Immunity to the sexual stages of Plasmodium falciparum can be induced during natural infections. Characterization of this immunity may facilitate the design of a transmission-blocking vaccine (TBV). This study aimed to assess the prevalence and serological correlates of functional transmission-blocking immunity in Gambian children (aged 1-4 years old) who were P. falciparum gametocyte carriers. Serological assays showed 100% response to fixed, whole parasites but only 42% to live gametes. Responses to the antigens Pfs230 and Pfs48/45 were 54.1% and 37.3%, respectively, in an IgG1 ELISA. 14/55 sera were capable of reducing the infectivity of laboratory isolate NF54 in a standard membrane-feeding assay (SMFA). This activity was strongly correlated with IgG1 responses to Pfs48/45 (r = 0.49, P < 0.001) and to a serological reaction with epitopes of the same molecule (r = 0.38, P = 0.003). A weaker correlation was observed with IgG1 to Pfs230 (r = 0.29, P = 0.03). In direct membrane feeding assays (DMFA) with autologous isolates, sera from 4/29 children showed transmission-blocking activity. There was no correlation with serological assays and the DMFA or between the SMFA and DMFA. This may be caused by variation in sexual stage antigens and/or alternative modes of transmission-blocking immunity, both of which have implications for vaccine implementation.
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http://dx.doi.org/10.1111/j.0141-9838.2004.00696.x | DOI Listing |
Front Parasitol
April 2024
National Engineering Research Center for Modernization of Traditional Chinese Medicine - Hakka Medical Resources Branch, Gannan Medical University, Ganzhou, China.
Background: Malaria is one of the leading causes of morbidity and/or mortality in tropical Africa. The spread and development of resistance to chemical antimalarial drugs and the relatively high cost of the latter are problems associated with malaria control and are reasons to promote the use of plants to meet healthcare needs to treat malaria. The aim of this study was to evaluate antiplasmodial activities of extracts of (Mah quat), which is traditionally used for the treatment of malaria in the western region of Cameroon.
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September 2024
Centro de Cálculo Científico de la Universidad de Los Andes (CeCalCULA), Universidad de Los Andes (ULA), Mérida, Venezuela.
Artemisinin-based treatments (ACTs) are the first therapy currently used to treat malaria produced by . However, in recent years, increasing evidence shows that some strains of are less susceptible to ACT in the Southeast Asian region. A data reanalysis of several omics approaches currently available about parasites of that have some degree of resistance to ACT was carried out.
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May 2024
Disease Control and Elimination (DCE), Medical Research Council The Gambia Unit at the London School of Hygiene and Tropical Medicine (LSHTM), Fajara, Gambia.
Further understanding of the molecular mediators of alternative RBC invasion phenotypes in endemic malaria parasites will support malaria blood-stage vaccine or drug development. This study investigated the prevalence of sialic acid (SA)-dependent and SA-independent RBC invasion pathways in endemic parasites from Cameroon and compared the schizont stage transcriptomes in these two groups to uncover the wider repertoire of transcriptional variation associated with the use of alternative RBC invasion pathway phenotypes. A two-color flow cytometry-based invasion-inhibition assay against RBCs treated with neuraminidase, trypsin, and chymotrypsin and deep RNA sequencing of schizont stages harvested in the first replication cycle in culture were employed in this investigation.
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August 2024
School of Public Health, Institute of Health, Bule Hora University, Bule Hora, Ethiopia.
Background: Malaria continues to be an important threat to public health and infects millions of children under 5 years of age each year. Although Ethiopia has set targets for at-risk group interventions to eradicate and manage malaria, the illness is still a serious public health problem in areas where it is endemic, especially in the unique lowlands in the Borena zone.
Objective: This study aimed to determine the prevalence of malaria and associated factors among children in Borena's pastoral communities, Oromia Regional State, southern Ethiopia, in 2022.
Front Parasitol
April 2024
Centre for Malaria Elimination, Institute of Tropical Medicine, Mount Kenya University, Thika, Kenya.
The Circumsporozoite Protein (PfCSP) has been used in developing the RTS,S, and R21 malaria vaccines. However, genetic polymorphisms within compromise the effectiveness of the vaccine. Thus, it is essential to continuously assess the genetic diversity of , especially when deploying it across different geographical regions.
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