Receptor basis of unusual tissue tropism of avian influenza H5N1 clade 2.3.4.4b virus in cattle

Receptor basis of unusual tissue tropism of avian influenza H5N1 clade 2.3.4.4b virus in cattle

Abstract The unusual tropism of H5N1 clade 2.3.4.4b for cattle mammary glands, causing necrotizing mastitis without major respiratory involvement, raises critical questions about its underlying mechanisms. We conducted glycomics and linkage-specific lectin histochemistry to characterize sialic acid (SA) receptor diversity and anatomical distribution, and virus binding assays and high-resolution electron microscopy (EM) to visualize virus-recepto…

How H5N1 Bird Flu Went Undetected for Weeks in Dairy Cattle

In early 2024, a baffling outbreak of H5N1 avian influenza emerged among dairy cattle in the Texas Panhandle, presenting a new and unexpected clinical manifestation of the virus. Unlike the typical respiratory illness caused by H5N1 in other mammals, affected cows exhibited severe necrotizing mastitis, an inflammatory condition predominantly targeting the mammary glands. This atypical tissue tropism challenged existing paradigms and delayed the …