Nina F. D. White

Artemisinin partial resistance (ART-R) in Plasmodium falciparum is a major challenge to malaria control globally. Over the last two decades, ART-R has spread widely across Southeast Asia, undermining public health strategies and hindering elimination. As of 2024, ART-R has now emerged in East Africa, with the potential to dramatically impact current efforts to control malaria in the region. Mitigating its spread requires detailed genomic surveillance of point mutations in the kelch13 gene, the primary known determinant of artemisinin resistance. Although extensive surveillance data on these markers is available, it is distributed across many literature studies and open databases. In this review, we aggregate spatiotemporal data for 112,933 P. falciparum samples collected between 1980 and 2023 into a single resource, providing the most comprehensive overview of kelch13 markers to date. We outline the history and current status of these mutations globally, with particular focus on their emergence in Southeast Asia and East/Northeast Africa. Concerningly, we find the recent increases in ART-R in Africa mirror patterns observed in Southeast Asia 10–15 years ago. We examine factors that may influence its spread, including fitness costs, treatment strategies, and local epidemiological dynamics, before discussing potential scenarios for how resistance may spread in Africa in coming years. This review provides a comprehensive account of how the situation of ART-R has unfolded globally so far, highlighting insights for researchers and public health bodies which aim to reduce its negative effects.

We describe the Pf8 data resource, the latest MalariaGEN release of curated genome variation data on over 33,000 Plasmodium falciparum samples from 99 partner studies and 122 locations over more than 50 years. This release provides open access to raw sequencing data and genotypes at over 12 million genomic positions. For the first time, it includes copy-number variation (CNV) calls in the drug-resistance associated genes gch1 and crt . As in Pf7, CNV calls are provided for mdr1 and plasmepsin2/3 , along with calls for deletion in hrp2 and hrp3, genes associated with rapid diagnostic test failures. This data resource additionally features derived datasets, interactive web applications for exploring patterns of drug resistance and variation in over 5,000 genes, an updated Python package providing methods for accessing and analysing the data, and open access analysis notebooks that can be used as starting points for further analyses. In addition, informative example analyses show contrasting profiles of the decline of chloroquine resistance-associated mutations in Africa, and variation in copy number variation across 10 distinct sub-populations. To the best of our knowledge, Pf8 is the largest open data set of genome variation in any eukaryotic species, making it an invaluable foundational resource for understanding evolution, including that of pathogens.

Sulfadoxine-pyrimethamine (SP), despite the emergence and spread of mutations in dhfr and dhps genes associated with lower treatment efficacy, is still recommended alone or in combination by the WHO for preventive treatment in pregnant women, children and infants. Therefore, it is important to understand the evolution of P. falciparum dhfr and dhps genes. Here, we used a subset of the MalariaGEN Pf7 dataset to describe haplotype frequencies across 22 African countries, including changes over time in The Gambia, Mali, Ghana and Kenya. We show that the triple mutant of dhfr, N51I/C59R/S108N, has remained the dominant haplotype across the continent with limited evidence of additional mutations. There is greater variation for dhps , with a total of 51 different haplotypes present. The dhps resistance mutation A437G has risen close to fixation across most of Africa, although at a lower frequency in the northwest malaria-endemic part of the continent (Gambia, Senegal and Mali). The A437G mutation is usually found together with K540E in East Africa, but K540E is still very rare in West Africa. Although samples from Madagascar have low genetic differentiation from samples from mainland East Africa at the whole genome level, we show that dhps K540E is highly differentiated between the two populations, being at very low frequency in Madagascar (4%). We used whole genome data to show that only 12 SNPs are more highly differentiated than K540E between Madagascar and East Africa, with aat1 and a possible novel drug resistance locus approximately 20kb 3’ of mdr1 having even higher F _ST . We highlight the value of longitudinal sampling and whole genome sequence data for understanding the heterogeneity and ongoing changes in anti-malarial drug resistance genetic markers.

Monitoring the genomic evolution of Plasmodium falciparum—the most widespread and deadliest of the human-infecting malaria species—is critical for making decisions in response to changes in drug resistance, diagnostic test failures, and vaccine effectiveness. The MalariaGEN data resources are the world’s largest whole genome sequencing databases for Plasmodium parasites. The size and complexity of such data is a barrier to many potential end users in both public health and academic research. A user-friendly method for accessing and exploring data on the genetic variation of P. falciparum would greatly enable efforts in studying and controlling malaria. We developed Pf-HaploAtlas, a web application enabling exploratory data analysis of genomic variation without requiring advanced technical expertise. The app provides analysis-ready data catalogues and visualisations of amino acid haplotypes for all 5,102 core P. falciparum genes. Pf-HaploAtlas facilitates comprehensive spatial and temporal exploration of genes and variants of interest by using data from 16,203 samples, from 33 countries, and spread between the years 1984 and 2018. The scope of Pf-HaploAtlas will expand with each new MalariaGEN Plasmodium data release. Pf-HaploAtlas is available online for public use at https://apps.malariagen.net/pf-haploatlas, which allows users to download the underlying amino acid haplotype data for further analyses, and its source code is freely available on GitHub under the MIT licence at https://github.com/malariagen/pf-haploatlas.

Studies in evolution, ecology and conservation are increasingly based on genetic and genomic data. With increased focus on molecular approaches, ethical concerns about destructive or more invasive techniques need to be considered, with a push for minimally invasive sampling to be optimised. Buccal swabs have been increasingly used to collect DNA in a number of taxa, including amphibians. However, DNA yield and purity from swabs are often low, limiting its use. In this study, we compare different types of swabs, preservation method and storage, and DNA extraction techniques in three case studies to assess the optimal approach for recovering DNA in anurans. Out of the five different types of swabs that we tested, Isohelix MS‐02 and Rapidry swabs generated higher DNA yields than other swabs. When comparing storage buffers, ethanol is a better preservative than a non‐alcoholic alternative. Dried samples resulted in similar or better final DNA yields compared to ethanol‐fixed samples if kept cool. DNA extraction via a Qiagen™ DNeasy Blood and Tissue Kit and McHale's salting‐out extraction method resulted in similar DNA yields but the Qiagen™ kit extracts contained less contamination. We also found that samples have better DNA recovery if they are frozen as soon as possible after collection. We provide recommendations for sample collection and extraction under different conditions, including budgetary considerations, size of individual animal sampled, access to cold storage facilities and DNA extraction methodology. Maximising efficacy of all of these factors for better DNA recovery will allow buccal swabs to be used for genetic and genomic studies in a range of vertebrates.

Artemisinin partial resistance (ART-R) in Plasmodium falciparum is one of the most pressing threats to global malaria control. Over the last two decades, ART-R has spread widely across Southeast Asia, compromising public health strategies and hindering elimination efforts. As of 2024, ART-R has now emerged in East Africa, with the potential to dramatically increase human mortality in the region. Mitigating the spread of ART-R requires detailed genomic surveillance of point mutations in the kelch13 gene, the primary determinant of resistance to artemisinin derivatives. Although extensive surveillance data on these markers is available, it is distributed across many literature studies and open databases. In this literature review, we aggregate publicly available spatiotemporal data for 112,933 P. falciparum samples between 1980 – 2023 into a single resource, providing the most comprehensive overview of kelch13 markers to date. By synthesising insights from these samples over a global scale, we outline the history and current status of kelch13 mutations associated with ART-R, with particular reference to their emergence in Southeast Asia and recent emergence in East and Northeast Africa. Concerningly, we find their recent increases in frequency in these areas of Africa are comparable to those observed in Southeast Asia 10-15 years ago. We review several factors that may influence the spread of ART-R going forwards, such as fitness costs, treatment strategies, and local epidemiological dynamics, before articulating possible scenarios on how resistance may spread in Africa in coming years. In summary, this review provides a unified, comprehensive account of how the situation of ART-R has unfolded globally so far, highlighting insights both for researchers in the field and public health bodies which aim to reduce its negative effects. More broadly, we highlight the critical role genomic surveillance has had, and will continue to have in combating the spread of ART-R.

Anilany helenae is a Critically Endangered frog native to the central highlands of Madagascar. Due to ongoing habitat loss of its known range, this species’ population is considered declining, while little is known about its ecology, behavior, and taxonomy. Within the context of developing tools that can aid the conservation of Madagascar’s amphibian fauna, and add to the continued understanding of their taxonomy, we assembled its complete mitochondrial genome (Genbank Accession number MZ751042). This contributes the first complete mitochondrial genome of a microhylid from Madagascar, despite there being over 100 species in the Cophylinae subfamily alone. Anilany helenae’s circular mitochondrial genome is 17,519 bp long, contains 37 genes, and exhibits differences in gene arrangement compared with other microhylids, including the placement of protein coding genes nad1 and nad2. A phylogeny of the 13 protein coding genes of the few Madagascan anuran mitogenomes available, along with species from Africa and East Asia, places A. helenae along with the New Guinean Mantophryne lateralis in a basal position with respect to the other microhylids in the tree.

The mountain chicken frog (Leptodactylus fallax) is a critically endangered frog native to the Caribbean islands of Dominica and Montserrat. Over the past 25 years their populations have declined by over 85%, largely due to a chytridiomycosis outbreak that nearly wiped out the Montserratian population. Within the context of developing tools that can aid in the conservation of the mountain chicken frog, we assembled its complete mitochondrial genome, contributing the first complete mitogenome of the genus Leptodactylus (Genbank Accession number MW260634). The circular genome is 18,669 bp long and contains 37 genes. A phylogenetic analysis reveals that L. fallax forms a clade with Leptodactylus melanonotus, highlighting the close relationship of Leptodactylus spp. relative to other species from the superfamily Hyloidea included in the analysis.