Bird flu viruses are a ticking time bomb for humanity, according to a groundbreaking study. But here's the twist: these viruses can outsmart one of our body's natural defenses, fever, which is usually a powerful weapon against infections.
Researchers from Cambridge and Glasgow universities have discovered a gene that influences a virus's ability to thrive at different temperatures. This gene, known as PB1, was found to be crucial in past pandemics, such as in 1957 and 1968, when it transferred from bird flu viruses to human flu viruses, leading to deadly outbreaks.
Human flu viruses typically cause infections in the upper respiratory tract, where temperatures are around 33°C. When our body detects a virus, it raises the temperature, creating a fever, which can reach up to 41°C. This fever is a natural defense mechanism to stop the virus from spreading and replicating. However, the study reveals that bird flu viruses are not as susceptible to this fever response.
In contrast to human flu viruses, avian influenza viruses thrive in the lower respiratory tract and can even infect the gut in birds, where temperatures are as high as 40-42°C. This adaptation allows them to resist the feverish conditions in humans, which is concerning.
The research team used mice models to simulate fever conditions and study the response to influenza viruses. They found that while fever effectively stops human-origin flu viruses, it may not be sufficient against avian flu viruses. A mere 2°C increase in body temperature can turn a deadly human-origin flu infection into a milder disease.
And here's where it gets controversial: the PB1 gene is a double-edged sword. When human and bird flu viruses infect the same host, they can exchange genes, including PB1. This gene swapping has occurred in previous pandemics, leading to more severe illnesses. But could this gene transfer also provide a potential avenue for developing new treatments?
Monitoring bird flu strains is essential to prepare for potential outbreaks, as Dr. Matt Turnbull, the study's lead author, emphasizes. Understanding how these viruses resist fever can help identify more dangerous strains.
However, the team also cautions that more research is needed before changing treatment guidelines. Treating fever with antipyretic medication, like ibuprofen or aspirin, may not always be beneficial and could even promote the spread of influenza A viruses in humans.
This study highlights the complex relationship between viruses and our body's defenses, leaving us with a crucial question: how can we stay one step ahead in the constant battle against evolving flu viruses?
