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Subject: Malaria

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Now showing 1 - 8 of 8
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    PublicationOpen Access
    Severe vivax malaria: a systematic review and meta-analysis of clinical studies since 1900
    (2014) Rahimi, Bilal Ahmad; Ammarin Thakkinstian; White, Nicholas J; Chukiat Sirivichayakul; Dondorp, Arjen M; Watcharee Chokejindachai; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit
    : The primary objective of this systematic review and meta-analysis was to describe the reported clinical characteristics and the geographical variation in prevalence of reported severe vivax malaria and its change over time derived from English-language
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    PublicationOpen Access
    Primaquine: the risks and the benefits
    (2014) Ashley, Elizabeth A; Judith Recht; White, Nicholas J; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit
    Primaquine is the only generally available anti-malarial that prevents relapse in vivax and ovale malaria, and the only potent gametocytocide in falciparum malaria. Primaquine becomes increasingly important as malaria-endemic countries move towards elimination, and although it is widely recommended, it is commonly not given to malaria patients because of haemolytic toxicity in subjects who are glucose-6-phosphate dehydrogenase (G6PD) deficient (gene frequency typically 3-30% in malaria endemic areas; >180 different genetic variants). In six decades of primaquine use in approximately 200 million people, 14 deaths have been reported. Confining the estimate to reports with known denominators gives an estimated mortality of one in 621,428 (upper 95% CI: one in 407,807). All but one death followed multiple dosing to prevent vivax malaria relapse. Review of dose-response relationships and clinical trials of primaquine in G6PD deficiency suggests that the currently recommended WHO single low dose (0.25 mg base/kg) to block falciparum malaria transmission confers a very low risk of haemolytic toxicity.
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    PublicationOpen Access
    Introducing the concept of a new pre-referral treatment for severely ill febrile children at community level: a sociological approach in Guinea-Bissau.
    (2014-02-06) Vermeersch, Audrey; Libaud-Moal, Anaëlle; Rodrigues, Amabelia; White, Nicholas J; Olliaro, Piero; Gomes, Melba; Ashley, Elizabeth A; Millet, Pascal; Millet, Pascal; Mahidol University. Faculty of Tropical Medicine.
    of severity and ensuing decisions were not specific for serious illness, indicating that initial training to recognize signs of severe disease and treatment availability for non-severe, fever-associated symptoms will be required to prevent overuse of a new
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    PublicationOpen Access
    Participants’ perceptions and understanding of a malaria clinical trial in Bangladesh
    (2014) Debashish Das; Cheah, Phaik Yeong; Fateha Akter; Dulal Paul; Akhterul Islam; Rasheda Samad; Ridwanur Rahman; Amir Hossain; Arjen Dondorp; Day, Nicholas P; White, Nicholas J; Mahtabuddin Hasan; Aniruddha Ghose; Ashley, Elizabeth A; Abul Faiz; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit
    Background: Existing evidence suggests that there is often limited understanding among participants in clinical trials about the informed consent process, resulting in their providing consent without really understanding the purpose of the study, specific procedures, and their rights. The objective of the study was to determine the subjects’ understanding of research, perceptions of voluntariness and motivations for participation in a malaria clinical trial. Methods: In this study semi-structured interviews of adult clinical trial participants with uncomplicated falciparum malaria were conducted in Ramu Upazila Health Complex, in Bangladesh. Results: Of 16 participants, the vast majority (81%) were illiterate. All subjects had a ‘therapeutic misconception’ i.e. the trial was perceived to be conducted primarily for the benefit of individual patients when in fact the main objective was to provide information to inform public health policy. From the patients’ perspective, getting well from their illness was their major concern. Poor actual understanding of trial specific procedures was reported despite participants’ satisfaction with treatment and nursing care. Conclusion: There is frequently a degree of overlap between research and provision of clinical care in malaria research studies. Patients may be motivated to participate to research without a good understanding of the principal objectives of the study despite a lengthy consent process. The findings suggest that use of a standard consent form following the current ICH-GCP guidelines does not result in achieving fully informed consent and the process should be revised, simplified and adapted to individual trial settings
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    PublicationOpen Access
    The acceptability of mass administrations of anti‑malarial drugs as part of targeted malaria elimination in villages along the Thai–Myanmar border
    (2016) Ladda Kajeechiwa; May Myo Thwin; Paw Wah Shee; Nan Lin Yee; Elvina Elvina; Peapah Peapah; Kyawt Kyawt; Poe Thit Oo; William PoWah; Min, Jacqueline Roger; Jacher Wiladphaingern; Seidlein, Lorenz von; Suphak Nosten; Nosten, Francois; Mahidol University. Faculty of Tropical Medicine. Mahidol Oxford Research Unit
    Background: A targeted malaria elimination project, including mass drug administrations (MDA) of dihydroartemisinin/ piperaquine plus a single low dose primaquine is underway in villages along the Thailand Myanmar border. The intervention has multiple components but the success of the project will depend on the participation of the entire communities. Quantitative surveys were conducted to study reasons for participation or non-participation in the campaign with the aim to identify factors associated with the acceptance and participation in the mass drug administrations. Methods: The household heads in four study villages in which MDAs had taken place previously were interviewed between January 2014 and July 2015. Results: 174/378 respondents (46 %) completed three rounds of three drug doses each, 313/378 (83 %) took at least three consecutive doses and 56/378 (15 %) did not participate at all in the MDA. The respondents from the two villages (KNH and TPN) were much more likely to participate in the MDA than respondents from the other two villages (HKT and TOT). The more compliant villages KNH and TPN had both an appearance of cohesive communities with similar demographic and ethnic backgrounds. By contrast the villages with low participation were unique. One village was fragmented following years of armed conflict and many respondents gave little inclination to cooperate with outsiders. The other village with low MDA coverage was characterised by a high percentage of short-term residents with little interest in community interventions. A universal reason for non-participation in the MDA applicable to all villages was an inadequate understanding of the intervention. Conclusions: It is unlikely that community engagement can unite fragmented communities in participating in an intervention, which benefits the community. Understanding the purpose and the reasons underlying the intervention is an important pre-condition for participation. In the absence of direct benefits and a complete understanding of the indirect benefits trust in the investigators is critical for participation.
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    PublicationOpen Access
    Malaria community health workers in Myanmar: a cost analysis
    (2016) Shwe Sin Kyaw; Drake, Tom; Aung Thi; Myat Phone Kyaw; Thaung Hlaing; Smithuis, Frank M.; White, Lisa J.; Lubell, Yoel; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit
    Background: Myanmar has the highest malaria incidence and attributed mortality in South East Asia with limited healthcare infrastructure to manage this burden. Establishing malaria Community Health Worker (CHW) programmes is one possible strategy to improve access to malaria diagnosis and treatment, particularly in remote areas. Despite considerable donor support for implementing CHW programmes in Myanmar, the cost implications are not well understood. Methods: An ingredients based micro-costing approach was used to develop a model of the annual implementation cost of malaria CHWs in Myanmar. A cost model was constructed based on activity centres comprising of training, patient malaria services, monitoring and supervision, programme management, overheads and incentives. The model takes a provider perspective. Financial data on CHWs programmes were obtained from the 2013 financial reports of the Three Millennium Development Goal fund implementing partners that have been working on malaria control and elimination in Myanmar. Sensitivity and scenario analyses were undertaken to outline parameter uncertainty and explore changes to programme cost for key assumptions. Results: The range of total annual costs for the support of one CHW was US$ 966–2486. The largest driver of CHW cost was monitoring and supervision (31–60 % of annual CHW cost). Other important determinants of cost included programme management (15–28 % of annual CHW cost) and patient services (6–12 % of annual CHW cost). Within patient services, malaria rapid diagnostic tests are the major contributor to cost (64 % of patient service costs). Conclusion: The annual cost of a malaria CHW in Myanmar varies considerably depending on the context and the design of the programme, in particular remoteness and the approach to monitoring and evaluation. The estimates provide information to policy makers and CHW programme planners in Myanmar as well as supporting economic evaluations of their cost-effectiveness.
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    PublicationOpen Access
    Ethical considerations in malaria research proposal review: empirical evidence from 114 proposals submitted to an Ethics Committee in Thailand
    (2015) Pornpimon Adams; Sukanya Prakobtham; Chanthima Limphattharacharoen; Pitchapa Vutikes; Srisin Khusmith; Krisana Pengsaa; Polrat Wilairatana; Jaranit Kaewkungwal; Mahidol University. Faculty of Tropical Medicine. Department of Tropical Hygiene
    Background: Malaria research is typically conducted in developing countries in areas of endemic disease. This raises specific ethical issues, including those related to local cultural concepts of health and disease, the educational background of study subjects, and principles of justice at the community and country level. Research Ethics Committees (RECs) are responsible for regulating the ethical conduct of research, but questions have been raised whether RECs facilitate or impede research, and about the quality of REC review itself. This study examines the review process for malaria research proposals submitted to the Ethics Committee of the Faculty of Tropical Medicine at Mahidol University, Thailand. Methods: Proposals for all studies submitted for review from January 2010 to December 2014 were included. Individual REC members’ reviewing forms were evaluated. Ethical issues (e.g., scientific merit, risk–benefit, sample size, or informed-consent) raised in the forms were counted and analysed according to characteristics, including study classification/ design, use of specimens, study site, and study population. Results: All 114 proposals submitted during the study period were analysed, comprising biomedical studies (17 %), drug trials (13 %), laboratory studies (24 %) and epidemiological studies (46 %). They included multi-site (13 %) and international studies (4 %), and those involving minority populations (28 %), children (17 %) and pregnant women (7 %). Drug trials had the highest proportion of questions raised for most ethical issues, while issues concerning privacy and confidentiality tended to be highest for laboratory and epidemiology studies. Clarifications on ethical issues were requested by the ethics committee more for proposals involving new specimen collection. Studies involving stored data and specimens tended to attract more issues around privacy and confidentiality. Proposals involving minority populations were more likely to raise issues than those that did not. Those involving vulnerable populations were more likely to attract concerns related to study rationale and design. Conclusions: This study stratified ethical issues raised in a broad spectrum of research proposals. The Faculty of Tropical Medicine at Mahidol University is a significant contributor to global malaria research output. The findings shed light on the ethical review process that may be useful for stakeholders, including researchers, RECs and sponsors, conducting malaria research in other endemic settings.
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    PublicationOpen Access
    FlexiChip package: an universal microarray with a dedicated analysis software for high-thoughput SNPs detection linked to anti-malarial drug resistance.
    (2009-10-15) Steenkeste, Nicolas; Dillies, Marie-Agnès; Khim, Nimol; Sismeiro, Odile; Chy, Sophy; Lim, Pharath; Crameri, Andreas; Bouchier, Christiane; Mercereau-Puijalon, Odile; Beck, Hans-Peter; Mallika Imwong; มัลลิกา อิ่มวงศ์; Dondorp, Arjen M.; Socheat, Duong; Rogier, Christophe; Coppée, Jean- Yves; Ariey, Frédéric; Steenkeste, Nicolas; Mahidol University. Faculty of Tropical Medicine
    BACKGROUND: A number of molecular tools have been developed to monitor the emergence and spread of anti-malarial drug resistance to Plasmodium falciparum. One of the major obstacles to the wider implementation of these tools is the absence of practical methods enabling high throughput analysis. Here a new Zip-code array is described, called FlexiChip, linked to a dedicated software program, which largely overcomes this problem. METHODS: Previously published microarray probes detecting single-nucleotide polymorphisms (SNP) associated with parasite resistance to anti-malarial drugs (ResMalChip) were adapted for a universal microarray FlexiChip format. To evaluate the overall sensitivity of the FlexiChip package (microarray + software), the results of FlexiChip were compared to ResMalChip microarray, using the same extension probes and with the same PCR products. In both cases, sequence results were used as gold standard to calculate sensitivity and specificity. FlexiChip results obtained with a set of field isolates were then compared to those assessed in an independent reference laboratory. RESULTS: The FlexiChip package gave results identical to the ResMalChip results in 92.7% of samples (kappa coefficient 0.8491, with a standard error 0.021) and had a sensitivity of 95.88% and a specificity of 97.68% compared to the sequencing as the reference method. Moreover the method performed well compared to the results obtained in the reference laboratories, with 99.7% of identical results (kappa coefficient 0.9923, S.E. 0.0523). CONCLUSION: Microarrays could be employed to monitor P. falciparum drug resistance markers with greater cost effectiveness and the possibility for high throughput analysis. The FlexiChip package is a promising tool for use in poor resource settings of malaria endemic countries.