A5059464467- Malaria Research and Control
- Mosquito-borne diseases and control
- Vector-borne infectious diseases
- Complement system in diseases
- Parasites and Host Interactions
- Travel-related health issues
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Immune Cell Function and Interaction
- vaccines and immunoinformatics approaches
- Hemoglobinopathies and Related Disorders
- Parasite Biology and Host Interactions
- Neonatal Respiratory Health Research
- Erythrocyte Function and Pathophysiology
- Immune cells in cancer
- Blood groups and transfusion
- Hepatitis B Virus Studies
- Cystic Fibrosis Research Advances
- Moringa oleifera research and applications
- Tracheal and airway disorders
- Phagocytosis and Immune Regulation
- Liver Disease and Transplantation
- Aquaculture disease management and microbiota
- Viral Infections and Vectors
- Antibiotic Resistance in Bacteria
- Platelet Disorders and Treatments
Charles Darwin University
2015-2024
Menzies School of Health Research
2015-2024
State University of Papua
2023
Background A very large biomass of intact asexual-stage malaria parasites accumulates in the spleen asymptomatic human individuals infected with Plasmodium vivax . The mechanisms underlying this intense tropism are not clear. We hypothesised that immature reticulocytes, which P develops, may display high densities spleen, thereby providing a niche for parasite survival. Methods and findings examined tissue 22 mostly untreated naturally exposed to falciparum undergoing splenectomy any...
Neutrophil activation results in Plasmodium parasite killing vitro, but neutrophil products including extracellular traps (NETs) mediate host organ damage and may contribute to severe malaria. The role of NETs the pathogenesis malaria has not been examined.In Papua, Indonesia, we enrolled adults with symptomatic falciparum (n = 47 uncomplicated, n 8 severe), vivax 37), or malariae 14) malaria; asymptomatic P 19) 21) parasitemia; healthy 23) without parasitemia. were quantified by...
Submicroscopic Plasmodium infections are an important parasite reservoir, but their clinical relevance is poorly defined. A cross-sectional household survey was conducted in southern Papua, Indonesia, using cluster random sampling. Data were recorded a standardized questionnaire. Blood samples collected for haemoglobin measurement. parasitaemia determined by blood film microscopy and PCR. Between April July 2013, 800 households 2,830 individuals surveyed. Peripheral detected 37.7%...
Abstract Splenomegaly frequently occurs in patients with Plasmodium falciparum (Pf) or P. vivax (Pv) malarial anemia, but mechanisms underlying this co‐occurrence are unclear. In malaria‐endemic Papua, Indonesia, we prospectively analyzed red blood cell (RBC) concentrations the spleen and spleen‐mimetic retention 37 subjects splenectomized for trauma hyperreactive splenomegaly, most of whom were infected . (median 357 g [range: 80–1918 g]) was correlated positively proportion red‐pulp on...
Clinical illness with Plasmodium falciparum or vivax compromises the function of dendritic cells (DC) and expands regulatory T (Treg) cells. Individuals asymptomatic parasitemia have clinical immunity, restricting parasite expansion preventing disease. The role DC Treg during infection is unclear. During a cross-sectional household survey in Papua, Indonesia, we examined number activation blood plasmacytoid (pDC), CD141(+), CD1c(+) myeloid (mDC) subsets using flow cytometry 168 afebrile...
Background Plasmodium knowlesi causes zoonotic malaria across Southeast Asia. First-line diagnostic microscopy cannot reliably differentiate P. from other human species. Rapid tests (RDTs) designed for falciparum and vivax are used routinely in co-endemic areas despite potential cross-reactivity species-specific antibody targets. Methods Ten RDTs were evaluated: nine to detect clinical infections Malaysia, assessing limit of detection (LoD) (PkA1-H.1) ( Pf3D7 ) cultures. Targets included...
In humans, ∼0.1% to 0.3% of circulating red blood cells (RBCs) are present as platelet-RBC (P-RBC) complexes, and it is 1% 2% in mice. Excessive P-RBC complexes found diseases that compromise RBC health (eg, sickle cell disease malaria) contribute pathogenesis. However, the physiological role healthy unknown. As a result damage accumulated over their lifetime, RBCs nearing senescence exhibit molecular changes akin those platelet-binding malaria. Therefore, we hypothesized targets for...
Abstract Plasmodium vivax lactate dehydrogenase (PvLDH) is an essential enzyme in the glycolytic pathway of P. . It widely used as a diagnostic biomarker and measure total-body parasite biomass malaria. However, dynamics PvLDH remains poorly understood. Here, we developed mathematical models that capture matrix ex vivo culture human host. We estimated key biological parameters characterising based on longitudinal data parasitemia concentration collected from -infected humans, with estimates...
The surveillance of malaria is generally undertaken on the assumption that samples passively collected at health facilities are comparable to or representative broader Plasmodium reservoir circulating in community. Further characterization and comparability hidden asymptomatic parasite needed inform potential impact sampling bias. This study explores strategy molecular by comparing genetic make-up falciparum vivax isolates passive versus active case detection. Sympatric P. were from a large...
The emergence and spread of multidrug-resistant Plasmodium falciparum vivax highlights the need for objective measures ex vivo drug susceptibility. Flow cytometry (FC) has potential to provide a robust rapid quantification parasite growth. Field isolates from Papua, Indonesia, underwent susceptibility testing against chloroquine, amodiaquine, piperaquine, mefloquine, artesunate. A single nucleic acid stain (i.e., hydroethidine (HE) P. SYBR Green I (SG) vivax) was used quantify infected red...
Plasmodium falciparum and vivax infections compromise dendritic cell (DC) function expand regulatory T (Treg) cells in both clinical disease (malaria) experimental human sub-microscopic infection. Conversely, asymptomatic microscopy-positive (patent) P. or infection endemic areas, blood DC increase retain HLA-DR expression Treg exhibit reduced activation, suggesting that contribute to the control of patent The effect (sub-patent) on malaria-endemic area residents remains unclear.In a...
Splenectomy increases the risk of severe and fatal infections; however, Plasmodium vivax malaria is unknown. We quantified species-specific risks other outcomes following splenectomy in patients attending a hospital Papua, Indonesia.Records all Mitra-Masyarakat Hospital 2004-2013 were reviewed, identifying those who underwent splenectomy. Subsequent specific clinical within 12 months for splenectomized compared to nonsplenectomized from their first recorded admission. In addition, trauma...
Abstract Commercial point-of-care tests remain insufficient for accurately detecting and differentiating low-level malaria infections in regions co-endemic with multiple non-falciparum species, including zoonotic Plasmodium knowlesi (Pk). A 5-plex chemiluminescent assay simultaneously measures pan- lactate dehydrogenase (pLDH), P. falciparum (Pf)-LDH, vivax (Pv)-LDH, Pf-histidine-rich protein-2 (HRP2), C-reactive protein. We assessed its diagnostic performance on whole blood (WB) samples...
The risk of severe malaria from the zoonotic parasite Plasmodium knowlesi approximates that P . falciparum In malaria, neutrophil activation contributes to inflammatory pathogenesis, including acute lung injury (ALI). role in pathogenesis has not been examined. We evaluated 213 patients with mono-infection (138 non-severe, 75 severe) and 49 -negative controls Malaysia. Markers (soluble elastase [NE], citrullinated histone [CitH3] circulating extracellular traps [NETs]) were quantified...
Genetic epidemiology can provide important insights into parasite transmission that inform public health interventions. The current study compared long-term changes in the genetic diversity and structure of co-endemic Plasmodium falciparum P. vivax populations. was conducted Papua Indonesia, where high-grade chloroquine resistance led to a universal policy Artemisinin-based Combination Therapy (ACT) 2006. Microsatellite typing population analyses were undertaken on available isolates...
Abstract Background and Objective The importance of extracellular traps (ETs) in chronic respiratory conditions is increasingly recognized but their role paediatric bronchiectasis poorly understood. specialized techniques currently required to study ETs preclude routine clinical use. A simple cost‐effective detection method needed support diagnostic applications. We aimed determine whether could be detected using light microscopy‐based assessment Romanowsky‐stained bronchoalveolar lavage...
Abstract Background Circulating myeloid-derived-suppressor-cells (MDSC) with immunosuppressive function are increased in human experimental Plasmodium falciparum infection, but have not been studied clinical malaria. Methods Using flow-cytometry, circulating polymorphonuclear-MDSC were evaluated cryopreserved samples from patients uncomplicated vivax (n = 8) and 4) severe 16) malaria Papua, Indonesia. Results The absolute number of significantly elevated compared to controls 10)....
Glucose-6-phosphate dehydrogenase (G6PD) deficiency offers some protection against malaria; however, the degree of is poorly described and likely to vary with G6PD genotype Plasmodium species. We present a novel approach quantify differential invasion rates P. falciparum between deficient normal red blood cells (RBCs) in an ex vivo model. A flow-cytometry based assay was developed distinguish normal, parasitized non-parasitized RBCs within same sample. Venous collected from heterozygous...
Plasmodium knowlesi is the major cause of zoonotic malaria in Southeast Asia. Rapid and accurate diagnosis enables effective clinical management. A novel diagnostic tool, Gazelle (Hemex Health, USA) detects haemozoin, a by-product haem metabolism found all infections. pilot phase refined haemozoin identification algorithm, with algorithm then tested against reference PCR larger cohort patients P. mono-infections febrile malaria-negative controls. Limit-of-detection analysis was conducted on...
Severe malaria after splenectomy has been reported with infections Plasmodium falciparum, knowlesi, and malariae, but is less well-characterized vivax. We describe a case of severe P. vivax hypotension, prostration, acute kidney injury occurring 2 months in Papua, Indonesia. The patient was treated successfully intravenous artesunate.