Browsing by Author "Ashley, Elizabeth"

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    PublicationOpen Access
    International health research monitoring: exploring a scientific and a cooperative approach using participatory action research.
    (2014-02-17) Chantler, Tracey; Cheah, Phaik Yeong; Miiro, George; Viriya Hantrakum; Nanvubya, Annet; Ayuo, Elizabeth; Kivaya, Esther; Kidola, Jeremiah; Kaleebu, Pontiano; Parker, Michael; Njuguna, Patricia; Ashley, Elizabeth; Guerin, Philippe J.; Lang, Trudie; Lang, Trudie; Mahidol University. Faculty of Tropical Medicine. Mahidol Oxford Tropical Medicine Research Unit.
    OBJECTIVES: To evaluate and determine the value of monitoring models developed by the Mahidol Oxford Tropical Research Unit and the East African Consortium for Clinical Research, consider how this can be measured and explore monitors' and investigators' experiences of and views about the nature, purpose and practice of monitoring. RESEARCH DESIGN: A case study approach was used within the context of participatory action research because one of the aims was to guide and improve practice. 34 interviews, five focus groups and observations of monitoring practice were conducted. SETTING AND PARTICIPANTS: Fieldwork occurred in the places where the monitoring models are coordinated and applied in Thailand, Cambodia, Uganda and Kenya. Participants included those coordinating the monitoring schemes, monitors, senior investigators and research staff. ANALYSIS: Transcribed textual data from field notes, interviews and focus groups was imported into a qualitative data software program (NVIVO V. 10) and analysed inductively and thematically by a qualitative researcher. The initial coding framework was reviewed internally and two main categories emerged from the subsequent interrogation of the data. RESULTS: The categories that were identified related to the conceptual framing and nature of monitoring, and the practice of monitoring, including relational factors. Particular emphasis was given to the value of a scientific and cooperative style of monitoring as a means of enhancing data quality, trust and transparency. In terms of practice the primary purpose of monitoring was defined as improving the conduct of health research and increasing the capacity of researchers and trial sites. CONCLUSIONS: The models studied utilise internal and network wide expertise to improve the ethics and quality of clinical research. They demonstrate how monitoring can be a scientific and constructive exercise rather than a threatening process. The value of cooperative relations needs to be given more emphasis in monitoring activities, which seek to ensure that research protects human rights and produces reliable data.
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    PublicationOpen Access
    Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study
    (2014-04-24) Carrara, Verena I.; Lwin, Khin Maung; Phyo, Aung Pyae; Ashley, Elizabeth; Wiladphaingern, Jacher; Sriprawat, Kanlaya; Rijken, Marcus; Boel, Machteld; McGready, Rose; Proux, Stephane; Chu, Cindy; Pratap Singhasivanon; ประตาป สิงหศิวานนท์; White, Nicholas; Nosten, Francois; Nosten, Francois; Mahidol University. Faculty of Tropical Medicine. Mahidol Oxford University Research Unit
    BACKGROUND: The Shoklo Malaria Research Unit has been working on the Thai-Myanmar border for 25 y providing early diagnosis and treatment (EDT) of malaria. Transmission of Plasmodium falciparum has declined, but resistance to artesunate has emerged. We expanded malaria activities through EDT and evaluated the impact over a 12-y period. METHODS AND FINDINGS: Between 1 October 1999 and 30 September 2011, the Shoklo Malaria Research Unit increased the number of cross-border (Myanmar side) health facilities from two to 11 and recorded the number of malaria consultations. Changes in malaria incidence were estimated from a cohort of pregnant women, and prevalence from cross-sectional surveys. In vivo and in vitro antimalarial drug efficacy were monitored. Over this period, the number of malaria cases detected increased initially, but then declined rapidly. In children under 5 y, the percentage of consultations due to malaria declined from 78% (95% CI 76-80) (1,048/1,344 consultations) to 7% (95% CI 6.2-7.1) (767/11,542 consultations), p<0.001. The ratio of P. falciparum/P. vivax declined from 1.4 (95% CI 1.3-1.4) to 0.7 (95% CI 0.7-0.8). The case fatality rate was low (39/75,126; 0.05% [95% CI 0.04-0.07]). The incidence of malaria declined from 1.1 to 0.1 episodes per pregnant women-year. The cumulative proportion of P. falciparum decreased significantly from 24.3% (95% CI 21.0-28.0) (143/588 pregnant women) to 3.4% (95% CI 2.8-4.3) (76/2,207 pregnant women), p<0.001. The in vivo efficacy of mefloquine-artesunate declined steadily, with a sharp drop in 2011 (day-42 PCR-adjusted cure rate 42% [95% CI 20-62]). The proportion of patients still slide positive for malaria at day 3 rose from 0% in 2000 to reach 28% (95% CI 13-45) (8/29 patients) in 2011. CONCLUSIONS: Despite the emergence of resistance to artesunate in P. falciparum, the strategy of EDT with artemisinin-based combination treatments has been associated with a reduction in malaria in the migrant population living on the Thai-Myanmar border. Although limited by its observational nature, this study provides useful data on malaria burden in a strategically crucial geographical area. Alternative fixed combination treatments are needed urgently to replace the failing first-line regimen of mefloquine and artesunate.
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    Potential pharmacokinetic interactions of primaquine and blood chizontocides healthy thai volunteers
    (2014) Borimas Hanboonkunupakarn; Podjanee Jittamala; พจนีย์ จิตตะมาลา; Tarning, Joel; Ashley, Elizabeth; Lee, Sue J; Salwaluk Panapipat; Nicholas Day; White, Nicholas J; Sasithon Pukrittayakamee; ศศิธร ผู้กฤตยาคามี; Mahidol University. Faculty of Tropical Medicine. Department of Clinical Tropical Medicine; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit; Mahidol University. Faculty of Tropical Medicine. Department of Tropical Hygiene
    Primaquine is a drug widely used with other schizontocides in treating malaria. It has been used with chloroquine for radical treatment of vivax malaria, and with artemisinin-based combination therapy (ACT) as a gametocytocide to contain the spread of artemisinin-resistant Plasmodium falciparum. Since primaquine and many other antimalarials are metabolized by cytochrome P450, drug-drug interactions are likely to occur. We conducted 3 crossover studies in healthy Thai adult volunteers to determine potential pharmacokinetic interactions between primaquine and three other important blood schizontocides, namely chloroquine, dihydroartemisinin-piperaquine, and pyronaridine-artesunate. In each study, all volunteers were randomised into two groups of three sequential hospital admissions to receive 30 mg base primaquine, the blood schizontocide under study (i.e., 600 mg base chloroquine, 120-960 mg dihydroartemisinin-piperaquine or 540-180 mg pyronaridineartesunate) and the combined drugs. The pharmacokinetic properties of all drugs were evaluated using a non-compartmental approach. An analysis of variance (ANOVA) was carried out on the log-transformed pharmacokinetic parameters for exposure to assess the drug-drug interactions. All treatment regimens were well-tolerated and none was associated with significant electrocardiographic QT prolongation. The single oral dose of primaquine did not result in any significant pharmacokinetic alterations of the studied schizontocides. In contrast, the co-administration with these long halflife schizontocides significantly increased plasma primaquine concentrations. These results suggest a synergistic effect of chloroquine and primaquine for curative treatment in vivax malaria. They also confirm the recent WHO guideline that primaquine is to be given in addition to ACT on the first day of treatment of falciparum malaria.