Sick wild house mice spend time away from their social groups, leading to a decrease in their potential for disease transmission according to a new study by evolutionary biologists from the University of Zurich in collaboration with the ETH Zurich. The results can improve models focused on predicting the spread of infectious diseases like influenza or Ebola in humans.
When animals get sick, they may change their behaviour, becoming less active, for example. The study’s lead author, Patricia Lopes from the Department of Evolutionary Biology and Environmental Studies at the University of Zurich, says that previous research in wild animals has generally ignored how this change in behaviour may affect social contacts in a group and how, in turn, these changes can impact the transmission of a disease.
Sick mice are not avoided, but remove themselves from the group
To tackle this problem, Patricia Lopes and her colleagues used a novel combination of experimental manipulations of free-living mice, radio frequency tracking of animals, social network analysis and disease modelling.
To simulate an infection, mice were injected with lipopolysaccharides (a component of the bacterial cell wall), which results in an immune response and generalized disease symptoms. In a paper published this week in the journal Scientific Reports, the team reveals that sick mice become disconnected from their social groups.
It is known that mice have the ability to detect other sick mice. Therefore, it was surprising to find that the animals in the same social group did not avoid the sick mouse. In fact, they went on interacting with the sick mouse and other mice more or less in the same way as before the experimental infection. “It was the sick mouse that removed itself from the group”, emphasizes Lopes. She suggests that such a change in the behaviour of the sick mouse may protect relatives in the same group from catching the disease, which could be beneficial from an evolutionary perspective.
Speed and extent of disease spread are greatly reduced
In a further step, the researchers used mathematical models to predict how an infectious disease would spread considering the changes in behaviour of the sick animals. “When we account for the behavioural changes and how they affect social contacts, we find that the speed and the extent of disease spread are greatly reduced,” says Lopes.
Ultimately, the study contributes to our understanding of the complexity inherent to disease transmission and highlights the importance of changes in behaviour of sick animals for predicting the outcome of outbreaks. The findings extend to humans, as humans are also known to alter their behaviours when sick. Such effects are possible in a number of diseases spread by social contact where contagiousness overlaps with behavioural symptoms, including influenza and Ebola. Understanding why we feel sick and how diseases spread is a pressing issue, particularly given projected increases in disease outbreak driven by the synergy of climate change, habitat disturbance and human connectivity.
Patricia C. Lopes, Per Block and Barbara König. Infection-induced behavioural changes reduce connectivity and the potential for disease spread in wild mice contact networks. Scientific Reports. August 22, 2016. doi: 10.1038/srep31790
Dr. Patricia C. Lopes
Department of Evolutionary Biology and Environmental Studies
University of Zurich
Phone: +41 44 635 52 77
Kurt Bodenmüller | Universität Zürich
Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington
The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy