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The American Journal of Tropical... Dec 2020Although continues to be the main target for malaria elimination, other species persist in Africa. Their clinical diagnosis is uncommon, whereas rapid diagnostic tests...
Although continues to be the main target for malaria elimination, other species persist in Africa. Their clinical diagnosis is uncommon, whereas rapid diagnostic tests (RDTs), the most widely used malaria diagnostic tools, are only able to distinguish between and non- species, the latter as "pan-species." Blood samples from health facilities were collected in southern Nigeria (Lagos and Calabar) in 2017 (October-December) and Calabar only in 2018 (October-November), and analyzed by several methods, namely, microscopy, quantitative real-time PCR (qPCR), and peptide serology targeting candidate antigens ( apical membrane antigen, . lactose dehydrogenase, and . circumsporozoite surface protein). Both microscopy and qPCR diagnostic approaches detected comparable proportions (∼80%) of all RDT-positive samples infected with the dominant malaria parasite. However, higher proportions of non- species were detected by qPCR than microscopy, 10% against 3% infections for and 3% against 0% for , respectively. No infection was detected. Infection rates for varied between age-groups, with the highest rates in individuals aged > 5 years. -specific seroprevalence rates fluctuated in those aged < 10 years but generally reached the peak around 20 years of age for all peptides. The heterogeneity and rates of these non-falciparum species call for increased specific diagnosis and targeting by elimination strategies.
Topics: Adolescent; Antigens, Protozoan; Child; Child, Preschool; Diagnostic Tests, Routine; Female; Humans; Infant; Malaria; Male; Microscopy; Nigeria; Plasmodium; Plasmodium malariae; Plasmodium ovale; Plasmodium vivax; Protozoan Proteins; Real-Time Polymerase Chain Reaction; Seroepidemiologic Studies; Surveys and Questionnaires
PubMed: 33124531
DOI: 10.4269/ajtmh.20-0593 -
The Lancet. Microbe Aug 2022High-quality evidence for the therapeutic efficacy and effectiveness of antimalarials for infections caused by Plasmodium malariae, Plasmodium ovale spp, and...
Effectiveness of pyronaridine-artesunate against Plasmodium malariae, Plasmodium ovale spp, and mixed-Plasmodium infections: a post-hoc analysis of the CANTAM-Pyramax trial.
BACKGROUND
High-quality evidence for the therapeutic efficacy and effectiveness of antimalarials for infections caused by Plasmodium malariae, Plasmodium ovale spp, and mixed-Plasmodium infections is scarce. In this study, we aimed to analyse the efficacy of pyronaridine-artesunate for the treatment of non-falciparum and mixed-species Plasmodium infections from a large phase 3b/4 clinical trial in central Africa.
METHODS
This post-hoc analysis was done in a random subset of samples from two sites (in the Democratic Republic of the Congo and in Gabon) of the CANTAM-Pyramax trial assessing pyronaridine-artesunate therapy. We randomly selected paired dried blood spot samples from day 0 and day 28 (or unforeseen visit) and analysed them by quantitative PCR for mixed Plasmodium infections or non-falciparum mono-infections. Day 28 (or unforeseen visit) samples positive for non-falciparum malaria were re-assessed by microscopy to identify microscopic versus submicroscopic infections. Analyses were done on two sample sets: a per-protocol set and an intention-to-treat set.
FINDINGS
Among 1502 randomly selected samples, 192 (12·8%) showed mixed-Plasmodium infections or non-falciparum mono-infections. We did not detect P vivax in the samples. For both the per-protocol and intention-to-treat sets, the overall day 28 cure rates for P malariae, P ovale curtisi, and P ovale wallikeri were 96·3% or higher (95% CIs from 81·0-99·9 to 95·7-100). Cure rates were consistently high in P malariae (99·2%, 95·7-100) and P ovale spp (97·9%, 88·7-99·9, for P ovale curtisi and 96·3%, 81·0-99·9, for P ovale wallikeri) infections.
INTERPRETATION
This post-hoc analysis provides important evidence supporting the high efficacy of pyronaridine-artesunate against mono-infections with P malariae, P ovale curtisi, or P ovale wallikeri and mixed-Plasmodium infections in a real-world setting.
FUNDING
Medicines for Malaria Venture.
Topics: Artesunate; Drug Combinations; Humans; Malaria; Naphthyridines; Plasmodium malariae; Plasmodium ovale
PubMed: 35654079
DOI: 10.1016/S2666-5247(22)00092-1 -
Scientific Reports Dec 2022Plasmodium malariae, a neglected human malaria parasite, contributes up to 10% of malaria infections in sub-Saharan Africa (sSA). Though P. malariae infection is...
Plasmodium malariae structure and genetic diversity in sub-Saharan Africa determined from microsatellite variants and linked SNPs in orthologues of antimalarial resistance genes.
Plasmodium malariae, a neglected human malaria parasite, contributes up to 10% of malaria infections in sub-Saharan Africa (sSA). Though P. malariae infection is considered clinically benign, it presents mostly as coinfections with the dominant P. falciparum. Completion of its reference genome has paved the way to further understand its biology and interactions with the human host, including responses to antimalarial interventions. We characterized 75 P. malariae isolates from seven endemic countries in sSA using highly divergent microsatellites. The P. malariae infections were highly diverse and five subpopulations from three ancestries (independent of origin of isolates) were determined. Sequences of 11 orthologous antimalarial resistance genes, identified low frequency single nucleotide polymorphisms (SNPs), strong linkage disequilibrium between loci that may be due to antimalarial drug selection. At least three sub-populations were detectable from a subset of denoised SNP data from mostly the mitochondrial cytochrome b coding region. This evidence of diversity and selection calls for including P. malariae in malaria genomic surveillance towards improved tools and strategies for malaria elimination.
Topics: Humans; Africa South of the Sahara; Antimalarials; Malaria; Microsatellite Repeats; Plasmodium malariae; Polymorphism, Single Nucleotide; Drug Resistance
PubMed: 36536036
DOI: 10.1038/s41598-022-26625-w -
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 -
The Journal of Molecular Diagnostics :... Oct 2021Plasmodium malariae and Plasmodium ovale are increasingly gaining public health attention as the global transmission of falciparum malaria is decreasing. However, the...
Plasmodium malariae and Plasmodium ovale are increasingly gaining public health attention as the global transmission of falciparum malaria is decreasing. However, the absence of reliable Plasmodium species-specific detection tools has hampered accurate diagnosis of these minor Plasmodium species. In this study, SYBR Green-based real-time PCR assays were developed for the detection of P. malariae and P. ovale using cooperative primers that significantly limit the formation and propagation of primers-dimers. Both the P. malariae and P. ovale cooperative primer-based assays had at least 10-fold lower detection limit compared with the corresponding conventional primer-based assays. More important, the cooperative primer-based assays were evaluated in a cross-sectional study using 560 samples obtained from two health facilities in Ghana. The prevalence rates of P. malariae and P. ovale among the combined study population were 18.6% (104/560) and 5.5% (31/560), respectively. Among the Plasmodium-positive cases, P. malariae and P. ovale mono-infections were 3.6% (18/499) and 1.0% (5/499), respectively, with the remaining being co-infections with Plasmodium falciparum. The study demonstrates the public health importance of including detection tools with lower detection limits in routine diagnosis and surveillance of nonfalciparum species. This will be necessary for comprehensively assessing the effectiveness of malaria interventions and control measures aimed toward global malaria elimination.
Topics: Adolescent; Adult; Child; Child, Preschool; Coinfection; Cross-Sectional Studies; DNA Primers; Female; Ghana; Humans; Limit of Detection; Malaria, Falciparum; Male; Plasmodium falciparum; Plasmodium malariae; Plasmodium ovale; Prevalence; RNA, Ribosomal, 18S; Real-Time Polymerase Chain Reaction; Young Adult
PubMed: 34425259
DOI: 10.1016/j.jmoldx.2021.07.022 -
PLoS Neglected Tropical Diseases May 2019A reduction in the global burden of malaria over the past two decades has encouraged efforts for regional malaria elimination. Despite the need to target all Plasmodium...
A reduction in the global burden of malaria over the past two decades has encouraged efforts for regional malaria elimination. Despite the need to target all Plasmodium species, current focus is mainly directed towards Plasmodium falciparum, and to a lesser extent P. vivax. There is a substantial lack of data on both global and local transmission patterns of the neglected malaria parasites P. malariae and P. ovale spp. We used a species-specific real-time PCR assay targeting the Plasmodium 18s rRNA gene to evaluate temporal trends in the prevalence of all human malaria parasites over a 22-year period in a rural village in Tanzania.We tested 2897 blood samples collected in five cross-sectional surveys conducted between 1994 and 2016. Infections with P. falciparum, P. malariae, and P. ovale spp. were detected throughout the study period, while P. vivax was not detected. Between 1994 and 2010, we found a more than 90% reduction in the odds of infection with all detected species. The odds of P. falciparum infection was further reduced in 2016, while the odds of P. malariae and P. ovale spp. infection increased 2- and 6-fold, respectively, compared to 2010. In 2016, non-falciparum species occurred more often as mono-infections. The results demonstrate the persistent transmission of P. ovale spp., and to a lesser extent P. malariae despite a continued decline in P. falciparum transmission. This illustrates that the transmission patterns of the non-falciparum species do not necessarily follow those of P. falciparum, stressing the need for attention towards non-falciparum malaria in Africa. Malaria elimination will require a better understanding of the epidemiology of P. malariae and P. ovale spp. and improved tools for monitoring the transmission of all Plasmodium species, with a particular focus towards identifying asymptomatic carriers of infection and designing appropriate interventions to enhance malaria control.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; DNA, Protozoan; Female; Humans; Infant; Malaria; Male; Middle Aged; Plasmodium falciparum; Plasmodium malariae; Plasmodium ovale; Prevalence; RNA, Ribosomal, 18S; Real-Time Polymerase Chain Reaction; Tanzania; Young Adult
PubMed: 31136585
DOI: 10.1371/journal.pntd.0007414 -
Clinical Microbiology and Infection :... May 2013Malaria rapid diagnostic tests (RDTs) are instrument-free tests that provide results within 20 min and can be used by community health workers. RDTs detect antigens... (Review)
Review
Malaria rapid diagnostic tests (RDTs) are instrument-free tests that provide results within 20 min and can be used by community health workers. RDTs detect antigens produced by the Plasmodium parasite such as Plasmodium falciparum histidine-rich protein-2 (PfHPR2) and Plasmodium lactate dehydrogenase (pLDH). The accuracy of RDTs for the diagnosis of uncomplicated P. falciparum infection is equal or superior to routine microscopy (but inferior to expert microscopy). Sensitivity for Plasmodium vivax is 75-100%; for Plasmodium ovale and Plasmodium malariae, diagnostic performance is poor. Design limitations of RDTs include poor sensitivity at low parasite densities, susceptibility to the prozone effect (PfHRP2-detecting RDTs), false-negative results due to PfHRP2 deficiency in the case of pfhrp2 gene deletions (PfHRP2-detecting RDTs), cross-reactions between Plasmodium antigens and detection antibodies, false-positive results by other infections and susceptibility to heat and humidity. End-user's errors relate to safety, procedure (delayed reading, incorrect sample and buffer volumes) and interpretation (not recognizing invalid test results, disregarding faint test lines). Withholding antimalarial treatment in the case of negative RDT results tends to be infrequent and tendencies towards over-prescription of antibiotics have been noted. Numerous shortcomings in RDT kits' labelling, instructions for use (correctness and readability) and contents have been observed. The World Health Organization and partners actively address quality assurance of RDTs by comparative testing of RDTs, inspections of manufacturing sites, lot testing and training tools but no formal external quality assessment programme of end-user performance exists. Elimination of malaria requires RDTs with lower detection limits, for which nucleic acid amplification tests are under development.
Topics: Antigens, Protozoan; Cross Reactions; Diagnostic Tests, Routine; Endemic Diseases; False Negative Reactions; Humans; Malaria; Sensitivity and Specificity
PubMed: 23438048
DOI: 10.1111/1469-0691.12151 -
Tropical Parasitology 2020Malaria, a mosquito-transmitted parasitic disease, has been targeted for elimination in many parts of the world. For many years, and have been known to cause malaria... (Review)
Review
Malaria, a mosquito-transmitted parasitic disease, has been targeted for elimination in many parts of the world. For many years, and have been known to cause malaria in humans. Now, is considered to be an important cause of malaria, especially in Southeast Asia. The emergence of zoonotic implication is a challenge in the elimination efforts of malaria in Southeast Asia. is known to cause severe complicated malaria in humans. parasite is transmitted between humans and wild macaque through mosquito vectors. It appears that the malaria disease severity and host immune evasion depend on antigenic variation exhibited at the surface of the infected erythrocyte. is sensitive to antimalarial drug artemisinin. Identification of vector species, their biting behavior, timely correct diagnosis, and treatment are important steps in disease management and control. There is a need to identify and implement effective intervention measures to cut the chain of transmissions from animals to humans. The zoonotic malaria definitely poses a significant challenge in elimination and subsequent eradication of all types of malaria from this globe.
PubMed: 32775284
DOI: 10.4103/tp.TP_17_18 -
Iranian Journal of Parasitology 2016Malaria is the most important transfusion-transmitted infection (TTI) in worldwide after viral hepatitis and human immunodeficiency virus (HIV) infection. The main... (Review)
Review
BACKGROUND
Malaria is the most important transfusion-transmitted infection (TTI) in worldwide after viral hepatitis and human immunodeficiency virus (HIV) infection. The main objective of the present study was to review and evaluate the transmission of malaria via blood transfusion in Iran.
METHODS
A literature search was done without time limitation in the electronic databases as follows: PubMed, Scopus, Google Scholar, Web of Science, Science Direct, scientific information database (SID), Magiran, IranMedex and Irandoc. The searches were limited to the published papers to English and Persian languages.
RESULTS
Six papers were eligible. From 1963 to 1983, 344 cases of Transfusion-transmitted malaria (TTM) had been reported from different provinces of Iran. The most prevalent species of involved in investigated cases of TTM was (79.24%). The screening results of 1,135 blood donors for malaria were negative by microscopic examination of peripheral blood smears and rapid diagnostic test (RDT) methods.
CONCLUSION
Lack of TTM report from Iran in the last three decades indicates that the screening of blood donors through interviewing (donor selection) may be effective in the prevention of the occurrence of transfusion-transmitted malaria.
PubMed: 28096847
DOI: No ID Found -
Parasites & Vectors Jun 2021Recent studies indicate that the prevalence of non-falciparum malaria, including Plasmodium malariae and Plasmodium ovale spp., is increasing, with some complications in... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Recent studies indicate that the prevalence of non-falciparum malaria, including Plasmodium malariae and Plasmodium ovale spp., is increasing, with some complications in infected individuals. The aim of this review is to provide a better understanding of the malaria prevalence and disease burden due to P. malariae and P. ovale spp.
METHODS
The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Joanna Briggs Institute prevalence study assessment tool were used to select and evaluate the studies, respectively. Six databases: PubMed, WHOLIS, Wiley Library, ScienceDirect, Web of Science and Google Scholar were used to screen articles published during the period January 2000-December 2020. The pooled prevalence estimates for P. malariae and P. ovale spp. were analysed using a random-effects model and the possible sources of heterogeneity were evaluated through subgroup analysis and meta-regression.
RESULTS
Out of the 3297 studies screened, only 113 studies were included; among which 51.33% were from the African Region. The P. malariae and P. ovale spp. pooled prevalence were 2.01% (95% CI 1.31-2.85%) and 0.77% (95% CI 0.50-1.10%) respectively, with the highest prevalence in the African Region. P. malariae was equally distributed among adults (2.13%), children (2.90%) and pregnant women (2.77%) (p = 0.862), whereas P. ovale spp. was more prevalent in pregnant women (2.90%) than in children ≤ 15 years (0.97%) and in patients > 15 years old (0.39%) (p = 0.021). In this review, data analysis revealed that P. malariae and P. ovale spp. have decreased in the last 20 years, but not significantly, and these species were more commonly present with other Plasmodium species as co-infections. No difference in prevalence between symptomatic and asymptomatic patients was observed for either P. malariae or P. ovale spp.
CONCLUSION
Our analysis suggests that knowledge of the worldwide burden of P. malariae and P. ovale spp. is very important for malaria elimination programmes and a particular focus towards improved tools for monitoring transmission for these non-falciparum species should be stressed upon to deal with increased infections in the future.
Topics: Coinfection; Global Health; Humans; Malaria; Plasmodium falciparum; Plasmodium malariae; Plasmodium ovale; Prevalence; Time Factors
PubMed: 34082791
DOI: 10.1186/s13071-021-04797-0