Multiple pieces of evidence point to the importance of moderate fever for host life, but the underlying processes are still unknown. Given the strict programs that regulate core body temperature and the physiological stress that comes from their disruption, this is challenging to prove in warm-blooded animal models.
A new study by the University of Alberta offered natural kinetics for the induction and regulation of fever and a broad range of tolerated temperatures. The results suggest that it may be better to let a mild fever run its course instead of automatically reaching for medication.
For the study, scientists used a eurythermic teleost fish model that offered fine control of febrile mechanisms through host-driven dynamic thermoregulation, more closely mimicking natural conditions for heating and cooling. A custom animal enclosure delivered multi-day thermal gradient stability without the use of physical barriers that are known to affect behavior.
This combination of animal model, enclosure design, and automated continuous per second tracking of animal locomotory patterns over both induction and resolution phases of the febrile period greatly enhanced analytical robustness and temporal resolution compared to previous studies.
Immunologist Daniel Barreda, lead author on the study and a joint professor in the Faculty of Agricultural, Life & Environmental Sciences and the Faculty of Science, said, “Collectively, our data show that moderate self-resolving fever offers earlier and selective rather than stronger induction of innate antimicrobial programs against infection, and that this results in markedly faster pathogen clearance.”
The researchers found that fever helped to clear the fish of infection in about seven days — half the time it took for those animals not allowed to exert fever. It also helped to shut down inflammation and repair tissues that had been injured.
“Moderate fever is self-resolving, meaning that the body can induce it and shut it down naturally without medication.”
“The health advantages of natural fever to humans still have to be confirmed through research, but because the mechanisms driving and sustaining fever are shared among animals, it is reasonable to expect similar benefits are going to happen in humans.”
“That suggests we should resist reaching for over-the-counter fever medications, also known as non-steroidal anti-inflammatory drugs or NSAIDs for short, at the first signs of a mild temperature.”
“NSAIDS take away the discomfort felt with fever, but you’re also likely giving away some of the benefits of this natural response.”
“We can take advantage of this natural fever response and the tools we have generated to identify animals that are sick or that may need a vaccination booster. Focusing on a subset of the population saves time and is less costly.”
Ultimately, Barreda hopes the findings will help strike a healthy balance between treating fever and benefiting from it.
Journal Reference:
- Farah Haddad, Amro M Soliman, Michael E Wong et al. Fever integrates antimicrobial defences, inflammation control, and tissue repair in a cold-blooded vertebrate. eLife. DOI: 10.7554/eLife.83644