Confirmed infections in cattle in nine states with first detection on March 25

Broader context of H5N1 evolution and spread

Introduction into Europe and the Americas of clade 2.3.4.4b

Spread in the Americas characterized by spillover to multiple mammalian hosts

Cattle infections form distinct clade across segments indicative of single spillover and cow-to-cow spread

Reassortment in birds prior to cattle spillover, but cattle clade appears non-reassorting

Full genome analysis of concatenated segments provides substantially finer resolution

Growing epizootic in cattle after introduction in ~Dec with subsequent spillback into birds

Molecular clock dating introduction into cattle

Human case outgroups to cattle infections, suggesting unsampled diversity and potentially a second cattle introduction

Epizootic origin appears to be Texas congruent with initial cases

But note sampling bias, where 119 of 189 cattle-derived sequences were sampled from Texas

Specific amino acid changes associated with cattle adaptation

Timeline of initial genomic data

Mar 25

First confirmed detection in Texas, with 10 farms in three states on Mar 30

Mar 27

Six viral genomes from Texas shared to GISAID by NVSL and a seventh on Apr 5

Apr 21

Raw reads for 239 samples shared to SRA (but lack metadata)

Apr 22

Karthik Gangavarapu assembles these reads and shares consensus genomes to GitHub

Apr 26

Florence Débarre shares metadata scraped from USDA YouTube presentation

May 1

Nguyen et al preprint shared to bioRxiv

May 2

Consensus genomes and metadata for 170 samples from Nguyen et al shared to GISAID by NVSL

May 3

Consensus genomes and metadata for Nguyen et al samples shared to GenBank

Current genomic data

Filtered to just cattle sequences

GISAID

177 consensus genomes with metadata (from Nguyen et al)

GenBank

176 consensus genomes with metadata available via this NCBI Virus query (from Nguyen et al)

SRA

211 samples without metadata available via this SRA Run Selector query

Sequences from cattle and other hosts

SRA

Currently 460 samples in BioProject PRJNA1102327 with 322 propagated to SRA Run Selector

Current Nextstrain dataflow

Prospective Nextstrain dataflow

Acknowledgements

H5N1 genomic data: APHIS National Veterinary Services lab at the USDA for sharing cattle sequences, other data producers from all over the world for sharing contextual sequences, GISAID for collating data and Karthik Gangavarapu and colleagues for sharing assembled consensus genomes

H5N1 genomic analysis: Louise Moncla, James Hadfield, John Huddleston

Nextstrain: Richard Neher, Ivan Aksamentov, John Anderson, Kim Andrews, Jennifer Chang, James Hadfield, Emma Hodcroft, John Huddleston, Jover Lee, Victor Lin, Cornelius Roemer, Thomas Sibley

Bedford Lab: John Huddleston,   James Hadfield,   Katie Kistler,   Thomas Sibley,   Jover Lee,   Miguel Paredes,   Marlin Figgins,   Victor Lin,   Jennifer Chang,   Eslam Abousamra,   Nashwa Ahmed,   Cécile Tran Kiem,   Kim Andrews,   Cristian Ovaduic,   Philippa Steinberg,   Jacob Dodds,   John SJ Anderson