The newly discovered group of Jingmenviruses has been shown to infect a wide range of hosts and has been associated with febrile illness in humans. During a survey for Jingmenviruses in ticks from Lower Saxony, Germany, Alongshan virus (ALSV) was identified in Ixodes spp. ticks. Additional virus screenings revealed the presence of ALSV in the bodies and saliva of ticks collected at several locations in Lower Saxony. Vector competence studies that included Ixodes ricinus and Dermacentor reticulatus validated the replication of ALSV within those tick species. In vitro feeding experiments with ALSV-injected Ixodes ricinus demonstrated effective viral transmission during blood feeding. To evaluate the potential viral transmission during a natural blood meal, sera from wild game and domestic animals were investigated. One serum sample from a red deer was found to be positive for ALSV RNA, while serological screenings in game and domestic animals revealed the presence of ALSV-specific antibodies at different locations in Lower Saxony. Overall, those results demonstrate the broad distribution of ALSV in ticks in Lower Saxony and hypothesize frequent exposure to animals based on serological investigations. Hence, its potential risk to human and animal health requires further investigation.

Tick-borne viruses (TBVs), notably Orthonairovirus haemorrhagiae (Crimean–Congo hemorrhagic fever virus, CCHFV), are emerging global health threats intensified by climate change. Rising temperatures and altered precipitation patterns are expanding the habitats of key tick vectors, increasing their survival and reproductive success. The African continent is characterized by many different climatic zones, and climatic shifts have increased or changed CCHFV transmission patterns, becoming greater risk to humans and livestock. Beyond Africa, CCHFV spread in Europe, the Middle East, and Asia and has been facilitated by factors such as livestock movement, deforestation, and migratory birds. Climate-driven shifts in tick seasonality, behavior, and vector competence may further enhance viral transmission. Addressing these challenges requires integrated responses, including enhanced surveillance, predictive modeling, and climate-adaptive vector control strategies. A One Health approach—linking environmental, animal, and human health domains—is essential. Innovative strategies such as anti-tick vaccines and sustainable vector control methods offer promise in reducing the burden of these diseases. Proactive, collaborative efforts at regional and international levels are crucial in tackling this growing public health challenge.

Ticks are hematophagous ectoparasites and key vectors of a wide range of pathogens, including viruses, bacteria, and protozoa. Climate change and environmental shifts have contributed to the expansion of tick populations and the pathogens they harbor. Ticks rely solely on their innate immune system to combat infections, utilizing mechanisms such as RNA interference, phagocytosis, and antimicrobial peptide expression. However, pathogens have evolved strategies to evade or manipulate these defenses to facilitate their replication and transmission. This study compares the infection dynamics of two tick-borne viruses: Orthoflavivirus encephalitidis (TBEV) and Alongshan virus (ALSV). TBEV, a well-adapted arbovirus, requires both tick and vertebrate hosts for its life cycle and is a major cause of human meningitis and encephalitis across Europe and Asia. In contrast, ALSV appears to be primarily restricted to ticks, with its dependence on vertebrate hosts still unclear. Transcriptomic analyses of Ixodes ricinus ticks revealed distinct gene expression patterns in response to these viruses. TBEV infection primarily regulated genes related to immunity, defense, and digestion-reflecting its adaptation to dual-host environments and acquisition via blood feeding. ALSV infection, however, influenced signaling and infection-related pathways, suggesting a more specialized adaptation to ticks. These findings underscore the differences in immune modulation and metabolic responses between TBEV and ALSV, highlighting the need for further genomic and proteomic studies to enhance our understanding of virus-vector interactions. Such insights could inform strategies for controlling tick-borne diseases and tracking pathogen evolution.