本文针对近期H5N1禽流感疫情进行了分析，该病毒已在全美50个州及各大洲的牲畜和野生鸟类中发现，加州超过600个奶牛群感染，占总数的45%。美国已确认58例人感染病例，其中2例感染源不明。文章探讨了病毒的传播途径、突变风险、历史疫情、治疗方法及疫苗有效性，并提出了多个研究方向，悬赏征集更深入的信息，以期提高公众对H5N1的认识和应对能力。

🌍H5N1禽流感已扩散至全美50个州及各大洲的牲畜和野生鸟类中，加州45%的奶牛群受到感染，且已出现58例人感染病例，其中2例感染源不明，传播似乎主要通过体液进行。

🧬H5N1病毒只需一个位点突变即可适应人体受体，尽管每个感染个体都可能产生该突变，但目前尚未明确其空气传播所需的条件。此外，流感病毒的基因片段重组特性可能导致高致病性混合毒株的产生。

💊在治疗方面，达菲(Tamiflu)在症状出现后12-48小时内服用最为有效，早期使用可显著缩短病程。预防性使用达菲可使接触者感染风险降低89%。另一种药物Xofluza效果更佳，但购买渠道受限。

💉传统疫苗方面，今年的流感疫苗不包含H5N1毒株。疫苗有效性因毒株匹配度而异，匹配良好时有效率约为49%-60%，匹配不佳时则降至19%。美国目前没有非处方检测试剂，但可从欧洲进口。

🔍文章提出多个研究方向，包括H5N1如何从鸟类传播到牛、感染牛群中实际患病比例、除达菲外更有效的治疗方法、交叉免疫的详细报告，以及更新死亡率和人际传播的估计。

Published on December 9, 2024 7:07 PM GMT

The following is an incorrect and incomplete post about the recent bird flu, H5N1. I am offering rewards to anyone who helps me improve it. My total budget is up to $5,000, and I commit to spending at least $1,000.

 

Payouts are a judgement call. I’ve marked some bullet points below with what I would have awarded them if they’d been suggested here (and would pay out if someone proved incorrect). 

 

Spread
The virus has been found in livestock and wild birds across all 50 states, and every continent. H5N1 has been found in 600+ dairy cow herds in CA, which is 45% of all CA herds. This is the first flu known to infect cows.There are 58 confirmed human cases in the US. of those, 2 do not have a known source; the remainder are from poultry and dairy cows.Spread appears to be primarily or exclusively through fluids, at least from cows.A new paper says that H5N1 only needs a single point mutation to switch to human receptors.
However given flu’s mutation rate and the number of virons produced by each infection, this should already happen at least once per infected cow, so clearly it’s not sufficient.What does it need to get airborne? ($300)
The flu virus taxon has something similar to chromosomes- instead of one strand of RNA it has 8 separate segments. If a cell is co-infected by two different strains it can mix and match segments. If those strains are from different species (e.g. bird and human flu mixing in pigs), this can result in virulent hybrids. ($250 to quantify this)
Reference Class
Past major epidemic scares in the US:
1976 Swine Flu Scare (small)2002: SARS (774 deaths worldwide)2009: Swine Flu H1N1 (151,700 to 575,400 deaths worldwide)
Past major epidemics in the US (death count):
1910s-1950s: Repeated Polio epidemics1918: Spanish Flu (675,000)1957: Asian Flu H2N2 (116,000)1968: Hong Kong Flu (100,000)1980s: AIDS2020: covid (1,219,48)
Treatment
Tamiflu
… is most effective when taken within 12-48 hours of symptom onset. Starting treatment within 12 hours can reduce illness duration by over 3 days compared to starting at 48 hoursWhen used prophylactically, Tamiflu reduced the risk of developing influenza by 89% in household contacts of infected individuals
Xofluza is more effective than Tamiflu but I can’t find anywhere to buy it onlineTraditional vaccines
This year’s flu vaccine contains an H1N1 but not an H5N1For years with good antigenic match between the vaccine and circulating strains, effectiveness estimates are typically around 49% to 60%. However, in years with poor matches, such as the 2014-2015 season, effectiveness dropped to as low as 19% (source)
The US does not have over the counter tests available, however you can import Fluorecare tests (flu A and B, RSV, and covid on one cartridge) from Europe for a fraction of the cost of an American covid test.
Specific requests:
Additional major epidemics or scares that didn’t pan out ($50 for first few, $25 for later)Detailed report on the usefulness of tamiflu ($500)How good is national flu monitoring? Should I take comfort in the low prevalence? ($100-$500)How did H5N1 spread from bird to cow if it requires fluids? ($500)What percent of cows in infected dairy herds were actually sick?($50)Is there something better than tamiflu? ($100 for a credible suggestion, $500 for details)Detailed report on cross immunity ($500)Any information that updates my estimates of mortality or human-to-human spread.

 

 

 

Details on payment: awards will be given over paypal or to a 501c3 of your choice. If you receive >$500 you will need to fill out a 1099 on tax1099.com. This means I won’t have your SSN but tax1099 will.

If the awards total to less than $500, I will double all awards given. If the total comes to between $500 and $1000, I will donate the excess to Lightcone. 

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