The H5N1 outbreaks in the U.S. are no longer isolated incidents 🧵
Human cases in California and Missouri appear to share the same clade, B3.13.
This link raises the possibility of a novel transmission pathway.
Milk products.
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Human cases in California and Missouri appear to share the same clade, B3.13.
This link raises the possibility of a novel transmission pathway.
Milk products.
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Both cases are classified as “unknown origin” since there is no evidence of direct exposure to poultry, which is the traditional reservoir for H5N1 in humans.
This lack of an avian connection points to a new, potentially mammalian host.
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This lack of an avian connection points to a new, potentially mammalian host.
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The detection of B3.13 in two states separated by over 1,500 miles points to a virus that may already be circulating beyond localized clusters.
The virus is not limited to isolated spillover events from birds but could be spreading through a shared pathway.
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The virus is not limited to isolated spillover events from birds but could be spreading through a shared pathway.
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The B3.13 clade represents a genetically stable form of H5N1.
The appearance of the same clade in different regions implies a SHARED risk factor.
This could involve infected livestock, contaminated food distribution systems, or an undetected vector facilitating human exposure to H5N1.
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The appearance of the same clade in different regions implies a SHARED risk factor.
This could involve infected livestock, contaminated food distribution systems, or an undetected vector facilitating human exposure to H5N1.
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A single clade being responsible for multiple cases increases the likelihood of a transmissible variant.
If B3.13 is capable of infecting humans across different locations and without direct exposure to birds, it signals that the virus may be adapting for broader human infectivity.
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If B3.13 is capable of infecting humans across different locations and without direct exposure to birds, it signals that the virus may be adapting for broader human infectivity.
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If the sequence from the infected toddler aligns with yesterday’s GISAID update, it points to a virus that is genetically intact and stable.
This stability means an evolutionary process that allows the virus to replicate efficiently and maintain its structure in a host environment.
This is particularly alarming when that host is a mammal.
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This stability means an evolutionary process that allows the virus to replicate efficiently and maintain its structure in a host environment.
This is particularly alarming when that host is a mammal.
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A match between the toddler’s sequence and the GISAID upload would indicate enough stability to infect humans without direct avian exposure.
H5N1 may already be circulating through alternative pathways, such as milk or other dairy products, with indirect human exposure.
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H5N1 may already be circulating through alternative pathways, such as milk or other dairy products, with indirect human exposure.
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What are the implications for global trade if dairy cattle are confirmed as a reservoir?
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