NewAtlas Scientists have discovered that avian influenza viruses have a gene that makes them incredibly resistant to heat, rendering our body’s natural defense system – fever – powerless in fighting infection. In fact, higher temperatures actually help the viruses replicate. Reserchers from the University of Cambridge and University of Glasgow have furthered our understanding of why bird flu is particularly dangerous when it infects humans, compared to seasonal influenza A viruses. And it comes down to one gene that appears to protect it from heat, known as BP1.
Fever is one of the oldest immune defenses found in mammals, raising core body temperature just enough to slow the replication of many pathogens, such as influenza A. Human-adapted seasonal influenza strains are finely tuned to the cooler environment of the upper airway, thriving at around 33 °C (91 °F) and losing steam rapidly as temperatures approach 40 °C (104 °F). Birds, on the other hand, run far hotter. Their normal body temperature sits between 40 °C and 42 °C (104 °F and 108 °F), and avian influenza viruses – including the highly pathogenic strains that occasionally spill over into humans – have evolved to replicate efficiently in that heat.