TRENDS IN PARASITOLOGY

Schistosoma mattheei and zoonotic schistosomiasis
Stothard JR, Juhász A and Musaya J
We highlight the epidemiological importance of Schistosoma mattheei, a common parasite of livestock with an underappreciated ability to infect people, being recently incriminated in both female and male genital schistosomiasis. Through hybridisation(s) with other schistosome species, its public health importance will grow as its zoonotic potential expands across southern Africa.
Ceratothoa famosa
Hadfield KA, Erasmus A and Smit NJ
Parasite infections: how inflammation alters brain function
de Brito Duval I, Cardozo ME, Souza JLN, de Medeiros Brito RM, Fujiwara RT, Bueno LL and Magalhães LMD
Parasitic infections can profoundly impact brain function through inflammation within the central nervous system (CNS). Once viewed as an immune-privileged site, the CNS is now recognized as vulnerable to immune disruptions from both local and systemic infections. Recent studies reveal that certain parasites, such as Toxoplasma gondii and Plasmodium falciparum, can invade the CNS or influence it indirectly by triggering neuroinflammation. These processes may disrupt brain homeostasis, influence neurotransmission, and lead to significant behavioral or cognitive changes. This review discusses the pathways by which parasites disrupt CNS function and highlights systemic inflammation as a critical link between peripheral infections and neuroinflammatory conditions, advancing understanding of parasite-associated neurological complications.
Integrating hybridization and introgression into host-parasite epidemiology, ecology, and evolution
Lukubye B and Civitello DJ
Hybridization and introgression between host species or between parasite species are emerging challenges for human, plant, and animal health, especially as global trends like climate change and urbanization increase overlap of species ranges. This creates opportunities for heterospecific crosses between diverged taxa that could generate novel host and parasite genotypes with unique traits (e.g., transmission rate, virulence, susceptibility, and resistance) compared with their parental taxa. However, there seems to be slow appreciation of this biological phenomenon in empirical and theoretical approaches to host-parasite interactions. This limits our understanding of the effects of hybridization on epidemiology, ecology, and evolution. Here, we address some pressing questions regarding the emergence and relevance of eukaryotic hybrid genotypes for disease dynamics.
The 125th anniversary symposium of Liverpool School of Tropical Medicine: the future of global health
Hussey L, Grant E, O'Heneghan-Yates N, Effron T, Mah S, Kelly L, McDonald K, Millar L, Blair K, Aliski E, Morris M, Johnson-Mills I, Mcleister L, Kelly E, Oram EJ, Guerra PC, Beck S, Edun-Hughes J, LaCourse J and Wright E
Unravelling malaria latency: parasite intrinsic and environmental factors influencing dormant liver stages
Zondag R, Ploeger E, Kocken CHM and Bártfai R
Hypnozoites - dormant Plasmodium parasites in the liver - can cause relapse infections and form a major obstacle to malaria eradication. The mechanisms controlling dormancy remain poorly understood, but hypnozoite formation and reactivation is likely regulated by a combination of parasite intrinsic factors and external stimuli. We reviewed current knowledge of Plasmodium dormancy and drew parallels with dormancy in other parasites and life-cycle stages. Epigenetic, post-transcriptional, or post-translational regulation probably jointly control hypnozoite dormancy at the intrinsic level. Additionally, environmental factors, such as vector availability, host wellbeing, and tissue microenvironment, could be instrumental to hypnozoite reactivation. A better understanding of how external stimuli influence the intrinsic reactivation switch at a mechanistic level will be required to expand the limited toolset to combat relapsing malaria.
Genetically attenuated parasites show promise as a next-generation malaria vaccine
Hafalla JCR, Borrmann S and Matuschewski K
Metabolically active, genetically attenuated Plasmodium falciparum parasite lines are promising second-generation malaria vaccine candidates. Lamers et al. and Roozen et al. demonstrated in recent Phase 1/2a trials that GA2 parasites, designed to arrest late during liver-stage development and transmitted via mosquito bites, can induce substantial protection against sporozoite challenge infection.
Neoparamoeba perurans
Lisnerová M, Pecková H and Fiala I
Advancing canopy-level entomological surveillance to monitor vector-borne and zoonotic disease dynamics
Le Breton C, Laporta GZ, Sallum MAM, Hesse H, Salgado-Lynn M, Manin BO and Fornace K
Faced with the increased frequency of zoonotic spillover in recent decades, emerging vector-borne diseases from nonhuman primates pose a significant threat to global public health. Understanding transmission dynamics driven by arthropod vectors between wildlife populations is critical for surveillance, modeling, and mitigation. Elevated canopy-level sampling is a valuable approach for elucidating vector behavior and sylvatic transmission. However, this is underused in many regions because of the logistical and mechanical challenges of repurposing ground-based trapping for the forest canopy. We review methods of canopy-level entomological surveillance, present case studies, and identify opportunities to integrate new technologies. Paired with robust experimental design, canopy-level trapping can complement existing surveillance of emerging zoonotic diseases and provide critical insights into the role of vectors driving spillover risks.
Sparicotyle chrysophrii
Mladineo I
Pitfalls in gut single-cell eukaryote research
Tito Tadeo RY and Stensvold CR
Gut single-celled eukaryotes (GSCEs) are found in billions of people worldwide, but we still know little about their functions and relationships in human gut ecology. Lately, retrospective analysis of bacterial data obtained by next-generation sequencing (NGS) methods has been used to identify links between GSCEs, gut bacteria, host metabolism, and host phenotypical traits, suggesting possible direct or indirect associations to favorable gut microbiome features and other health parameters. Here, we highlight some of the pitfalls related to the research strategy typically used so far and propose action points that could pave the way for a more accurate understanding of GSCEs in human health and disease.
Ctenocephalides felis (cat flea)
Pereira A, Cruz A, Novo T and Maia C
Genome-scale, functional screen of Plasmodium sexual replication
Prajapati SK and Williamson KC
Malaria mortality remains above 500 000 people annually, demonstrating the need for new and innovative control approaches. Using a genome-scale, functional screen of Plasmodium sexual replication, Sayers et al. identified over 300 genes essential for malaria transmission through the mosquito, providing many new candidates for drug and vaccine development.
Vaccines in a time of global boiling and megacities
Hotez PJ
Neglected tropical diseases are accelerating because of climate change and urbanization to create new clusters of vast urban areas beset by poverty and environmental degradation. These hot and contaminated megacities could enable the rise of parasitic and other tropical infections. A new generation of antiparasitic vaccines will be needed.
Malaria monoclonals block brain binding
Rogerson SJ, Walker IS and Aitken EH
In Plasmodium falciparum malaria, infected cells accumulate in blood vessels of organs, including the brain. Recently, Reyes et al. identified monoclonal antibodies that stop infected cells from binding to the endothelial protein C receptor (EPCR) in a model of brain blood vessels. EPCR-blocking monoclonals could form the basis of new treatments for severe malaria.
Ecological risk factors for the establishment of West Nile virus in Britain
Kirby G, Vaux AGC, Ferguson HM and Medlock JM
West Nile virus (WNV) is a zoonotic mosquito-borne virus which is emerging across Europe, largely due to climate and other environmental changes. Detection of WNV at increasingly northern latitudes raises concern that WNV may be introduced to Britain, where ecological conditions could eventually support sustained transmission. Establishment of WNV depends on spatial and temporal overlap between infectious migratory birds and native vectors. However, understanding of the distributions and phenology of key vector species in Britain is incomplete and must be updated to prioritise activities for WNV surveillance and response. Here, we review recent findings related to WNV ecology in continental Europe and the ecology of British mosquito species in order to evaluate the risk of WNV establishment in Britain.
Do tissue-dwelling trypanosomes sustain transmission populations?
Larcombe SD, Munday JC and McCulloch R
Trypanosoma brucei infectious populations are marked by considerable diversity in the parasite's major antigen, the variant surface glycoprotein (VSG). However, most parasites in the bloodstream are non-replicating, questioning how VSG diversity arises. Beaver et al. show that extravascular parasites in host tissues many explain this paradox and provide insight into trypanosome transmission.
Trypanosoma equiperdum
Hervé P, Bringaud F and Rivière L
Overview of national and local efforts to eliminate malaria in Thailand
Saeung M, Jupatanakul N, Hii J, Thanispong K, Chareonviriyaphap T and Manguin S
Success in the national control of malaria during the past decades has led to the reorientation of Thailand's program toward the elimination of this disease. The country established and implemented a National Malaria Elimination Strategy, resulting in a substantial decline in cases. Although the reduction varied, Sisaket Province stands out as a success. In accordance with the national strategy, the province adopted a 1-3-7 surveillance strategy and engaged in multisectoral collaboration, positioning itself to achieve malaria-free status and advancing to the prevention of re-establishment (PoR) phase. Scaling up this approach and applying the lessons learned from the success in Sisaket Province, as a solid foundation, could prove beneficial at both the national and international levels.
Ixodes ricinus (Castor bean tick)
Robbertse L, Šíma R, Hajdušek O and Perner J
Alteration of host gene and protein expression by manipulative parasites
Li CH and Poulin R
Host manipulation mechanisms remain poorly understood. We summarize recent studies using -omics approaches (transcriptomics, proteomics) to explore alteration in gene expression in hosts infected by manipulative parasites. To guide future research, we highlight the common pattern of neuromodulation, as well as other diverse combinations of functions targeted across different host manipulation systems.