In addition, they develop forecasting models that calculate how mosquito populations develop and which monitoring and prevention measures are most promising. The West Nile virus is a virus transmitted by mosquitoes that mainly circulates between birds and mosquitoes and has been regularly detected i…
In addition, they develop forecasting models that calculate how mosquito populations develop and which monitoring and prevention measures are most promising. The West Nile virus is a virus transmitted by mosquitoes that mainly circulates between birds and mosquitoes and has been regularly detected in Germany since 2018. Since several years, the virus has been spreading increasingly north and west in Europe. Most human infections run mild or unnoticed, but in some cases it can lead to severe courses with meningitis or encephalitis. Horses can also become severely ill. Spatial spread model for West Nile virus Two young researchers at the BNITM have now developed models to better understand the spread dynamics of mosquitoes and viruses. In a study published in the specialist journal One Health, Pride Duve led the development of a spatially resolved mathematical model for the spread of the West Nile virus in Germany between 2019 and 2025. The model links temperature data for Germany with the migration patterns of migratory and resident birds and with the biology of Culex mosquitoes as vectors. The simulations depict known outbreak areas in eastern Germany and show a 'spread corridor' from the eastern federal states over parts of the north to southwest. In these regions, temperatures prevailed in the summer of the past few years that favored the multiplication of mosquitoes and the development of the virus. Migratory birds probably carried the virus into new areas. Notably, the model not only depicts established hotspots but also plausibly explains individual, isolated cases in previously little-affected regions. In some areas, the model had already predicted an increased risk years before the first cases were reported. 'Our model calculations show that West Nile cases in Germany do not follow chance, but a recurring spatial pattern. Temperature, migratory birds and local mosquito density together determine where in a season cases can be expected', says Pride Duve, mathematician and lead author of the study at the Bernhard-Nocht-Institute for Tropical Medicine. Where West Nile fever recurs In another work, Leif Rauhöft has developed, together with colleagues, a process-based model for the life cycle of Culex mosquito species that are considered the main vectors of West Nile virus in Germany. The model describes the development of mosquitoes from eggs over larvae and pupae to adult animals under realistic temperature conditions and was checked with field data from Germany. This allows the relatively accurate calculation of when in a region with particularly high mosquito activity can be expected. 'For health authorities and veterinarians, the question is quite concretely: When does our mosquito season begin, when do we have to be particularly vigilant? Our model depicts the development of the main West Nile vectors so well that we can hit the beginning and peak of the season relatively accurately', says Leif Rauhöft, doctoral student at the Bernhard-Nocht-Institute for Tropical Medicine. Building on these foundations, Pride Duve and colleagues have played through different control strategies for West Nile fever in a further model.
Simulated were among other things the reduction of mosquito populations through the control of breeding sites, the vaccination of horses in affected regions as well as increased personal protection against mosquitoes in humans, for example through insect repellents and clothing that covers the body. The model calculates for various combinations of these building blocks how the number and course of outbreaks change when individual or combined measures are implemented and can be tested in a free web application. Ways to a warning system for West Nile fever
Perspectively, the model approaches could flow into a national or regional early warning system for West Nile fever. In such a system, current climate data, results from bird and horse monitoring as well as information on mosquito populations would be regularly combined and translated into risk maps. Authorities could decide on this basis where surveillance is intensified, breeding sites are reduced or information campaigns are started. The researchers emphasize at the same time that model calculations do not replace field surveillance, but complement it. They help to structure open questions and set priorities - for example, where additional data would be particularly valuable. At the same time, the work serves as an example of how young scientists can make a practical contribution to understanding and controlling vector-borne diseases with mathematical methods. About the West Nile virus
The West Nile virus belongs to the family of Flaviviridae and is mainly transmitted by mosquitoes of the genus Culex. Birds serve as so-called amplifying hosts, in which the virus can multiply strongly. Mosquitoes take up the virus when feeding on blood and can transmit it with further bites. Humans and horses are considered dead-end hosts. They can become ill, but do not play a role in the spread of the virus because the amount of virus in the blood is not sufficient to infect further mosquitoes. Most infections in humans run asymptomatic or with mild flu-like symptoms, so that the actual number of cases is likely higher than the reported numbers. A small part of those affected develops a so-called neuroinvasive disease, in which the virus attacks the central nervous system. Affected individuals can, for example, suffer from meningitis. In individual cases, the disease can be fatal. In Germany, West Nile virus was first detected in 2018 in birds in eastern Germany. Since then, the virus has established itself in many federal states in Germany. Cases in birds and horses are mainly registered in the summer and early autumn months. Reports of human-acquired infections are also increasing. Climate changes with longer and warmer summers create favorable conditions for virus multiplication and promote the spread of the virus.
Source: Bernhard-Nocht-Institute for Tropical Medicine Original publications: - Pride Duve et al.; Modelling the impact of temperature and bird migration on the spread of West Nile virus; One Health, 22:101386, DOI: 10.1016/j.onehlt.2026.101386 - Pride Duve et al.; Modelling the control of West Nile virus using mosquito reduction methods, equid vaccination, and human behavioural adoption of personal protective equipment; Ecological Modelling, 517: 111605, 2026, DOI: 10.1016/j.ecolmodel.2026.111605 - Leif Rauhöft et al.; A process-based model simulating the life cycle of Culex pipiens s.s./Cx. torrentium in Germany; Parasites & Vectors, 19:207, 2026, DOI: 10.1186/s13071-026-07410-4
