimately, symplostatin-4, myricetin, and fisetin were better than stenopalustroside at trapping FP-2 in its inactive state as revealed by comparative RSMD plots with X-ray structures of FP-2 co-crystallized with inhibitors. Comparative estimates of free energy of binding using the Molecular Mechanics-Poisson Boltzmann Surface Area (MMPBSA) method suggested that His174 protonation may further enhance stenopalustroside-FP-2 interaction. The unique binding signatures of the ligands within the FP-2 active site groove and its sub-sites may explain the subtle differences in their IC50 values and their mechanism of inhibition.
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Affiliation(s)
- Olaposi I Omotuyi
- Center for Drug Discovery and Therapeutic Innovation, Nagasaki University, Nagasaki, Japan,
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148
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Ashley EA, Dhorda M, Fairhurst RM, Amaratunga C, Lim P, Suon S, Sreng S, Anderson JM, Mao S, Sam B, Sopha C, Chuor CM, Nguon C, Sovannaroth S, Pukrittayakamee S, Jittamala P, Chotivanich K, Chutasmit K, Suchatsoonthorn C, Runcharoen R, Hien TT, Thuy-Nhien NT, Thanh NV, Phu NH, Htut Y, Han KT, Aye KH, Mokuolu OA, Olaosebikan RR, Folaranmi OO, Mayxay M, Khanthavong M, Hongvanthong B, Newton PN, Onyamboko MA, Fanello CI, Tshefu AK, Mishra N, Valecha N, Phyo AP, Nosten F, Yi P, Tripura R, Borrmann S, Bashraheil M, Peshu J, Faiz MA, Ghose A, Hossain MA, Samad R, Rahman MR, Hasan MM, Islam A, Miotto O, Amato R, MacInnis B, Stalker J, Kwiatkowski DP, Bozdech Z, Jeeyapant A, Cheah PY, Sakulthaew T, Chalk J, Intharabut B, Silamut K, Lee SJ, Vihokhern B, Kunasol C, Imwong M, Tarning J, Taylor WJ, Yeung S, Woodrow CJ, Flegg JA, Das D, Smith J, Venkatesan M, Plowe CV, Stepniewska K, Guerin PJ, Dondorp AM, Day NP, White NJ. Spread of artemisinin resistance in Plasmodium falciparum malaria. N Engl J Med 2014; 371:411-23. [PMID: 25075834 PMCID: PMC4143591 DOI: 10.1056/nejmoa1314981] [Citation(s) in RCA: 1514] [Impact Index Per Article: 151.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Artemisinin resistance in Plasmodium falciparum has emerged in Southeast Asia and now poses a threat to the control and elimination of malaria. Mapping the geographic extent of resistance is essential for planning containment and elimination strategies. METHODS Between May 2011 and April 2013, we enrolled 1241 adults and children with acute, uncomplicated falciparum malaria in an open-label trial at 15 sites in 10 countries (7 in Asia and 3 in Africa). Patients received artesunate, administered orally at a daily dose of either 2 mg per kilogram of body weight per day or 4 mg per kilogram, for 3 days, followed by a standard 3-day course of artemisinin-based combination therapy. Parasite counts in peripheral-blood samples were measured every 6 hours, and the parasite clearance half-lives were determined. RESULTS The median parasite clearance half-lives ranged from 1.9 hours in the Democratic Republic of Congo to 7.0 hours at the Thailand-Cambodia border. Slowly clearing infections (parasite clearance half-life >5 hours), strongly associated with single point mutations in the "propeller" region of the P. falciparum kelch protein gene on chromosome 13 (kelch13), were detected throughout mainland Southeast Asia from southern Vietnam to central Myanmar. The incidence of pretreatment and post-treatment gametocytemia was higher among patients with slow parasite clearance, suggesting greater potential for transmission. In western Cambodia, where artemisinin-based combination therapies are failing, the 6-day course of antimalarial therapy was associated with a cure rate of 97.7% (95% confidence interval, 90.9 to 99.4) at 42 days. CONCLUSIONS Artemisinin resistance to P. falciparum, which is now prevalent across mainland Southeast Asia, is associated with mutations in kelch13. Prolonged courses of artemisinin-based combination therapies are currently efficacious in areas where standard 3-day treatments are failing. (Funded by the U.K. Department of International Development and others; ClinicalTrials.gov number, NCT01350856.).
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149
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Plasmodium falciparum founder populations in western Cambodia have reduced artemisinin sensitivity in vitro. Antimicrob Agents Chemother 2014; 58:4935-7. [PMID: 24867977 DOI: 10.1128/aac.03055-14] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Reduced Plasmodium falciparum sensitivity to short-course artemisinin (ART) monotherapy manifests as a long parasite clearance half-life. We recently defined three parasite founder populations with long half-lives in Pursat, western Cambodia, where reduced ART sensitivity is prevalent. Using the ring-stage survival assay, we show that these founder populations have reduced ART sensitivity in vitro at the early ring stage of parasite development and that a genetically admixed population contains subsets of parasites with normal or reduced ART sensitivity.
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150
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Wai KT, Kyaw MP, Oo T, Zaw P, Nyunt MH, Thida M, Kyaw TT. Spatial distribution, work patterns, and perception towards malaria interventions among temporary mobile/migrant workers in artemisinin resistance containment zone. BMC Public Health 2014; 14:463. [PMID: 24884534 PMCID: PMC4032392 DOI: 10.1186/1471-2458-14-463] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 05/12/2014] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Mobile populations are at a high risk of malaria infection and suspected to carry and spread resistant parasites. The Myanmar National Malaria Control Programme focuses on preventive interventions and vector control measures for the temporary mobile/migrant workers in Myanmar Artemisinin Resistance Containment Zones. METHODS A prospective cross-sectional study was conducted in 2012 in Kawthaung and Bokepyin townships of Tanintharyi Region, Myanmar, covering 192 mobile/migrant aggregates. The objectives were to identify the spatial distribution of the mobile/migrant populations, and to assess knowledge, attitudes, perceptions, and practices concerning malaria prevention and control, and their preferred methods of interventions. The structure of the 192 migrant aggregates was investigated using a migrant mapping tool. Individual and household information was collected by structured interviews of 408 respondents from 39 aggregates, supplemented by 12 in-depth interviews of health care providers, authorities, volunteers, and employers. Data were analyzed by triangulating quantitative and qualitative data. RESULTS The primary reasons for the limitation in access to formal health services for suspected malaria within 24 hours were identified to be scattered distribution of migrant aggregates, variable working hours and the lack of transportation. Only 19.6% of respondents reported working at night from dusk to dawn. Among study populations, 73% reported a perceived risk of contracting malaria and 60% reported to know how to confirm a suspected case of malaria. Moreover, only 15% was able to cite correct antimalarial drugs, and less than 10% believed that non-compliance with antimalarial treatment may be related to the risk of drug resistance. About 50% of study population reported to seeking health care from the public sector, and to sleep under ITNs/LLINs the night before the survey. There was a gap in willingness to buy ITNs/LLINs and affordability (88.5% vs. 60.2%) which may affect their sustained and consistent use. Only 32.4% across all aggregates realized the importance of community participation in effective malaria prevention and control. CONCLUSIONS Community-based innovative approaches through strong collaboration and coordination of multi-stakeholders are desirable for relaying information on ITNs/LLINs, rapid diagnostic test, and artemisinin combination therapy and drug resistance successfully across the social and economic diversity of mobile/migrant aggregates in Myanmar.
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Affiliation(s)
- Khin Thet Wai
- Department of Medical Research (Lower Myanmar), No. 5 Ziwaka Road, 11191 Yangon, Myanmar
| | - Myat Phone Kyaw
- Department of Medical Research (Lower Myanmar), No. 5 Ziwaka Road, 11191 Yangon, Myanmar
| | - Tin Oo
- Department of Medical Research (Lower Myanmar), No. 5 Ziwaka Road, 11191 Yangon, Myanmar
| | - PeThet Zaw
- Department of Medical Research (Lower Myanmar), No. 5 Ziwaka Road, 11191 Yangon, Myanmar
| | - Myat Htut Nyunt
- Department of Medical Research (Lower Myanmar), No. 5 Ziwaka Road, 11191 Yangon, Myanmar
| | - Moe Thida
- Department of Medical Research (Lower Myanmar), No. 5 Ziwaka Road, 11191 Yangon, Myanmar
| | - Thar Tun Kyaw
- Department of Health, National Malaria Control Programme, Nay Pyi Taw, Myanmar
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