Bird flu could be far more dangerous to humans than previously understood, as new research indicates it may be resistant to one of the body’s key defence mechanisms: fever. When the human body detects an infection, it raises its temperature in an effort to inhibit viral replication and prevent more severe illness. However, a new study conducted by teams at the University of Cambridge and the University of Glasgow suggests that avian influenza may be able to withstand this natural response.
++ Momento raro na savana: cena fofa mostra filhote de leão explorando o local com a mãe
According to the findings, bird flu viruses continue to replicate even when exposed to elevated temperatures — conditions under which human flu strains would typically struggle. Researchers believe this resilience may stem from the virus’s origins in birds, whose normal body temperature is significantly higher than that of humans.
While human influenza generally remains in the upper respiratory tract, where temperatures average around 33°C, avian flu strains tend to settle in the lower respiratory tract, where temperatures can reach between 40°C and 42°C.
The study, published in Science, found that flu viruses carrying an avian-origin PB1 subunit — part of the enzyme complex essential for viral replication — showed continued growth at these higher temperatures.
Scientists say this behaviour may help explain why bird-derived influenza strains can cause more severe illness in humans.
Dr Matt Turnbull, the study’s lead author from the Medical Research Council Centre for Virus Research at the University of Glasgow, told Science Daily: “The ability of viruses to swap genes is a continued source of threat for emerging flu viruses. We’ve seen it happen before during previous pandemics, such as in 1957 and 1968, where a human virus swapped its PB1 gene with that from an avian strain. This may help explain why these pandemics caused serious illness in people.
++ Ioan Gruffudd and Bianca Wallace welcome daughter Mila Mae
“It’s crucial that we monitor bird flu strains to help us prepare for potential outbreaks. Testing potential spillover viruses for how resistant they are likely to be to fever may help us identify more virulent strains.”
The research comes in the wake of the first human death from the H5N5 avian influenza virus in the United States earlier this month. According to the Washington State Department of Health, the victim — a man from Grays Harbor County, around 125 kilometres southwest of Seattle — kept a flock of domestic poultry that may have been exposed to infected wild birds. The US Centers for Disease Control and Prevention said there is currently no evidence to suggest that the case has increased the overall risk to public health.
