Biology subjects

Hamik, J.

Publications and source records attributed to Hamik, J..

3 recordsLinked to original sources

bioRxiv2026

Long-Term Surveillance Reveals Establishment of Aedes albopictus in Eastern Nebraska, USA

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.

ecology↗

bioRxiv2026

When clades collide: Genomic admixture in blacklegged ticks (Ixodes scapularis) from the Great Plains

Ixodes scapularis ticks transmit a number of pathogens important to human health, including Borrelia burgdorferi, the causative agent of Lyme disease. While I. scapularis is found across the Eastern United States, Lyme disease transmission is largely limited to the Northeast and Upper Midwest and is nearly absent in the South. This indicates that differences in northern versus southern clades of I. scapularis are associated with differences in Lyme disease transmission risk. I. scapularis is undergoing range expansion, including into the Great Plains region of the United States. Determining where I. scapularis populations in the Great Plains originated can inform future risk of Lyme disease transmission in this region. In this study, we use a population genomics framework to characterize diversity, structure, and B. burgdorferi infection rates of I. scapularis populations in the Great Plains region. We generated whole genome sequence data and single nucleotide polymorphism (SNP) datasets from I. scapularis ticks collected in Iowa, Kansas, Nebraska, and South Dakota to compare to publicly available data from across the species range. Our analysis of 200 I. scapularis SNP datasets indicated geographically well-defined populations that correspond to historical northern and southern ancestral clades of I. scapularis. Ticks from South Dakota, Iowa, and northeastern Nebraska are genetically similar populations from the Upper Midwest, while ticks from Kansas are more genetically similar to ticks from the Southeast. Ticks collected in the central eastern region of Nebraska, however, represent an evenly admixed population of both northern and southern genomic backgrounds. Analysis of B. burgdorferi reads from genomic datasets shows [~]50% infection rate in ticks from Iowa and northeastern Nebraska, whereas ticks from Kansas show no evidence of B. burgdorferi infection. Of note, evenly admixed ticks from the central eastern region of Nebraska also show no evidence of B. burgdorferi infection. These results provide further evidence that tick genomics may influence traits associated with B. burgdorferi infection status, and thus the potential for Lyme disease transmission. As the range of I. scapularis continues to expand, bringing historically isolated populations into contact, there is a clear need to understand the consequence of genomic admixture for B. burgdorferi transmission potential to inform future risk of Lyme disease in the United States.

genomics↗

bioRxiv2025

Genomic Characterization of a Severe West Nile Virus Transmission Season using a Single Reaction Amplicon Sequencing Approach

West Nile virus (WNV) is an endemic arthropod-borne virus that has routinely caused seasonal outbreaks in the United States since it was first detected in 1999. While phylogenetic studies have shown how WNV has diversified and undergone genotype replacement since introduction, more geographically focused studies are needed to understand intricate transmission dynamics at local and regional scales. In this study, we validate the IDT xGen WNV panel, a novel single reaction amplicon-based Next-Generation Sequencing approach, to generate high-quality WNV genomes and compare it to the "Primal Scheme" assay for WNV, a common amplicon sequencing strategy. We show that the IDT xGen WNV panel generated complete and accurate WNV genomes and was more robust to amplicon drop out compared to the current sequencing approaches. Additionally, we used this approach to generate 100 complete WNV genomes from surveillance pools of mosquitoes collected in Nebraska during the 2023 outbreak. Our discrete phylogeographic analysis revealed substantial genetic diversity in WNV genomes from 2023 with minimal clustering across the state. This study demonstrated the utility of a single reaction amplicon-based sequencing approach to generate quality WNV genomes from routine surveillance samples and characterize WNV transmission dynamics in a high-incidence setting.

genomics↗