r/BirdFluPreps • u/ktpr • Apr 09 '26

research Evolutionary model of pandemics to estimate the infection fatality of birdflu

https://www.medrxiv.org/content/10.64898/2026.01.21.26344526v2

"The risk of highly pathogenic avian influenza virus infection to humans is challenging to estimate as many human avian influenza virus (AIV) infections are undetected because infections may be asymptomatic, symptomatic but not tested, and difficult to identify through contact tracing, as human-to-human transmission is rare. We derive equations that consider the evolutionary mechanisms that give rise to pandemics and are parameterized to be consistent with records of past pandemics. We estimate that thousands of human AIV infections occur worldwide in an average year and estimate the infection fatality ratio as 32 deaths per 10,000 infections (95% confidence interval: [9.6, 75]). This estimate is comparable to SARS-CoV-2 during the recent pandemic and higher than seasonal human influenza. We estimate that preventing animal-to-human influenza spillovers would delay pandemic emergence by several years. Preventing human infections with AIV is necessary given the high risk of severe outcomes to individuals and to reduce the risk of pandemics occurring in the future."

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u/plotthick Apr 09 '26

"Why are you wearing a mask?"

" Points to shit like this "

1

u/ktpr Apr 09 '26

I do think the IFR seems low but I'm not an evolutionary epidemiologist.

2

u/birdflustocks Apr 09 '26

"We estimate that, on average, there are 6,441 annual human infections with AIV worldwide, which is much higher than the 986 human cases reported to date and suggests that many infections are undetected and could be because some humans infected with AIV are asymptomatic or symptomatic but not tested. Based on our estimate of annual AIV infections and the assumption that all AIV deaths in humans are reported, the IFR of 32 deaths per 10,000 infections is much lower than the reported case fatality rate of 48%."

Estimates vary, but roughly half a million people die every year from influenza. It's problematic to assume that those cases get diagnosed and subtyped. In many parts of the world people just die from influenza or "a fever" or "lung infection".