Publication date: November 2025 Source: #ticks and #tick-borne Diseases, Volume 16, Issue 6 Author(s): Jiangping Ren

CONCLUSIONS: The present data indicated that EtAMA2 had dual functions as a virulence factor critical for early invasion and a promising vaccine antigen. This study thereby provided new insights for future drug target screening and development of a vaccine against coccidiosis.

Publication date: Available online 6 December 2025 Source: Acta Tropica Author(s): Eira Nurfarisha Mohd Latif, Aizura Syafinaz Ahmad Adlan, Yee-Ling Lau, Fei-Wen Cheong

Jingmenvirus is a group of segmented flaviviruses detected in arthropods and vertebrates that has attracted growing public health interest due to the recognition of some members as emerging human arboviral pathogens. As part of a study aimed at deciphering the virome of medically and veterinary important ticks in Costa Rica, we detected Jingmen tick virus (JMTV) in engorged Amblyomma mixtum ticks collected from horses. We assembled three complete genome segments and one partial segment from tick pools. Phylogenetic analyses revealed that JMTV from Costa Rica (JMTV Costa Rica) shares a common viral ancestor with JMTV viruses identified in ticks from the Caribbean and Latin America, with putative reassortment events detected across segments. Two distinct clades of Jingmen viruses were identified in the American continent, suggesting two distinct introductions: one from Europe/Asia and the other from Africa/Asia. Of note, JMTV Costa Rica falls in the same clade as viruses from Europe and Turkey, including sequences found in humans. Our study constitutes the first report of JMTV associated with Amblyomma mixtum. This tick species feeds on a wide range of hosts, including wildlife, domestic animals, and frequently parasitizes humans in Central America. Further research involving the detection of active or past infections in humans and horses after tick bites are needed to evaluate the risk of JMTV-associated arboviral infection in Central America, including Costa Rica.

Publication date: Available online 5 December 2025 Source: Acta Tropica Author(s): Muhammad Fajri Rohkmad, Semuel Sandy, Mirna Widiyanti, Setyo Adiningsih, Agung Puja Kesuma, Yustinus Maladan, Yusnita Mirna Anggraeni, Tri Ramadhani, Mara Ipa, Muhammad Choirul Hidajat, Hanna Kawulur, Chandra Mukti Kurniawan, Adrianus Don Kopo, NLP Indi Dharmayanti, Triwibowo Ambar Garjito, Antonius Oktavian, Harimat Hendarwan

Dengue fever is an arbovirus disease caused by the dengue virus and has been diagnosed in Burkina Faso for many years. In recent decades, the disease has become a growing concern, thereby impacting the public health system. Several factors contribute to the pathogenesis of dengue fever, including the immune system and the virulence of different serotypes. Additionally, multiple complex conditions, including the spread of the Aedes mosquito vector and meteorological factors, contribute to the...

by Victoria M. Cox, Katie Tiley, Roberto Rosa, Andrea Pugliese, Paola Angelini, Marco Carrieri, Samir Bhatt, Marco Tamba, Giovanni Marini, Mattia Calzolari, Ilaria Dorigatti As West Nile Virus (WNV) is expanding its geographical range across Europe, there is an urgent need to characterise and better understand its transmission drivers to inform public health surveillance, disease control, and preparedness planning. We utilised 10 consecutive years of large-scale and fine-resolution WNV entomological field surveillance data from the Emilia-Romagna region in northern Italy, to evaluate the relationships between WNV infection rates in Culex mosquitoes and environmental and climatic conditions as well as WNV presence in the avian reservoir. We used fine-scale spatiotemporal regression models including non-linearities, to assess the drivers of presence and prevalence of WNV-positive mosquitoes. We validated the model estimates against reported cases of human WNV neuroinvasive disease in the region. We found evidence of established hotspots of mosquito WNV infection across multiple years. The presence of WNV in local birds was positively associated with presence and prevalence of WNV-positive mosquitoes (mean regression coefficients: 0.776 (95% CrI, 0.469, 1.08) and 0.226 (95% CrI, 0.053, 0.399) respectively), and the proportion of agricultural land use was positively associated with presence of WNV-positive mosquitoes (4.20 (95% CrI, 2.65, 5.75)). We identified a minimum temperature threshold around 13°C, below which mosquito WNV infection was reduced. Our findings provide evidence of the impact of temperature and environment on Culex populations and WNV infection dynamics at the local level, which were highly correlated with human case reports. The estimated role of the minimum temperature and the observed and projected increase in this variable under climate change suggest that WNV will continue to represent a risk for human and animal health in the region in future decades. Future work should focus on better understanding the mechanisms behind infection drivers, on the optimal implementation of surveillance and control activities around high-risk areas, and on the assessment of how specific land use practices could represent potential solutions to WNV infection.

Plasmodium-induced malaria infection remains a leading global health threat. Host defense peptides (HDPs), key components of innate immunity, target multiple stages of Plasmodium development through direct antimicrobial activity and immunomodulation. These peptides represent promising agents as antimalarial compounds due to their dual role in directly targeting Plasmodium parasites and modulating host immune responses. Several HDPs, including defensins, cathelicidins, NK-2 peptide, platelet...

Publication date: November 2025 Source: #ticks and #tick-borne Diseases, Volume 16, Issue 6 Author(s): Hinpetch Daungsupawong, Viroj Wiwanitkit

Salmonella Typhimurium is a major zoonotic pathogen, with pigs acting as important subclinical carriers. To explore the specific intestinal immune response at the cellular level, we used Single-cell RNA sequencing (scRNA-seq), enabling detailed analysis of immune cell types and gene expression profiles during infection. In addition to enterocytes, our results revealed the presence of diverse immune populations, including monocytes/macrophages, dendritic cells, innate lymphoid cells (ILCs), thirteen T cell subtypes and five B cell populations were identified, revealing pronounced infection-driven alterations in cellular composition and transcriptional states. Among T cells, naive and follicular CD4+/CD8+ {beta} T cells and NK T cells were expanded, whereas effector CD8+ T cells and CD2- and SELLhi {gamma} {delta} T cells were decreased. B-cell populations shifted toward activated and cycling states, with decreased antibody-secreting, resting, and transitioning cells. Dendritic cells and monocyte/macrophage populations were expanded, and group 3 ILCs and enterocytes were markedly reduced. Pathway analyses revealed robust cell type-specific immunometabolic remodeling, including enhanced protein-folding and stress-adaptive pathways in T and B cells, heightened inflammatory, interferon, and cytokine signaling in myeloid populations, and coordinated metabolic and immune adjustments in epithelial cells, highlighting the complexity of host responses to Salmonella infection. This study provides the first scRNA-seq landscape of the porcine ileum during S. Typhimurium infection, offering insight into host immune cell dynamics and immunometabolic responses.

Objectives: This study provides the first confirmed record of the malaria vector Anopheles pseudopunctipennis in Cochabamba city, Bolivia, ending nearly 90 years of suspected presence since the malaria epidemics of the 1930s and 1940s. Additionally, it assesses the potential suitability of the region for this mosquito species. Methods: Mosquito larvae were collected as part of a comprehensive survey of Culicidae in Cochabamba city and its suburbs. Larvae of An. pseudopunctipennis were collected on April 16, 2024, and reared to the fourth instar in the laboratory. One male specimen obtained from collected larvae was pinned. Specimens were morphologically identified using a standard identification key and species re-description. The larval identification was based on its unique spiracular apparatus, while adults were identified by their characteristic black hind tarsomeres and unspotted wing costa. The specimens are preserved in the Laboratory of Medical Entomology at UMSS, Cochabamba. Results: A single larval habitat was identified in Lincoln Park, in the center of Cochabamba. It consisted of a 184-square-meter pond with a cement bottom, clear water with very slow flow from a small spring, and abundant Rhizoclonium algae. A Maxent habitat suitability model indicated that the Cochabamba Valley provides suitable environmental conditions for An. pseudopunctipennis. Conclusions: This study provides the first concrete evidence of An. pseudopunctipennis in Cochabamba city, confirming its presence after decades of speculation. However, its low abundance and limited larval habitats due to urbanization and pollution suggest that it poses no significant malaria transmission risk in the area.

In temperate regions, vector-borne disease risk is mediated by cold winter conditions, however, the cold tolerance of key vector taxa remains poorly understood. Culicoides biting midges are the primary vectors of several pathogens of medical and veterinary importance including bluetongue virus, where seasonal cold weather in temperate regions limits midge activity and pathogen transmission. Here, we provide the first comprehensive assessment of cold tolerance across all developmental stages of Culicoides nubeculosus, a widely used laboratory species that is endemic to northern Europe. Eggs, first-instar larvae, fourth-instar larvae, pupae, and adults were exposed to acute (1 h) and extended (6 and 24 h) cold treatments spanning -1 to -18 {degrees}C, with survival, development, emergence, and adult wing size quantified. Culicoides nubeculosus showed substantial but stage-specific cold tolerance, with survival limits of [≤] -18 {degrees}C for eggs, -14 {degrees}C for pupae, -10 {degrees}C for L1 larvae and adults, and -7 {degrees}C for L4 larvae. While the effect of cold exposure duration varied across temperatures and life stages, extended exposure generally reduced survival at lower temperatures. Cold stress caused sublethal effects, including reduced adult emergence when eggs or larvae were exposed and reductions in adult wing size of up to ~10%, depending on the life stage. These results reveal substantial cold tolerance across the full life history of C. nubeculosus, suggesting that factors beyond temperature influence population phenology. Our findings provide new insights into Culicoides ecology, with implications for seasonal vector population dynamics and arbovirus transmission risk in temperate regions.

Mitophagy selectively removes depolarised and damaged mitochondria, promoting cell viability. Some members of the Orthoflavivirus genus activate mitophagy to allow extended replication times in a surviving cell, while others inhibit mitophagy to favour viral spread. Viral genome replication is catalysed by non-structural protein 5 (NS5), the largest and most conserved protein in the orthoflaviviruses (OFVs). Here, we used quantitative proteomics to identify host cell interactors of Zika virus (ZIKV), Usutu virus (USUV), and West Nile virus (WNV) NS5 proteins. A total of 141 cellular interactors were found, of which 26 were common to all three NS5s. RNA interference (RNAi)-mediated knockdown of those proteins most significantly enriched revealed putative proviral and restriction activities associated. Knockdown of host myoferlin and LGALS3BP led to decreases in the virus titres, suggesting that both positively promote viral replication. Silencing of mitophagy-related prohibitin 2 (PHB2) resulted in significant increases in ZIKV and USUV titres, as well as intracellular levels of genomic RNA. Supporting a connection between this antiviral behaviour and mitophagy, an inhibitor of this pathway also led to larger virus titres and genomic viral RNA. During an infection, PHB2 protein levels gradually decreased, becoming transiently undetectable, and suggesting that it is specifically targeted and degraded by virus-mediated activities. Ectopic expression of NS5 alone did not affect PHB2 intracellular abundance, however a significant decrease was observed in cells expressing the viral protease NS2B/NS3. Its elimination, however, was more pronounced in cells where both viral enzymes were co-expressed, suggesting that NS5 could be assisting PHB2 recognition by NS2B/NS3. Overall, our results support that PHB2 is an orthoflaviviral restriction factor which is targeted for degradation to favour viral replication.

CONCLUSIONS: This study presents the first comprehensive evidence of diverse tick-borne pathogens circulating in cattle ticks from Lao PDR, revealing high genetic similarity to globally recognized strains alongside distinct region-specific detection patterns. Notably, it also constitutes the first report of A. marginale, E. minasensis, B. bigemina, B. bovis, and Theileria sp. in cattle ticks in the country. These findings underscore the urgent need for integrated tick and pathogen surveillance...

Parasitic crustaceans represent a significant threat to both freshwater and marine aquaculture, with several families capable of inducing severe diseases with high mortality rates and therefore significant economic losses. Among them, isopods of the genus Braga (Cymothoidae) are haematophagous parasites of neotropical fish, causing anaemia, tissue damage, and mortality. Braga nasuta, endemic to Brazil, has been reported from various hosts, including ornamental species exported worldwide. During routine examination of imported cardinal tetra (Paracheirodon axelrodi, Schultz, 1956), the authors detected that one of the fish harbored an adult male isopod (~6.21 mm long, 2.66 mm wide) attached anterior to the dorsal fin. Based on morphological identification, the parasite was identified as Braga nasuta. No secondary pathogens were observed in affected fish. Given the global trade in ornamental species, the introduction of B. nasuta into non-native regions underscores the importance of quarantine and parasite monitoring. While the potential ability of this parasite to establish populations in Europe requires further studies, vigilance is warranted to prevent potential spread and ecological impact. In this study, the authors document the first occurrence of B. nasuta in Europe, detected on a cardinal tetra (P. axelrodi) imported to a Hungarian public aquarium.

Background: Aedes aegypti mosquitoes use diverse chemosensory cues to select an oviposition site. These cues are thought to provide information on factors such as food availability, predators, pathogens, and competitors. Most research on the stimuli attracting female Ae. aegypti to oviposit in natural or artificial containers has focused on the properties of the vessel and water, such as size, color, water quality, concentration of dissolved organic matter, and microorganisms. One understudied aspect of oviposition containers is periphyton, the complex community of microorganisms that can grow on the inner walls of containers where gravid Ae. aegypti females lay their eggs. Periphyton can potentially act as an indicator of the suitability of the container for females looking for an oviposition site, and as a source of food for future mosquito larvae. We were interested in understanding if container periphyton attracts gravid Ae. aegypti females for oviposition and to assess the microbial composition of the periphyton community. Methods: To answer these questions, we conducted a series of attraction and oviposition assays and collected samples from the periphyton used in these assays for 16s rRNA fingerprinting. Results: We demonstrated that periphyton promotes oviposition by Ae. aegypti. Results from 16s rRNA fingerprinting of periphyton specimens revealed that these communities exhibit high complexity and contain microbial taxa from several classes, including Cyanobacteria, Proteobacteria, Anaerolineae, and Cytophagia. Conclusions: Understanding the chemosensory interactions between mosquitoes and periphyton involved in egg laying could prompt the development and formulation of novel attractants useful in mosquito control.

BACKGROUND: Accurate diagnosis is essential for achieving the 2030 goal of eliminating gambiense human African trypanosomiasis (gHAT) transmission. In recent years, novel screening and confirmatory laboratory tests, including rapid diagnostic tests incorporating recombinant antigens (2nd generation RDTs), an inhibition ELISA (iELISA) and RT-qPCR, have been developed. However, data on their diagnostic performance remain limited. This study aimed to evaluate the specificity of these newly...

Publication date: Available online 5 December 2025 Source: Acta Tropica Author(s): Attila J Trájer

Cambodia is approaching the final stages of malaria elimination, reporting only 1,384 cases in 2023 and aiming to eliminate all species of human malaria by 2025. Given the importance of surveillance in control and elimination efforts, the National Center for Parasitology, Entomology, and Malaria Control (CNM) elected to assess its malaria surveillance system to identify strengths and gaps and make recommendations. The WHO Malaria Surveillance Assessment Toolkit was utilized to evaluate 68...

AbstractSince its invasion of the United States in the 1980s, #Aedes albopictus (Skuse, 1894) has become a major pest and a significant public health threat in the Southeastern United States. Despite its importance, we know little about its population genetics at fine spatial scales that correspond to the level of management units. To remedy this lack of information, we analyzed Ae. albopictus spatial variation in mosquito abundance and genetic structure in an urban–rural landscape over 2 years (2016 and 2018) in Wake County, NC, United States. We used a reduced representation sequencing method to generate between 1,100 and 30,000 single-nucleotide polymorphisms for population genetic analyses. We found spatial variation in both the abundance and genetic diversity, and significant differences in genetic divergence among sites that varied between the 2 years. The year-to-year variation in the population genetic patterns at the within-county scale suggests a dynamic system that requires extensive geographic, temporal, and genomic sampling to resolve.

CONCLUSIONS: Our results suggest that human YF epidemics are largely driven by vaccination coverage and environmental conditions that aid transmission in vectors and hosts. This sustains the local sylvatic cycle across administrative and political boundaries. These results reinforce the need to study YF spillover and dispersion dynamics at the human-animal-environment interface to improve disease control and devise multisectoral mitigation strategies.

by Jing Chen, Lin han Zhong, Jin xia Chen, Hui xin Song, Lin ke Zou, Xiao qing Bi, Bing qian Zhao, Mei zhen Li, Kun Li, Kang Wang, Jia jun Yang, Jin Cui, Li Wang, Bin Zhou Flaviviridae viruses constitute formidable zoonotic agents with substantial global health and economic ramifications, attributable to their adeptness at circumventing host immune surveillance and establishing persistent infections across human and animal populations. Despite their pervasive impact, broadly effective antiviral strategies remain elusive. Emerging studies underscore the pivotal role of RNA modifications, particularly 5-methylcytosine (m5C), in fine-tuning host–pathogen interactions. Expanding upon prior evidence linking NSUN2-mediated m5C deposition to Classical swine fever virus (CSFV, Pestivirus of Flaviviridae) persistence, the present study demonstrates that Japanese encephalitis virus (JEV, Flavivirus of Flaviviridae) similarly commandeers host epitranscriptomic machinery. Specifically, JEV-encoded RNA-dependent RNA polymerase (RdRp) engages the SAE1 to induce SUMO3/4-mediated stabilization of NSUN2. Elevated NSUN2 promotes m5C methylation of Cebpd mRNA, expediting transcript degradation and dampening cGAS-STING-driven antiviral signaling. This regulatory cascade facilitates viral replication and persistence. This regulatory axis supports sustained viral replication and persistence. Notably, a homologous mechanism is operative in Orthomyxoviridae infection, indicating evolutionary convergence on NSUN2 as a proviral effector. Overall, these unprecedented findings define a conserved RdRp-SAE1-NSUN2-CEBPD axis as a key epitranscriptomic immune evasion strategy and nominate m5C methyltransferases as tractable targets for host-directed, broad-spectrum antiviral therapy.

Publication date: Available online 5 December 2025 Source: Acta Tropica Author(s): Muhammad Fajri Rohkmad, Semuel Sandy, Mirna Widiyanti, Setyo Adiningsih, Agung Puja Kesuma, Yustinus Maladan, Yusnita Mirna Anggraeni, Tri Ramadhani, Mara Ipa, Muhammad Choirul Hidajat, Hanna Kawulur, Chandra Mukti Kurniawan, Adrianus Don Kopo, NLP Indi Dharmayanti, Triwibowo Ambar Garjito, Antonius Oktavian, Harimat Hendarwan

Bluetongue virus (BTV), with a genome of ten double-stranded RNA segments (S1-S10), is an emerging animal pathogen causing major economic losses in livestock worldwide. BTV replication involves RNA-RNA and RNA-protein interactions, with RNA-binding proteins, VP6 and NS2 playing key roles in genome assembly and RNA packaging. To explore the dynamics of RNA segment interactions and the roles of VP6 and NS2 in RNA complex formation, we used RNA fluorescence in-situ Hybridisation Chain Reaction (HCR), along with site-specific mutagenesis and reverse genetics. We found that RNA segments interact sequentially, from the smallest (S10) to the largest (S1), forming a single complex that includes the entire genome. This process is independent of VP6 or NS2, although NS2 enhances the assembly of larger segments. Additionally, we show that VP6 binds to +ssRNAs before their incorporation into viral assembly factory (inclusion bodies/VIBs). These findings reveal that RNA-RNA interactions, rather than primary replicase proteins, govern the sorting and recruitment of genome segments. Our data offer new insights into BTV RNA packaging, showing that genome segments destined for packaging and dsRNA synthesis are segregated through complex formation, distinct from +ssRNAs used in protein synthesis, including those encoding the replicase complex.

Arthropod-borne viruses, also known as arboviruses, cause disease worldwide. These viruses alternate between vertebrates and arthropods, facing distinct selection pressures in each host type. Surprisingly, whether specific mechanisms facilitate host alternation remains unclear. Here, we use bluetongue virus (BTV) as a model to investigate two phenomena potentially facilitating host alternation: adaptive mutations and genome formula variation (GFV). First, we searched for mutations indicative of host adaptation in cattle, sheep, and midges infected during an epizooty. We found a limited number of parallel mutations. This result suggests that adaptive mutations are not a main mechanism facilitating host alternation in BTV. Second, we investigated a link of GFV with a proxy of viral fitness, the speed of virus dissemination in midges. We analyzed the genome formula (GF) in experimentally-infected Culicoides imicola midges, either with an infection disseminated into the head or not. GFs differed between dissemination levels, suggesting a link between GF and the speed of virus dissemination. Finally, we investigated the mechanisms underlying GF generation. Currently, two scenarios have been proposed: random generation followed by selection, or directed generation through molecular mechanisms. To limit the influence of selection, we analyzed the GF after a single replication cycle in cell culture. GF values converged towards specific values among replicates. Moreover, GFs differed between arthropod and vertebrate cells. Thus, GF generation is not purely stochastic and is probably influenced by host-specific mechanisms. Overall, our findings highlight GFV as a potential mechanism facilitating BTV alternation across hosts, but not classical mutation-driven evolution.