Tick and Mosquito-Borne Disease Risk in a Changing Climate

Expected start date：July-2023

Climate change and globalization have increased the incidence of life-threatening infections transmitted by ticks and mosquitos in Europe, including tick-borne encephalitis (TBE), Dengue fever, and West Nile encephalitis. However, little is known about the effect of climate change on the replication of pathogens in the vectors (i.e., ticks and mosquitoes) and the activity of the vectors in temperate regions, leading to uncertain outcomes in previous models. Dr. Tove Hoffman, AXA Fellow at Uppsala University, aims to investigate key aspects influencing the capacity of vector-borne pathogens to adapt to a changing climate. This will enable better estimations of the risk of vector-borne infection outbreaks in new regions.

Dr. Hoffman’s project aims to investigate the northward expansion of various tick species and its relation to tick-borne diseases, such as TBE and Lyme borreliosis in temperate regions. She will collect Ixodes ricinus ticks from areas in Sweden and onsite climatic and vegetation data to investigate the effect of climate change on tick abundance and pathogen infection rates. Additionally, Dr. Hoffman aims to develop a user-friendly app to engage citizens in the monitoring of medically important tick species, including Dermacentor reticulatus and Hyalomma marginatum, to assess their northward expansion in Europe. She also aims to engage horse and dog owners in identifying tick species and collecting ticks for confirmation. Horse and dog owners are selected because they are more likely to find ectoparasites or the parasites that live on the surface of an animal’s body as they regularly groom their animals.

Furthermore, Dr. Hoffman’s project will enable predictions about the ability of tropical mosquito-borne viruses to survive in temperate regions despite seasonal changes. It is already known that warm temperatures might help viruses replicate, but they can also shorten the lifespan of mosquitoes. In temperate regions, mosquitoes can live longer, and therefore may be able to carry similar amounts of virus as those found in tropical regions. Moreover, very little is known about how viruses survive the winter hibernation of mosquitoes. To better understand this, Dr. Hoffman will use molecular and virological methods to investigate how tropical viruses replicate and persist in mosquitoes during summer and after simulated winter hibernation.

The project will translate the research findings into models that will assess the risk of spread and establishment of tick- and mosquito-borne infections under various climate scenarios in Northern Europe. To do so, Dr. Hoffman will use the data generated from the field collections and the infection experiments, macro-climatic data obtained from the Swedish Meteorological and Hydrological Institute, and public health care records.The outcomes of this research could lead to the development of better clinical diagnostic tests and prevention strategies, such as mosquito control, which would be crucial for policymakers looking to mitigate the climate change impact on public health.

April 2023