78 results
Search Results
Now showing 1 - 10 of 78
Publication Metadata only Prognostic indicators in adults hospitalized with falciparum malaria in Western Thailand(2013-07-11) Paul N. Newton; Kasia Stepniewska; Arjen Dondorp; Kamolrat Silamut; Wirongrong Chierakul; Sanjeev Krishna; Timothy Me Davis; Yupin Suputtamongkol; Brian Angus; Sasithon Pukrittayakamee; Ronnatrai Ruangveerayuth; Josh Hanson; Nicholas Pj Day; Nicholas J. White; Wellcome Trust; Mahidol University; Nuffield Department of Clinical Medicine; University of London; University of Western Australia; Faculty of Medicine, Siriraj Hospital, Mahidol University; Mae Sot General Hospital; Menzies School of Health Researchhas probably been an important contributor. Prognostic indices based on WHO 2000 definitions, and other simpler indices based on fewer variables, provide clinically useful predictions of outcome in Asian adults with severe malaria. © 2013 Newton et alPublication Metadata only Increased gametocytemia after treatment: An early parasitological indicator of emerging sulfadoxine-pyrimethamine resistance in falciparum malaria(2008-06-01) Karen I. Barnes; Francesca Little; Aaron Mabuza; Nicros Mngomezulu; John Govere; David Durrheim; Cally Roper; Bill Watkins; Nicholas J. White; University of Cape Town; Malaria Control Programme; Organisation Mondiale de la Sante; London School of Hygiene & Tropical Medicine; Nuffield Department of Clinical Medicine; Mahidol University; Hunter Medical Research Institute, Australia), respectively, among those with parasites containing 1-5 dhfr/dhps mutations. Conclusions. An increased duration and density of gametocyte carriage after sulfadoxine-pyrimethamine treatment was an early indicator of drug resistance. This increased gametocytemiaPublication Metadata only High heritability of malaria parasite clearance rate indicates a genetic basis for artemisinin resistance in western Cambodia(2010-05-01) Tim J C Anderson; Shalini Nair; Standwell Nkhorna; Jeff T. Williams; Mallika Imwong; Poravuth Yi; Duong Socheat; Debashish Das; Kesinee Chotivanich; Nicholas P J Day; Nicholas J. White; Arjen M. Dondorp; Texas Biomedical Research Institute; Mahidol University; Churchill Hospital; Natl. Ctr. Parasitol.In western Cambodia, malaria parasites clear slowly from the blood after treatment with artemisinin derivatives, but it is unclear whether this results from parasite, host, or other factors specific to this population. We measured heritability of clearance rate by evaluating patients infected with identical or nonidentical parasite genotypes, using methods analogous to human twin studies. A substantial proportion (56%-58%) of the variation in clearance rate is explained by parasite genetics. This has 2 important implications: (1) selection with artemisinin derivatives will tend to drive resistance spread and (2) because heritability is high, the genes underlying parasite clearance rate may be identified by genome-wide association. © 2010 by the Infectious Diseases Society of America. All rights reserved.Publication Metadata only Epidemiology of Plasmodium vivax malaria infection in Nepal(2018-01-01) Komal Raj Rijal; Bipin Adhikari; Prakash Ghimire; Megha Raj Banjara; Borimas Hanboonkunupakarn; Mallika Imwong; Kesinee Chotivanich; Kedar Prasad Ceintury; Bibek Kumar Lal; Garib Das Thakur; Nicholas P.J. Day; Nicholas J. White; Sasithon Pukrittayakamee; Minister for Health and Population Nepal; Tribhuvan University; Mahidol University; Nuffield Department of Clinical Medicine; Royal Instituteof Health, Government of Nepal. The epidemiological trends and malariometric indicators were analyzed. Vivax malaria has predominated over falciparum malariain the past53 years, with P. vivax malaria comprising 70-95% of the annual malaria infections.... Analyzing the overall trend between 2002 (12, 786 cases) until 2016 (1,009 cases) shows a case reduction by 92%. The proportion of imported malaria cases has increased from 18% of cases in 2001 to 50% in 2016. The current trends of malariometric indicesPublication Metadata only Parasite clearance rates in Upper Myanmar indicate a distinctive artemisinin resistance phenotype: A therapeutic efficacy study(2016-01-01) Kyaw Myo Tun; Atthanee Jeeyapant; Mallika Imwong; Min Thein; Sai Soe Moe Aung; Tin Maung Hlaing; Prayoon Yuentrakul; Cholrawee Promnarate; Mehul Dhorda; Charles J. Woodrow; Arjen M. Dondorp; Elizabeth A. Ashley; Frank M. Smithuis; Nicholas J. White; Nicholas P.J. Day; Defence Services Medical Research Centre; Myanmar Oxford Clinical Research Unit; Mahidol University; Nuffield Department of Clinical Medicine; Medical Action Myanmar; Worldwide Antimalarial Resistance NetworkBackground: Artemisinin resistance in Plasmodium falciparum extends across Southeast Asia where it is associated with worsening partner drug resistance and a decline in the efficacy of frontline artemisinin-based combination therapy. Dihydroartemisinin-piperaquine (DP) is an essential component of preventive and curative treatment in the region, but its therapeutic efficacy has fallen in Cambodia. Methods: A prospective clinical and parasitological evaluation of DP was conducted at two sites in Upper Myanmar between August 2013 and December 2014, enrolling 116 patients with acute uncomplicated falciparum malaria. Patients received DP orally for 3 days together with primaquine 0.25 mg/kg on admission. Parasite clearance half-lives based on 6 hourly blood smears, and day 42 therapeutic responses were assessed as well as parasite K13 genotypes. Results: Median parasite clearance half-life was prolonged, and clearance half-life was greater than 5 h in 21 % of patients. Delayed parasite clearance was significantly associated with mutations in the propeller region of the parasite k13 gene. The k13 F446I mutation was found in 25.4 % of infections and was associated with a median clearance halflife of 4.7 h compared with 2.7 h for infections without k13 mutations (p < 0.001). There were no failures after 42 days of follow-up, although 18 % of patients had persistent parasitaemia on day 3. Conclusion: The dominant k13 mutation observed in Upper Myanmar, F446I, appears to be associated with an intermediate rate of parasite clearance compared to other common mutations described elsewhere in the Greater Mekong Subregion. Discerning this phenotype requires relatively detailed clearance measurements, highlighting the importance of methodology in assessing artemisinin resistance.Publication Metadata only A selective sweep driven by pyrimethamine treatment in Southeast Asian malaria parasites(2003-09-01) Shalini Nair; Jeff T. Williams; Alan Brockman; Lucy Paiphun; Mayfong Mayxay; Paul N. Newton; Jean Paul Guthmann; Frank M. Smithuis; Tran Tinh Hien; Nicholas J. White; François Nosten; Tim J.C. Anderson; Texas Biomedical Research Institute; Shoklo Malaria Research Unit; Mahidol University; National University of Laos; John Radcliffe Hospital; Mahosot Hospital; Epicentre; Artsen Zonder Grenzen; Cho Quan HospitalM), indicative of a single origin of resistant alleles. Furthermore, we found the same or similar microsatellite haplotypes flanked resistant dhfr alleles sampled from 11 parasite populations in five SE Asian countries indicating recent invasion of a single... be selected easily in the laboratory. Yet our data clearly indicate a single origin of resistant dhfr alleles sampled over a large region of SE Asia. (2) The wide valley (∼6 cM) of reduced variation around dhfr provides "proof-of-principle" that genome-widePublication Metadata only Clinical trials of artesunate plus sulfadoxine-pyrimethamine for Plasmodium falciparum malaria in Afghanistan: Maintained efficacy a decade after introduction(2016-02-25) Ghulam Rahim Awab; Mallika Imwong; Sasithon Pukrittayakamee; Fazel Alim; Warunee Hanpithakpong; Joel Tarning; Arjen M. Dondorp; Nicholas P.J. Day; Nicholas J. White; Charles J. Woodrow; Mahidol University; Ministry of Public Health; Nuffield Department of Clinical Medicineefficacy was high in all the trials, with an adequate clinical and parasitological response (ACPR) of more than 95 % in all groups and trial stages. Genotyping for drug-resistance alleles at dhfr indicated fixation of the S108 N mutation and a prevalence... treatment of P. falciparum in Afghanistan. The molecular data indicate that despite a substantial fall in incidence, resistance has not developed to artemisinins, or intensified to the ACT partner drug components.Publication Metadata only Erythrocyte transketolase activity, markers of cardiac dysfunction and the diagnosis of infantile beriberi(2011-02-01) Douangdao Soukaloun; Sue J. Lee; Karen Chamberlain; Ann M. Taylor; Mayfong Mayxay; Kongkham Sisouk; Bandit Soumphonphakdy; Khaysy Latsavong; Kongsin Akkhavong; Douangkham Phommachanh; Vanmaly Sengmeuang; Khonsavanh Luangxay; Theresa McDonagh; Nicholas J. White; Paul N. Newton; Mahosot Hospital; Nuffield Department of Clinical Medicine; Mahidol University; MRC Human Nutrition Research; University of Health Sciences; Royal Brompton Hospitalthiamin deficiency or indices of cardiac dysfunction as potential surrogate markers.Methodology/Principal Findings:A case control study of 47 infants with beriberi and age-matched afebrile and febrile controls was conducted in Vientiane, Laos. Basal....7) % and specificity (95%CI) of 56.1 (39.7 to 71.5) % for predicting infantile beriberi.Conclusions/Significance:Basal ETK is a more accurate biochemical marker of infantile beriberi than the activation coefficient. Raised plasma troponin T may be a useful indicatorPublication Metadata only A population survey of the glucose-6-phosphate dehydrogenase (G6PD) 563C>T (Mediterranean) mutation in Afghanistan(2014-02-21) Natsuda Jamornthanyawat; Ghulam R. Awab; Naowarat Tanomsing; Sasithon Pukrittayakamee; Fazel Yamin; Arjen M. Dondorp; Nicholas P.J. Day; Nicholas J. White; Charles J. Woodrow; Mallika Imwong; Mahidol University; Ministry of Public Health; University of Oxfordtest). Multivariate analysis of ethnicity and geographical location indicated an adjusted odds ratio of 3.50 (95% CI 1.36-9.02) for the Pashtun/Pashai group, while location showed only a trend towards higher prevalence in eastern provinces (adjusted... selection of the Mediterranean variant in Afghanistan. Overall, the data confirm that the Mediterranean variant of G6PD is common in many ethnic groups in Afghanistan, indicating that screening for G6PD deficiency is required in all individuals beforePublication Metadata only Fluid resuscitation of adults with severe falciparum malaria: Effects on acid-base status, renal function, and extravascular lung water(2013-04-01) Josh P. Hanson; Sophia W.K. Lam; Sanjib Mohanty; Shamshul Alam; Rajyabardhan Pattnaik; Kishore C. Mahanta; Mahatab Uddin Hasan; Prakaykaew Charunwatthana; Saroj K. Mishra; Nicholas P.J. Day; Nicholas J. White; Arjen M. Dondorp; Mahidol University; Ispat General Hospital; Chittagong Medical College Hospital; Nuffield Department of Clinical Medicineresuscitation guided by transpulmonary thermodilution (PiCCO) in an intensive care setting. Systemic hemodynamics, microvascular indices and measures of acidosis, renal function, and pulmonary edema were followed prospectively. Results: All patients were... time points (rs = 0.55; p = 0.003 and rs = 0.43; p = 0.03, respectively). Persisting sequestration was evident in 7 of 15 patients (47%) 48 hours after enrollment. Conclusions: Lactic acidosis-the strongest prognostic indicator in adults with severe