Ticks and Tick-borne Diseases

Neoehrlichia mikurensis is widely detected in tick populations across Europe, yet its host range beyond small rodents remains poorly understood. Large wild mammals are frequently exposed to tick vectors, but their role in the transmission cycle of this bacterium is unclear. Wild boars (Sus scrofa) are among the most abundant large mammals in southern Sweden and commonly inhabit tick-infested environments, making them a potentially relevant host species. In this study, spleen samples from 87 wild boars collected between 2023 and 2025 across southern and central Sweden were analysed for the presence of N. mikurensis DNA using quantitative polymerase chain reaction. N. mikurensis DNA was not detected in any of the analysed samples, despite sampling in regions where the bacterium is known to be prevalent in ticks. These results indicate that wild boars may have a limited role in the maintenance of N. mikurensis in Sweden, although the possibility of rare or transient infection cannot be excluded. Despite being based on negative findings, this study contributes to a more comprehensive understanding of the host range of N. mikurensis and highlights the importance of continued evaluation of wildlife species in the transmission dynamics of tick-borne pathogens.

Tick-borne disease risk reflects the combined influence of vector abundance, pathogen prevalence, human exposure, and seasonal activity, yet these components are rarely integrated at the county level. We developed species-specific ecological risk scores for three medically important tick species (Acari: Ixodidae): Amblyomma americanum (L.), Dermacentor variabilis (Say), and Ixodes scapularis Say, across all 102 Illinois counties using data from 2019 to 2022. County-level predicted tick abundance and pathogen prevalence were scaled and combined using equal weights to generate primary vector-level risk scores. Robustness to the equal-weight assumption was evaluated by systematically varying the relative weights assigned to abundance and pathogen prevalence, while a separate sensitivity analysis incorporated reported tick-bite incidence where available. Associations with human disease were evaluated using negative binomial regression of tick-borne disease case counts on the corresponding risk scores, with county population included as an offset. Monthly phenology indicators were constructed by integrating human disease cases, reported tick bites, and sampled tick abundance and were evaluated in relation to temperature and precipitation. Seasonal risk was estimated by combining county-level vector risk with species-specific monthly phenology, generating monthly risk surfaces that were deployed through an interactive R Shiny application. Higher risk scores were significantly associated with greater disease case rates for each tick species. County rankings were highly stable under moderate changes in abundance and prevalence weighting. Seasonal activity differed among species, with A. americanum and D. variabilis showing concentrated warm-season risk and I. scapularis exhibiting a broader seasonal profile. These county-level seasonal risk maps identify where and when relative tick-borne disease risk is elevated in Illinois, supporting targeted prevention, surveillance, and clinical awareness.

Vegetation plays a critical role in shaping fine-scale tick density by structuring local microclimates, habitat resources, and host interactions that largely determine tick survival and activity, with implications for tick-borne disease transmission. Tick burden in the United States continues to increase, with annual reported tick-borne disease cases more than doubling from 2004 through 2019. These trends call for a broader scope of tick-mitigation strategies that go beyond traditional prevention measures that focus on personal protection; and there is an opportunity to inform habitat-level interventions. Here, we quantify fine-scale vegetation structure across 48 subplots at tick surveillance sites in Western Massachusetts to assess local habitat features associated with Ixodes scapularis density and potential for human-tick contact risk. In assessing understory and overstory vegetation attributes, this study identified life stage-specific differences in predicted tick density, with higher adult densities in areas with deeper leaf litter and presence of invasive plant species and nymphs associated with high presence of ferns. Both adult and nymphal Ix. scapularis were predicted at higher densities in relatively low basal area forests (18.9 to 26.9 m2/hectare). This study design provides a simple, low-cost framework for organizations looking to incorporate tick-informed forest measurement ecology into their public health tick surveillance protocols with minimal training.

Mosquito-borne orthoflaviviruses pose a significant threat to human and animal health worldwide. In Europe, West Nile (WNV), Usutu (USUV) and Bagaza (BAGV) viruses have expanded their geographic distribution and are detected with increasing frequency. Following the emergence of BAGV in 2021, we investigated the circulation dynamics and genomic diversity of orthoflaviviruses in southern Portugal, where their epidemiology remains poorly understood. Active Orthoflavivirus surveillance was conducted in birds and mosquitoes during 2021-2023 using serological and molecular assays, complemented by viral genome sequencing and phylogenomic analyses. Viral RNA was detected in 3.5% (41/1,171) of birds, while seroneutralization assays identified an overall seroprevalence of 55.3% (503/910). WNV RNA (lineage-1, strains WMed-1.2 and WMed-1.3) was detected annually in resident birds, including Alectoris rufa, Cyanopica cooki and Garrulus glandarius (1.5%, 18/1,171), and in Culex univittatus mosquitoes (0.8%, 2/255). Together with a WNV-specific seroprevalence of 28.5% (259/910) in birds, these findings support sustained local circulation. USUV RNA (Africa 3.1 sub-lineage) was detected in A. rufa in 2021 and 2023 (0.2%, 2/1,171), but seroprevalence was low (1.3%, 8/623), consistent with intermittent circulation. BAGV RNA (genotype-2) was detected only during the 2021 outbreak in A. rufa and Emberiza calandra (1.8%, 21/1,171), although BAGV-specific antibodies (6.6%, 60/910) were detected for up to two years after the outbreak, suggesting continued exposure or low-level circulation. Overall, our findings reveal contrasting circulation dynamics of orthoflaviviruses in southern Portugal. Sustained WNV circulation implies the need to strengthen avian and human surveillance in Portugal to better assess its public health risk, while the sporadic detection of USUV and BAGV underscores the value of long-term, integrated One Health surveillance for improving early warning and preparedness for emerging mosquito-borne diseases.

Orientia tsutsugamushi is the causative agent of scrub typhus infection in humans. This pathogen is transmitted into mammalian hosts including humans through Leptotrombidium mites. Till date, detection of O. tsutsugamushi in human was performed using PCR assay with 56kDa type specific antigen (TSA56), 47kDa outer membrane protein (47kDa-OMP) and groEL chaperonin gene. To understand the efficiency of different genes for the detection of O. tsutsugamushi in Leptotrombidium mites, we performed a comparative PCR assay with various universal primers targeting different genes including TSA56, 47kDa-OMP and groEL gene. We have collected 500 Leptotrombidium mites from Vellore, Tamil Nadu and, the mites were segregated into 50 pools with 10 mites in each pool were used for DNA extraction. The molecular detection of O. tsutsugamushi was performed using PCR assays (including conventional, nested and duplex PCR). The comparative PCR analysis showed nested PCR of groEL gene has high efficiency in detecting the presence of O. tsutsugamushi in chigger samples compared to other genes. Interestingly, groEL target demonstrated high efficiency for detection of O. tsutsugamushi in chigger samples and, when used with nested primers, can facilitate differentiation of O. tsutsugamushi from other rickettsial pathogens. Thus, we conclude groEL gene nested PCR assay can be used routinely to detect O. tsutsugamushi in trombiculid mites.

Mycobacterium bovis causes tuberculosis (TB) in cattle, badgers (Meles meles), other wildlife, and humans, posing major animal and public health challenges in Britain and Ireland. Shared genotypes between cattle and badgers have been reported at regional scales, but whether this concordance holds at finer spatial scales, where control interventions operate, and whether it varies by genotype combination, remains unknown. Resolving this is critical for interpreting cross-species transmission risk and designing targeted control measures. We analyzed 1,248 M. bovis isolates from cattle and badgers (Northern Ireland, 1986-2018), including samples from a small, densely sampled intervention research area, using Multi-Locus Variable Number of Tandem Repeats Analysis (MLVA) and kernel discriminant analysis (KDA) across multiple spatial scales (25-95% density contours). We identified 36 MLVA types with four shared between species and one (MLV06) endemic to the area. Spatial concordance varied by type combination and scale: MLVA004-MLVA297 showed strong, bidirectional, scale-robust concordance; MLVA006-MLVA297 was concordant only at fine spatial scales; MLVA004-MLVA006 showed weak, asymmetric concordance; and no concordance was detected when all three types were analysed together. Our findings reveal spatial concordance between shared M. bovis genotypes varied by genotype combination and scale, indicating genotype-specific dynamics within this multi-host system.

Lateral gene transfer (LGT) from organellar to eukaryotic genomes is ubiquitous, resulting in the presence of widespread nuclear mitochondrial DNA segments (NUMTs) and/or plastid gene transfers. While LGT from bacterial associates of eukaryotes is generally less common, many arthropod genomes are littered with LGT originating from Wolbachia (order Rickettsiales) - a vertically transmitted, obligate intracellular symbiont of invertebrates. This contrasts with Rickettsia, a related genus including many important human pathogens, which has not been shown to promulgate LGT within its arthropod vectors. Here, we present the 8.6 Gb genome of a cell line derived from A. variegatum (the tropical bont tick), which is the primary vector of Rickettsia africae (agent of African tick-bite fever). In addition to numerous NUMTs and diverse families of transposable elements, an almost-complete chromosome of R. africae origin was identified in the cell line genome, localised to the putative sex chromosome. Sequencing of field-collected A. variegatum confirmed the presence of this large LGT in wild ticks, although the absence of transferred genes from the R. africae plasmid provided a means to differentiate LGT from genuine rickettsial infections. These findings highlight the imperative to consider the possibility of LGT when screening vectors for pathogens by PCR.

Domestic dogs may influence human microbiota and act as reservoirs or sentinels for zoonotic bacteria, yet little is known about these dynamics in Southeast Asia. Using full-length 16S rRNA gene sequencing from rectal swabs, we analyzed microbiota from dog-owner pairs from four villages of rural Thailand (Nan province) to assess microbial diversity, shared taxa, and zoonotic potential. Dogs exhibited higher microbial and putative pathogen diversity than humans, particularly during the rainy season. While dog-owner pairs shared more bacteria than unrelated individuals, overall overlap remained limited - likely driven by their dogs free-roaming lifestyles and broader environmental exposures. However, co-occurrence of putative zoonotic pathogens such as Shigella spp. and Klebsiella pneumoniae suggests dogs could serve as useful indicators for specific public health risks, with further targeted pathogen screening needed to validate these results. Our findings highlight the value of integrating dogs into zoonotic surveillance programs, particularly in regions with free-ranging dog populations and close human-animal contact.

The 2026 Andes virus (ANDV) outbreak aboard the MV Hondius cruise ship resulted in 11 confirmed cases and 3 deaths and raised questions regarding the origin of infection, with much media focus resting on a landfill in Tierra del Fuego. We evaluated competing exposure hypotheses by assembling open data on reservoir host occurrences, rodent serosurveys, and historical ANDV outbreaks along with the index case's self-documented, publicly-posted citizen-science digital record of their movements. Historical outbreaks associated with human-to-human transmission were concentrated within a restricted region spanning southern Chile and adjacent western Argentina, coinciding with the distribution of the principal reservoir host, Oligoryzomys longicaudatus, and areas identified as elevated risk by multiple ecological and genetic models. The index case was documented within this transmission focus shortly before the putative exposure period. Together, our open data approach was able to rapidly locate initial exposure within the established ANDV transmission focus and develop scenarios to prioritise further epidemiological investigation.

Generating high-quality genome assemblies for small animals with large genomes is complex due to their small body size, DNA contamination, and repetitive elements. Ticks exemplify these complexities, while also being a global health threat to humans, domestic animals, and wildlife. Advances in long-read sequencing platforms now make it feasible to obtain large amounts of raw sequence data from individual specimens, but challenges remain. Key genome workflow challenges include error correction, assembly, transposable element annotation, and chromosome assignment and synteny. Here we examine three individual Dermacentor reticulatus ticks using deep Oxford Nanopore sequencing. Comparing and contrasting bioinformatic tools for raw read and assembly manipulation allows us to identify the parameters that provide a high-quality haploid genome assembly among 38 assemblies. We find Dorado error corrected raw read data from approximately two flow cells are needed, but limiting assembly coverage to 40x produces the highest quality assemblies. Then we examined the effects of optimal workflow parameters on downstream analyses of gene synteny and manual transposable element annotation of the three tick assemblies in comparison to an independent assembly of a fourth D. reticulatus individual from a different country. Gene synteny analysis allows chromosome assignment of scaffolds and transposable element identification was improved markedly with manual curation. Finally, we compared the genetic variation of D. reticulatus across two populations and found similar genetic diversity. Our study provides a clear workflow to obtain high-quality assemblies from Oxford Nanopore sequences and genetic characterization of a species with a large, complex, and repetitive genome.

Recent zoonotic coronavirus outbreaks have sparked an interest in understanding coronaviruses circulating in animal reservoirs. While bats are recognised as major reservoirs for these viruses, coronaviruses have also been detected in a wide range of terrestrial small mammals, particularly rodents. However, coronavirus diversity in these mammals, specifically in Europe, is still poorly characterised. In this study, we detected and characterised coronaviruses in terrestrial small mammals and bats from Belgium, France, Germany, and Ireland. We screened tissue samples from rodents and shrews and environmental bat guano using pan-coronavirus real-time and conventional PCRs, with positive results confirmed by sanger sequencing. Among 2667 bat and 1152 terrestrial mammal samples, we detected 59 positive samples, 36 from bats and 23 from rodents, from which we recovered 60 coronavirus sequences, spanning both Alphacoronavirus and Betacoronavirus lineages. Through next generation sequencing we identified one Pipistrellus pygmaeus bat guano sample carrying two distinct alphacoronaviruses, representing Nyctacovirus and Pedacovirus subgenera. Among rodents, most coronavirus-positive samples originated from a zoo in Belgium, where several CoV lineages co-circulated. The identified rodent coronaviruses clustered among previously described rodent-associated lineages, some of which also include human and other mammal-derived coronavirus sequences. Consistent with previous studies, we found sarbecoviruses in horseshoe bats (particularly Rhinolophus ferrumequinum and R. hipposideros) and merbecoviruses in Plecotus auritus bats, and these viruses are distantly related to the human coronaviruses of the respective families. Similar to bat coronaviruses, some rodent coronaviruses strains seemed to be association with specific rodent species. In conclusion, our study enhances the understanding of coronaviruses in rodents and bats, revealing potential hotspots for these viruses and their implication for human and animal health. These findings underscore the necessity for continued surveillance of coronaviruses in wildlife reservoirs to mitigate future zoonotic spillover risks.

Brucellosis is a globally distributed and widely under-appreciated zoonotic bacterial disease that causes infertility and abortion in livestock and febrile illness in humans, sometimes with debilitating sequelae. Brucellosis incidence estimates typically focus on acute presentations and range from 50 to 100 per 100,000 people per year for endemic settings, showing marked variation within and between countries. Estimating brucellosis incidence in low-resource settings is complicated by lack of access to and utilisation of health care and high-quality diagnostic testing for many people in rural communities. To estimate brucellosis incidence in a pastoralist population in northern Tanzania, we developed a Bayesian model that integrates multiple data sources including diagnostic test results from a hospital-based prevalence study performed in 2016-2017, test sensitivity and specificity, and data from a community-based healthcare utilisation survey in 2019-2020. We show that this population experienced a high incidence of brucellosis with wide uncertainty, with estimates of 387.6 (95% HPDI: 103.3 - 903.5) illnesses per 100,000 people per year for the total population, 199.7 (95% HPDI: 16.2 - 584.6) for individuals aged >15 years, and 632.4 (95% HPDI: 180.1 - 1379.4) for children aged [≤]15 years. These incidence estimates were among the highest in the world to date. The wide density intervals for these incidence estimates reflect uncertainty in the underlying parameter values used. Sensitivity analyses show that healthcare utilisation influenced incidence estimates the most. This result indicates that accounting for low levels of healthcare utilisation is essential to avoid under-estimating disease incidence. Our findings illustrate that brucellosis is a frequent cause of illness in this population. Increased access to treatment, prevention, and accurate diagnostic testing would greatly improve understanding of brucellosis epidemiology and the health of many people living in similar at-risk communities.

Background: Visceral leishmaniasis (VL) is caused by Leishmania donovani and differentiates under the influence of biotope-specific gut bacteria in the Leishmania donovani-transmitting sand fly vector, Phlebotomus argentipes, which coexists with the Leishmania donovani-non-transmitting Sergentomyia species in the Indian subcontinent. Hypothesis: Sergentomyia are primarily herpetophilic. Interestingly, we identified a specific population of anthropophilic Sergentomyia babu babu, a proven naturally non-competent vector for transmitting Leishmania donovani, with high abundance and human-bite incidences in VL-non-endemic regions, compared with VL-endemic regions of India. Thus, the possibility of egesting gut bacteria to humans from VL-non-transmitting Sergentomyia and inducing downstream immune cascades remains undeniable. Innovation: We characterized gut bacteria from anthropophilic Sergentomyia babu babu in both VL-endemic and VL-non-endemic regions of India and found that a heat-inactivated formulation of Heyndrickxia sporothermodurans [NCBI Sequence Read Archive (SRA): PRJNA1403236], isolated from anthropophilic Sergentomyia babu babu from a VL-non-endemic region, prevented and cured L. donovani infection by inducing IL-23~Th17. More importantly, it also prevented the initial parasite establishment by inducing phagocytosis, ROS, and TNF- in circulatory Ly6G-CD11b+Ly6Chi monocytes. To the best of our knowledge, this is the first report confirming that the gut bacteria of VL-non-transmitting sand flies are critical and need to be investigated in depth for developing therapeutics and/or prophylactics against visceral leishmaniasis (VL), and suggests that possible bite-transfer of gut bacteria from disease-non-transmitting vectors to hosts may restrict disease pathogenicity. Further clinical trials are needed to warrant (Indian patent: 202511041013, April 28, 2025).

While mosquito invasions and associated pathogens are increasingly prominent in Europe, evidence gaps remain for many northerly regions where proactive management interventions may be most effective. At the regional periphery of Europe, there remains a significant knowledge gap concerning mosquito vector distributions in Northern Ireland. This study aimed to address this major gap by systematically surveying larval and adult mosquito populations in key habitats (ponds, reedbeds, saltmarsh, wet grasslands, wet woodlands, and urban gardens). We further identified environmental drivers of important vector species abundance and screened collected specimens with molecular techniques to identify presence of cryptic human-biting vector species. In Northern Ireland, mosquitoes (including potential bridge vectors of West Nile and Usutu viruses) were found to be widely distributed. Between May and August 2025, a total of 2430 mosquitoes (951 adults and 1479 larvae) were collected over 196 trap nights and 76 larval collections. Collections encompassed 17 species, with Culex pipiens/torrentium being the most widely distributed and abundant taxon recorded. Mosquito abundances were greatest in reedbed habitats, related negatively with rainfall and peaked in June and July. A subset of Culex pipiens/torrentium mosquitoes were identified to species/biotype level using PCR, with the majority (89.3%) identified as Culex pipiens pipiens and 9.3% as Culex torrentium. Importantly, the first detections of Culex pipiens/molestus hybrids (1.8%) on the island of Ireland were found. This work underscores the wide, yet previously undocumented abundance and distribution of potential zoonotic vectors in Northern Ireland and provides an important baseline for management planning and future research, while contributing to broader understandings of environmental population drivers and distributions.

In sub-Saharan Africa, human and animal health is threatened by African trypanosomoses. These diseases are caused by trypanosomes that are transmitted primarily by tsetse flies. Vector control remains one of the most effective strategies for reducing disease transmission, but requires a minimum level of knowledge of the population biology, ecology and dispersal patterns of the targeted vectors. In this respect, population genetic approaches using appropriate polymorphic genetic markers can provide valuable tools to inform and optimize control strategies. Senegal is currently engaged in a national tsetse control programme and has been identified as a study country within a European Union-funded research initiative, COMBAT (controlling and progressively minimizing the burden of animal trypanosomosis). Baseline entomological studies are currently underway in the Sine Saloum (Southern Senegal). This preliminary study aimed to characterize the population genetic structure and connectivity of tsetse fly species present in Southern Senegal, Glossina palpalis gambiensis and G. morsitans submorsitans, in order to assess their population sizes (geographically and demographically), population densities and dispersal capacities. The two species exhibited markedly contrasting population structures. The first, G. p. gambiensis, displayed an isolation by distance with rather dense subpopulations exchanging immigrants at short distances (1.6 km/generation) and continuously from Sine-Saloum to Casamance, in line with the apparent continuity of the mangrove network found along this coast. In contrast, G. m. submorsitans presented a relatively dense population over a 75 km wide area, fragmented into sparsely distributed, very dense and interconnected pockets. These findings indicate that G. p. gambiensis likely constitutes a large metapopulation comprising 3266 effective individuals on average (and up to 7765), whereas G. m. submorsitans appeared as a single and large population, scattered in small pockets that could be readily replenished by immigrants from distant areas in case of control. These results suggest that elimination is not a realistic option for any of these two populations. Alternatively, localized integrated pest management is likely to be the most effective approach for controlling the negative effects of these biting flies on domestic animals, by reducing trypanosome transmission. However, further entomological investigations and the use of more informative genetic markers are needed to obtain a more precise understanding of the epidemiological processes involved.

A native entomopathogenic nematode isolate, Heterorhabditis indica Che4.1, was recovered from soils in Valencia (Spain), and its symbiotic bacterium, Photorhabdus akhurstii Che4.1, was isolated and characterized. Nematode identification was confirmed by ITS and 28S rDNA sequencing, while genome-based analyses supported the taxonomic assignment of the bacterial symbiont. The nematode-bacterium complex exhibited insecticidal activity against Spodoptera exigua and Spodoptera littoralis. H. indica Che4.1 showed an LC of 53.7 infective juveniles (IJs)/mL against S. exigua, comparable to that of the commercial reference Larvanem (54.3 IJs/mL). Against S. littoralis, Che4.1 exhibited an approximately twofold lower LC than Larvanem (77.3 versus 155.9 IJs/mL), with non-overlapping 95% confidence intervals. The complete genome of P. akhurstii Che4.1 consists of a single circular chromosome of 5.66 Mb encoding a diverse repertoire of putative virulence factors, including toxin complex (Tc) components, YenTc-like proteins, Mcf toxins, App-family proteins, Pra/Prb proteins, and chitinases, together with several predicted secondary metabolite biosynthetic gene clusters. LC-MS/MS analyses of bacterial culture supernatants and infected insect cadavers detected multiple predicted virulence-associated proteins, including Tc-related, YenTc-like, App-family, and Pra/Prb proteins. In addition, bacterial cell-free supernatants caused 68.8-81.3% mortality in S. exigua neonates under laboratory conditions. Together, these findings reveal a diverse repertoire of potential virulence determinants in P. akhurstii Che4.1 and demonstrate the insecticidal potential of its native nematodebacterium complex. The performance of H. indica Che4.1 relative to a commercial reference supports further evaluation of this isolate for biological control of Spodoptera spp., particularly under greenhouse and field conditions.

Importance: Coccidioidomycosis, also known as Valley fever, is a serious fungal disease caused by inhaling Coccidioides spores aerosolized from the soil. Despite rising public health concern, the distribution and incidence of coccidioidomycosis in the US remain poorly characterized as not all states are required to report cases, and case under-ascertainment is presumed to be high, particularly outside of the endemic region. Objective: To estimate monthly, county-level coccidioidomycosis incidence across the US while accounting for widespread under-ascertainment. Design, Setting, and Participants: We integrated multisource data, including human cases diagnosed in electronic health records, serological testing of dogs, and ecological and sociodemographic predictors, in a machine learning model estimating monthly, county-level coccidioidomycosis incidence. The model was trained on surveillance data from Arizona and California from 2013 to 2023, then applied to predict incidence in states across the contiguous US over the same time period. Main Outcomes and Measures: Incidence of coccidioidomycosis at the monthly county level. Results: The model predicted coccidioidomycosis incidence from 2013 to 2023 for 3,108 counties from all states in the contiguous US. The model identified 60 counties in non-reporting states where predicted incidence was [≥]2 cases per 100,000 population (considered moderate to high incidence). In states with mandatory reporting outside of Arizona and California, the model predicted county-level incidence rates that were 28% higher (95% bootstrap interval, 0.1%-69.8%) than those captured in national surveillance, equating to a total of 608 potentially missed cases per year (95% bootstrap interval, 340-964). Conclusions and Relevance: In this cross-sectional study, the model quantified case under-ascertainment for coccidioidomycosis relative to Arizona and California, and highlighted the potential for alternative data sources to fill in gaps in mandatory reporting. Estimating incidence while accounting for under-ascertainment and non-reporting may help efforts to improve public and physician awareness and to detect emergence in new regions.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging, tick-borne zoonosis caused by severe fever with thrombocytopenia syndrome virus (SFTSV) and is associated with high case-fatality rates in humans and cats. No vaccines or antiviral drugs are currently available for the prevention or treatment of feline SFTS. Because cats with SFTS often develop blood viral RNA loads exceeding those in severe human cases, we hypothesized that some naturally recovered cats develop strong neutralizing antibody responses and may serve as a potential source of antibody-rich serum for passive immunotherapy. We compared 80% plaque-reduction neutralization test (PRNT80) titers in convalescent sera from six human SFTS survivors and 14 cats that had recovered from naturally acquired SFTS, then evaluated the therapeutic efficacy of convalescent cat serum in SFTSV-infected, interferon receptor-deficient AG129 mice. Some SFTS-recovered cats showed high PRNT80 titers. Passive administration of high-titer convalescent cat serum early after infection protected SFTSV-infected mice. A single dose given at 2 or 3 days post-infection completely protected mice, whereas treatment at 4 days post-infection resulted in 40% survival. Administration on two consecutive days was associated with lower late-phase viremia in surviving mice. Sera from three independent SFTS-recovered cats improved survival, with greater effects observed for sera with higher neutralizing antibody titers. These findings indicate that some cats recovering from SFTS can develop high neutralizing antibody titers and their sera can exert therapeutic effects in an SFTSV-infected mouse model. These findings support further evaluation of passive immunotherapy as a treatment strategy for feline SFTS.

Aedes albopictus (Skuse), the Asian tiger mosquito, is a highly competent arboviral vector whose range has expanded substantially across the United States over the past four decades. Despite predictive models placing Nebraska within the species' climatically suitable range, its establishment status in the state has remained poorly characterized. Here, we report results from a nine-year mosquito surveillance program (2017-2025) conducted across 44 Nebraska counties in collaboration with the Nebraska Department of Health and Human Services. Ae. albopictus was detected in five counties, with sustained, annually increasing populations documented in Richardson, Douglas, and Lancaster counties. Richardson County recorded continuous detections during 2017-2025, with proportional representation rising to 60.50% of collected mosquitoes by 2025. In Douglas and Lancaster counties, temporal advancement of first seasonal detection in 2024 and 2025 provide evidence consistent with successful overwintering rather than annual reintroduction. A cumulative degree-day model predicted adult emergence in mid-May across all county-year combinations, consistently preceding trap deployment by two to seven weeks and revealing a systematic early-season surveillance gap. Generalized linear mixed-effects models indicated that trap-level detection persistence, rather than urban location, was the primary predictor of yearly Ae. albopictus positivity, suggesting that current invasion dynamics are driven by focal source populations. These findings provide strong evidence for the establishment of Ae. albopictus in eastern Nebraska and highlight the need for earlier seasonal surveillance and standardized criteria to define establishment in northward-expanding vector populations.

Marmosets (MAR, Callithrix jacchus) are nonhuman primates extensively studied in a broad array of preclinical biomedical research areas. However, the limited number of available immunological reagents remains a critical shortcoming of these models. We successfully developed monoclonal antibodies (mAbs) pairs that can be used in immunoassays for the identification and quantification of the biomarkers of inflammation C-reactive protein (CRP), CXCL-10 (IP-10), interleukin (IL)-4, IL-6, and IL-10. Recombinant MAR protein variants were produced in mammalian cells, purified and used for mice immunization. Hybridoma clones were selected first for their capacity to bind the recombinant proteins. All possible pair combinations of these mAbs were then tested for their capacity to identify their targets in MAR-derived samples. These MAR samples consisted of supernatant of PBMCs exposed ex vivo to different stimulants, and plasma samples from animals stimulated in vivo with a low-dose intravenous LPS inoculation. The majority of the mAbs that recognized the recombinant proteins failed to bind to the MAR-derived homologs. However, we found MAR-derived reactive mAbs and selected pairs with optimal sensitivity and signal-to-noise ratio for immunoassays that included Luminex multiplexing assays, ELISA, and ELISpot assays. These immunoreagents and assays will improve the translational value of different MAR biomedical models.