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Journal of Clinical Microbiology May 2022
Topics: Animals; Humans; Malaria; Malaysia; Plasmodium knowlesi; Zoonoses
PubMed: 35583365
DOI: 10.1128/jcm.01686-21 -
Journal of Tropical Medicine 2022Worldwide, transmission of emerging and reemerging malaria infections poses a significant threat to human health in the Sub-Saharan Africa, one that can quickly... (Review)
Review
Worldwide, transmission of emerging and reemerging malaria infections poses a significant threat to human health in the Sub-Saharan Africa, one that can quickly overwhelm public health resources. While the disease burden of malaria in the Sub-Saharan Africa appears to be on a gradual decline, it is characterized by spatial and temporal variability occasioning a sorry state for the Global South Countries. New evidence on long-term complications of malaria heightens our awareness of its public health impact. Given the likelihood of misdiagnosis, and the unknown levels of malaria transmission across different landscapes, many missed opportunities for prevention occur. Africa's population growth, unplanned urbanization, habitat destruction, and trans-border travel are contributing to a rise in the calamitous epidemiology of malaria. Despite empirical statistics demonstrating a downward trend in the malaria disease burden attributable to the scale-up of multiple control strategies, including new diagnostic technologies, malaria remains a global threat to human health in Sub-Sahara Africa. Malaria is a severe public health threat globally, despite several advancements and innovations in its control. Six species of the genus including and are known to infect humans. However, greatest disease burden and fatalities are caused by . Globally, about 3 billion individuals are at risk of contracting malaria disease every year, with over 400,000 fatalities reported in the Sub-Saharan Africa. World Health Organization (WHO) 2018 malaria report indicated that approximately 405,000 mortalities and 228 million cases were reported worldwide, with Africa carrying the highest disease burden. Over the last decade, there has been a significant decline in malaria deaths and infections, which may be related to the availability of effective diagnostic techniques. However, in certain areas, the rate of decline has slowed or even reversed the gains made so far. Accurate diagnosis, adequate treatment, and management of the disease are critical WHO-set goals of eliminating malaria by 2030. Microscopy, rapid diagnostic tests (RDTs), nucleic acid amplification tests (NAATs), and biosensors are all currently accessible diagnostic methods. These technologies have substantial flaws and triumphs that could stymie or accelerate malaria eradication efforts. The cost, ease, accessibility, and availability of skilled persons all influence the use of these technologies. These variables have a direct and indirect ramification on the entire management portfolio of patients. Despite the overall decline in the malaria disease burden driven partly by new diagnostic technologies, a sobering pattern marked by limited number of studies and spatial as well as temporal heterogeneity remains a concern. This review summarizes the principle, performance, gaps, accomplishments, and applicability of numerous malaria diagnostic techniques and their potential role in reducing the malaria disease burden in Sub-Saharan Africa.
PubMed: 35360189
DOI: 10.1155/2022/7324281 -
Frontiers in Cell and Developmental... 2021Malaria caused by results in over 400,000 deaths annually, predominantly affecting African children. In addition, non-falciparum species including vivax and knowlesi... (Review)
Review
Malaria caused by results in over 400,000 deaths annually, predominantly affecting African children. In addition, non-falciparum species including vivax and knowlesi cause significant morbidity and mortality. Vascular dysfunction is a key feature in malaria pathogenesis leading to impaired blood perfusion, vascular obstruction, and tissue hypoxia. Contributing factors include adhesion of infected RBC to endothelium, endothelial activation, and reduced nitric oxide formation. Endothelial glycocalyx (eGC) protects the vasculature by maintaining vessel integrity and regulating cellular adhesion and nitric oxide signaling pathways. Breakdown of eGC is known to occur in infectious diseases such as bacterial sepsis and dengue and is associated with adverse outcomes. Emerging studies using biochemical markers and imaging suggest that eGC breakdown occurs during infection and is associated with markers of malaria disease severity, endothelial activation, and vascular function. In this review, we describe characteristics of eGC breakdown in malaria and discuss how these relate to vascular dysfunction and adverse outcomes. Further understanding of this process may lead to adjunctive therapy to preserve or restore damaged eGC and reduce microvascular dysfunction and the morbidity/mortality of malaria.
PubMed: 34858979
DOI: 10.3389/fcell.2021.751251 -
Scientific Reports May 2021Degradation of the endothelial glycocalyx is associated with mortality in adult falciparum malaria. However, its role in the pathogenesis of non-falciparum malaria is... (Clinical Trial)
Clinical Trial Observational Study
Degradation of the endothelial glycocalyx is associated with mortality in adult falciparum malaria. However, its role in the pathogenesis of non-falciparum malaria is unknown. In Malaysian patients with knowlesi (n = 200) and vivax (n = 61) malaria, and in healthy controls (n = 50), we measured glycocalyx breakdown products plasma syndecan-1 and urinary glycosaminoglycans, and evaluated correlations with biomarkers of disease severity. Urinary glycosaminoglycans were increased in patients with knowlesi and vivax malaria compared to healthy controls, and in knowlesi malaria were highest in those with severe disease. In knowlesi malaria, plasma syndecan-1 was also highest in those with severe disease, and correlated with markers of endothelial activation (angiopoietin-2, osteoprotegerin, ICAM-1), asymmetric dimethylarginine (ADMA) and impaired microvascular reactivity. Syndecan-1 also correlated with endothelial activation (ICAM-1, angiopoietin-2) and ADMA in vivax malaria. In knowlesi malaria increased syndecan-1 was associated with acute kidney injury, after controlling for age and parasitemia. In knowlesi malaria, the difference in median syndecan-1 between severe and non-severe disease was more marked in females than males. Endothelial glycocalyx degradation is increased in knowlesi and vivax malaria, and associated with disease severity and acute kidney injury in knowlesi malaria. Agents that inhibit glycocalyx breakdown may represent adjunctive therapeutics for severe non-falciparum malaria.
Topics: Acute Kidney Injury; Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Endothelium, Vascular; Female; Glycocalyx; Humans; Malaria, Vivax; Male; Middle Aged; Plasmodium knowlesi; Plasmodium vivax; Prospective Studies; Severity of Illness Index
PubMed: 33963210
DOI: 10.1038/s41598-021-88962-6 -
Clinical Infectious Diseases : An... Oct 2019Plasmodium knowlesi causes severe and fatal malaria, and incidence in Southeast Asia is increasing. Factors associated with death are not clearly defined.
BACKGROUND
Plasmodium knowlesi causes severe and fatal malaria, and incidence in Southeast Asia is increasing. Factors associated with death are not clearly defined.
METHODS
All malaria deaths in Sabah, Malaysia, from 2015 to 2017 were identified from mandatory reporting to the Sabah Department of Health. Case notes were reviewed, and a systematic review of these and all previously reported fatal P. knowlesi cases was conducted. Case fatality rates (CFRs) during 2010-2017 were calculated using incidence data from the Sabah Department of Health.
RESULTS
Six malaria deaths occurred in Sabah during 2015-2017, all from P. knowlesi. Median age was 40 (range, 23-58) years; 4 cases (67%) were male. Three (50%) had significant cardiovascular comorbidities and 1 was pregnant. Delays in administering appropriate therapy contributed to 3 (50%) deaths. An additional 26 fatal cases were included in the systematic review. Among all 32 cases, 18 (56%) were male; median age was 56 (range, 23-84) years. Cardiovascular-metabolic disease, microscopic misdiagnosis, and delay in commencing intravenous treatment were identified in 11 of 32 (34%), 26 of 29 (90%), and 11 of 31 (36%) cases, respectively. The overall CFR during 2010-2017 was 2.5/1000: 6.0/1000 for women and 1.7/1000 for men (P = .01). Independent risk factors for death included female sex (odds ratio, 2.6; P = .04), and age ≥45 years (odds ratio, 4.7; P < .01).
CONCLUSIONS
Earlier presentation, more rapid diagnosis, and administration of intravenous artesunate may avoid fatal outcomes, particularly in females, older adults, and patients with cardiovascular comorbidities.
Topics: Administration, Intravenous; Adult; Age Factors; Aged; Aged, 80 and over; Antimalarials; Artemisinins; Comorbidity; Female; Humans; Incidence; Malaria; Malaysia; Male; Middle Aged; Plasmodium knowlesi; Pregnancy; Risk Factors; Sex Factors; Young Adult
PubMed: 30624597
DOI: 10.1093/cid/ciz011 -
Parasitology Nov 2023Of the 5 human malarial parasites, and are the most prevalent species globally, while and are less prevalent and typically occur as mixed-infections. , previously... (Review)
Review
Of the 5 human malarial parasites, and are the most prevalent species globally, while and are less prevalent and typically occur as mixed-infections. , previously considered a non-human primate (NHP) infecting species, is now a cause of human malaria in Malaysia. The other NHP species, , , , , and cause malaria in primates, which are mainly reported in southeast Asia and South America. The non- NHP species also emerged and were found to cross-transmit from their natural hosts (NHP) – to human hosts in natural settings. Here we have reviewed and collated data from the literature on the NHPs-to-human-transmitting species. It was observed that the natural transmission of these NHP parasites to humans had been reported from 2010 onwards. This study shows that: (1) the majority of the non- NHP mixed species infecting human cases were from Yala province of Thailand; (2) mono/mixed infections with other human-infecting species were prevalent in Malaysia and Thailand and (3) and were found in Central and South America.
Topics: Animals; Humans; Malaria; Plasmodium knowlesi; Primates; Asia, Southeastern; Plasmodium vivax
PubMed: 37929579
DOI: 10.1017/S003118202300077X -
International Journal of Environmental... Mar 2022is a non-human parasite that causes zoonotic disease in humans. This systematic review aims to highlight and summarize studies describing human behaviors and activities... (Review)
Review
OBJECTIVES
is a non-human parasite that causes zoonotic disease in humans. This systematic review aims to highlight and summarize studies describing human behaviors and activities that expose humans to mosquito bites. English entries in PubMed, Web of Science, and Science Direct from 2010 to 2020 were systematically perused, and the results were synthesized. Methodological quality was assessed using the Joanna Briggs Institute quality appraisal checklists.
SETTING
Studies that described malaria preventive measures were included. Laboratory, in vivo, in vitro, and animal studies were excluded.
PRIMARY AND SECONDARY OUTCOME MEASURES
The main outcome of the review was findings from studies describing the behavior that exposed a person or a group to infection.
RESULTS
Twelve eligible studies were of good or medium quality. Attitude, disease misconceptions, perceived threat of disease, lack of motivation, and supernatural or traditional beliefs causing individuals to seek treatment from traditional healers influenced the exposure of individuals or communities to malaria. Other factors were forestry activities (2.48, 1.45-4.23,95% CI, = 0.0010) and sleeping outdoors (3.611, 1.48-8.85, 95% CI, = 0.0049).
CONCLUSIONS
Future studies must consider the importance of human behavior and community perspective on the infection to provide novel information to improve the current zoonotic malaria programs. Policymakers should concentrate on understanding human behavior and activities that expose individuals or communities to mosquito bites, in order to better design socially feasible interventions.
Topics: Animals; Humans; Insect Bites and Stings; Malaria; Motivation; Plasmodium knowlesi; Zoonoses
PubMed: 35329359
DOI: 10.3390/ijerph19063675 -
Genome Medicine Nov 2023Malaria continues to be a major threat to global public health. Whole genome sequencing (WGS) of the underlying Plasmodium parasites has provided insights into the...
BACKGROUND
Malaria continues to be a major threat to global public health. Whole genome sequencing (WGS) of the underlying Plasmodium parasites has provided insights into the genomic epidemiology of malaria. Genome sequencing is rapidly gaining traction as a diagnostic and surveillance tool for clinical settings, where the profiling of co-infections, identification of imported malaria parasites, and detection of drug resistance are crucial for infection control and disease elimination. To support this informatically, we have developed the Malaria-Profiler tool, which rapidly (within minutes) predicts Plasmodium species, geographical source, and resistance to antimalarial drugs directly from WGS data.
RESULTS
The online and command line versions of Malaria-Profiler detect ~ 250 markers from genome sequences covering Plasmodium speciation, likely geographical source, and resistance to chloroquine, sulfadoxine-pyrimethamine (SP), and other anti-malarial drugs for P. falciparum, but also providing mutations for orthologous resistance genes in other species. The predictive performance of the mutation library was assessed using 9321 clinical isolates with WGS and geographical data, with most being single-species infections (P. falciparum 7152/7462, P. vivax 1502/1661, P. knowlesi 143/151, P. malariae 18/18, P. ovale ssp. 5/5), but co-infections were identified (456/9321; 4.8%). The accuracy of the predicted geographical profiles was high to both continental (96.1%) and regional levels (94.6%). For P. falciparum, markers were identified for resistance to chloroquine (49.2%; regional range: 24.5% to 100%), sulfadoxine (83.3%; 35.4- 90.5%), pyrimethamine (85.4%; 80.0-100%) and combined SP (77.4%). Markers associated with the partial resistance of artemisinin were found in WGS from isolates sourced from Southeast Asia (30.6%).
CONCLUSIONS
Malaria-Profiler is a user-friendly tool that can rapidly and accurately predict the geographical regional source and anti-malarial drug resistance profiles across large numbers of samples with WGS data. The software is flexible with modifiable bioinformatic pipelines. For example, it is possible to select the sequencing platform, display specific variants, and customise the format of outputs. With the increasing application of next-generation sequencing platforms on Plasmodium DNA, Malaria-Profiler has the potential to be integrated into point-of-care and surveillance settings, thereby assisting malaria control. Malaria-Profiler is available online (bioinformatics.lshtm.ac.uk/malaria-profiler) and as standalone software ( https://github.com/jodyphelan/malaria-profiler ).
Topics: Humans; Animals; Antimalarials; Parasites; Coinfection; Malaria; Plasmodium; Malaria, Falciparum; Chloroquine; Malaria, Vivax; Drug Resistance; Plasmodium falciparum
PubMed: 37950308
DOI: 10.1186/s13073-023-01247-7 -
Malaria Journal May 2023Many rural communities in Malaysian Borneo and Southeast Asia are at risk of Plasmodium knowlesi malaria. Multiple factors contribute to infection, however, a deep...
Seeing malaria through the eyes of affected communities: using photovoice to document local knowledge on zoonotic malaria causation and prevention practices among rural communities exposed to Plasmodium knowlesi malaria in Northern Borneo Island.
BACKGROUND
Many rural communities in Malaysian Borneo and Southeast Asia are at risk of Plasmodium knowlesi malaria. Multiple factors contribute to infection, however, a deep understanding of illness causation and prevention practices among at-risk communities remains limited. This study aims to document local knowledge on malaria causation and preventive practices of rural communities in Sabah, Malaysia, using photovoice-a participatory research method.
METHODS
From January to June 2022, a photovoice study was conducted with rural communities in Matunggong subdistrict, Malaysia, to explore their experiences with and local knowledge of non-human primate malaria and prevention practices. The study included (1) an introductory phase in which participants were introduced to the photovoice method; (2) a documentation phase in which participants captured and narrated photos from their communities; (3) a discussion phase in which participants discussed photos and relevant topics through a series of three focus group discussions (FGDs) per village; and (4) a dissemination phase where selected photos were shared with key stakeholders through a photo exhibition. A purposively selected sample of 26 participants (adults > 18 years old, male, and female) from four villages participated in all phases of the study. The study activities were conducted in Sabah Malay dialect. Participants and the research team contributed to data review and analyses.
RESULTS
Rural communities in Sabah, Malaysia possess local knowledge that attributes non-human primate malaria to natural factors related to the presence of mosquitoes that bite humans and which carry "kuman-malaria" or malaria parasite. Participants revealed various preventive practises ranging from traditional practises, including burning dried leaves and using plants that produce foul odours, to non-traditional approaches such as aerosols and mosquito repellents. By engaging with researchers and policymakers, the participants or termed as co-researchers in this study, showcased their ability to learn and appreciate new knowledge and perspectives and valued the opportunity to share their voices with policymakers. The study successfully fostered a balance of power dynamics between the co-researchers, research team members and policymakers.
CONCLUSION
There were no misconceptions about malaria causation among study participants. The insights from study participants are relevant because of their living experience with the non-human malaria. It is critical to incorporate rural community perspectives in designing locally effective and feasible malaria interventions in rural Sabah, Malaysia. Future research can consider adapting the photovoice methodology for further research with the community toward building locally tailored-malaria strategies.
Topics: Adult; Animals; Humans; Plasmodium knowlesi; Rural Population; Borneo; Malaria; Asia, Southeastern; Malaysia
PubMed: 37237418
DOI: 10.1186/s12936-023-04603-5 -
Malaria Journal Dec 2022In the last decade Plasmodium knowlesi has been detected in humans throughout South East Asia. The highest risk groups for this infection are males, adults and those... (Review)
Review
BACKGROUND
In the last decade Plasmodium knowlesi has been detected in humans throughout South East Asia. The highest risk groups for this infection are males, adults and those performing forest-related work. Furthermore, asymptomatic cases of P. knowlesi malaria have been reported including among women and children.
METHODS
Pubmed, Scopus and the Web of Science databases for literature describing asymptomatic P. knowlesi malaria published between 2010 and 2020 were searched. A systematic literature review was conducted to identify studies reporting the prevalence and incidence of laboratory confirmed asymptomatic P. knowlesi cases in humans, their clinical and demographic characteristics, and methods used to diagnose these cases.
RESULTS
By analysing over 102 papers, thirteen were eligible for this review. Asymptomatic P. knowlesi infections have been detected in 0.03%-4.0% of the population depending on region, and infections have been described in children as young as 2 years old. Various different diagnostic methods were used to detect P. knowlesi cases and there were differing definitions of asymptomatic cases in these studies. The literature indicates that regionally-differing immune-related mechanisms may play a part on the prevalence of asymptomatic P. knowlesi.
CONCLUSION
Differing epidemiological characteristics of asymptomatic P. knowlesi malaria in different regions reinforces the need to further investigate disease transmission mechanics. Effective public health responses to changes in P. knowlesi epidemiology require proactive intervention and multisectoral collaboration.
Topics: Child; Humans; Female; Child, Preschool; Plasmodium knowlesi; Communicable Diseases, Emerging
PubMed: 36474243
DOI: 10.1186/s12936-022-04339-8