1,315 results on '"vivax malaria"'
Search Results
2. Effectiveness of Novel Approaches to Radical Cure With Tafenoquine and Primaquine (EFFORT)
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University of Melbourne, National Centre for Parasitology, Entomology and Malaria Control, Cambodia, Mahidol Oxford Tropical Medicine Research Unit, Ethiopian Public Health Institute, Universitas Sumatera Utara, Arba Minch University, and Aga Khan University
- Published
- 2024
3. A Revised Tafenoquine Dose to Improve Radical Cure for Vivax Malaria (TADORE)
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University of Melbourne, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Arba Minch University, Addis Ababa University, Papuan Community Health and Development Foundation, Indonesia, Eijkman Research Center for Molecular Biology, National Research and Innovation Agency, Indonesia, Curtin University, and Papua New Guinea Institute of Medical Research
- Published
- 2024
4. Short Course Primaquine for the Radical Cure of P. Vivax Malaria - Indonesia (SCOPE)
- Author
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Gadjah Mada University, Universitas Sumatera Utara, Indonesia University, Yayasan Pengembangan Kesehatan dan Masyarakat, Indonesian National Malaria Control Program, Ministry of Health, National Research and Innovation Agency of Indonesia, Burnet Institute, University of Melbourne, Medicines for Malaria Venture, PATH, UNITAID, and Institute of Tropical Medicine, Belgium
- Published
- 2024
5. A hybrid transmission model for Plasmodium vivax accounting for superinfection, immunity and the hypnozoite reservoir.
- Author
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Mehra, Somya, Taylor, Peter G., McCaw, James M., and Flegg, Jennifer A.
- Abstract
Malaria is a vector-borne disease that exacts a grave toll in the Global South. The epidemiology of Plasmodium vivax, the most geographically expansive agent of human malaria, is characterised by the accrual of a reservoir of dormant parasites known as hypnozoites. Relapses, arising from hypnozoite activation events, comprise the majority of the blood-stage infection burden, with implications for the acquisition of immunity and the distribution of superinfection. Here, we construct a novel model for the transmission of P. vivax that concurrently accounts for the accrual of the hypnozoite reservoir, (blood-stage) superinfection and the acquisition of immunity. We begin by using an infinite-server queueing network model to characterise the within-host dynamics as a function of mosquito-to-human transmission intensity, extending our previous model to capture a discretised immunity level. To model transmission-blocking and antidisease immunity, we allow for geometric decay in the respective probabilities of successful human-to-mosquito transmission and symptomatic blood-stage infection as a function of this immunity level. Under a hybrid approximation—whereby probabilistic within-host distributions are cast as expected population-level proportions—we couple host and vector dynamics to recover a deterministic compartmental model in line with Ross-Macdonald theory. We then perform a steady-state analysis for this compartmental model, informed by the (analytic) distributions derived at the within-host level. To characterise transient dynamics, we derive a reduced system of integrodifferential equations, likewise informed by our within-host queueing network, allowing us to recover population-level distributions for various quantities of epidemiological interest. In capturing the interplay between hypnozoite accrual, superinfection and acquired immunity—and providing, to the best of our knowledge, the most complete population-level distributions for a range of epidemiological values—our model provides insights into important, but poorly understood, epidemiological features of P. vivax. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
- View/download PDF
6. Reducing the Risk of P. Vivax After Falciparum Infections in Co-endemic Areas (PRIMA)
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International Centre for Diarrhoeal Disease Research, Bangladesh, Tribhuvan University, Nepal, Arba Minch University, and Addis Ababa University
- Published
- 2023
7. 云南边境地区疟疾输入再传播风险和防控需求.
- Author
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周耀武, 丁春丽, 杨忠平, 林祖锐, 田鹏, 孙晓东, 段凯霞, 陈柒言, 赵玉龙, 许建卫, and 周红宁
- Abstract
Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
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8. Development of a Plasmodium vivax malaria model for evaluating the effects of control strategies on the malaria burden in Democratic People’s Republic of Korea
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Hye Seong, Jiyeon Suh, Jun Yong Choi, Jeehyun Lee, and Joon-Sup Yeom
- Subjects
vivax malaria ,mathematical modeling ,RDT ,tafenoquine ,DPRK ,Public aspects of medicine ,RA1-1270 - Abstract
BackgroundPlasmodium vivax malaria has been one of the most troublesome diseases in the Democratic People’s Republic of Korea (DPRK). Given that a majority of malaria cases are concentrated near the demilitarized zone, concerted elimination efforts from both the Republic of Korea (ROK) and DPRK are essential for a malaria-free Korean Peninsula. This study assessed the impact of rapid diagnostic tests (RDTs) and tafenoquine on malaria incidence in DPRK.MethodsWe patterned the current model structure from the previously developed Plasmodium vivax malaria dynamic transmission model for ROK. Model parameters were adjusted using demographic and climate data from malaria-risk areas in DPRK, and the model was calibrated to annual malaria incidences from 2014 to 2018 in DPRK, as reported by the World Health Organization. Subsequently, we estimated the preventable malaria cases over a decade after introducing RDTs and tafenoquine compared to using microscopy alone and primaquine, respectively. Sensitivity analysis was performed to account for uncertainty in model parameters.ResultsWhen comparing RDTs to microscopy, a one-day reduction in diagnostic time due to the introduction of RDTs led to a reduction in malaria incidence by 26,235 cases (65.6%) over the next decade. With a two-day reduction, incidences decreased by 33,635 (84.1%). When comparing a single dose of tafenoquine with a 14-day primaquine regimen, the former prevented 1,222 (77.5%) relapse cases and 4,530 (11.3%) total cases over the years.ConclusionThe continuous and simultaneous implementation of RDTs and tafenoquine emerges as a potent strategy to considerably reduce malaria in DPRK.
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- 2024
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9. Therapeutic Efficacy of Chloroquine Plus Primaquine in the Treatment of Uncomplicated Plasmodium Vivax (CQ+PQ)
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Ethiopian Public Health Institute and Dinka Dugassa, Principal Investigator
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- 2023
10. TES of Chloroquine for Pv in the Philippines in 2016 (TES)
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World Health Organization and Fe Espino, Principal Investigator, Head of Parasitology Department
- Published
- 2023
11. TES of Artemether-lumefantrine for Pf and Chloroquine for Pv in the Philippines From 2013-2014 (TES)
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World Health Organization and Fe Espino, Principal Investigator, Head of Parasitology Department
- Published
- 2023
12. Short Course Primaquine for the Radical Cure of P. Vivax - Papua New Guinea (SCOPE)
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Papua New Guinea Institute of Medical Research, Papua New Guinea National Department of Health, Menzies School of Health Research, University of Melbourne, Medicines for Malaria Venture, PATH, and UNITAID
- Published
- 2023
13. A randomised controlled trial to compare the efficacy, safety, and tolerability of low dose, short course primaquine in adults with uncomplicated P. vivax malaria in two hospitals in India
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Sundus Shafat Ahmad, Reena Verma, Robert J. Commons, Nitika, Sauman Singh-Phulgenda, Rutuja Chhajed, Praveen K. Bharti, Beauty Behera, Syed Mohammad Naser, Salil Kumar Pal, Parinita Halder Ranjit, Rajendra Kumar Baharia, Bhavin Solanki, K. J. Upadhyay, Philippe J. Guerin, Amit Sharma, Ric N. Price, Manju Rahi, and Kamala Thriemer
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P. vivax ,Vivax malaria ,Radical cure ,Primaquine ,Malaria elimination, Randomised controlled trial ,Medicine (General) ,R5-920 - Abstract
Abstract Background Plasmodium vivax remains a major challenge for malaria control and elimination due to its ability to cause relapsing illness. To prevent relapses the Indian National Center for Vector Borne Diseases Control (NCVBDC) recommends treatment with primaquine at a dose of 0.25 mg/kg/day provided over 14 days. Shorter treatment courses may improve adherence and treatment effectiveness. Methods This is a hospital-based, randomised, controlled, open-label trial in two centres in India. Patients above the age of 16 years, with uncomplicated vivax malaria, G6PD activity of ≥ 30% of the adjusted male median (AMM) and haemoglobin levels ≥ 8 g/dL will be recruited into the study and randomised in a 1:1 ratio to receive standard schizonticidal treatment plus 7-day primaquine at 0.50 mg/kg/day or standard care with schizonticidal treatment plus 14-day primaquine at 0.25 mg/kg/day. Patients will be followed up for 6 months. The primary endpoint is the incidence risk of any P. vivax parasitaemia at 6 months. Safety outcomes include the incidence risk of severe anaemia (haemoglobin < 8 g/dL), the risk of blood transfusion, a > 25% fall in haemoglobin and an acute drop in haemoglobin of > 5 g/dL during primaquine treatment. Discussion This study will evaluate the efficacy and safety of a 7-day primaquine regimen compared to the standard 14-day regimen in India. Results from this trial are likely to directly inform national treatment guidelines. Trial registration Trial is registered on CTRI portal, Registration No: CTRI/2022/12/048283.
- Published
- 2024
- Full Text
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14. A randomised controlled trial to compare the efficacy, safety, and tolerability of low dose, short course primaquine in adults with uncomplicated P. vivax malaria in two hospitals in India.
- Author
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Ahmad, Sundus Shafat, Verma, Reena, Commons, Robert J., Nitika, Singh-Phulgenda, Sauman, Chhajed, Rutuja, Bharti, Praveen K., Behera, Beauty, Naser, Syed Mohammad, Pal, Salil Kumar, Ranjit, Parinita Halder, Baharia, Rajendra Kumar, Solanki, Bhavin, Upadhyay, K. J., Guerin, Philippe J., Sharma, Amit, Price, Ric N., Rahi, Manju, and Thriemer, Kamala
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RANDOMIZED controlled trials , *VECTOR-borne diseases , *PRIMAQUINE , *MALARIA , *VECTOR control , *SAFETY standards - Abstract
Background: Plasmodium vivax remains a major challenge for malaria control and elimination due to its ability to cause relapsing illness. To prevent relapses the Indian National Center for Vector Borne Diseases Control (NCVBDC) recommends treatment with primaquine at a dose of 0.25 mg/kg/day provided over 14 days. Shorter treatment courses may improve adherence and treatment effectiveness. Methods: This is a hospital-based, randomised, controlled, open-label trial in two centres in India. Patients above the age of 16 years, with uncomplicated vivax malaria, G6PD activity of ≥ 30% of the adjusted male median (AMM) and haemoglobin levels ≥ 8 g/dL will be recruited into the study and randomised in a 1:1 ratio to receive standard schizonticidal treatment plus 7-day primaquine at 0.50 mg/kg/day or standard care with schizonticidal treatment plus 14-day primaquine at 0.25 mg/kg/day. Patients will be followed up for 6 months. The primary endpoint is the incidence risk of any P. vivax parasitaemia at 6 months. Safety outcomes include the incidence risk of severe anaemia (haemoglobin < 8 g/dL), the risk of blood transfusion, a > 25% fall in haemoglobin and an acute drop in haemoglobin of > 5 g/dL during primaquine treatment. Discussion: This study will evaluate the efficacy and safety of a 7-day primaquine regimen compared to the standard 14-day regimen in India. Results from this trial are likely to directly inform national treatment guidelines. Trial registration: Trial is registered on CTRI portal, Registration No: CTRI/2022/12/048283. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. Safety and Efficacy of Different Regimens of Primaquine on Vivax Malaria Treatment in G6PD Deficient Patients
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Oswaldo Cruz Foundation, Conselho Nacional de Desenvolvimento Científico e Tecnológico, and Wuelton Marcelo Monteiro, PhD, Director of Research
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- 2023
16. Incidence of Vivax Along the Thai Burma Border (VHC)
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Mahidol University
- Published
- 2023
17. Complicated vivax malaria in pregnancy: A case report in rural area of Indonesia.
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Surya, Raymond, Manurung, Edward Sugito, and Saroyo, Yudianto Budi
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DRUG therapy for malaria ,MALARIA diagnosis ,PREMATURE infants ,PARASITEMIA ,FEVER ,HYPOCHROMIC anemia ,RURAL conditions ,VITAL signs ,RAPID diagnostic tests ,AMNIOTIC liquid ,MALARIA ,SHIVERING ,PREGNANCY complications ,BLOOD testing ,APGAR score ,ANTIMALARIALS ,PRIMAQUINE ,IRON deficiency anemia ,PARASITIC diseases in pregnancy ,SYMPTOMS ,DISEASE complications ,PREGNANCY - Published
- 2023
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18. Plasmodium Vivax Malaria and Cardiac Complication
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Rochmah, Fitria Siwi Nur, Istianah, Siti, Nurdiyanto, Heri, editor, Miladiyah, Isnatin, editor, and Jamil, Nur Aisyah, editor
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- 2023
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19. Short-course, high-dose primaquine regimens for the treatment of liver-stage vivax malaria in children
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Brioni R. Moore, Sam Salman, Roselyn Tobe, John Benjamin, Gumul Yadi, Bernadine Kasian, Moses Laman, Leanne J. Robinson, Madhu Page-Sharp, Inoni Betuela, Kevin T. Batty, Laurens Manning, Ivo Mueller, and Timothy M.E. Davis
- Subjects
Primaquine ,Vivax malaria ,Children ,Pharmacokinetics ,Safety ,Short-course regimen ,Infectious and parasitic diseases ,RC109-216 - Abstract
Objectives: To assess the pharmacokinetics, safety, and tolerability of two high-dose, short-course primaquine (PQ) regimens compared with standard care in children with Plasmodium vivax infections. Methods: We performed an open-label pediatric dose-escalation study in Madang, Papua New Guinea (Clinicaltrials.gov NCT02364583). Children aged 5-10 years with confirmed blood-stage vivax malaria and normal glucose-6-phosphate dehydrogenase activity were allocated to one of three PQ treatment regimens in a stepwise design (group A: 0.5 mg/kg once daily for 14 days, group B: 1 mg/kg once daily for 7 days, and group C: 1 mg/kg twice daily for 3.5-days). The study assessments were completed at each treatment time point and fortnightly for 2 months after PQ administration. Results: Between August 2013 and May 2018, 707 children were screened and 73 met the eligibility criteria (15, 40, and 16 allocated to groups A, B, and C, respectively). All children completed the study procedures. The three regimens were safe and generally well tolerated. The pharmacokinetic analysis indicated that an additional weight adjustment of the conventionally recommended milligram per kilogram PQ doses is not necessary to ensure the therapeutic plasma concentrations in pediatric patients. Conclusions: A novel, ultra-short 3.5-day PQ regimen has potential benefits for improving the treatment outcomes in children with vivax malaria that warrants further investigation in a large-scale clinical trial.
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- 2023
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20. Characteristics of molecular markers associated with chloroquine resistance in Plasmodium vivax strains from vivax malaria cases in Yunnan Province, China
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Hongyun Ding, Ying Dong, Yan Deng, Yanchun Xu, Yan Liu, Jing Wu, Mengni Chen, Canglin Zhang, and Weibin Zheng
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Molecular marker ,Multidrug resistance 1 gene ,Plasmodium vivax ,Vivax malaria ,Strains ,Yunnan Province ,Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Chloroquine (CQ) has been the preferred clinical treatment for vivax malaria in Yunnan Province since 1958, with over 300,000 patients. This study aimed to help make trend predictions regarding variations the in anti-malarial drug susceptibility of Plasmodium vivax distributed in Yunnan Province and effectively implement monitoring measures on the efficacy of anti-malarial drugs for vivax malaria. Methods Blood samples collected from patients with mono-P. vivax infections were employed in this study based on the principle of cluster sampling. The whole gene of P. vivax multidrug resistance 1 protein gene (pvmdr1) was amplified by nested-PCR techniques and the PCR amplification produce were sequenced by Sanger bidirectional sequencing. The mutant loci and haplotypes of coding DNA sequence (CDS) were identified by comparison with the reference sequence (NC_009915.1) of the P. vivax Sal I isolate. Parameters such as Ka/Ks ratio were calculated using MEGA 5.04 software. Results A total of 753 blood samples from patients infected with mono-P. vivax were collected, of which 624 blood samples yielded the full gene sequence (4392 bp) of the pvmdr1 gene, with 283, 140, 119, and 82 sequences from 2014, 2020, 2021 and 2022, respectively. A total of 52 single nucleotide polymorphic (SNP) loci were detected for the 624 CDSs, of which 92.3% (48/52), 34.6% (18/52), 42.3% (22/52), and 36.5% (19/52) SNPs were detected in 2014, 2020, 2021 and 2022, respectively. All of 624 CDSs were defined for a total of 105 mutant haplotypes, with CDSs of 2014, 2020, 2021, and 2022 containing 88, 15, 21, and 13 haplotypes, respectively. Of the 105 haplotypes, the threefold mutant haplotype (Hap_87) was the starting point for stepwise evolution, and the most drastic tenfold mutations were Hap_14 and Hap_78, and the fivefold, sixfold, sevenfold, and eightfold mutations. Conclusions In the majority of vivax malaria cases in Yunnan Province, most of them were infected with strains carrying demonstrating highly mutated in pvmdr1 genes. However, the dominant mutation strains types varied from year to year, which warrants further exploration in order to confirm the correlation between with phenotypic changes in P. vivax strains and their susceptibility to anti-malarial drugs such as chloroquine.
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- 2023
- Full Text
- View/download PDF
21. Short-course, high-dose primaquine regimens for the treatment of liver-stage vivax malaria in children.
- Author
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Moore, Brioni R., Salman, Sam, Tobe, Roselyn, Benjamin, John, Yadi, Gumul, Kasian, Bernadine, Laman, Moses, Robinson, Leanne J., Page-Sharp, Madhu, Betuela, Inoni, Batty, Kevin T., Manning, Laurens, Mueller, Ivo, and Davis, Timothy M.E.
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MALARIA , *PRIMAQUINE , *GLUCOSE-6-phosphate dehydrogenase , *CHILD patients , *PATIENT compliance - Abstract
• A novel 3.5-day primaquine (PQ) regimen was well tolerated and relatively safe. • Supervised doses given with food ameliorated the gastrointestinal adverse effects. • Pharmacokinetic data support the ultra-short PQ regimens with a twice-daily dosing. • Short-course PQ regimens will likely improve treatment acceptability and adherence. To assess the pharmacokinetics, safety, and tolerability of two high-dose, short-course primaquine (PQ) regimens compared with standard care in children with Plasmodium vivax infections. We performed an open-label pediatric dose-escalation study in Madang, Papua New Guinea (Clinicaltrials.gov NCT02364583). Children aged 5-10 years with confirmed blood-stage vivax malaria and normal glucose-6-phosphate dehydrogenase activity were allocated to one of three PQ treatment regimens in a stepwise design (group A: 0.5 mg/kg once daily for 14 days, group B: 1 mg/kg once daily for 7 days, and group C: 1 mg/kg twice daily for 3.5-days). The study assessments were completed at each treatment time point and fortnightly for 2 months after PQ administration. Between August 2013 and May 2018, 707 children were screened and 73 met the eligibility criteria (15, 40, and 16 allocated to groups A, B, and C, respectively). All children completed the study procedures. The three regimens were safe and generally well tolerated. The pharmacokinetic analysis indicated that an additional weight adjustment of the conventionally recommended milligram per kilogram PQ doses is not necessary to ensure the therapeutic plasma concentrations in pediatric patients. A novel, ultra-short 3.5-day PQ regimen has potential benefits for improving the treatment outcomes in children with vivax malaria that warrants further investigation in a large-scale clinical trial. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
22. Characteristics of molecular markers associated with chloroquine resistance in Plasmodium vivax strains from vivax malaria cases in Yunnan Province, China.
- Author
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Ding, Hongyun, Dong, Ying, Deng, Yan, Xu, Yanchun, Liu, Yan, Wu, Jing, Chen, Mengni, Zhang, Canglin, and Zheng, Weibin
- Subjects
- *
P-glycoprotein , *PLASMODIUM vivax , *TRYPANOSOMA , *MALARIA , *CHLOROQUINE , *HAPLOTYPES - Abstract
Background: Chloroquine (CQ) has been the preferred clinical treatment for vivax malaria in Yunnan Province since 1958, with over 300,000 patients. This study aimed to help make trend predictions regarding variations the in anti-malarial drug susceptibility of Plasmodium vivax distributed in Yunnan Province and effectively implement monitoring measures on the efficacy of anti-malarial drugs for vivax malaria. Methods: Blood samples collected from patients with mono-P. vivax infections were employed in this study based on the principle of cluster sampling. The whole gene of P. vivax multidrug resistance 1 protein gene (pvmdr1) was amplified by nested-PCR techniques and the PCR amplification produce were sequenced by Sanger bidirectional sequencing. The mutant loci and haplotypes of coding DNA sequence (CDS) were identified by comparison with the reference sequence (NC_009915.1) of the P. vivax Sal I isolate. Parameters such as Ka/Ks ratio were calculated using MEGA 5.04 software. Results: A total of 753 blood samples from patients infected with mono-P. vivax were collected, of which 624 blood samples yielded the full gene sequence (4392 bp) of the pvmdr1 gene, with 283, 140, 119, and 82 sequences from 2014, 2020, 2021 and 2022, respectively. A total of 52 single nucleotide polymorphic (SNP) loci were detected for the 624 CDSs, of which 92.3% (48/52), 34.6% (18/52), 42.3% (22/52), and 36.5% (19/52) SNPs were detected in 2014, 2020, 2021 and 2022, respectively. All of 624 CDSs were defined for a total of 105 mutant haplotypes, with CDSs of 2014, 2020, 2021, and 2022 containing 88, 15, 21, and 13 haplotypes, respectively. Of the 105 haplotypes, the threefold mutant haplotype (Hap_87) was the starting point for stepwise evolution, and the most drastic tenfold mutations were Hap_14 and Hap_78, and the fivefold, sixfold, sevenfold, and eightfold mutations. Conclusions: In the majority of vivax malaria cases in Yunnan Province, most of them were infected with strains carrying demonstrating highly mutated in pvmdr1 genes. However, the dominant mutation strains types varied from year to year, which warrants further exploration in order to confirm the correlation between with phenotypic changes in P. vivax strains and their susceptibility to anti-malarial drugs such as chloroquine. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
23. Assessing the Operational Feasibility of Integrating Point-of-Care G6PD Testing into Plasmodium vivax Malaria Management in Vietnam.
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Gerth-Guyette, Emily, Nguyen, Huyen Thanh, Nowak, Spike, Hoang, Nga Thu, Mai, Đặng Thị Tuyết, Thị Sang, Vũ, Long, Nguyễn Đức, Mvundura, Mercy, Nguyen, Nhu, Domingo, Gonzalo J., and Phúc, Bùi Quang
- Subjects
MALARIA ,PLASMODIUM vivax ,POINT-of-care testing ,GLUCOSE-6-phosphate dehydrogenase ,CLINICAL trials - Abstract
Plasmodium vivax cases represent more than 50% of a diminishing malaria case load in Vietnam. Safe and effective radical cure strategies could support malaria elimination by 2030. This study investigated the operational feasibility of introducing point-of-care quantitative glucose-6-phosphate dehydrogenase (G6PD) testing into malaria case management practices. A prospective interventional study was conducted at nine district hospitals and commune health stations in Binh Phuoc and Gia Lai provinces in Vietnam over the period of October 2020 to October 2021. The STANDARD™ G6PD Test (SD Biosensor, Seoul, Republic of Korea) was incorporated to inform P. vivax case management. Case management data and patient and health care provider (HCP) perspectives, as well as detailed cost data were collected. The G6PD test results were interpreted correctly by HCP and the treatment algorithm was adhered to for the majority of patients. One HCP consistently ran the test incorrectly, which was identified during the monitoring and resulted in provision of refresher training and updating of training materials and patient retesting. There was wide acceptability of the intervention among patients and HCP albeit with opportunities to improve the counseling materials. Increasing the number of facilities to which the test was deployed and decreases in the malaria cases resulted in higher per patient cost for incorporating G6PD testing into the system. Commodity costs can be reduced by using the 10-unit kits compared to the 25 unit kits, particularly when the case loads are low. These results demonstrate intervention feasibility while also highlighting specific challenges for a country approaching malaria elimination. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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24. Glucose 6 Phosphate Dehydrogenase (G6PD) quantitation using biosensors at the point of first contact: a mixed method study in Cambodia
- Author
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Bipin Adhikari, Rupam Tripura, Lek Dysoley, James J. Callery, Thomas J. Peto, Chhoeun Heng, Thy Vanda, Ou Simvieng, Sarah Cassidy-Seyoum, Benedikt Ley, Kamala Thriemer, Arjen M. Dondorp, and Lorenz von Seidlein
- Subjects
Village malaria workers ,Community ,Vivax malaria ,G6PD ,Quantitative ,Radical cure ,Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Quantitative measurement of Glucose-6-Phosphate Dehydrogenase (G6PD) enzyme activity is critical to decide on appropriate treatment and provision of radical cure regimens for vivax malaria. Biosensors are point-of-care semi-quantitative analysers that measure G6PD enzyme activity. The main objective of this study was to evaluate the operational aspects of biosensor deployment in the hands of village malaria workers (VMWs) in Cambodia over a year. Methods Following initial orientation and training at Kravanh Referral Hospital, each VMW (n = 28) and laboratory technician (n = 5) was provided a biosensor (STANDARD SD Biosensor, Republic of Korea) with supplies for routine use. Over the next 12 months VMWs convened every month for refresher training, to collect supplies, and to recalibrate and test their biosensors. A quantitative self-administered questionnaire was used to assess the skills necessary to use the biosensor after the initial training. Subsequently, VMWs were visited at their location of work for field observation and evaluation using an observer-administered questionnaire. All quantitative questionnaire-based data were analysed descriptively. Semi-structured interviews (SSIs) were conducted among all participants to explore their experience and practicalities of using the biosensor in the field. SSIs were transcribed and translated into English and underwent thematic analysis. Results A total of 33 participants completed the training and subsequently used the biosensor in the community. Quantitative assessments demonstrated progressive improvement in skills using the biosensor. VMWs expressed confidence and enthusiasm to use biosensors in their routine work. Providing G6PD testing at the point of first contact avoids a multitude of barriers patients have to overcome when travelling to health centres for G6PD testing and radical cure. Deploying biosensors in routine work of VMWs was also considered an opportunity to expand and strengthen the role of VMWs as health care providers in the community. VMWs reported practical concerns related to the use of biosensor such as difficulty in using two pipettes, difficulty in extracting the code chip from the machine, and the narrow base of buffer tube. Conclusions VMWs considered the biosensor a practical and beneficial tool in their routine work. Providing VMWs with biosensors can be considered when followed by appropriate training and regular supervision. Providing community management of vivax malaria at the point of first contact could be key for elimination.
- Published
- 2022
- Full Text
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25. Glucose-6-Phosphate Dehydrogenase (G6PD) Measurement Using Biosensors by Community-Based Village Malaria Workers and Hospital Laboratory Staff in Cambodia: A Quantitative Study.
- Author
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Adhikari, Bipin, Tripura, Rupam, Dysoley, Lek, Peto, Thomas J., Callery, James J., Heng, Chhoeun, Vanda, Thy, Simvieng, Ou, Cassidy-Seyoum, Sarah, Thriemer, Kamala, Dondorp, Arjen M., Ley, Benedikt, and Seidlein, Lorenz von
- Subjects
GLUCOSE-6-phosphate dehydrogenase ,RAPID diagnostic tests ,HOSPITAL laboratories ,HOSPITAL personnel ,MALARIA - Abstract
Vivax malaria can relapse after an initial infection due to dormant liver stages of the parasite. Radical cure can prevent relapses but requires the measurement of glucose-6-phosphate dehydrogenase enzyme (G6PD) activity to identify G6PD-deficient patients at risk of drug-induced haemolysis. In the absence of reliable G6PD testing, vivax patients are denied radical curative treatment in many places, including rural Cambodia. A novel Biosensor, 'G6PD Standard' (SD Biosensor, Republic of Korea; Biosensor), can measure G6PD activity at the point of care. The objectives of this study were to compare the G6PD activity readings using Biosensors by village malaria workers (VMWs) and hospital-based laboratory technicians (LTs), and to compare the G6PD deficiency categorization recommended by the Biosensor manufacturer with categories derived from a locally estimated adjusted male median (AMM) in Kravanh district, Cambodia. Participants were enrolled between 2021 and 2022 in western Cambodia. Each of the 28 VMWs and 5 LTs received a Biosensor and standardized training on its use. The G6PD activities of febrile patients identified in the community were measured by VMWs; in a subset, a second reading was done by LTs. All participants were tested for malaria by rapid diagnostic test (RDT). The adjusted male median (AMM) was calculated from all RDT-negative participants and defined as 100% G6PD activity. VMWs measured activities in 1344 participants. Of that total, 1327 (98.7%) readings were included in the analysis, and 68 of these had a positive RDT result. We calculated 100% activity as 6.4 U/gHb (interquartile range: 4.5 to 7.8); 9.9% (124/1259) of RDT-negative participants had G6PD activities below 30%, 15.2% (191/1259) had activities between 30% and 70%, and 75.0% (944/1259) had activities greater than 70%. Repeat measurements among 114 participants showed a significant correlation of G6PD readings (r
s = 0.784, p < 0.001) between VMWs and LTs. Based on the manufacturer's recommendations, 285 participants (21.5%) had less than 30% activity; however, based on the AMM, 132 participants (10.0%) had less than 30% activity. The G6PD measurements by VMWs and LTs were similar. With the provisions of training, supervision, and monitoring, VMWs could play an important role in the management of vivax malaria, which is critical for the rapid elimination of malaria regionally. Definitions of deficiency based on the manufacturer's recommendations and the population-specific AMM differed significantly, which may warrant revision of these recommendations. [ABSTRACT FROM AUTHOR]- Published
- 2023
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26. G6PD Assessment Before Primaquine for Radical Treatment of Vivax Malaria (GAP)
- Author
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Mahidol Oxford Tropical Medicine Research Unit and Nangarhar University
- Published
- 2020
27. Reducing the risk of Plasmodium vivax after falciparum infections in co-endemic areas—a randomized controlled trial (PRIMA)
- Author
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Kamala Thriemer, Tamiru Shibru Degaga, Michael Christian, Mohammad Shafiul Alam, Benedikt Ley, Mohammad Sharif Hossain, Mohammad Golam Kibria, Tedla Teferi Tego, Dagimawie Tadesse Abate, Sophie Weston, Amalia Karahalios, Megha Rajasekhar, Julie A. Simpson, Angela Rumaseb, Hellen Mnjala, Grant Lee, Rodas Temesgen Anose, Fitsum Getahun Kidane, Adugna Woyessa, Kevin Baird, Inge Sutanto, Asrat Hailu, and Ric N. Price
- Subjects
Vivax malaria ,Falciparum malaria ,Radical cure ,Universal radical cure ,Vivax elimination ,Co-endemic ,Medicine (General) ,R5-920 - Abstract
Abstract Background Plasmodium vivax forms dormant liver stages that can reactivate weeks or months following an acute infection. Recurrent infections are often associated with a febrile illness and can cause a cumulative risk of severe anaemia, direct and indirect mortality, and onward transmission of the parasite. There is an increased risk of P. vivax parasitaemia following falciparum malaria suggesting a rationale for universal use of radically curative treatment in patients with P. falciparum malaria even in the absence of detectable P. vivax parasitaemia in areas that are co-endemic for both species. Methods This is a multicentre, health care facility-based, randomized, controlled, open-label trial in Bangladesh, Indonesia and Ethiopia. Patients with uncomplicated falciparum malaria, G6PD activity of ≥70% of the adjusted male median (AMM) and haemoglobin levels ≥8g/dl are recruited into the study and randomized to either receive standard schizonticidal treatment plus 7-day high dose primaquine (total dose 7mg/kg) or standard care in a 1:1 ratio. Patients are followed up weekly until day 63. The primary endpoint is the incidence risk of any P. vivax parasitemia on day 63. Secondary endpoints include incidence risk on day 63 of symptomatic P. vivax malaria and the risk of any P. falciparum parasitaemia. Secondary safety outcomes include the proportion of adverse events and serious adverse events, the incidence risk of severe anaemia (Hb
- Published
- 2022
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28. Methylene Blue Against Vivax Malaria in Ethiopia (BlueAL)
- Author
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Ludwig-Maximilians - University of Munich, Jimma University, and Olaf Mueller, Prof. Dr.
- Published
- 2020
29. Biomarkers of P. Vivax Relapse
- Author
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University of North Carolina, Chapel Hill
- Published
- 2020
30. Glucose 6 Phosphate Dehydrogenase (G6PD) quantitation using biosensors at the point of first contact: a mixed method study in Cambodia.
- Author
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Adhikari, Bipin, Tripura, Rupam, Dysoley, Lek, Callery, James J., Peto, Thomas J., Heng, Chhoeun, Vanda, Thy, Simvieng, Ou, Cassidy-Seyoum, Sarah, Ley, Benedikt, Thriemer, Kamala, Dondorp, Arjen M., and von Seidlein, Lorenz
- Subjects
- *
GLUCOSE-6-phosphate dehydrogenase , *BIOSENSORS , *MEDICAL personnel , *TRAVEL hygiene , *GLUCOSE - Abstract
Background: Quantitative measurement of Glucose-6-Phosphate Dehydrogenase (G6PD) enzyme activity is critical to decide on appropriate treatment and provision of radical cure regimens for vivax malaria. Biosensors are point-of-care semi-quantitative analysers that measure G6PD enzyme activity. The main objective of this study was to evaluate the operational aspects of biosensor deployment in the hands of village malaria workers (VMWs) in Cambodia over a year. Methods: Following initial orientation and training at Kravanh Referral Hospital, each VMW (n = 28) and laboratory technician (n = 5) was provided a biosensor (STANDARD SD Biosensor, Republic of Korea) with supplies for routine use. Over the next 12 months VMWs convened every month for refresher training, to collect supplies, and to recalibrate and test their biosensors. A quantitative self-administered questionnaire was used to assess the skills necessary to use the biosensor after the initial training. Subsequently, VMWs were visited at their location of work for field observation and evaluation using an observer-administered questionnaire. All quantitative questionnaire-based data were analysed descriptively. Semi-structured interviews (SSIs) were conducted among all participants to explore their experience and practicalities of using the biosensor in the field. SSIs were transcribed and translated into English and underwent thematic analysis. Results: A total of 33 participants completed the training and subsequently used the biosensor in the community. Quantitative assessments demonstrated progressive improvement in skills using the biosensor. VMWs expressed confidence and enthusiasm to use biosensors in their routine work. Providing G6PD testing at the point of first contact avoids a multitude of barriers patients have to overcome when travelling to health centres for G6PD testing and radical cure. Deploying biosensors in routine work of VMWs was also considered an opportunity to expand and strengthen the role of VMWs as health care providers in the community. VMWs reported practical concerns related to the use of biosensor such as difficulty in using two pipettes, difficulty in extracting the code chip from the machine, and the narrow base of buffer tube. Conclusions: VMWs considered the biosensor a practical and beneficial tool in their routine work. Providing VMWs with biosensors can be considered when followed by appropriate training and regular supervision. Providing community management of vivax malaria at the point of first contact could be key for elimination. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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31. Relationship between Duffy Genotype/Phenotype and Prevalence of Plasmodium vivax Infection: A Systematic Review
- Author
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Yelson Alejandro Picón-Jaimes, Ivan David Lozada-Martinez, Javier Esteban Orozco-Chinome, Jessica Molina-Franky, Domenica Acevedo-Lopez, Nicole Acevedo-Lopez, Maria Paz Bolaño-Romero, Fabriccio J. Visconti-Lopez, D. Katterine Bonilla-Aldana, and Alfonso J. Rodriguez-Morales
- Subjects
Plasmodium vivax ,vivax malaria ,Duffy blood group system ,Plasmodium Duffy antigen binding protein ,prevalence ,Medicine - Abstract
The Duffy protein, a transmembrane molecule, functions as a receptor for various chemokines and facilitates attachment between the reticulocyte and the Plasmodium Duffy antigen-binding protein. Duffy expression correlates with the Duffy receptor gene for the chemokine, located on chromosome 1, and exhibits geographical variability worldwide. Traditionally, researchers have described the Duffy negative genotype as a protective factor against Plasmodium vivax infection. However, recent studies suggest that this microorganism’s evolution could potentially diminish this protective effect. Nevertheless, there is currently insufficient global data to demonstrate this phenomenon. This study aimed to evaluate the relationship between the Duffy genotype/phenotype and the prevalence of P. vivax infection. The protocol for the systematic review was registered in PROSPERO as CRD42022353427 and involved reviewing published studies from 2012 to 2022. The Medline/PubMed, Web of Science, Scopus, and SciELO databases were consulted. Assessments of study quality were conducted using the STROBE and GRADE tools. A total of 34 studies were included, with Africa accounting for the majority of recorded studies. The results varied significantly regarding the relationship between the Duffy genotype/phenotype and P. vivax invasion. Some studies predominantly featured the negative Duffy genotype yet reported no malaria cases. Other studies identified minor percentages of infections. Conversely, certain studies observed a higher prevalence (99%) of Duffy-negative individuals infected with P. vivax. In conclusion, this systematic review found that the homozygous Duffy genotype positive for the A allele (FY*A/*A) is associated with a higher incidence of P. vivax infection. Furthermore, the negative Duffy genotype does not confer protection against vivax malaria.
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- 2023
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32. Causal effects on low Apgar at 5-min and stillbirth in a malaria maternal–fetal health outcome investigation: a large perinatal surveillance study in the Brazilian Amazon
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Julio Abel Seijas-Chávez, Melissa S. Nolan, Mary K. Lynn, Maria José Francalino da Rocha, Muana da Costa Araújo, Fernando Luiz Affonso Fonseca, and Gabriel Zorello Laporta
- Subjects
Infectious Pregnancy Complications ,Maternal–Fetal Medicine ,Maternal Health ,Newborns ,Plasmodium falciparum Malaria ,Vivax Malaria ,Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Malaria elimination in Brazil poses several challenges, including the control of Plasmodium falciparum foci and the hidden burden of Plasmodium vivax in pregnancy. Maternal malaria and fetal health outcomes were investigated with a perinatal surveillance study in the municipality of Cruzeiro do Sul, Acre state, Brazilian Amazon. The research questions are: what are the causal effects of low birth weight on low Apgar at 5-min and of perinatal anaemia on stillbirth? Methods From November 2018 to October 2019, pregnant women of ≥ 22 weeks or puerperal mothers, who delivered at the referral maternity hospital (Juruá Women and Children’s Hospital), were recruited to participate in a malaria surveillance study. Clinical information was obtained from a questionnaire and abstracted from medical reports. Haemoglobin level and presence of malarial parasites were tested by haematology counter and light microscopy, respectively. Low Apgar at 5-min and stillbirth were the outcomes analysed in function of clinical data and epidemiologic risk factors for maternal malaria infection using both a model of additive and independent effects and a causal model with control of confounders and use of mediation. Results In total, 202 (7.2%; N = 2807) women had malaria during pregnancy. Nearly half of malaria infections during pregnancy (n = 94) were P. falciparum. A total of 27 women (1.03%; N = 2632) had perinatal malaria (19 P. vivax and 8 P. falciparum). Perinatal anaemia was demonstrated in 1144 women (41.2%; N = 2779) and low birth weight occurred in 212 newborns (3.1%; N = 2807). A total of 75 newborns (2.7%; N = 2807) had low (
- Published
- 2021
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33. Prevalence of glucose-6-phosphate dehydrogenase deficiency (G6PDd) and clinical implication for safe use of primaquine in malaria-endemic areas of Hainan Province, China
- Author
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Wen Zeng, Ning Liu, Yuchun Li, Ai Gao, Mengyi Yuan, Rui Ma, Na Jiang, Dingwei Sun, Guangze Wang, and Xinyu Feng
- Subjects
G6PD ,primaquine ,vivax malaria ,spatial cluster ,prevalence ,Public aspects of medicine ,RA1-1270 - Abstract
Primaquine, the only licensed antimalarial drug for eradication of Plasmodium vivax and Plasmodium ovale malaria, may cause acute hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDd) during treatment. The different prevalence and distribution patterns of G6PDd in Hainan, the ancient malaria-endemic area, are unclear. This study included 5,622 suspected malaria patients between 2009 and 2011 in 11 counties of Hainan. Glucose-6-phosphate dehydrogenase deficiency prevalence was determined using the fluorescent spot test (FST) and malaria patients was confirmed by a positive light microscopy. The G6PDd prevalence for different ethnic groups, genders, and counties were calculated and compared using χ2-test. Spatial cluster and Spearman rank correlation of G6PDd prevalence and malaria incidence were analyzed. The overall G6PDd prevalence of study population was 7.45%. The G6PDd prevalence of males, Li ethnic minority, and malaria patients was significantly higher than that of females, Han ethnic majority, and non-malarial patients (p < 0.01), respectively. The spatial cluster of G6PDd and malaria located in south-western and central-southern Hainan, respectively, with no significant correlation. The study provides essential information on G6PDd prevalence in ancient malaria-endemic areas of Hainan Province. We also highlight the need for a better understanding of the mechanisms underlying the relationship between G6PDd prevalence and malaria incidence. These findings provide a reference for the safety of the primaquine-based intervention, even after malaria elimination.
- Published
- 2022
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34. Population genomics in neglected malaria parasites.
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Brashear, Awtum M. and Liwang Cui
- Subjects
PLASMODIUM vivax ,PLASMODIUM ,MALARIA ,GENOMICS ,NUCLEOTIDE sequencing ,DRUG resistance ,EPIDEMIOLOGY - Abstract
Malaria elimination includes neglected human malaria parasites Plasmodium vivax, Plasmodium ovale spp., and Plasmodium malariae. Biological features such as association with low-density infection and the formation of hypnozoites responsible for relapse make their elimination challenging. Studies on these parasites rely primarily on clinical samples due to the lack of long-term culture techniques. With improved methods to enrich parasite DNA from clinical samples, whole-genome sequencing of the neglected malaria parasites has gained increasing popularity. Population genomics of more than 2200 P. vivax global isolates has improved our knowledge of parasite biology and host-parasite interactions, identified vaccine targets and potential drug resistance markers, and provided a new way to track parasite migration and introduction and monitor the evolutionary response of local populations to elimination efforts. Here, we review advances in population genomics for neglected malaria parasites, discuss how the rich genomic information is being used to understand parasite biology and epidemiology, and explore opportunities for the applications of malaria genomic data in malaria elimination practice. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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35. Neurological Complications of Malaria.
- Author
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Trivedi, Sweety and Chakravarty, Ambar
- Abstract
Purpose of Review: To discuss the neurological complications and pathophysiology of organ damage following malaria infection. Recent Findings: The principal advancement made in malaria research has been a better understanding of the pathogenesis of cerebral malaria (CM), the most dreaded neurological complication generally caused by Plasmodium falciparum infection. However, no definitive treatment has yet been evolved other than the use of antimalarial drugs and supportive care. The development of severe cerebral edema in CM results from two distinct pathophysiologic mechanisms. First, the development of "sticky" red blood cells (RBCs) leads to cytoadherence, where red blood cells (RBCs) get stuck to the endothelial walls and between themselves, resulting in clogging of the brain microvasculature with resultant hypoxemia and cerebral edema. In addition, the P. falciparum-infected erythrocyte membrane protein 1 (PfEMP1) molecules protrude from the raised knob structures on the RBCs walls and are in themselves made of a combination of human and parasite proteins in a tight complex. Antibodies to surfins, rifins, and stevors from the parasite are also located in the RBC membrane. On the human microvascular side, a range of molecules involved in host–parasite interactions, including CD36 and intracellular adhesion molecule 1, is activated during interaction with other molecules such as endothelial protein C receptor and thrombospondin. As a result, an inflammatory response occurs with the dysregulated release of cytokines (TNF, interleukins 1 and 10) which damage the blood–brain barrier (BBB), causing plasma leakage and brain edema. This second mechanism of CNS injury often involves multiple organs in adult patients in endemic areas but remains localized only to the central nervous system (CNS) among African children. Summary: Neurological sequelae may follow both P. falciparum and P. vivax infections. The major brain pathology of CM is brain edema with diffuse brain swelling resulting from the combined effects of reduced perfusion and hypoxemia of cerebral neurons due to blockage of the microvasculature by parasitized RBCs as well as the neurotoxic effect of released cytokines from a hyper-acute immune host reaction. A plethora of additional neurological manifestations have been associated with malaria, including posterior reversible encephalopathy syndrome (PRES), reversible cerebral vasoconstriction syndrome (RCVS), malarial retinopathy, post-malarial neurological syndrome (PMNS), acute disseminated encephalomyelitis (ADEM), Guillain-Barré syndrome (GBS), and cerebellar ataxia. Lastly, the impact of the COVID-19 pandemic on worldwide malaria control programs and the possible threat from co-infections is briefly discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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36. Estimating the Risk of Plasmodium Vivax Relapses in Afghanistan (VRA)
- Author
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National Malaria and Leishmaniasis Control Program, Afghanistan and Mahidol University
- Published
- 2019
37. Chloroquine Population Pharmacokinetics in Pre and Post-partum Women (KCP)
- Published
- 2019
38. Development of a Plasmodium vivax malaria model for evaluating the effects of control strategies on the malaria burden in Democratic People's Republic of Korea.
- Author
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Seong H, Suh J, Choi JY, Lee J, and Yeom JS
- Subjects
- Humans, Incidence, Democratic People's Republic of Korea epidemiology, Plasmodium vivax drug effects, Aminoquinolines therapeutic use, Diagnostic Tests, Routine statistics & numerical data, Adult, Male, Middle Aged, Malaria, Vivax epidemiology, Malaria, Vivax prevention & control, Antimalarials therapeutic use
- Abstract
Background: Plasmodium vivax malaria has been one of the most troublesome diseases in the Democratic People's Republic of Korea (DPRK). Given that a majority of malaria cases are concentrated near the demilitarized zone, concerted elimination efforts from both the Republic of Korea (ROK) and DPRK are essential for a malaria-free Korean Peninsula. This study assessed the impact of rapid diagnostic tests (RDTs) and tafenoquine on malaria incidence in DPRK., Methods: We patterned the current model structure from the previously developed Plasmodium vivax malaria dynamic transmission model for ROK. Model parameters were adjusted using demographic and climate data from malaria-risk areas in DPRK, and the model was calibrated to annual malaria incidences from 2014 to 2018 in DPRK, as reported by the World Health Organization. Subsequently, we estimated the preventable malaria cases over a decade after introducing RDTs and tafenoquine compared to using microscopy alone and primaquine, respectively. Sensitivity analysis was performed to account for uncertainty in model parameters., Results: When comparing RDTs to microscopy, a one-day reduction in diagnostic time due to the introduction of RDTs led to a reduction in malaria incidence by 26,235 cases (65.6%) over the next decade. With a two-day reduction, incidences decreased by 33,635 (84.1%). When comparing a single dose of tafenoquine with a 14-day primaquine regimen, the former prevented 1,222 (77.5%) relapse cases and 4,530 (11.3%) total cases over the years., Conclusion: The continuous and simultaneous implementation of RDTs and tafenoquine emerges as a potent strategy to considerably reduce malaria in DPRK., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Seong, Suh, Choi, Lee and Yeom.)
- Published
- 2024
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39. Population genomics in neglected malaria parasites
- Author
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Awtum M. Brashear and Liwang Cui
- Subjects
malaria ,neglected ,genomics ,population genomics ,vivax malaria ,Microbiology ,QR1-502 - Abstract
Malaria elimination includes neglected human malaria parasites Plasmodium vivax, Plasmodium ovale spp., and Plasmodium malariae. Biological features such as association with low-density infection and the formation of hypnozoites responsible for relapse make their elimination challenging. Studies on these parasites rely primarily on clinical samples due to the lack of long-term culture techniques. With improved methods to enrich parasite DNA from clinical samples, whole-genome sequencing of the neglected malaria parasites has gained increasing popularity. Population genomics of more than 2200 P. vivax global isolates has improved our knowledge of parasite biology and host-parasite interactions, identified vaccine targets and potential drug resistance markers, and provided a new way to track parasite migration and introduction and monitor the evolutionary response of local populations to elimination efforts. Here, we review advances in population genomics for neglected malaria parasites, discuss how the rich genomic information is being used to understand parasite biology and epidemiology, and explore opportunities for the applications of malaria genomic data in malaria elimination practice.
- Published
- 2022
- Full Text
- View/download PDF
40. Prevalence of glucose 6-phosphate dehydrogenase deficiency in highly malaria-endemic municipalities in the Brazilian Amazon: A region-wide screening study
- Author
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Joabi Rocha Nascimento, Jose Diego Brito-Sousa, Anne Cristine Gomes Almeida, Marly M Melo, Monica Regina Farias Costa, Laila Rowena Albuquerque Barbosa, Reinaldo Nery Ramos, Alexandre Vilhena Silva-Neto, Patricia Carvalho da Silva Balieiro, Erick Frota Gomes Figueiredo, Emanuelle Lira Silva, Djane Clarys Baia-da-Silva, Quique Bassat, Gustavo Romero, Gisely Cardoso Melo, Vanderson Souza Sampaio, Marcus Lacerda, and Wuelton Monteiro
- Subjects
Vivax malaria ,Primaquine ,G6PD deficiency ,Brazilian Amazon ,Elimination ,Hemolysis ,Public aspects of medicine ,RA1-1270 - Abstract
Summary: Background: Difficulties associated with the assessment of glucose-6-phosphate dehydrogenase deficiency (G6PDd), particularly in remote areas, hinders the safe use of 8-aminoquinolines such as primaquine (PQ) and tafenoquine against Plasmodium vivax malaria due to the risk of haemolysis. Methods: This cross-sectional study was conducted in 41 malaria-endemic municipalities of six states in the Brazilian Amazon, between 2014 and 2018. Male individuals were screened for G6PDd using the qualitative Fluorescent Spot Test using fingerpick-collected whole blood samples. Point and interval estimates of the G6PDd prevalence were calculated for each state. Deficient samples were genotyped for the most prevalent variants in the Amazon. Frequencies of P. vivax malaria recurrences were estimated for G6PDd and non-G6PDd patients. Interpretation: This is one of the largest surveys ever conducted in Latin America, covering the entire malaria endemic area in the Brazilian Amazon. These results indicate that an important proportion of the population is at risk of hemolysis if exposed to PQ and its congener drug tafenoquine. The adoption of G6PDd screening protocols is essential to ensure the safety of individuals treated with those drugs and should also be considered when implementing malaria elimination strategies. Findings: A total of 14,847 individuals were included, of which 5.6% presented G6PDd. The state of Acre had the highest G6PDd prevalence (8.3%), followed by Amapá (5.8%), Pará (5.7%), Rondônia (5.4%), Roraima (4.2%) and Amazonas (4.0%). From 828 genotyped samples, African A+ (6.2%), African A− (39.3%) and wild-type (non-African non-Mediterranean; 54.2%) variants were found. A greater proportion of malaria recurrences was found among G6PD deficient individuals [16.7% vs 4.1%, Risk ratio 3.52 (2.16–5.74) p
- Published
- 2022
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41. Assessing the Operational Feasibility of Integrating Point-of-Care G6PD Testing into Plasmodium vivax Malaria Management in Vietnam
- Author
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Emily Gerth-Guyette, Huyen Thanh Nguyen, Spike Nowak, Nga Thu Hoang, Đặng Thị Tuyết Mai, Vũ Thị Sang, Nguyễn Đức Long, Mercy Mvundura, Nhu Nguyen, Gonzalo J. Domingo, and Bùi Quang Phúc
- Subjects
vivax malaria ,tafenoquine ,primaquine ,diagnostics ,G6PD deficiency ,hemolytic anemia ,Medicine - Abstract
Plasmodium vivax cases represent more than 50% of a diminishing malaria case load in Vietnam. Safe and effective radical cure strategies could support malaria elimination by 2030. This study investigated the operational feasibility of introducing point-of-care quantitative glucose-6-phosphate dehydrogenase (G6PD) testing into malaria case management practices. A prospective interventional study was conducted at nine district hospitals and commune health stations in Binh Phuoc and Gia Lai provinces in Vietnam over the period of October 2020 to October 2021. The STANDARD™ G6PD Test (SD Biosensor, Seoul, Republic of Korea) was incorporated to inform P. vivax case management. Case management data and patient and health care provider (HCP) perspectives, as well as detailed cost data were collected. The G6PD test results were interpreted correctly by HCP and the treatment algorithm was adhered to for the majority of patients. One HCP consistently ran the test incorrectly, which was identified during the monitoring and resulted in provision of refresher training and updating of training materials and patient retesting. There was wide acceptability of the intervention among patients and HCP albeit with opportunities to improve the counseling materials. Increasing the number of facilities to which the test was deployed and decreases in the malaria cases resulted in higher per patient cost for incorporating G6PD testing into the system. Commodity costs can be reduced by using the 10-unit kits compared to the 25 unit kits, particularly when the case loads are low. These results demonstrate intervention feasibility while also highlighting specific challenges for a country approaching malaria elimination.
- Published
- 2023
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42. Eficacia de la tafenoquina en la profilaxis y tratamiento de la malaria por Plasmodium vivax, revisión sistemática y metaanálisis.
- Author
-
Lorena Cubillos, Astrid, Porras, Alexandra, and Rico, Alejandro
- Abstract
Introduction: Tafenoquine was approved in 2018 by the Food and Drug Administration in the United States and in 2019 by the Therapeutic Goods Administration in Australia. Its administration in a single dose and its mechanism of action in the acute and latent phases of the disease have been studied to change the treatment regimen for Plasmodium vivax malaria. Objective: To evaluate the available scientific evidence of the efficacy of tafenoquine in prophylaxis and treatment between 2009 and 2019. Materials and methods: We established the MeSH and DeCS descriptors and we used the syntax ((Malaria Vivax) AND (tafenoquine) AND (prophylaxis)) OR [(Malaria Vivax) AND (tafenoquine) AND (relapse)] in the following databases: Pubmed, The Cochrane Central Register of Controlled Clinical Trials (CENTRAL), ISIS Web of Science, Lilacs, and Scopus. The results obtained were subjected to critical analysis (CASPE matrix). The quantitative analysis was performed with risk differences in survival analysis (Kaplan Meier) in the final three articles. Results: Three studies underwent meta-analysis (Llanos-Cuentas, 2014; Llanos-Cuentas, 2019, and Lacerda, 2019) to evaluate the efficacy of the treatment with tafenoquine compared to primaquine. A global risk difference of 0.04 was obtained (95% CI: 0.00-0.08; p=0.07). Tafenoquine did not show inferiority in the efficacy of treatment compared to the primaquine scheme. Conclusion: Tafenoquine is a therapeutic alternative to primaquine that improves adherence, which could bring Colombia closer to the goals of the World Technical Strategy against Malaria 2016-2030. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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- View/download PDF
43. Reducing the risk of Plasmodium vivax after falciparum infections in co-endemic areas-a randomized controlled trial (PRIMA).
- Author
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Thriemer, Kamala, Degaga, Tamiru Shibru, Christian, Michael, Alam, Mohammad Shafiul, Ley, Benedikt, Hossain, Mohammad Sharif, Kibria, Mohammad Golam, Tego, Tedla Teferi, Abate, Dagimawie Tadesse, Weston, Sophie, Karahalios, Amalia, Rajasekhar, Megha, Simpson, Julie A., Rumaseb, Angela, Mnjala, Hellen, Lee, Grant, Anose, Rodas Temesgen, Kidane, Fitsum Getahun, Woyessa, Adugna, and Baird, Kevin
- Subjects
- *
PLASMODIUM vivax , *RANDOMIZED controlled trials , *BLOOD transfusion , *MALARIA , *DISEASE relapse , *DRUG therapy for malaria , *MALARIA diagnosis , *PROTOZOA , *RESEARCH , *RESEARCH methodology , *EVALUATION research , *COMPARATIVE studies , *PROTEINURIA , *ANTIMALARIALS , *PRIMAQUINE - Abstract
Background: Plasmodium vivax forms dormant liver stages that can reactivate weeks or months following an acute infection. Recurrent infections are often associated with a febrile illness and can cause a cumulative risk of severe anaemia, direct and indirect mortality, and onward transmission of the parasite. There is an increased risk of P. vivax parasitaemia following falciparum malaria suggesting a rationale for universal use of radically curative treatment in patients with P. falciparum malaria even in the absence of detectable P. vivax parasitaemia in areas that are co-endemic for both species.Methods: This is a multicentre, health care facility-based, randomized, controlled, open-label trial in Bangladesh, Indonesia and Ethiopia. Patients with uncomplicated falciparum malaria, G6PD activity of ≥70% of the adjusted male median (AMM) and haemoglobin levels ≥8g/dl are recruited into the study and randomized to either receive standard schizonticidal treatment plus 7-day high dose primaquine (total dose 7mg/kg) or standard care in a 1:1 ratio. Patients are followed up weekly until day 63. The primary endpoint is the incidence risk of any P. vivax parasitemia on day 63. Secondary endpoints include incidence risk on day 63 of symptomatic P. vivax malaria and the risk of any P. falciparum parasitaemia. Secondary safety outcomes include the proportion of adverse events and serious adverse events, the incidence risk of severe anaemia (Hb<5g/dl and <7g/dl) and/or the risk for blood transfusion, the incidence risk of ≥ 25% fall in haemoglobin with and without haemoglobinuria, and the incidence risk of ≥ 25% fall in haemoglobin to under 7g/dl with and without haemoglobinuria.Discussion: This study evaluates the potential benefit of a universal radical cure for both P. vivax and P. falciparum in different endemic locations. If found safe and effective universal radical cure could represent a cost-effective approach to clear otherwise unrecognised P. vivax infections and hence accelerate P. vivax elimination.Trial Registration: NCT03916003 . Registered on 12 April 2019. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
44. Researchers at Wellcome Sanger Institute Release New Study Findings on Malaria (Lineage-informative microhaplotypes for recurrence classification and spatio-temporal surveillance of Plasmodium vivax malaria parasites).
- Subjects
MOSQUITO-borne diseases ,PROTOZOAN diseases ,PLASMODIUM vivax ,WHOLE genome sequencing ,REPORTERS & reporting - Abstract
A new study conducted by researchers at the Wellcome Sanger Institute focuses on the challenges of classifying recurrent Plasmodium vivax infections, which hinders the surveillance of antimalarial efficacy and transmission. The researchers propose the use of lineage-informative microhaplotypes, which are multi-allelic markers within small segments of the genome, to accurately capture the familial relatedness of the infections. They have developed a framework to identify and select panels of microhaplotypes that can be used for this purpose. The study demonstrates the effectiveness of this approach in predicting geographic origin and capturing local infection outbreaks. The framework is open-source and can be customized for other species or data resources. [Extracted from the article]
- Published
- 2024
45. Reports Outline Malaria Study Findings from Medical College and Hospital (The clinical, hematological, and biochemical profiles of patients with complications due to Plasmodium vivax malaria: A case series).
- Subjects
MOSQUITO-borne diseases ,PROTOZOAN diseases ,DISSEMINATED intravascular coagulation ,PLASMODIUM vivax ,ACUTE kidney failure - Abstract
A recent study conducted in West Bengal, India, has found that Plasmodium vivax malaria, previously thought to cause mild or uncomplicated infections, can actually lead to severe and life-threatening complications. The study examined the clinical, hematological, and biochemical profiles of eight patients with complications due to P. vivax malaria. The most common symptoms observed were fever, headache, and myalgias, and some patients experienced altered mental status, hypotension, and seizures. However, all patients showed excellent response to anti-malarial therapy, highlighting the importance of early diagnosis and treatment initiation. [Extracted from the article]
- Published
- 2024
46. Data from Dilla University Broaden Understanding of Malaria (Efficacy and safety of chloroquine plus primaquine for the treatment of Plasmodium vivax malaria in Hamusit site, Northwestern Ethiopia).
- Subjects
PLASMODIUM vivax ,MALARIA ,CHLOROQUINE ,PRIMAQUINE ,MOSQUITO-borne diseases - Abstract
A study conducted at Dilla University in Ethiopia assessed the efficacy and safety of chloroquine plus primaquine for the treatment of Plasmodium vivax malaria. The study found that the co-administration of chloroquine with primaquine was effective and well-tolerated, with a fast resolution of fever and a high parasite clearance rate. However, a 7.4% failure rate was observed, indicating the need for further monitoring of the therapeutic efficacy of P. vivax. The study highlights the importance of addressing drug resistance and recurrent vivax malaria in Ethiopia. [Extracted from the article]
- Published
- 2024
47. Researchers from Mahidol University Detail Findings in Malaria (Factors Associated With Severe plasmodium Vivax Malaria: a 15-year Retrospective Study).
- Subjects
PLASMODIUM vivax ,MALARIA ,RESEARCH personnel ,MOSQUITO-borne diseases ,PROTOZOAN diseases ,GLUCOSE-6-phosphate dehydrogenase deficiency - Abstract
A study conducted by researchers from Mahidol University in Bangkok, Thailand, aimed to determine the proportion of adult patients with severe Plasmodium vivax malaria and identify the clinical factors associated with malaria severity. The study found that there has been a shift in the predominant species causing malaria in Thailand from Plasmodium falciparum to Plasmodium vivax due to malaria elimination efforts. Factors significantly associated with severe P. vivax malaria included glucose-6-phosphate dehydrogenase deficiency, fever on admission, gametocytemia, severe anemia, low serum albumin level, and elevated serum aspartate aminotransferase level. The study suggests that patients with these risk factors should be monitored more carefully for deterioration and managed accordingly. Further research is needed to determine interventions that can prevent non-severe patients with these risk factors from developing severe infection. [Extracted from the article]
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- 2024
48. Scientists identify molecules associated with recurrence in blood samples from malaria patients.
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MALARIA ,BLOOD sampling ,SCIENTIFIC literature ,MOSQUITO-borne diseases ,PROTOZOAN diseases - Abstract
A recent study conducted by Brazilian researchers has identified possible biomarkers associated with the recurrence of vivax malaria, the most common type of malaria in Brazil. The ability of the parasite Plasmodium vivax to produce dormant forms in the host's liver that can be reactivated months after treatment makes it difficult to control. The study analyzed blood plasma samples from 110 patients and found that patients with recurrent malaria exhibited modulation in lipid pathways involved in the host's immune system. The researchers hope that these findings will contribute to the development of antimalarial drugs and better understanding of recurrence. [Extracted from the article]
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- 2024
49. Falciparum but not vivax malaria increases the risk of hypertensive disorders of pregnancy in women followed prospectively from the first trimester
- Author
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Whitney E. Harrington, Kerryn A. Moore, Aung Myat Min, Mary Ellen Gilder, Nay Win Tun, Moo Kho Paw, Jacher Wiladphaingern, Stephane Proux, Kesinee Chotivanich, Marcus J. Rijken, Nicholas J. White, François Nosten, and Rose McGready
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First trimester ,Falciparum malaria ,Pre-eclampsia ,Gestational hypertension ,Vivax malaria ,Medicine - Abstract
Abstract Background Malaria and hypertensive disorders of pregnancy (HDoP) affect millions of pregnancies worldwide, particularly those of young, first-time mothers. Small case-control studies suggest a positive association between falciparum malaria and risk of pre-eclampsia but large prospective analyses are lacking. Methods We characterized the relationship between malaria in pregnancy and the development of HDoP in a large, prospectively followed cohort. Pregnant women living along the Thailand-Myanmar border, an area of low seasonal malaria transmission, were followed at antenatal clinics between 1986 and 2016. The relationships between falciparum and vivax malaria during pregnancy and the odds of gestational hypertension, pre-eclampsia, or eclampsia were examined using logistic regression amongst all women and then stratified by gravidity. Results There were 23,262 singleton pregnancies in women who presented during the first trimester and were followed fortnightly. Falciparum malaria was associated with gestational hypertension amongst multigravidae (adjusted odds ratio (AOR) 2.59, 95%CI 1.59–4.23), whereas amongst primigravidae, it was associated with the combined outcome of pre-eclampsia/eclampsia (AOR 2.61, 95%CI 1.01–6.79). In contrast, there was no association between vivax malaria and HDoP. Conclusions Falciparum but not vivax malaria during pregnancy is associated with hypertensive disorders of pregnancy.
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- 2021
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50. Rolling out the radical cure for vivax malaria in Asia: a qualitative study among policy makers and stakeholders
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Bipin Adhikari, Ghulam Rhahim Awab, and Lorenz von Seidlein
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Radical cure regimen ,Vivax malaria ,Implementation ,G6PD ,Point of care ,Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Wide-spread implementation of treatment regimens for the radical cure of vivax malaria is hindered by a range of factors. This has resulted in an increase in the relative proportion of vivax malaria and is an important obstacle in the achievement of global malaria elimination by 2030. The main objective of this study was to explore the current policies guiding the treatment plans on vivax malaria, and the factors affecting the implementation of radical cure in South/South East Asian and Asian Pacific countries. Methods This was a qualitative study among respondents who represented national malaria control programmes (NMCPs) or had a role and influence in the national malaria policies. 33 respondents from 17 countries in South/South East Asia and Asia Pacific participated in interviews between October 15 and December 15, 2020. Semi-structured interviews were conducted virtually except for two face to face interviews and audio-recorded. Transcribed audio-records underwent thematic analysis using QSR NVivo. Results Policies against vivax malaria were underprioritized, compared with the focus on falciparum malaria and, in particular, drug resistant Plasmodium falciparum strains. Despite the familiarity with primaquine (PQ) as the essential treatment to achieve the radical cure, the respondents contested the need for G6PD testing. Optional G6PD testing was reported to have poor adherence. The fear of adverse events led health workers to hesitate prescribing PQ. In countries where G6PD was mandatory, respondents experienced frequent stockouts of G6PD rapid diagnostic kits in peripheral health facilities, which was compounded by a short shelf life of these tests. These challenges were echoed across participating countries to various degrees. Most respondents agreed that a shorter treatment regimen, such as single dose tafenoquine could resolve these problems but mandatory G6PD testing will be needed. The recommendation of shorter regimens including tafenoquine or high dose PQ requires operational evidence demonstrating the robust performance of point of care G6PD tests (biosensors). Conclusion There was sparse implementation and low adherence to the radical cure in South/South East Asian and Asian pacific countries. Shorter treatment regimens with appropriate point of care quantitative G6PD tests may resolve the current challenges. Operational evidence on point of care quantitative G6PD tests that includes the feasibility of integrating such tests into the radical cure regimen are critical to ensure its implementation.
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- 2021
- Full Text
- View/download PDF
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