Socioeconomic disparities in Plasmodium falciparum infection risk in Southern Malawi: mediation analyses.

This study investigated the mediators of the association between socioeconomic position (SEP) and Plasmodium falciparum (Pf) infection in Southern region of Malawi. We utilized data from the 2014 International Center of Excellence for Malaria Research (ICEMR) surveys from Malawi in which blood samples of all individuals from selected households in Blantyre, Thyolo and Chikhwawa were tested for Pf parasitemia. We assessed household SEP and potential mediators - housing quality, food security, education status of household heads, and use of long-lasting Insecticide-treated nets (LLINs) and nutritional status.

A simulation-based method to inform serosurvey design for estimating the force of infection using existing blood samples.

The extent to which dengue virus has been circulating globally and especially in Africa is largely unknown. Testing available blood samples from previous cross-sectional serological surveys offers a convenient strategy to investigate past dengue infections, as such serosurveys provide the ideal data to reconstruct the age-dependent immunity profile of the population and to estimate the average per-capita annual risk of infection: the force of infection (FOI), which is a fundamental measure of transmission intensity. In this study, we present a novel methodological approach to inform the size and age distribution of blood samples to test when samples are acquired from previous surveys.

A non-reactive natural product precursor of the duocarmycin family has potent and selective antimalarial activity.

We identify a selective nanomolar inhibitor of blood-stage malarial proliferation from a screen of microbial natural product extracts. The responsible compound, PDE-I, is a precursor of the anticancer duocarmycin family that preserves the class's sequence-specific DNA binding but lacks its signature DNA alkylating cyclopropyl warhead. While less active than duocarmycin, PDE-I retains comparable antimalarial potency to chloroquine.

Critical prerequisites for Covid-19 vaccine acceleration: A developing economy perspective.

This study aims to explore the critical prerequisites for accelerating the distribution of the COVID-19 vaccine in developing countries by using Ghana as a case study. A qualitative study method and content analysis approach was used. In-depth interviews were conducted with health experts from the Ghana Health Service, World Health Organization (WHO), AstraZeneca, Novartis, and Medtronic Inc.

Bloodstream infection with Acinetobacter baumanii in a Plasmodium falciparum positive infant: a case report.

Background: The increasing incidence of multi-antibiotic-resistant bacterial infections, coupled with the risk of co-infections in malaria-endemic regions, complicates accurate diagnosis and prolongs hospitalization, thereby increasing the total cost of illness. Further, there are challenges in making the correct choice of antibiotic treatment and duration, precipitated by a lack of access to microbial culture facilities in many hospitals in Ghana. The aim of this case report is to highlight the need for blood cultures or alternative rapid tests to be performed routinely in malaria patients, to diagnose co-infections with bacteria, especially when symptoms persist after antimalarial treatment.

Classification of invasive bloodstream infections and Plasmodium falciparum malaria using autoantibodies as biomarkers.

A better understanding of disease-specific biomarker profiles during acute infections could guide the development of innovative diagnostic methods to differentiate between malaria and alternative causes of fever. We investigated autoantibody (AAb) profiles in febrile children (≤ 5 years) admitted to a hospital in rural Ghana. Serum samples from 30 children with a bacterial bloodstream infection and 35 children with Plasmodium falciparum malaria were analyzed using protein microarrays (Protoplex Immune Response Assay, ThermoFisher).

Viral metagenomics revealed novel betatorquevirus species in pediatric inpatients with encephalitis/meningoencephalitis from Ghana.

The cause of acute encephalitis/meningoencephalitis in pediatric patients remains often unexplained despite extensive investigations for large panel of pathogens. To explore a possible viral implication, we investigated the virome of cerebrospinal fluid specimens of 70 febrile pediatric inpatients with clinical compatible encephalitis/meningoencephalitis. Using viral metagenomics, we detected and genetically characterized three novel human Torque teno mini virus (TTMV) species (TTMV-G1-3).

Functional analysis of the leading malaria vaccine candidate AMA-1 reveals an essential role for the cytoplasmic domain in the invasion process.

A key process in the lifecycle of the malaria parasite Plasmodium falciparum is the fast invasion of human erythrocytes. Entry into the host cell requires the apical membrane antigen 1 (AMA-1), a type I transmembrane protein located in the micronemes of the merozoite. Although AMA-1 is evolving into the leading blood-stage malaria vaccine candidate, its precise role in invasion is still unclear.

Sequence requirements for the export of the Plasmodium falciparum Maurer's clefts protein REX2.

A short motif termed Plasmodium export element (PEXEL) or vacuolar targeting signal (VTS) characterizes Plasmodium proteins exported into the host cell. These proteins mediate host cell modifications essential for parasite survival and virulence. However, several PEXEL-negative exported proteins indicate that the currently predicted malaria exportome is not complete and it is unknown whether and how these proteins relate to PEXEL-positive export.

Plasmodium falciparum possesses two GRASP proteins that are differentially targeted to the Golgi complex via a higher- and lower-eukaryote-like mechanism.

Plasmodium falciparum, the causative agent of malaria, relies on a complex protein-secretion system for protein targeting into numerous subcellular destinations. Recently, a homologue of the Golgi re-assembly stacking protein (GRASP) was identified and used to characterise the Golgi organisation in this parasite. Here, we report on the presence of a splice variant that leads to the expression of a GRASP isoform.

Spatial dissection of the cis- and trans-Golgi compartments in the malaria parasite Plasmodium falciparum.

The Golgi apparatus forms the heart of the secretory pathway in eukaryotic cells where proteins are modified, processed and sorted. The transport of proteins from the endoplasmic reticulum (ER) to the cis-side of the Golgi complex takes place at specialized ER sub-domains known as transitional ER (tER). We used the Plasmodium falciparum orthologue of Sec13p to analyse tER organization.

A conserved region in the EBL proteins is implicated in microneme targeting of the malaria parasite Plasmodium falciparum.

The proliferation of the malaria parasite Plasmodium falciparum within the human host is dependent upon invasion of erythrocytes. This process is accomplished by the merozoite, a highly specialized form of the parasite. Secretory organelles including micronemes and rhoptries play a pivotal role in the invasion process by storing and releasing parasite proteins.

Re-defining the Golgi complex in Plasmodium falciparum using the novel Golgi marker PfGRASP.

Plasmodium falciparum, the causative agent of malaria, relies on a sophisticated protein secretion system for host cell invasion and transformation. Although the parasite displays a secretory pathway similar to those of all eukaryotic organisms, a classical Golgi apparatus has never been described. We identified and characterised the putative Golgi matrix protein PfGRASP, a homologue of the Golgi re-assembly stacking protein (GRASP) family.

Localization of organellar proteins in Plasmodium falciparum using a novel set of transfection vectors and a new immunofluorescence fixation method.

The apicoplast and mitochondrion of the malaria parasite Plasmodium falciparum are important intracellular organelles and targets of several anti-malarial drugs. In recent years, our group and others have begun to piece together the metabolic pathways of these organelles, with a view to understanding their functions and identifying further anti-malarial targets. This has involved localization of putative organellar proteins using fluorescent reporter proteins such as green fluorescent protein (GFP).

Dissecting apicoplast targeting in the malaria parasite Plasmodium falciparum.

Transit peptides mediate protein targeting into plastids and are only poorly understood. We extracted amino acid features from transit peptides that target proteins to the relict plastid (apicoplast) of malaria parasites. Based on these amino acid characteristics, we identified 466 putative apicoplast proteins in the Plasmodium falciparum genome.