A5032846376- Malaria Research and Control
- Mosquito-borne diseases and control
- Vector-borne infectious diseases
- Antibiotic Resistance in Bacteria
- Parasites and Host Interactions
- Trypanosoma species research and implications
- Complement system in diseases
- HIV Research and Treatment
- Computational Drug Discovery Methods
- Research on Leishmaniasis Studies
- Venomous Animal Envenomation and Studies
- Aquaculture disease management and microbiota
- Invertebrate Immune Response Mechanisms
- Drug Transport and Resistance Mechanisms
- Global Maternal and Child Health
- Drug-Induced Hepatotoxicity and Protection
- Evolution and Genetic Dynamics
- Birth, Development, and Health
- Child Nutrition and Water Access
- Hepatitis B Virus Studies
- Travel-related health issues
- Toxoplasma gondii Research Studies
- Plant responses to water stress
- vaccines and immunoinformatics approaches
- Pregnancy and preeclampsia studies
Shoklo Malaria Research Unit
2013-2022
Mahidol University
2014-2022
Mahidol Oxford Tropical Medicine Research Unit
2011-2022
Background. Deployment of mefloquine–artesunate (MAS3) on the Thailand–Myanmar border has led to a sustained reduction in falciparum malaria, although antimalarial efficacy declined substantially recent years. The role Plasmodium K13 mutations (a marker artemisinin resistance) reducing treatment remains controversial. Methods. Between 2003 and 2013, we studied MAS3 1005 patients with uncomplicated P. malaria relation molecular markers resistance. Results. Polymerase chain reaction...
shows a strict host tropism for reticulocytes. We identified transferrin receptor 1 (TfR1) as the
Microscopic examination of Giemsa-stained thin blood smears remains the gold standard method used to quantify and stage malaria parasites. However, this technique is tedious requires trained microscopists. We have developed a fast simple flow cytometry stage, various parasites in red cells whole or vitro cultured Plasmodium falciparum. The were stained with dihydroethidium Hoechst 33342 SYBR Green I leukocytes identified an antibody against CD45. Depending on DNA stains used, samples...
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 Plasmodium falciparum declined, but resistance to artesunate emerged. We expanded malaria activities through EDT evaluated impact over a 12-y period. Methods Findings Between 1 October 1999 30 September 2011, increased number cross-border (Myanmar side) health facilities from two 11 recorded consultations. Changes in incidence...
Background The transition from enucleated reticulocytes to mature normocytes is marked by substantial remodeling of the erythrocytic cytoplasm and membrane. Despite conspicuous changes, most studies describe maturing reticulocyte as a homogenous erythropoietic cell type. While staging based on fluorescent RNA stains such thiazole orange have been useful in clinical setting; these 'sub-vital' may confound delicate biology preclude their use heamoparasite invasion studies. Design Methods Here...
With the rapidly increasing abundance and accessibility of genomic data, there is a growing interest in using population genetic approaches to characterize fine-scale dispersal organisms, providing insight into biological processes across broad range fields including ecology, evolution epidemiology. For sexually recombining haploid organisms such as human malaria parasite P. falciparum, however, have been no systematic assessments type data methods required resolve fine scale connectivity....
Investigations of Plasmodium vivax are restricted to samples collected from infected persons or primates, because this parasite cannot be maintained in vitro cultures. Contamination P. isolates with host leukocytes and platelets is detrimental a range ex vivo molecular investigations. Easy-to-produce CF11 cellulose filters have recently provided us an inexpensive method for the removal platelets. This contrasted previous reports unacceptably high levels red blood cell (IRBC) retention by...
Abstract The incidence of Plasmodium vivax infection has declined markedly in Malaysia over the past decade despite evidence high-grade chloroquine resistance. Here we investigate genetic changes a P. population approaching elimination 51 isolates from Sabah, and compare these with data 104 Thailand Indonesia. Sabah displays extensive structure, mirroring that previously seen emergence artemisinin-resistant falciparum founder populations Cambodia. Fifty-four percent have identical genomes,...
Chloroquine has been recommended for Plasmodium vivax infections >60 years, but resistance is increasing. To guide future therapies, the cumulative benefits of using slowly eliminated (chloroquine) vs rapidly (artesunate) antimalarials, and risks adding radical cure (primaquine) were assessed in a 3-way randomized comparison conducted on Thailand-Myanmar border.
Chloroquine or dihydroartemisinin-piperaquine with either 7- 14-day primaquine regimens provided highly effective radical cure of vivax malaria on the Thailand-Myanmar border. Short course higher dose for may improve efficacy by improving adherence.
The Horn of Africa harbors the largest reservoir Plasmodium vivax in continent. Most sub-Saharan has remained relatively vivax-free due to a high prevalence human Duffy-negative trait, but emergence strains able invade reticulocytes poses major public health threat. We undertook first population genomic investigation P. from region, comparing genomes 24 Ethiopian isolates against data Southeast Asia identify important local adaptions. Duffy binding protein amplification Ethiopia was 79%,...
Despite the high burden of Plasmodium vivax malaria in South Asian countries, genetic diversity circulating parasite populations is not well described. Determinants antimalarial drug susceptibility for P. region have been characterised. Our genomic analysis global (n = 558) establishes isolates 92) as a distinct subpopulation, which shares ancestry with some East African and parasites. Signals positive selection are linked to resistance-associated loci including pvkelch10, pvmrp1, pvdhfr...
Background. Chloroquine (CQ) remains the treatment of choice for Plasmodium vivax malaria. Initially confined to parts Indonesia and Papua, resistance P. CQ seems be spreading, alternative treatments are required. Methods. We conducted a randomized controlled study compare efficacy tolerability dihydroartemisinin-piperaquine (DP) in 500 adults children with acute malaria on Northwestern border Thailand. Results. Both drugs were well tolerated. Fever parasite clearance times slower than DP...
Abstract Background Plasmodium vivax is a major cause of malaria and still primarily treated with chloroquine. Chloroquine inhibits the polymerization haem to inert haemozoin. Free monomers are thought catalyze oxidative damage spp. trophozoite, stage when haemoglobin catabolism maximal. However preliminary in vitro observations on P. clinical isolates suggest that only ring stages (early trophozoites) sensitive In this study, specific action chloroquine was investigated synchronous...
The establishment of a Plasmodium vivax in vitro culture system is critical for the development new vaccine, drugs and diagnostic tests. Although short-term cultures have been successfully set up, their reproducibility laboratories without direct access to P. vivax-infected patients has limited by need fresh parasite isolates. We explored possibility using isolates reticulocytes, both cryopreserved, perform invasion initiate culture. Invasion results obtained with cryopreserved reticulocytes...
We explored the potential of pooled sequencing to swiftly and economically identify selective sweeps due emerging artemisinin (ART) resistance in a South-East Asian malaria parasite population. ART is defined by slow clearance from blood ART-treated patients mutations kelch gene (chr. 13) have been strongly implicated play role. constructed triplicate pools 70 slow-clearing (resistant) fast-clearing (sensitive) infections collected Thai-Myanmar border sequenced these high (∼ 150-fold) read...
Although Plasmodium vivax parasites are the predominant cause of malaria outside sub-Saharan Africa, they not always prioritised by elimination programmes. P. is resilient and poses challenges through its ability to re-emerge from dormancy in human liver. With observed growing drug-resistance increasing reports life-threatening infections, new tools inform efforts needed. In order halt transmission, we need better understand dynamics movement parasites, reservoirs infection design targeted...
Abstract Traditionally, patient travel history has been used to distinguish imported from autochthonous malaria cases, but the dormant liver stages of Plasmodium vivax confound this approach. Molecular tools offer an alternative method identify, and map cases. Using machine learning approaches incorporating hierarchical fixation index decision tree analyses applied 799 P. genomes 21 countries, we identified 33-SNP, 50-SNP 55-SNP barcodes (GEO33, GEO50 GEO55), with high capacity predict...
Whole genome sequencing (WGS) of Plasmodium vivax is problematic due to the reliance on clinical isolates which are generally low in parasitaemia and sample volume. Furthermore, contain a significant contaminating background host DNA confounds efforts map short read sequence target P. DNA. Here, we discuss methodology significantly improve success WGS natural (non-adapted) patient isolates. Using 37 from Indonesia, Thailand, travellers, assessed application CF11-based white blood cell...
ABSTRACT Assessment of in vitro susceptibility is a fundamental component antimalarial surveillance studies, but wide variations the measurement parasite growth and calculation inhibitory constants make comparisons data from different laboratories difficult. Here we describe Web-based, high-throughput analysis reporting tool (IVART) generating for large sets. Fourteen primary sets examining laboratory-determined to artemisinin derivatives combination therapy partner drugs were collated 11...
Abstract Background Haematological changes associated with malaria in pregnancy are not well documented, and have focused predominantly on anaemia. Examined here is thrombocytopaenia pregnant women infected Plasmodium falciparum or vivax a low transmission area the north-western border of Thailand. Methods In this observational study we reviewed platelet counts from routine complete blood count (CBC) cohort healthy Karen attending weekly antenatal clinics. A 75,000/μL was threshold at 2...
In regions of coendemicity for Plasmodium falciparum and vivax where mefloquine is used to treat P. infection, drug pressure mediated by increased copy numbers the multidrug resistance 1 gene (pvmdr1) may select mefloquine-resistant Surveillance not undertaken routinely owing in part methodological challenges detection amplification. Using genomic data on 88 samples from western Thailand, we identified pvmdr1 amplification 17 isolates, all exhibiting tandem copies a 37.6-kilobase pair region...