| epidemiological characteristics of imported and locally-acquired malaria in singapore. | the objective of the study was to determine the trend of malaria, the epidemiological characteristics, the frequency of local transmission and the preventive and control measures taken. | 2009 | 19890574 |
| knowlesi malaria in vietnam. | the simian malaria parasite plasmodium knowlesi is transmitted in the forests of southeast asia. symptomatic zoonotic knowlesi malaria in humans is widespread in the region and is associated with a history of spending time in the jungle. however, there are many settings where knowlesi transmission to humans would be expected but is not found. a recent report on the ra-glai population of southern central vietnam is taken as an example to help explain why this may be so. | 2009 | 19941646 |
| severe malaria - a case of fatal plasmodium knowlesi infection with post-mortem findings: a case report. | zoonotic malaria caused by plasmodium knowlesi is an important, but newly recognized, human pathogen. for the first time, post-mortem findings from a fatal case of knowlesi malaria are reported here. | 2010 | 20064229 |
| plasmodium knowlesi malaria in vietnam: some clarifications. | a recently published comment on a report of plasmodium knowlesi infections in vietnam states that this may not accurately represent the situation in the study area because the pcr primers used may cross-hybridize with plasmodium vivax. nevertheless, p. knowlesi infections have been confirmed by sequencing. in addition, a neighbour-joining tree based on the 18s s-type ssurrna gene shows that the vietnamese samples clearly cluster with the p. knowlesi isolates identified in malaysia and are distin ... | 2010 | 20082717 |
| [plasmodium knowlesi: cause of naturally acquired malaria in humans]. | | 2010 | 20146160 |
| [a fifth plasmodium that can cause malaria]. | since 2004, malaria with a "fifth" plasmodium, plasmodium knowlesi (common in macaque monkeys), has been diagnosed in a number of people in southeast asia. this article gives a short overview of the epidemiology, clinical picture, diagnostics and treatment of p. knowlesi infection. | 2010 | 20160773 |
| the pigment of the malarial parasites plasmodium knowlesi and plasmodium gallinaceum. | | 1947 | 20270803 |
| studies on malarial parasites; effects of ascorbic acid on malaria (plasmodium knowlesi) in monkeys. | | 1946 | 20277733 |
| [malaria and other risks]. | | 2010 | 20334791 |
| plasmodium knowlesi in human, indonesian borneo. | plasmodium knowlesi is now established as the fifth plasmodium species to cause malaria in humans. we describe a case of p. knowlesi infection acquired in indonesian borneo that was imported into australia. clinicians need to consider this diagnosis in a patient who has acquired malaria in forest areas of southeast asia. | 2010 | 20350383 |
| small variant surface antigens and plasmodium evasion of immunity. | antigenic variation at the plasmodium-infected erythrocyte surface plays a critical role in malaria disease severity and host immune evasion. our current understanding of the role of plasmodium variant surface antigens in antigenic variation and immune evasion is largely limited to the extensive work carried out on the plasmodium falciparum var gene family. although homologues of var genes are not present in other malaria species, small variant gene families comprising the rif and stevor genes i ... | 2010 | 20353305 |
| evidence for negative selection on the gene encoding rhoptry-associated protein 1 (rap-1) in plasmodium spp. | assessing how natural selection, negative or positive, operates on genes with low polymorphism is challenging. we investigated the genetic diversity of orthologous genes encoding the rhoptry-associated protein 1 (rap-1), a low polymorphic protein of malarial parasites that is involved in erythrocyte invasion. we applied evolutionary genetic methods to study the polymorphism in rap-1 from plasmodium falciparum (n=32) and plasmodium vivax (n=6), the two parasites responsible for most human malaria ... | 2010 | 20363375 |
| plasmodium cdp-dag synthase: an atypical gene with an essential n-terminal extension. | cytidine diphosphate diacylglycerol synthase (cds) diverts phosphatidic acid towards the biosynthesis of cdp-dag, an obligatory liponucleotide intermediate in anionic phospholipid biosynthesis. the 78kda predicted plasmodium falciparum cds (pfcds) is recovered as a 50 kda conserved c-terminal cytidylyltransferase domain (c-pfcds) and a 28kda fragment that corresponds to the unusually long hydrophilic asparagine-rich n-terminal extension (n-pfcds). here, we show that the two fragments of pfcds ar ... | 2010 | 20385136 |
| structure-based design of novel small-molecule inhibitors of plasmodium falciparum. | malaria is endemic in most developing countries, with nearly 500 million cases estimated to occur each year. the need to design a new generation of antimalarial drugs that can combat the most drug-resistant forms of the malarial parasite is well recognized. in this study, we wanted to develop inhibitors of key proteins that form the invasion machinery of the malarial parasite. a critical feature of host-cell invasion by apicomplexan parasites is the interaction between the carboxy terminal tail ... | 2010 | 20426475 |
| [emerging and spread of the fifth plasmodium spp. pathogenic for human malaria: plasmodium knowlesi]. | the beginning of the third millennium has been characterized by the emerging and progressive characterization of a novel malaria plasmodium pathogen of simian origin (plasmodium knowlesi), which now represents the fifth human malaria parasite. evolutionary, environmental, and diagnostic-clinical features are briefly outlined on the ground of the most recent literature evidences. | 2010 | 20433003 |
| prophylactic and curative activities of extracts from warburgia ugandensis sprague (canellaceae) and zanthoxylum usambarense (engl.) kokwaro (rutaceae) against plasmodium knowlesi and plasmodium berghei. | this work reports the anti-plasmodial activities of warburgia ugandensis and zanthoxylum usambarense commonly used as phytomedicines against malaria by some kenyan communities. | 2010 | 20435133 |
| evaluation of a loop-mediated isothermal amplification method as a tool for diagnosis of infection by the zoonotic simian malaria parasite plasmodium knowlesi. | loop-mediated isothermal amplification (lamp) is a novel method that rapidly amplifies target dna with high specificity under isothermal conditions. it has been applied as a diagnostic tool for several infectious diseases, including viral, bacterial, and parasitic diseases. in the present study, we developed a lamp method for the molecular diagnosis of plasmodium knowlesi infection (pklamp) and evaluated its sensitivity, specificity, and clinical applicability. we designed three sets of pklamp p ... | 2010 | 20444968 |
| [monkey malaria in a traveller from malaysia]. | | 2010 | 20456798 |
| [plasmodium knowlesi--the fifth species causing human malaria]. | four species have been known to bring on human malaria, the most severe disease being caused by plasmodium falciparum. in 2007, after returning from malaysia, a finnish tourist was found to be infected with a fifth plasmodium species, p. knowlesi which usually infects macaques. over the past few years, hundreds of human cases have been found in malaysia. the clinical disease caused by p. knowlesi appears less severe than p. falciparum infection, but more severe than infection with other malaria- ... | 2010 | 20486493 |
| diagnostic difficulties with plasmodium knowlesi infection in humans. | | 2010 | 20507769 |
| plasmodium knowlesi in humans: a review on the role of its vectors in malaysia. | plasmodium knowlesi in humans is life threatening, is on the increase and has been reported from most states in malaysia. anopheles latens and anopheles cracens have been incriminated as vectors. malaria is now a zoonoses and is occurring in malaria free areas of malaysia. it is also a threat to eco-tourism. the importance of the vectors and possible control measures is reviewed here. | 2010 | 20562807 |
| management of plasmodium knowlesi malaria without pcr confirmation. | plasmodium knowlesi morphologically resembles p. malariae; pcr assays are able to differentiate between the 2 species correctly. however, pcr is not available in many hospitals in p. knowlesi endemic areas, particularly in southeast asia. in places where pcr is not available, anti-malarial drugs for p. malariae or other non-p. falciparum or p. falciparum species are effective against p. knowlesi. even with a wrong diagnosis of another malaria species by light microscopy instead of p. knowlesi, t ... | 2010 | 20578477 |
| molecular epidemiological investigation of plasmodium knowlesi in humans and macaques in singapore. | singapore reported its first locally acquired human plasmodium knowlesi infection in 2007, involving a soldier who had undergone training in a forested area where long-tailed macaques are frequently seen. comprehensive disease surveillance and monitoring system that was set up after the initial case detected four additional human p. knowlesi cases in 2007 and one in 2008. all involved military personnel who had undergone training in the forested area, and none had traveled out of singapore 1 mon ... | 2011 | 20586605 |
| [a new, sixth human malaria parasite]. | | 2010 | 20589791 |
| first case of detection of plasmodium knowlesi in spain by real time pcr in a traveller from southeast asia. | previously, plasmodium knowlesi was not considered as a species of plasmodium that could cause malaria in human beings, as it is parasite of long-tailed (macaca fascicularis) and pig-tailed (macaca nemestrina) macaques found in southeast asia. a case of infection by p. knowlesi is described in a spanish traveller, who came back to spain with daily fever after his last overseas travel, which was a six-month holiday in forested areas of southeast asia between 2008 and 2009. his p. knowlesi infecti ... | 2010 | 20663184 |
| malaria: what can apes teach humans? | | 2010 | 20722593 |
| clinical and parasitological response to oral chloroquine and primaquine in uncomplicated human plasmodium knowlesi infections. | plasmodium knowlesi is a cause of symptomatic and potentially fatal infections in humans. there are no studies assessing the detailed parasitological response to treatment of knowlesi malaria infections in man and whether antimalarial resistance occurs. | 2010 | 20723228 |
| co-infections with plasmodium knowlesi and other malaria parasites, myanmar. | to determine the frequency of co-infections with plasmodium species in southern myanmar, we investigated the prevalence of p. knowlesi. more than 20% of patients with malaria had p. knowlesi infection, which occurred predominantly as a co-infection with either p. falciparum or p. vivax. | 2010 | 20735938 |
| complication of corticosteroid treatment by acute plasmodium malariae infection confirmed by small-subunit rrna sequencing. | we report a case of acute plasmodium malariae infection complicating corticosteroid treatment for membranoproliferative glomerulonephritis in a patient from an area where p. malariae infection is not endemic. a peripheral blood smear showed typical band-form trophozoites compatible with p. malariae or plasmodium knowlesi. ssu rrna sequencing confirmed the identity to be p. malariae. | 2010 | 20739487 |
| observations on infection by plasmodium knowlesi (ape malaria) in the treatment of general paralysis of the insane. | | 1935 | 20779410 |
| the emerging of the fifth malaria parasite (plasmodium knowlesi): a public health concern? | after examining the most recent scientific evidences, which assessed the role of some malaria plasmodia that have monkeys as natural reservoirs, the authors focus their attention on plasmodium knowlesi. the infective foci attributable to this last plasmodium species have been identified during the last decade in malaysia, in particular in the states of sarawak and sabah (malaysian borneo), and in the pahang region (peninsular malaysia). the significant relevance of molecular biology assays (poly ... | 2010 | 20835518 |
| comparative genomic analysis of simple sequence repeats in three plasmodium species. | simple sequence repeats (ssrs) are known to be responsible for genetic complexities and play major roles in gene and genome evolution. to this respect, malaria parasites are known to have rapidly evolving and complex genomes with complicated and differential pathogenic behaviors. hence, by studying the whole genome comparative ssrs patterns, one can understand genomic complexities and differential evolutionary patterns of these species. we herein utilized the whole genome sequence information of ... | 2010 | 20924609 |
| identification and characterization of the plasmodium vivax thrombospondin-related apical merozoite protein. | malaria caused by plasmodium vivax is a major public health problem worldwide that affects 70-80 million people in the middle east, asia, western pacific, south america and the caribbean. despite its epidemiological importance, few antigens from this parasite species have been characterized to date compared to plasmodium falciparum, due in part to the difficulties of maintaining an in vitro culture of p. vivax. this study describes the identification of the p. falciparum thrombospondin-related a ... | 2010 | 20942952 |
| chemotherapy of plasmodium knowlesi infections in macaca mulatta monkeys. | | 1946 | 20983207 |
| chemotherapy of plasmodium knowlesi infections in macaca mulatta monkeys. | | 1946 | 20994722 |
| knowlesi malaria in monkeys; microscopic pathological circulatory physiology of rhesus monkeys during acute plasmodium knowlesi malaria. | | 1945 | 21016051 |
| modelling knowlesi malaria transmission in humans: vector preference and host competence. | plasmodium knowlesi, a malaria species that normally infects long-tailed macaques, was recently found to be prevalent in humans in southeast asia. while human host competency has been demonstrated experimentally, the extent to which the parasite can be transmitted from human back to mosquito vector in nature is unclear. | 2010 | 21080968 |
| a taqman real-time pcr assay for the detection and quantitation of plasmodium knowlesi. | the misdiagnosis of plasmodium knowlesi by microscopy has prompted a re-evaluation of the geographic distribution, prevalence and pathogenesis of this species using molecular diagnostic tools. in this report, a specific probe for p. knowlesi, that can be used in a previously described taqman real-time pcr assay for detection of plasmodium spp., and plasmodium falciparum, plasmodium vivax, plasmodium malariae and plasmodium ovale, was designed and validated against clinical samples. | 2010 | 21114872 |
| the position of mefloquine as a 21st century malaria chemoprophylaxis. | malaria chemoprophylaxis prevents the occurrence of the symptoms of malaria. travellers to high-risk plasmodium falciparum endemic areas need an effective chemoprophylaxis. | 2010 | 21143906 |
| identification of the five human plasmodium species including p. knowlesi by real-time polymerase chain reaction. | recently, plasmodium knowlesi has been recognised as the fifth plasmodium species causing malaria in humans. hundreds of human cases infected with this originally simian plasmodium species have been described in asian countries and increasing numbers are reported in europe from travellers. the growing impact of tourism and economic development in south and southeast asia are expected to subsequently lead to a further increase in cases both among locals and among travellers. p. knowlesi is easily ... | 2010 | 21161559 |
| de novo origin of new genes with introns in plasmodium vivax. | the origin of new genes is critical for organisms adapting to new niches. here, we present evidence for a recent de novo origin of at least 13 protein-coding genes in the genome of plasmodium vivax. although recently de novo originated genes have often been suggested to be initially intronless, five of the genes identified in our analysis contain introns in their coding regions. further investigations revealed that these introns likely evolved from previously intergenic regions together with the ... | 2011 | 21241695 |
| human plasmodium knowlesi infections in klang valley, peninsula malaysia: a case series. | we report seven cases of naturally acquired human plasmodium knowlesi infections which were admitted to our centre from july 2007 till june 2008. diagnosis was confirmed by nested pcr. cases of p. knowlesi infections, dubbed the fifth type of human malaria, have been reported in east malaysia (sabah and sarawak) as well as in the state of pahang in peninsula malaysia. these seven patients appear to be the first few reported cases of p. knowlesi infection in the klang valley, peninsula malaysia. ... | 2010 | 21265252 |
| malaria infection by sporozoite challenge induces high functional antibody titres against blood stage antigens after a dna prime, poxvirus boost vaccination strategy in rhesus macaques. | a dna prime, poxvirus (copak) boost vaccination regime with four antigens, i.e. a combination of two plasmodium knowlesi sporozoite (csp/ssp2) and two blood stage (ama1/msp142) genes, leads to self-limited parasitaemia in 60% of rhesus monkeys and survival from an otherwise lethal infection with p. knowlesi. in the present study, the role of the blood stage antigens in protection was studied in depth, focusing on antibody formation against the blood stage antigens and the functionality thereof. | 2011 | 21303498 |
| imported plasmodium knowlesi malaria in a french tourist returning from thailand. | we report a case of imported plasmodium knowlesi malaria in a french tourist following a vacation in thailand. this case shows, first, tourists may contract knowlesi malaria even only staying on the beach and second, the diagnosis remains difficult, even with polymerase chain reaction methods. | 2011 | 21460005 |
| plasmodium knowlesi in a traveller returning to new zealand. | the recent discovery that plasmodium knowlesi causes malaria in human populations, established it as the fifth species of plasmodium that may do so. a case of p. knowlesi malaria is described in a helicopter pilot from new zealand, who became ill after returning from recurring visits to malaysian borneo in june 2010. his p. knowlesi infection was not detected using microscopic examination and a rapid diagnostic test for malaria, but was confirmed by both pcr (polymerase chain reaction) and seque ... | 2011 | 21481643 |
| antimalarial effects of human immunodeficiency virus protease inhibitors in rhesus macaques. | the antimalarial activity of the human immunodeficiency virus protease inhibitors indinavir and saquinavir was evaluated in rhesus macaques for the first time. indinavir effectively suppressed the growth of plasmodium cynomolgi and plasmodium knowlesi in vivo after a 7- or 3-day treatment, respectively, with clinically relevant doses, whereas saquinavir showed only weak activity against p. cynomolgi. | 2011 | 21486958 |
| plasmodium knowlesi: reservoir hosts and tracking the emergence in humans and macaques. | plasmodium knowlesi, a malaria parasite originally thought to be restricted to macaques in southeast asia, has recently been recognized as a significant cause of human malaria. unlike the benign and morphologically similar p. malariae, these parasites can lead to fatal infections. malaria parasites, including p. knowlesi, have not yet been detected in macaques of the kapit division of malaysian borneo, where the majority of human knowlesi malaria cases have been reported. in order to extend our ... | 2011 | 21490952 |
| plasmodium knowlesi malaria in children. | plasmodium knowlesi can cause severe malaria in adults; however, descriptions of clinical disease in children are lacking. we reviewed case records of children (age <15 years) with a malaria diagnosis at kudat district hospital, serving a largely deforested area of sabah, malaysia, during january-november 2009. sixteen children with pcr-confirmed p. knowlesi monoinfection were compared with 14 children with p. falciparum monoinfection diagnosed by microscopy or pcr. four children with knowlesi m ... | 2011 | 21529389 |
| improved performance with saliva and urine as alternative dna sources for malaria diagnosis by mitochondrial dna-based pcr assays. | clin microbiol infect abstract: saliva and urine from malaria-infected individuals contain trace amounts of plasmodium dna, and therefore, could be used as alternative specimens for diagnosis. a nested pcr targeting the mitochondrial cytochrome b gene (cytb-pcr) of four human malaria species and plasmodium knowlesi was developed and tested with 693 blood samples from febrile patients living in diverse malaria-endemic areas of thailand, and compared with microscopy and nested pcr targeting small- ... | 2011 | 21595789 |
| review of cases with the emerging fifth human malaria parasite, plasmodium knowlesi. | human malaria has been known to be caused by 4 plasmodium species, with plasmodium falciparum causing the most-severe disease. recently, numerous reports have described human malaria caused by a fifth plasmodium species, plasmodium knowlesi, which usually infects macaque monkeys. hundreds of human cases have been reported from malaysia, several cases have been reported in other southeast asian countries, and a few cases have been reported in travelers visiting these areas. similarly to p. falcip ... | 2011 | 21596677 |
| vaccination with plasmodium knowlesi ama1 formulated in the novel adjuvant co-vaccine ht™ protects against blood-stage challenge in rhesus macaques. | plasmodium falciparum apical membrane antigen 1 (pfama1) is a leading blood stage vaccine candidate. plasmodium knowlesi ama1 (pkama1) was produced and purified using similar methodology as for clinical grade pfama1 yielding a pure, conformational intact protein. combined with the adjuvant covaccine ht™, pkama1 was found to be highly immunogenic in rabbits and the efficacy of the pkama1 was subsequently tested in a rhesus macaque blood-stage challenge model. six rhesus monkeys were vaccinated wi ... | 2011 | 21655233 |
| specific, sensitive and rapid detection of human plasmodium knowlesi infection by loop-mediated isothermal amplification (lamp) in blood samples. | abstract: background: the emergence of plasmodium knowlesi in humans, which is in many cases misdiagnosed by microscopy as plasmodium malariae due to the morphology similarity, has contributed to the needs of detection and differentiation of malaria parasites. up to date, nested pcr targeted on plasmodium ssrrna genes is described as the most sensitive and specific method for plasmodium detection. however, this methodology is costly and requires trained personnel for its implementation. loop-med ... | 2011 | 21774805 |
| evolutionary analysis of circumsporozoite surface protein and merozoite surface protein-1 (csp and msp-1) sequences of malaria parasites. | malaria, one of the world's most common diseases, is caused by the intracellular protozoan parasite known as plasmodium. in this study, we have determined the evolutionary relationship of two single-copy proteins, circumsporozoite protein (csp) and merozoite surface protein-1 (msp-1), among plasmodium species using various bioinformatics tools and softwares. these two proteins are major blood stage antigens of plasmodium species. this study demonstrates that the circumsporozoite protein of plasm ... | 2011 | 21769195 |
| plasmodium knowlesi reinfection in human. | to the editor: in 2004, a large number of patients infected with plasmodium knowlesi (simian malarial species) were reported in sarawak, malaysia (1). p. knowlesi infection was also reported in peninsular malaysia (2). here we report a case of human p. knowlesi reinfection. phylogenetic sequence analysis shows that the first and second infections were caused by different strains of p. knowlesi. | 2011 | 21762601 |
| severe plasmodium knowlesi malaria in a tertiary care hospital, sabah, malaysia. | the simian parasite plasmodium knowlesi causes severe human malaria; the optimal treatment remains unknown. we describe the clinical features, disease spectrum, and response to antimalarial chemotherapy, including artemether-lumefantrine and artesunate, in patients with p. knowlesi malaria diagnosed by pcr during december 2007-november 2009 at a tertiary care hospital in sabah, malaysia. fifty-six patients had pcr-confirmed p. knowlesi monoinfection and clinical records available for review. twe ... | 2011 | 21762579 |
| co-infections of plasmodium knowlesi, p. falciparum, and p. vivax among humans and anopheles dirus mosquitoes, southern vietnam. | a single anopheles dirus mosquito carrying sporozoites of plasmodium knowlesi, p. falciparum, and p. vivax was recently discovered in khanh phu, southern vietnam. further sampling of humans and mosquitoes in this area during 2009-2010 showed p. knowlesi infections in 32 (26%) persons with malaria (n = 125) and in 31 (43%) sporozoite-positive an. dirus mosquitoes (n = 73). co-infections of p. knowlesi and p. vivax were predominant in mosquitoes and humans, while single p. knowlesi infections were ... | 2011 | 21762577 |
| dimerization of plasmodium vivax dbp is induced upon receptor binding and drives recognition of darc. | plasmodium vivax and plasmodium knowlesi invasion depends on the parasite duffy-binding protein dbl domain (rii-pvdbp or rii-pkdbp) engaging the duffy antigen receptor for chemokines (darc) on red blood cells. inhibition of this key interaction provides an excellent opportunity for parasite control. there are competing models for whether plasmodium ligands engage receptors as monomers or dimers, a question whose resolution has profound implications for parasite biology and control. we report cry ... | 2011 | 21743458 |
| anti-inflammatory cytokines predominate in acute human plasmodium knowlesi infections. | plasmodium knowlesi has entered the human population of southeast asia. naturally acquired knowlesi malaria is newly described with relatively little available data, including data on the host response to infection. therefore pre-treatment cytokine and chemokine profiles were determined for 94 p. knowlesi, and for comparison, 20, p. vivax and 22 p. falciparum, patients recruited in malaysian borneo. nine, five and one patient with p. knowlesi, p. falciparum and p. vivax respectively had complica ... | 2011 | 21687657 |
| Plasmodium knowlesi Malaria in humans and macaques, Thailand. | Naturally acquired human infections with Plasmodium knowlesi are endemic to Southeast Asia. To determine the prevalence of P. knowlesi malaria in malaria-endemic areas of Thailand, we analyzed genetic characteristics of P. knowlesi circulating among naturally infected macaques and humans. This study in 2008-2009 and retrospective analysis of malaria species in human blood samples obtained in 1996 from 1 of these areas showed that P. knowlesi accounted for 0.67% and 0.48% of human malaria cases, ... | 2011 | 22000348 |
| Identification of Gene Encoding Plasmodium knowlesi Phosphatidylserine Decarboxylase by Genetic Complementation in Yeast and Characterization of in Vitro Maturation of Encoded Enzyme. | The 23-megabase genome of Plasmodium falciparum, the causative agent of severe human malaria, contains ~5300 genes, most of unknown function or lacking homologs in other organisms. Identification of these gene functions will help in the discovery of novel targets for the development of antimalarial drugs and vaccines. The P. falciparum genome is unusually A + T-rich, which hampers cloning and expressing these genes in heterologous systems for functional analysis. The large repertoire of genetic ... | 2012 | 22057268 |
| a review of parasitic zoonoses in a changing southeast asia. | parasitic zoonoses are common and widely distributed in the southeast asian region. however, the interactions between parasites, hosts and vectors are influenced by environmental, socio-cultural and livestock production changes that impact on the distribution, prevalence and severity of disease. in this review we provide an update on new knowledge in the context of ongoing changes for the food-borne pig associated zoonoses taenia solium and trichinella spp., the food-borne trematodes opisthorchi ... | 2011 | 21846580 |
| characterization and tissue-specific expression patterns of the plasmodium chabaudi cir multigene family. | variant antigens expressed on the surface of parasitized red blood cells (prbcs) are important virulence factors of malaria parasites. whereas plasmodium falciparum erythrocyte membrane proteins 1 (pfemp1) are responsible for sequestration of mature parasites, little is known about putative ligands mediating cytoadherence to host receptors in other plasmodium species. candidates include members of the pir superfamily found in the human parasite plasmodium vivax (vir), in the simian pathogen plas ... | 2011 | 21929749 |
| Plasmodium knowlesi: A Malaria Parasite of Monkeys and Humans (*). | Plasmodium knowlesi is a malaria parasite of monkeys of Southeast Asia that is transmitted by mosquitoes of the Anopheles leucosphyrus group. Humans are frequently infected with this parasite and misdiagnosed as being infected with Plasmodium malariae. The parasite was a major monkey animal model for developing antimalarial vaccines and investigations of the biology of parasite invasion. P. knowlesi is the first monkey malaria parasite genome to be sequenced and annotated. | 2012 | 22149265 |
| plasmodium knowlesi infection in humans, cambodia, 2007-2010. | two cases of plasmodium knowlesi infection in humans were identified in cambodia by 3 molecular detection assays and sequencing. this finding confirms the widespread distribution of p. knowlesi malaria in humans in southeast asia. further wide-scale studies are required to assess the public health relevance of this zoonotic malaria parasite. | 2011 | 22000366 |
| sequence analysis on the mitochondrial coxi gene of recent clinical isolates of plasmodium knowlesi in klang valley, peninsular malaysia. | the cytochrome oxidase subunit i (coxi) gene sequences of three recent (2007-2008) clinical plasmodium knowlesi isolates from klang valley, peninsular malaysia, were determined and compared with those of older (1960's) peninsular malaysia, recent isolates from sarawak (on borneo island), and an isolate from thailand. multiple alignment of the sequences showed that the three clinical isolates were more similar to the older peninsular malaysia isolates than to those from sarawak and thailand. phyl ... | 2011 | 22041769 |
| Species-Specific Features of DARC, the Primate Receptor for Plasmodium vivax and Plasmodium knowlesi. | The DARC (Duffy antigen/receptor for chemokines) gene, also called Duffy or FY, encodes a membrane-bound chemokine receptor. Two malaria parasites, Plasmodium vivax and Plasmodium knowlesi, use DARC to trigger internalization into red blood cells. Although much has been reported on the evolution of DARC null alleles, little is known about the evolution of the coding portion of this gene or the role that protein sequence divergence in this receptor may play in disease susceptibility or zoonosis. ... | 2011 | 21878684 |
| plasmodium knowlesi: an overlooked italian discovery? | | 2011 | 21890752 |
| plasmodium knowlesi malaria in malaysia. | plasmodium knowlesi, a simian malaria parasite, is now recognised as the fifth cause of human malaria and can lead to fatal infections in humans. knowlesi malaria cases are widely distributed in east and west malaysia and account for more than 50% of admissions for malaria in certain hospitals in the state of sarawak. this paper will begin with a description of the early studies on p. knowlesi, followed by a review of the epidemiology, diagnosis, clinical and laboratory features, and treatment o ... | 2010 | 21939162 |
| centenary celebrations article: plasmodium knowlesi: from macaque monkeys to humans in south-east asia and the risk of its spread in india. | the identification of a large focus of plasmodium knowlesi in malaysian borneo and subsequent reports from several countries in south-east asia has led its recognition as the fifth human malaria parasite. the natural preferred hosts of this species still continue to be macaque monkeys that live in broad-leaf rain forests. this review describes the distribution of macaque monkeys, the anopheles species belonging to the leucosphyrus group that have been incriminated as vectors, morphological and c ... | 2011 | 23024487 |
| genome comparison of human and non-human malaria parasites reveals species subset-specific genes potentially linked to human disease. | genes underlying important phenotypic differences between plasmodium species, the causative agents of malaria, are frequently found in only a subset of species and cluster at dynamically evolving subtelomeric regions of chromosomes. we hypothesized that chromosome-internal regions of plasmodium genomes harbour additional species subset-specific genes that underlie differences in human pathogenicity, human-to-human transmissibility, and human virulence. we combined sequence similarity searches wi ... | 2011 | 22215999 |
| duffy blood group system and the malaria adaptation process in humans. | malaria is an acute infectious disease caused by the protozoa of the genus plasmodium. the antigens of the duffy blood group system, in addition to incompatibilities in transfusions and hemolytic disease of the newborn, are of great interest in medicine due to their association with the invasion of red blood cells by the parasite plasmodium vivax. for invasions to occur an interaction between the parasites and antigens of the duffy blood group system is necessary. in caucasians six antigens are ... | 2011 | 23284245 |
| plasmodium knowlesi malaria: assessing the risk to the british armed forces. | plasmodium knowlesi is a zoonosis and is now recognised as the fifth commonly occurring form of human malaria. it is endemic in south east asia, including some areas previously declared malaria free or at low risk for malaria. the epidemiology of the disease is very different to other forms of malaria which are determined by transmission by anthrophilic mosquitoes from human reservoirs. in contrast plasmodium knowlesi malaria has a monkey reservoir and disease is transmitted to humans by mosquit ... | 2012 | 23402069 |
| [plasmodium knowlesi: an emerging species in humans?]. | plasmodium knowlesi is typically found in macaques and has recently been recognized as the fifth plasmodium species to cause malaria in humans. several cases of p. knowlesi malaria have been reported in people in southeast asia. most cases are simple but approximately one in 10 patients develops complications. the morphology of p. knowlesi parasites in human infections closely resembles that of plasmodium malariae or plasmodium falciparum, so a molecular method is the optimum diagnostic procedur ... | 2012 | 23353028 |
| the n-terminal segment of plasmodium falciparum surfin4.1 is required for its trafficking to the red blood cell cytosol through the endoplasmic reticulum. | plasmodium falciparum surfin is a type i transmembrane protein that shares domains with molecules expressed on the surface of the red blood cells (rbcs) infected with a variety of malaria parasite species, such as p. falciparum pfemp1, plasmodium vivax vir proteins, and plasmodium knowlesi sicavar. thus, understanding the export mechanism of surfin to the rbc may provide fundamental insights into how malaria parasites export their proteins to rbc cytosol in general. we re-evaluate surfin4.1 for ... | 2012 | 23287798 |
| adaptation of the genetically tractable malaria pathogen plasmodium knowlesi to continuous culture in human erythrocytes. | research into the aetiological agent of the most widespread form of severe malaria, plasmodium falciparum, has benefitted enormously from the ability to culture and genetically manipulate blood-stage forms of the parasite in vitro. however, most malaria outside africa is caused by a distinct plasmodium species, plasmodium vivax, and it has become increasingly apparent that zoonotic infection by the closely related simian parasite plasmodium knowlesi is a frequent cause of life-threatening malari ... | 2012 | 23267069 |
| identification of circulating biomarkers in sera of plasmodium knowlesi-infected malaria patients--comparison against plasmodium vivax infection. | plasmodium knowlesi was identified as the fifth major malaria parasite in humans. it presents severe clinical symptoms and leads to mortality as a result of hyperparasitemia in a short period of time. this study aimed to improve the current understanding of p. knowlesi and identify potential biomarkers for knowlesi malaria. | 2015 | 25656928 |
| deaths due to plasmodium knowlesi malaria in sabah, malaysia: association with reporting as plasmodium malariae and delayed parenteral artesunate. | the simian parasite plasmodium knowlesi is recognized as a common cause of severe and fatal human malaria in sabah, malaysia, but is morphologically indistinguishable from and still commonly reported as plasmodium malariae, despite the paucity of this species in sabah. since december 2008 sabah department of health has recommended intravenous artesunate and referral to a general hospital for all severe malaria cases of any species. this paper reviews all malaria deaths in sabah subsequent to the ... | 2012 | 22905799 |
| neglected tropical diseases among the association of southeast asian nations (asean): overview and update. | the ten member states of the association of southeast asian nations (asean) constitute an economic powerhouse, yet these countries also harbor a mostly hidden burden of poverty and neglected tropical diseases (ntds). almost 200 million people live in extreme poverty in asean countries, mostly in the low or lower middle-income countries of indonesia, the philippines, myanmar, viet nam, and cambodia, and many of them are affected by at least one ntd. however, ntds are prevalent even among upper mi ... | 2015 | 25880767 |
| immunogenicity of bacterial-expressed recombinant plasmodium knowlesi merozoite surface protein-142 (msp-142). | plasmodium knowlesi is the fifth plasmodium species that can infect humans. the plasmodium merozoite surface protein-1(42) (msp-1(42)) is a potential candidate for malaria vaccine. however, limited studies have focused on p. knowlesi msp-1(42). | 2013 | 24354660 |
| estimating geographical variation in the risk of zoonotic plasmodium knowlesi infection in countries eliminating malaria. | infection by the simian malaria parasite, plasmodium knowlesi, can lead to severe and fatal disease in humans, and is the most common cause of malaria in parts of malaysia. despite being a serious public health concern, the geographical distribution of p. knowlesi malaria risk is poorly understood because the parasite is often misidentified as one of the human malarias. human cases have been confirmed in at least nine southeast asian countries, many of which are making progress towards eliminati ... | 2016 | 27494405 |
| vertical stratification of adult mosquitoes (diptera: culicidae) within a tropical rainforest in sabah, malaysia. | malaria cases caused by plasmodium knowlesi, a simian parasite naturally found in long-tailed and pig-tailed macaques, are increasing rapidly in sabah, malaysia. one hypothesis is that this increase is associated with changes in land use. a study was carried out to identify the anopheline vectors present in different forest types and to observe the human landing behaviour of mosquitoes. | 2016 | 27430261 |
| transmission and control of plasmodium knowlesi: a mathematical modelling study. | plasmodium knowlesi is now recognised as a leading cause of malaria in malaysia. as humans come into increasing contact with the reservoir host (long-tailed macaques) as a consequence of deforestation, assessing the potential for a shift from zoonotic to sustained p. knowlesi transmission between humans is critical. | 2014 | 25058400 |
| plasmodium knowlesi malaria an emerging public health problem in hulu selangor, selangor, malaysia (2009-2013): epidemiologic and entomologic analysis. | while transmission of the human plasmodium species has declined, a significant increase in plasmodium knowlesi/plasmodium malariae cases was reported in hulu selangor, selangor, malaysia. thus, a study was undertaken to determine the epidemiology and the vectors involved in the transmission of knowlesi malaria. | 2014 | 25223878 |
| genetic diversity and natural selection of the plasmodium knowlesi circumsporozoite protein nonrepeat regions. | plasmodium knowlesi is a simian malaria parasite that has been identified to cause malaria in humans. to date, several thousand cases of human knowlesi malaria have been reported around southeast asia. thus far, there is no detailed study on genetic diversity and natural selection of p. knowlesi circumsporozoite protein (csp), a prominent surface antigen on the sporozoite of the parasite. in the present study, the genetic diversity and natural selection acting on the nonrepeat regions of the gen ... | 2015 | 26379157 |
| severe plasmodium knowlesi infection with multi-organ failure imported to germany from thailand/myanmar. | during the last two decades human infections with plasmodium knowlesi are increasingly diagnosed in south east asia and have also been reported in travellers. a severe case of imported p. knowlesi infection in a 73-year old german is presented, who had been travelling through myanmar and thailand for three weeks. microscopy showed a parasitaemia of 3% and different parasite stages including band-forms resembling plasmodium malariae. due to the clinical picture of severe malaria and the microscop ... | 2014 | 25367021 |
| zoonotic malaria - global overview and research and policy needs. | the four main plasmodium species that cause human malaria, plasmodium falciparum, plasmodium vivax, plasmodium malariae, and plasmodium ovale, are transmitted between humans by mosquito vectors belonging to the genus anopheles. it has recently become evident that plasmodium knowlesi, a parasite that typically infects forest macaque monkeys, can be transmitted by anophelines to cause malaria in humans in southeast asia. plasmodium knowlesi infections are frequently misdiagnosed microscopically as ... | 2014 | 25184118 |
| high proportion of knowlesi malaria in recent malaria cases in malaysia. | plasmodium knowlesi is a simian parasite that has been recognized as the fifth species causing human malaria. naturally-acquired p. knowlesi infection is widespread among human populations in southeast asia. the aim of this epidemiological study was to determine the incidence and distribution of malaria parasites, with a particular focus on human p. knowlesi infection in malaysia. | 2014 | 24886266 |
| human red blood cell-adapted plasmodium knowlesi parasites: a new model system for malaria research. | plasmodium knowlesi is a simian malaria parasite primarily infecting macaque species in southeast asia. although its capacity to infect humans has been recognized since the early part of the last century, it has recently become evident that human infections are widespread and potentially life threatening. historically, p. knowlesi has proven to be a powerful tool in early studies of malaria parasites, providing key breakthroughs in understanding many aspects of plasmodium biology. however, the ... | 2014 | 24506567 |
| first case of a naturally acquired human infection with plasmodium cynomolgi. | since 1960, a total of seven species of monkey malaria have been reported as transmissible to man by mosquito bite: plasmodium cynomolgi, plasmodium brasilianum, plasmodium eylesi, plasmodium knowlesi, plasmodium inui, plasmodium schwetzi and plasmodium simium. with the exception of p. knowlesi, none of the other species has been found to infect humans in nature. in this report, it is described the first known case of a naturally acquired p. cynomolgi malaria in humans.the patient was a 39-year- ... | 2014 | 24564912 |
| recent advances in the management of plasmodium knowlesi infection. | plasmodium knowlesi (p. knowlesi) has been detected to be the fifth malarial parasite that can cause malaria in human beings. the parasite is known to commonly infect macaque monkeys. the infection is highly prevalent in south-east asia. it has morphologic similarities to plasmodium malariae and plasmodium falciparum. p. knowlesi is known to replicate every 24 h in the human host and hence, causes "quotidian malaria." it causes a wide spectrum of clinical manifestations and sometimes can cause f ... | 0 | 24754024 |
| colonization of anopheles cracens: a malaria vector of emerging importance. | anopheles cracens has been incriminated as a vector for the simian malaria parasite, plasmodium knowlesi, that is the fifth plasmodium species infecting humans. little experimental data exists on this mosquito species due to the lack of its availability in laboratories. | 2013 | 23537404 |
| entomologic investigation of plasmodium knowlesi vectors in kuala lipis, pahang, malaysia. | the first natural infection of plasmodium knowlesi in humans was recorded in 1965 in peninsular malaysia. extensive research was then conducted and it was postulated that it was a rare incident and that simian malaria will not be easily transmitted to humans. however, at the turn of the 21st century, knowlesi malaria was prevalent throughout southeast asia and is life threatening. thus, a longitudinal study was initiated to determine the vectors, their seasonal variation and preference to humans ... | 2012 | 22727041 |
| using infective mosquitoes to challenge monkeys with plasmodium knowlesi in malaria vaccine studies. | when rhesus monkeys (macaca mulatta) are used to test malaria vaccines, animals are often challenged by the intravenous injection of sporozoites. however, natural exposure to malaria comes via mosquito bite, and antibodies can neutralize sporozoites as they traverse the skin. thus, intravenous injection may not fairly assess humoral immunity from anti-sporozoite malaria vaccines. to better assess malaria vaccines in rhesus, a method to challenge large numbers of monkeys by mosquito bite was deve ... | 2014 | 24893777 |
| the plasmodium class xiv myosin, myob, has a distinct subcellular location in invasive and motile stages of the malaria parasite and an unusual light chain. | myosin b (myob) is one of the two short class xiv myosins encoded in the plasmodium genome. class xiv myosins are characterized by a catalytic "head," a modified "neck," and the absence of a "tail" region. myosin a (myoa), the other class xiv myosin in plasmodium, has been established as a component of the glideosome complex important in motility and cell invasion, but myob is not well characterized. we analyzed the properties of myob using three parasite species as follows: plasmodium falciparu ... | 2015 | 25802338 |
| increased detection of plasmodium knowlesi in sandakan division, sabah as revealed by plasmonex™. | plasmodium knowlesi is a simian malaria parasite that is widespread in humans in malaysian borneo. however, little is known about the incidence and distribution of this parasite in the sandakan division, malaysian borneo. therefore, the aim of the present epidemiological study was to investigate the incidence and distribution of p. knowlesi as well as other plasmodium species in this division based on a most recent developed hexaplex pcr system (plasmonex™). | 2013 | 23902626 |
| malaria risk factor assessment using active and passive surveillance data from aceh besar, indonesia, a low endemic, malaria elimination setting with plasmodium knowlesi, plasmodium vivax, and plasmodium falciparum. | as malaria transmission declines, it becomes more geographically focused and more likely due to asymptomatic and non-falciparum infections. to inform malaria elimination planning in the context of this changing epidemiology, local assessments on the risk factors for malaria infection are necessary, yet challenging due to the low number of malaria cases. | 2016 | 27619000 |
| association between landscape factors and spatial patterns of plasmodium knowlesi infections in sabah, malaysia. | the zoonotic malaria species plasmodium knowlesi has become the main cause of human malaria in malaysian borneo. deforestation and associated environmental and population changes have been hypothesized as main drivers of this apparent emergence. we gathered village-level data for p. knowlesi incidence for the districts of kudat and kota marudu in sabah state, malaysia, for 2008-2012. we adjusted malaria records from routine reporting systems to reflect the diagnostic uncertainty of microscopy fo ... | 0 | 26812373 |
| seasonal and spatial dynamics of the primary vector of plasmodium knowlesi within a major transmission focus in sabah, malaysia. | the simian malaria parasite plasmodium knowlesi is emerging as a public health problem in southeast asia, particularly in malaysian borneo where it now accounts for the greatest burden of malaria cases and deaths. control is hindered by limited understanding of the ecology of potential vector species. | 2015 | 26448052 |
| population genomic structure and adaptation in the zoonotic malaria parasite plasmodium knowlesi. | malaria cases caused by the zoonotic parasite plasmodium knowlesi are being increasingly reported throughout southeast asia and in travelers returning from the region. to test for evidence of signatures of selection or unusual population structure in this parasite, we surveyed genome sequence diversity in 48 clinical isolates recently sampled from malaysian borneo and in five lines maintained in laboratory rhesus macaques after isolation in the 1960s from peninsular malaysia and the philippines. ... | 2015 | 26438871 |
| humans frequently exposed to a range of non-human primate malaria parasite species through the bites of anopheles dirus mosquitoes in south-central vietnam. | recent studies have described natural human infections of the non-human primate parasites plasmodium knowlesi and plasmodium cynomolgi. in southeast asia, mosquitoes of the anopheles leucosphyrus group bite both humans and monkeys in the forest and thus offer a possible route for plasmodium species to bridge the species barrier. in this study we analysed the species composition of malarial sporozoites infecting the salivary glands of anopheles dirus in order to determine their potential role as ... | 2015 | 26178324 |