SLU researchers answer four questions about hantaviruses

Frauke Ecke, Senior Lecturer at SLU and Professor of Ecology at the University of Helsinki, and Hussein Khalil, Assistant Professor at SLU, answer questions about hantaviruses and the research currently being conducted:

What are hantaviruses?

Hantaviruses belong to a genus of viruses mainly carried and spread by rodents. These viruses are generally host-specific, meaning that a particular hantavirus is carried by only one or a few host species. What they have in common is that they are transmitted to humans through inhalation of particles from urine, feces, or saliva of infected animals. The Andes virus, a hantavirus found in South America, is an exception. In very rare cases, it can spread between humans.

There is a difference between the hantaviruses found in Europe and those found in the Americas. In Sweden and the Nordic countries, we have human infections (“vole fever”) caused by Puumala hantavirus, a hantavirus spread only by the bank vole. This infection usually causes a relatively mild illness with flu-like symptoms, but it can also temporarily impair kidney function. 

The hantaviruses found in North, Central, and South America, on the other hand, can cause very serious infections, and many cases are fatal. These viruses are spread by rodents belonging to a group known as New World mice.

How common are outbreaks like the one on the cruise ship?

They are very rare. Only a few known cases of so-called cluster outbreaks of hantavirus infections transmitted between humans have been documented. These have specifically involved the Andes virus.

What is more common in Sweden and the Nordic countries is outbreaks of "vole fever" across large geographic areas following periods when bank vole populations are abundant. Such outbreaks potentially occur every three to four years due to the rodents’ relatively regular population cycles.

How serious a problem are animal-borne diseases like hantavirus today?

The number of outbreaks of animal-borne diseases in humans is increasing globally, posing major challenges to public health. The increase is mainly caused by degredation of natural habitats, loss of biodiversity, climate change, and the combination of these factors. The rise in infectious diseases originating in wild animals is a global challenge, and the EU, amongst others, is investing significant resources in increasing our understanding of disease outbreaks and preventing future pandemics.

How does SLU’s research contribute to stopping the spread of animal-borne diseases?

We aim to understand the ecology behind outbreaks of zoonotic diseases. Therefore, we study the presence of pathogens in the surrounding environment, in vectors and disease carriers such as mosquitoes and ticks, and in host animals such as rodents and bats. We also study how pathogens spread to humans. Our research began in Sweden but now covers disease systems in different parts of the world.

Our studies on "vole fever" and other infectious diseases help us understand, predict, and mitigate future outbreaks of animal-borne diseases. In several EU projects, we also evaluate how measures such as ecological restoration, the reintroduction of wild animals through rewilding, and public health interventions can help reduce the occurrence and spread of animal-borne diseases.

Read more: 

RESTOREID: can forest restoration protect us from animal-borne infectious disease?

BEPREP - How to prevent the next pandemic?