Scientists from the Institute of Vertebrate Biology of the Czech Academy of Sciences have documented the long-term presence and genetic diversity of lymphocytic choriomeningitis virus (LCMV) in populations of house mice in western Czechia. The study, published in the international journal Zoonoses and Public Health, shows that this zoonotic virus can persist in one area for more than two decades, despite its very low prevalence in the host population.
LCMV is a rodent-borne virus that usually causes mild or asymptomatic infection in humans, but in certain groups it can lead to serious health complications, including meningitis or fetal damage when infection occurs during pregnancy. Nevertheless, the long-term dynamics of this virus in natural populations have remained poorly understood to date.
The research team analysed samples of house mice collected in a single region of western Czechia over 24 years, from 2000 to 2023. Using molecular methods and whole-genome sequencing, the authors tracked not only the presence of the virus itself, but also its genetic structure over time and space.
The results show that the virus repeatedly occurred at the same locality throughout the entire study period. Genetic analyses, however, suggest that virus persistence is a dynamic process, involving exchange between neighbouring mouse populations, despite their relatively limited dispersal.
“We have shown that even a very locally distributed virus can persist in natural populations for decades. This is important not only from a virological perspective, but also for understanding long-term risks to human health,” says Joëlle Goüy de Bellocq, head of the research team at the Institute of Vertebrate Biology of the Czech Academy of Sciences.
The long-term persistence of the virus is likely strongly influenced by the specific biology of its host. House mice live in small, relatively closed populations, and the virus can also be transmitted from mother to offspring (so-called vertical transmission), allowing it to be maintained over long periods without frequent spread between localities.
“Vertical transmission of the virus, combined with the spatial structure of mouse populations, creates conditions that allow the virus to persist in the landscape over the long term without being easily detectable,” adds Joëlle Goüy de Bellocq.
From a public health perspective, it is crucial that although the risk of human infection is geographically limited, it remains stable over time. This means that even after many years, the virus may still pose a potential threat in a given area.
“Our results show that targeted monitoring and local measures focused on controlling mouse populations can be a very effective tool for reducing the risk of virus transmission to humans,” concludes Alena Fornůsková, co-author of the study from the Institute of Vertebrate Biology of the Czech Academy of Sciences.
The study also highlights the importance of long-term sample collection and the archiving of biological material, as these are essential for such analyses to be possible. The research thus contributes not only to a better understanding of the ecology of zoonotic viruses but also to the development of more effective public health protection strategies.
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