Molecular epidemiology of the Tick borne encephalitis virus

Tick-borne encephalitis virus (TBEV) is a neurotropic flavivirus that causes severe central nervous system infections. In this research project, we combine field samples, patient samples, sequencing, and bioinformatics to deepen our understanding of the virus’s molecular diversity and pathogenesis.

We analyze the genetic composition of TBEV isolated from both ticks and patients, aiming to map how viral genetic variation influences disease progression. The project builds on previous work on quasispecies and viral population structures in Scandinavia and forms part of our long-term strategy to understand TBEV evolution in relation to disease and spread.

A new PhD project at Örebro University focuses on patient-associated analyses of TBEV using whole genome sequencing, clinical sampling, and immunological profiling. The project integrates bioinformatics with molecular biology and recently began examining links between viral variants and neuroinflammatory markers.

We also participate in the Norwegian-led SE-TBE project, coordinated by Åshild Andreassen at the Norwegian Institute of Public Health (FHI) and funded by the Ministry of Health and Care Services (HOD), 2024–2026. This project includes tick surveillance and molecular analysis of TBEV in patient and vector material. The project is supported by the Research Committee of Region Örebro County and is conducted in collaboration with clinical researchers, virologists, and psychologists.

Selected publications:
Maharjan, U., Skudal, H.K., Asghar, N., Soleng, A., Johansson, M., Heggen Lindstedt, H.E., Koskela von Sydow, A., Pettersson, J.H.-O., Johansen, W., Fevang, B., Bjerkreim, R., Basnet, S., Vikse, R., Andreassen, Å.K., Alfsnes, K. (2025) Novel variants of tick-borne encephalitis virus from patient and tick samples in Norway. Ticks and Tick-borne Diseases In press

Kjær, L.J., Johansson, M., Lindgren, P.-E., Asghar, N., Wilhelmsson, P., Fredlund, H., Christensson, M., Wallenhammar, A., Bødker, R., Rasmussen, G., Kjellander, P. (2023). Potential drivers of human tick-borne encephalitis in the Örebro region of Sweden, 2010–2021. Scientific Reports, 13(1).

Wallenhammar, A., Lindqvist, R., Asghar, N., Gunaltay, S., Fredlund, H., Davidsson, Å., Andersson, S., Överby, A.K., Johansson, M. (2020). Revealing new tick-borne encephalitis virus foci by screening antibodies in sheep milk. Parasites & Vectors, 13(1).

Asghar, N., Pettersson, J.H.-O., Dinnetz, P., Andreassen, Å., Johansson, M. (2017). Deep sequencing analysis of tick-borne encephalitis virus from questing ticks at a hotspot in nature reveals similarities between quasispecies pools of the virus. Journal of General Virology, 98(3), 413–421.

Asghar, N., Lindblom, P., Melik, W., Lindqvist, R., Haglund, M., Forsberg, P., Överby, A., Andreassen, Å., Lindgren, P.-E., Johansson, M. (2014). Tick-borne encephalitis virus sequenced directly from questing and blood-feeding ticks reveals quasispecies variance. PLOS ONE, 9(7), e103264.