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The East African Health Research Journal 2020Burundi is cited among countries where malaria remains endemic. Notably, malaria is highly endemic in Imbo region, a lowland lying astride Lake Tanganyika. Among key...
BACKGROUND
Burundi is cited among countries where malaria remains endemic. Notably, malaria is highly endemic in Imbo region, a lowland lying astride Lake Tanganyika. Among key malaria riposte interventions includes the promotion of Long-Lasting Insecticidal Nets (LLINs), but its incidence rate has not reduced. In this paper, we present the distribution of malaria species in 2 settings within Imbo region by accounting for the seasonal variations and the mostly infected populations.
METHODS
The study was conducted from 2 Health Care Centres of Murambi and Rugombo in Cibitoke District, Northern Burundi. Blood samples were collected on blood slides and the samples were used to confirm the presence of malaria parasites by microscopy.
RESULTS
The study observed an average malaria parasite prevalence of 32.5% across the selected site. Majority of patients 459(95.2%) were infected by P. falciparum while 8(1.7%) patients were infected by P. malariae. Patients from Murambi were more infected than those from Rugombo. P. falciparum was the most highly prevalent specie in the 2 localities. High prevalence was observed in children aged between 2 and 5 years. Among older participants P. falciparum still predominated and mixed infections were rather the least prevalent.
CONCLUSION
This study showed that P. falciparum and P. malariae are the most parasites involved in malaria morbidity in North Imbo region. The transmission of P. falciparum was observed year-round. Patients in Murambi are most exposed to malaria infections than those in Rugombo. Further research at large scale including entomological studies is required to better understand the relationship between Entomological Inoculation Rates (EIR) and malaria transmission levels in this setting.
PubMed: 34308237
DOI: 10.24248/eahrj.v4i2.643 -
Malaria Journal Dec 2020While the World Health Organization (WHO) Southeast Asia region has the second highest incidence of malaria worldwide, malaria in Vietnam is focal to few provinces,...
BACKGROUND
While the World Health Organization (WHO) Southeast Asia region has the second highest incidence of malaria worldwide, malaria in Vietnam is focal to few provinces, where delayed parasite clearance to anti-malarial drugs is documented. This study aims to understand Plasmodium species distribution and the genetic diversity of msp1 and msp2 of parasite populations using molecular tools.
METHODS
A total of 222 clinical isolates from individuals with uncomplicated malaria were subjected to Plasmodium species identification by nested real-time PCR. 166 isolates positive for Plasmodium falciparum mono infections were further genotyped for msp1 (MAD20, K1, and RO33), and msp2 allelic families (3D7 and FC27). Amplicons were resolved through capillary electrophoresis in the QIAxcel Advanced system.
RESULTS
Mono-infections were high and with 75% P. falciparum, 14% Plasmodium vivax and 9% P. falciparum/P. vivax co-infections, with less than 1% Plasmodium malariae identified. For msp1, MAD20 was the most prevalent (99%), followed by K1 (46%) allelic family, with no sample testing positive for RO33 (0%). For msp2, 3D7 allelic family was predominant (97%), followed by FC27 (10%). The multiplicity of infection of msp1 and msp2 was 2.6 and 1.1, respectively, and the mean overall multiplicity of infection was 3.7, with the total number of alleles ranging from 1 to 7.
CONCLUSIONS
Given the increasing importance of antimalarial drugs in the region, the genetic diversity of P. falciparum msp1 and msp2 should be regularly monitored with respect to treatment outcomes and/or efficacy studies in regions, where there are ongoing changes in the malaria epidemiology.
Topics: Antigens, Protozoan; Coinfection; Genetic Variation; Genotype; Malaria; Malaria, Falciparum; Malaria, Vivax; Merozoite Surface Protein 1; Plasmodium falciparum; Plasmodium malariae; Plasmodium vivax; Protozoan Proteins; Vietnam
PubMed: 33384023
DOI: 10.1186/s12936-020-03561-6 -
Protein Science : a Publication of the... Sep 2021Malaria is a parasitic illness caused by the genus Plasmodium from the apicomplexan phylum. Five plasmodial species of P. falciparum (Pf), P. knowlesi, P. malariae, P.... (Review)
Review
Malaria is a parasitic illness caused by the genus Plasmodium from the apicomplexan phylum. Five plasmodial species of P. falciparum (Pf), P. knowlesi, P. malariae, P. ovale, and P. vivax (Pv) are responsible for causing malaria in humans. According to the World Malaria Report 2020, there were 229 million cases and ~ 0.04 million deaths of which 67% were in children below 5 years of age. While more than 3 billion people are at risk of malaria infection globally, antimalarial drugs are their only option for treatment. Antimalarial drug resistance keeps arising periodically and thus threatens the main line of malaria treatment, emphasizing the need to find new alternatives. The availability of whole genomes of P. falciparum and P. vivax has allowed targeting their unexplored plasmodial enzymes for inhibitor development with a focus on multistage targets that are crucial for parasite viability in both the blood and liver stages. Over the past decades, aminoacyl-tRNA synthetases (aaRSs) have been explored as anti-bacterial and anti-fungal drug targets, and more recently (since 2009) aaRSs are also the focus of antimalarial drug targeting. Here, we dissect the structure-based knowledge of the most advanced three aaRSs-lysyl- (KRS), prolyl- (PRS), and phenylalanyl- (FRS) synthetases in terms of development of antimalarial drugs. These examples showcase the promising potential of this family of enzymes to provide druggable targets that stall protein synthesis upon inhibition and thereby kill malaria parasites selectively.
Topics: Amino Acyl-tRNA Synthetases; Antimalarials; Catalytic Domain; Drug Discovery; Enzyme Inhibitors; Gene Expression; Humans; Lysine-tRNA Ligase; Malaria, Falciparum; Models, Molecular; Phenylalanine-tRNA Ligase; Plasmodium falciparum; Protein Binding; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand; Protein Interaction Domains and Motifs; Protozoan Proteins; Small Molecule Libraries
PubMed: 34184352
DOI: 10.1002/pro.4148 -
Malaria Journal Oct 2020Suriname has accomplished a steep decline in malaria burden, even reaching elimination levels. Plasmodium serology data are not available for Suriname and even extremely...
Malaria serology data from the Guiana shield: first insight in IgG antibody responses to Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae antigens in Suriname.
BACKGROUND
Suriname has accomplished a steep decline in malaria burden, even reaching elimination levels. Plasmodium serology data are not available for Suriname and even extremely scarce within the region, therefore malaria serology testing was introduced, country customized cut-off values were determined and a study was performed to explore the antibody status for Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae.
METHODS
A cross-sectional survey was conducted between July 2017 and March 2018 in two areas of the interior with different malaria settings: Stoelmanseiland, representing Maroon villages and Benzdorp, a gold mining area, with mostly Brazilian miners. Dried blood spots (DBS) were collected (n = 197) and antibody presence against seven Plasmodium antigens was detected using a multiplex bead-based, IgG antibody assay. Demographic information was gathered through a questionnaire. Country customized cut-off values were generated from a Surinamese malaria-naïve reference population (n = 50).
RESULTS
Serological analysis for the reference population revealed cut-off values ranging from 14 MFI for LSA-1 to 177 MFI for PmMSP-1. Seroprevalence against any of the three MSP-1 antibodies was similar in both regions and surpassed 75%. Single seropositivity against PfMSP-1 antibodies was higher in Stoelmanseiland (27.0%) than Benzdorp (9.3%), in line with the historical malaria burden of Stoelmanseiland, while the reverse was observed for PvMSP-1 antibodies. Despite sporadic reports of P. malariae infections, PmMSP-1 antibody presence was 39.6%. A more detailed examination of P. falciparum serology data displayed a higher seroprevalence in villagers (90.7%) than in Brazilians (64.6%) and a highly diverse antigenic response with 22 distinct antibody combinations.
CONCLUSIONS
The results on the malaria antibody signature of Maroon villagers and Brazilian miners living in Suriname displayed a high Plasmodium seroprevalence, especially for P. falciparum in villagers, still reflecting the historical malaria burden. The seroprevalence data for both regions and the observed combinations of P. falciparum antibodies provided a valuable dataset from a historically important region to the international malaria serology knowledge. First insight in malaria serology data for Suriname indicated that the use of other target groups and assessment of age-dependent seroprevalence are required to successfully use malaria serology as tool in the national elimination strategy.
Topics: Adult; Aged; Antibodies, Protozoan; Antigens, Protozoan; Brazil; Cross-Sectional Studies; Female; Humans; Immunoglobulin G; Malaria; Malaria, Falciparum; Malaria, Vivax; Male; Merozoite Surface Protein 1; Middle Aged; Mining; Plasmodium falciparum; Plasmodium malariae; Plasmodium vivax; Prevalence; Seroepidemiologic Studies; Suriname; Young Adult
PubMed: 33032606
DOI: 10.1186/s12936-020-03434-y -
Nature Communications Mar 2023Plasmodium falciparum (Pf) is the dominant malaria parasite in Nigeria though P. vivax (Pv), P. ovale (Po), and P. malariae (Pm) are also endemic. Blood samples...
Plasmodium falciparum (Pf) is the dominant malaria parasite in Nigeria though P. vivax (Pv), P. ovale (Po), and P. malariae (Pm) are also endemic. Blood samples (n = 31,234) were collected from children aged 0-14 years during a 2018 nationwide HIV survey and assayed for Plasmodium antigenemia, Plasmodium DNA, and IgG against Plasmodium MSP1-19 antigens. Of all children, 6.6% were estimated to have Pm infection and 1.4% Po infection with no Pv infections detected. The highest household wealth quintile was strongly protective against infection with Pm (aOR: 0.11, 95% CI: 0.05-0.22) or Po (aOR= 0.01, 0.00-0.10). Overall Pm seroprevalence was 34.2% (95% CI: 33.3-35.2) with lower estimates for Po (12.1%, 11.6-12.5) and Pv (6.3%, 6.0-6.7). Pm seropositivity was detected throughout the country with several local government areas showing >50% seroprevalence. Serological and DNA indicators show widespread exposure of Nigerian children to Pm with lower rates to Po and Pv.
Topics: Humans; Child; Seroepidemiologic Studies; Nigeria; Plasmodium; Malaria; Malaria, Vivax; Plasmodium falciparum; Antigens, Protozoan; Immunoglobulin G; Malaria, Falciparum; Plasmodium vivax
PubMed: 36914649
DOI: 10.1038/s41467-023-37010-0 -
Malaria Journal Oct 2020Ghana is among the high-burden countries for malaria infections and recently reported a notable increase in malaria cases. While asymptomatic parasitaemia is...
BACKGROUND
Ghana is among the high-burden countries for malaria infections and recently reported a notable increase in malaria cases. While asymptomatic parasitaemia is increasingly recognized as a hurdle for malaria elimination, studies on asymptomatic malaria are scarce, and usually focus on children and on non-falciparum species. The present study aims to assess the prevalence of asymptomatic Plasmodium falciparum and non-falciparum infections in Ghanaian adults in the Ashanti region during the high transmission season.
METHODS
Asymptomatic adult residents from five villages in the Ashanti Region, Ghana, were screened for Plasmodium species by rapid diagnostic test (RDT) and polymerase chain reaction (PCR) during the rainy season. Samples tested positive were subtyped using species-specific real-time PCR. For all Plasmodium ovale infections additional sub-species identification was performed.
RESULTS
Molecular prevalence of asymptomatic Plasmodium infection was 284/391 (73%); only 126 (32%) infections were detected by RDT. While 266 (68%) participants were infected with Plasmodium falciparum, 33 (8%) were infected with Plasmodium malariae and 34 (9%) with P. ovale. The sub-species P. ovale curtisi and P. ovale wallikeri were identified to similar proportions. Non-falciparum infections usually presented as mixed infections with P. falciparum.
CONCLUSIONS
Most adult residents in the Ghanaian forest zone are asymptomatic Plasmodium carriers. The high Plasmodium prevalence not detected by RDT in adults highlights that malaria eradication efforts must target all members of the population. Beneath Plasmodium falciparum, screening and treatment must also include infections with P. malariae, P. o. curtisi and P. o. wallikeri.
Topics: Adult; Asymptomatic Infections; Diagnostic Tests, Routine; Female; Ghana; Humans; Malaria; Malaria, Falciparum; Male; Middle Aged; Plasmodium falciparum; Plasmodium malariae; Plasmodium ovale; Prevalence; Real-Time Polymerase Chain Reaction; Young Adult
PubMed: 33046056
DOI: 10.1186/s12936-020-03441-z -
Infectious Diseases of Poverty Nov 2023Plasmodium malariae was always neglected compared with P. falciparum and P. vivax. In the present study, we aimed to describe the epidemiology of reported cases infected...
BACKGROUND
Plasmodium malariae was always neglected compared with P. falciparum and P. vivax. In the present study, we aimed to describe the epidemiology of reported cases infected with P. malariae in the past decade to raise awareness of the potential threat of this malaria parasite in China.
METHODS
Individual data of malaria cases infected with P. malariae reported in China in the past decade were collected via the China Information System for Disease Control and Prevention and Parasitic Diseases Information Reporting Management System, to explore their epidemiological characteristics. Pearson Chi-square tests or Fisher's Exact Test was used in the statistical analysis.
RESULTS
From 2013 to 2022, a total of 581 P. malariae cases were reported in China, and mainly concentrated in 20-59 years old group (P < 0.001), and there was no significant trend in the number of cases reported per month. Moreover, four kinds of P. malariae cases were classified, including 567 imported cases from 41 countries in 8 regions and distributed in 27 provinces (autonomous regions, municipalities) in China, six indigenous cases in a small outbreak in Hainan, seven recurrent cases in Guangdong and Shanghai, and one induced case in Shanghai, respectively. In addition, only 379 cases (65.2%) were diagnosed as malaria on the first visit (P < 0.001), and 413 cases (71.1%) were further confirmed as P. malariae cases (P = 0.002). Meanwhile, most cases sought healthcare first in the health facilities at the county and prefectural levels, but only 76.7% (161/210) and 73.7% (146/198) cases were diagnosed as malaria, and the accuracy of confirmed diagnosis as malaria cases infected with P. malariae was only 77.2% (156/202) and 69.9% (167/239) in these health facilities respectively.
CONCLUSIONS
Even though malaria cases infected with P. malariae didn't account for a high proportion of reported malaria cases nationwide, the threat posed by widely distributed imported cases, a small number of indigenous cases, recurrent cases and induced case cannot be ignored in China. Therefore, it is necessary to raise awareness and improve the surveillance and response to the non-falciparum species such as P. malariae, and prevent the reestablishment of malaria transmission after elimination.
Topics: Humans; Young Adult; Adult; Middle Aged; Plasmodium malariae; China; Malaria; Malaria, Falciparum; Malaria, Vivax
PubMed: 37986018
DOI: 10.1186/s40249-023-01156-2 -
Transfusion Jan 2024Malaria is caused by protozoa of the genus Plasmodium and transmitted by Anopheles mosquitos. In the US, blood donors are assessed for malaria risk, including donor...
BACKGROUND
Malaria is caused by protozoa of the genus Plasmodium and transmitted by Anopheles mosquitos. In the US, blood donors are assessed for malaria risk, including donor travel or previous residence in endemic areas and history of malaria by questionnaire and deferred for three months or three years, respectively.
METHODS
The Procleix Plasmodium Assay is a qualitative nucleic acid test based on transcription-mediated amplification (TMA) for the detection of 18S ribosomal RNA of P. falciparum, P. ovale, P. vivax, P. malariae, and P. knowlesi for use on the Procleix Panther system. Analytical sensitivity was evaluated with in vitro transcripts and infected red blood cells. For clinical specificity, 12,800 individual donations and 283 pools of 16 samples from routine US donors were screened. Malaria risk was evaluated by testing 862 donors deferred for 3 years. Reactive results were confirmed with in-house real-time TMA assay and serology.
RESULTS
Assay sensitivity was 8.47-11.89 RNA copies/mL and 2.10-6.82 infected red cells/mL. Specificity was 99.99% in 12,800 individual donations and 100% in 283 pools of 16. Of 862 tested deferred donor samples, one donor (0.12%) confirmed positive individually and in pools; he remained confirmed positive for 13 months. The infected donor was a prior resident of a malaria-endemic area in West Africa.
CONCLUSIONS
The Procleix Plasmodium Assay showed high sensitivity and specificity and detected Plasmodium RNA in an asymptomatic presenting donor. This assay may prove helpful as a screening test versus the use of risk questions to reduce the number of donors deferred for malaria risk.
Topics: Animals; Humans; Male; Blood Transfusion; Malaria; Malaria, Falciparum; Plasmodium; RNA
PubMed: 38018462
DOI: 10.1111/trf.17612 -
The Journal of Infectious Diseases Mar 2020Plasmodium malariae is considered a minor malaria parasite, although its global disease burden is underappreciated. The aim of this study was to develop an induced...
BACKGROUND
Plasmodium malariae is considered a minor malaria parasite, although its global disease burden is underappreciated. The aim of this study was to develop an induced blood-stage malaria (IBSM) model of P. malariae to study parasite biology, diagnostic assays, and treatment.
METHODS
This clinical trial involved 2 healthy subjects who were intravenously inoculated with cryopreserved P. malariae-infected erythrocytes. Subjects were treated with artemether-lumefantrine after development of clinical symptoms. Prior to antimalarial therapy, mosquito-feeding assays were performed to investigate transmission, and blood samples were collected for rapid diagnostic testing and parasite transcription profiling. Serial blood samples were collected for biomarker analysis.
RESULTS
Both subjects experienced symptoms and signs typical of early malaria. Parasitemia was detected 7 days after inoculation, and parasite concentrations increased until antimalarial treatment was initiated 25 and 21 days after inoculation for subjects 1 and 2 respectively (peak parasitemia levels, 174 182 and 50 291 parasites/mL, respectively). The parasite clearance half-life following artemether-lumefantrine treatment was 6.7 hours. Mosquito transmission was observed for 1 subject, while in vivo parasite transcription and biomarkers were successfully profiled.
CONCLUSIONS
An IBSM model of P. malariae has been successfully developed and may be used to study the biology of, diagnostic testing for, and treatment of this neglected malaria species.
CLINICAL TRIALS REGISTRATION
ACTRN12617000048381.
Topics: Adolescent; Animals; Anopheles; Antimalarials; Artemether, Lumefantrine Drug Combination; Feeding Behavior; Humans; Malaria; Male; Parasitemia; Plasmodium malariae; Transcriptome; Young Adult
PubMed: 30852586
DOI: 10.1093/infdis/jiz102 -
Open Forum Infectious Diseases May 2020We assessed the efficacy of artemisinin-based combination therapies for treatment of uncomplicated malaria, with or without co-infecting spp., in Sumatera, Indonesia.
BACKGROUND
We assessed the efficacy of artemisinin-based combination therapies for treatment of uncomplicated malaria, with or without co-infecting spp., in Sumatera, Indonesia.
METHODS
Febrile patients aged >6 months with uncomplicated were randomized to receive dihydroartemisinin-piperaquine or artemether-lumefantrine, plus single-dose primaquine, and were followed for 42 days. Mixed infections were included; infections received 14 days of primaquine. We retrospectively restricted the analysis to cases with polymerase chain reaction (PCR)-confirmed parasitemia. Recurrent parasitemia in follow-up was identified by species-specific nested PCR.
RESULTS
Of the 3731 participants screened, 302 were enrolled and randomized. In the dihydroartemisinin-piperaquine arm, infections were confirmed by PCR in 59 participants, with mixed infections in 23 (39.0%). In the artemether-lumefantrine arm, infections were confirmed by PCR in 55 participants, with mixed infections in 16 (29.0%). Both regimens were well tolerated, and symptoms improved rapidly in all treated participants. In the dihydroartemisinin-piperaquine arm, 1 recurrence (on day 7) and 6 recurrences (1 had a mixed infection with ) were identified during days 3-42 of follow-up. In the artemether-lumefantrine arm, 1 recurrence occurred on day 35. Submicroscopic persistence occurred during follow-up in 21 (37%) of 57 receiving dihydroartemisinin-piperaquine and 20 (39%) of 51 receiving artemether-lumefantrine.
CONCLUSIONS
In Sumatera, both regimens effectively cleared initial parasitemia, but and persisted in some individuals. Molecular species detection should be deployed in antimalarial efficacy trials in Indonesia.
TRIAL REGISTRATION
NCT02325180.
PubMed: 32420402
DOI: 10.1093/ofid/ofaa116