The activities of suaveolol and other compounds from Hyptis suaveolens and Momordica charantia against the aetiological agents of African trypanosomiasis, leishmaniasis and malaria.

African trypanosomiasis and malaria are among the most severe health challenges to humans and livestock in Africa and new drugs are needed. Leaves of Hyptis suaveolens Kuntze (Lamiaceae) and Momordica charantia L. (Cucurbitaceae) were extracted with hexane, ethyl acetate, and then methanol, and subjected to silica gel column chromatography.

Putative molecular markers of resistance to antimalarial drugs in malaria parasites from Ghana.

Introduction: Antimalarial drugs including artemisinin-based combination therapy (ACT) regimens and sulphadoxine-pyrimethamine (SP) are used in Ghana for malaria therapeutics and prophylaxis respectively. The genetic basis of development of drug resistance involves single nucleotide polymorphisms in genes encoding proteins for multiple cellular and metabolic processes. The prevalence of single nucleotide polymorphisms in nine genes linked to ACT and SP resistance in the malaria parasite population was determined.

Effectiveness of artemether-lumefantrine for treating uncomplicated malaria in low- and high-transmission areas of Ghana.

Background: Artemisinin-based combination therapy (ACT) has been effective in the supervised treatment of uncomplicated malaria in Ghana. Since ACT usage is primarily unsupervised, this study aimed to determine the effectiveness of artemether-lumefantrine (AL) for treating malaria patients in two transmission settings in Ghana.

Methods: Eighty-four individuals with uncomplicated Plasmodium falciparum malaria were recruited from Lekma Hospital (LH) in Accra (low-transmission area; N = 28), southern Ghana, and King's Medical Centre (KMC) in Kumbungu (high-transmission area; N = 56), northern Ghana.

Assessment of artemisinin tolerance in Plasmodium falciparum clinical isolates in children with uncomplicated malaria in Ghana.

Background: Artemisinin-based combination therapy (ACT) is the first-line treatment for uncomplicated malaria in Ghana. Artemisinin (ART) tolerance in Plasmodium falciparum has arisen in Southeast Asia and recently, in parts of East Africa. This is ascribed to the survival of ring-stage parasites post treatment.

Therapeutic efficacy of dihydroartemisinin-piperaquine combination for the treatment of uncomplicated malaria in Ghana.

In 2020, Dihydroartemisinin-Piperaquine (DHAP) was adopted as a second-line antimalarial for treatment of uncomplicated malaria in Ghana following a review of the country's antimalarial medicines policy. Available data obtained in 2007 had shown PCR-uncorrected therapeutic efficacy of 93.3% using a 28-day follow-up schedule.

Genetic deletions and high diversity of histidine-rich proteins 2 and 3 genes in parasite populations in Ghana.

Rapid diagnostic tests (RDTs) are used to diagnose malaria in Ghana and other malaria endemic countries. histidine-rich protein 2 (PFHRP2 based RDTs are widely used, however the occurrence of deletions of the gene in some parasites have resulted in false negative test results. Monoclonal antibodies of PFHRP2 cross reacts with PFHRP3 because they share structural similarities and this complements the detection of the parasites by RDT.

Transcriptome-module phenotype association study implicates extracellular vesicles biogenesis in artemisinin resistance.

malaria is still an important disease in sub-Saharan Africa (sSA). Great strides have been made in its control spear-headed by artemisinin (ART)-based combination therapies (ACTs). However, concerns about the imminent spread of ART-resistant (ARTr) malaria parasites to sSA threaten gains already made.

Plasmodium falciparum merozoite invasion ligands, linked antimalarial resistance loci and ex vivo responses to antimalarials in The Gambia.

Background: Artemether/lumefantrine is the most commonly used artemisinin-based combination treatment (ACT) for malaria in sub-Saharan Africa. Drug resistance to ACT components is a major threat to malaria elimination efforts. Therefore, rigorous monitoring of drug efficacy is required for adequate management of malaria and to sustain the effectiveness of ACTs.

Malaria artemisinin resistance: an extracellular vesicles export hypothesis.

Plasmodium falciparum causes malaria, and its resistance to artemisinin (ART) - a drug used for managing malaria - threatens to interfere with the effective control of malaria. ART resistance (ARTr) is driven by increased tolerance to oxidative stress and reduced haemoglobin trafficking to the food vacuole. We discuss how extracellular vesicles (EVs) may play a role in developing ARTr.

Assessing the Roles of Molecular Markers of Antimalarial Drug Resistance and the Host Pharmacogenetics in Drug-Resistant Malaria.

Malaria caused by the parasites is a major public health concern in malaria-endemic regions with causing the most severe form of the disease. The use of antimalarial drugs for the management of the disease proves to be one of the best methods to manage the disease. Unfortunately, has developed resistance to almost all the current in-use antimalarial drugs.

Novel pfk13 polymorphisms in Plasmodium falciparum population in Ghana.

The molecular determinants of Plasmodium falciparum artemisinin resistance are the single nucleotide polymorphisms in the parasite's kelch propeller domain, pfk13. Validated and candidate markers are under surveillance in malaria endemic countries using artemisinin-based combination therapy. However, pfk13 mutations which may confer parasite artemisinin resistance in Africa remains elusive.

Trends and predictive factors for treatment failure following artemisinin-based combination therapy among children with uncomplicated malaria in Ghana: 2005-2018.

Background: Since the introduction of artemisinin-based combination therapy (ACT) in Ghana in 2005 there has been a surveillance system by the National Malaria Control Programme (NMCP) and the University of Ghana Noguchi Memorial Institute for Medical Research (UG-NMIMR) to monitor the therapeutic efficacy of ACTs for the treatment of uncomplicated malaria in the country. We report trends and determinants of failure following treatment of Ghanaian children with artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) combinations.

Methods: Per protocol analyses as well as cumulative incidence of day 28 treatment failure from Kaplan Meier survival analyses were used to describe trends of failure over the surveillance period of 2005-2018.

Comprehensive characterization of purine and pyrimidine transport activities in Trichomonas vaginalis and functional cloning of a trichomonad nucleoside transporter.

Trichomoniasis is a common and widespread sexually-transmitted infection, caused by the protozoan parasite Trichomonas vaginalis. T. vaginalis lacks the biosynthetic pathways for purines and pyrimidines, making nucleoside metabolism a drug target.

Implicating extracellular vesicles in Plasmodium falciparum artemisinin resistance development.

Plasmodium falciparum malaria remains a disease of significant public health impact today. With the risk of emerging artemisinin resistance stalling malaria control efforts, the need to deepen our understanding of the parasite's biology is dire. Extracellular vesicles (EVs) are vital to the biology of P.

Malaria Parasites in Ghana Show Signatures of Balancing Selection at Artemisinin Resistance Predisposing Background Genes.

Sub-Saharan Africa is courting the risk of artemisinin resistance (ARTr) emerging in malaria parasites. Current molecular surveillance efforts for ARTr have been built on the utility of kelch13 () validated molecular markers. However, whether these molecular markers will serve the purpose of early detection of artemisinin-resistant parasites in Ghana is hinged on a dependent evolution.

High Prevalence of Molecular Markers of Plasmodium falciparum Resistance to Sulphadoxine-Pyrimethamine in Parts of Ghana: A Threat to ITPTp-SP?

Malaria in pregnancy is a huge public health problem as it is the cause of maternal anaemia, still birth, premature delivery, low birth weight among others. To tackle this problem, WHO recommended the administration, during pregnancy, of intermittent preventive treatment with sulphadoxine-pyrimethamine (IPTp-SP). The introduction of this policy is likely to create SP drug pressure which may lead to the emergence of parasite strains resistant to the drug.

Treatment of COVID-19 with Chloroquine: Implication for Malaria Chemotherapy Using ACTs in Disease Endemic Countries.

Based on reports of parasite resistance and on World Health Organization recommendation, chloroquine was replaced with the artemisinin-based combination therapies (ACTs) as the first choice of drugs for the treatment of uncomplicated malaria. Disuse of chloroquine led to restoration of drug-sensitive parasite to some extent in certain countries. Ever since chloroquine and hydroxychloroquine were touted as potential treatment for coronavirus disease 2019 (COVID-19), there has been a dramatic surge in demand for the drugs.

Plasmodium falciparum genetic factors rather than host factors are likely to drive resistance to ACT in Ghana.

Background: Artemisinin-based combination therapy (ACT) partner drugs, currently used in Ghana are lumefantrine, amodiaquine and piperaquine. Plasmodium falciparum isolates with reduced susceptibility to these partner drugs may affect treatment outcome. Mutations in pfmdr1 gene is linked to reduced parasite susceptibility to amodiaquine and lumefantrine.

Estimation of parasite age and synchrony status in Plasmodium falciparum infections.

Human malaria parasites have complex but poorly understood population dynamics inside their human host. In some but not all infections, parasites progress synchronously through the 48 h lifecycle following erythrocyte invasion, such that at any one time there is a limited spread of parasites at a particular time (hours) post-invasion. Patients presenting with older parasites, and with asynchronous infections, have been reported to have higher risks of fatal outcomes, associated with higher parasite biomass and multiplication rates respectively.

Plasmodium falciparum Kelch Propeller Polymorphisms in Clinical Isolates from Ghana from 2007 to 2016.

The continuous surveillance of polymorphisms in the kelch propeller domain of from Africa is important for the discovery of the actual markers of artemisinin resistance in the region. The information on the markers is crucial for control strategies involving chemotherapy and chemoprophylaxis for residents and nonimmune travelers to the country. Polymorphisms in the kelch propeller domain of Ghanaian malaria parasites from three different ecological zones at several time periods were assessed.

Therapeutic efficacy of artesunate-amodiaquine and artemether-lumefantrine combinations for uncomplicated malaria in 10 sentinel sites across Ghana: 2015-2017.

Background: Routine surveillance on the therapeutic efficacy of artemisinin-based combination therapy (ACT) has been ongoing in Ghana since 2005. The sixth round of surveillance was conducted between 2015 and 2017 to determine the therapeutic efficacy of artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) in 10 sentinel sites across the country.

Methods: The study was a one-arm, prospective, evaluation of the clinical, parasitological, and haematological responses to directly observed treatment with AS-AQ and AL among children 6 months to 9 years old with uncomplicated falciparum malaria.

Amplification of GTP-cyclohydrolase 1 gene in Plasmodium falciparum isolates with the quadruple mutant of dihydrofolate reductase and dihydropteroate synthase genes in Ghana.

Sulfadoxine-pyrimethamine (SP) is used as malaria chemoprophylaxis for pregnant women and children in Ghana. Plasmodium falciparum resistance to SP is linked to mutations in the dihydropteroate synthase gene (pfdhps), dihydrofolate reductase gene (pfdhfr) and amplification of GTP cyclohydrolase 1 (pfgch1) gene. The pfgch1 duplication is associated with pfdhfr L164, a crucial mutant for high level pyrimethamine resistance which is rare in Ghana.

Seasonal variations in Plasmodium falciparum parasite prevalence assessed by varying diagnostic tests in asymptomatic children in southern Ghana.

Plasmodium falciparum infections presenting either as symptomatic or asymptomatic may contain sexual stage parasites (gametocytes) that are crucial to malaria transmission. In this study, the prevalence of microscopic and submicroscopic asexual and gametocyte parasite stages were assessed in asymptomatic children from two communities in southern Ghana. Eighty children aged twelve years and below, none of whom exhibited signs of clinical malaria living in Obom and Cape Coast were sampled twice, one during the rainy (July 2015) and subsequently during the dry (January 2016) season.

Prevalence of Plasmodium falciparum delayed clearance associated polymorphisms in adaptor protein complex 2 mu subunit (pfap2mu) and ubiquitin specific protease 1 (pfubp1) genes in Ghanaian isolates.

Background: Plasmodium falciparum delayed clearance with the use of artemisinin-based combination therapy (ACTs) has been reported in some African countries. Single nucleotide polymorphisms (SNPs) in two genes, P. falciparum adaptor protein complex 2 mu subunit (pfap2mu) and ubiquitin specific protease 1 (pfubp1), have been linked to delayed clearance with ACT use in Kenya and recurrent imported malaria in Britain.