Highly pathogenic avian influenza A(H7N3) virus in poultry workers, Mexico, 2012

Abstract

We identified 2 poultry workers with conjunctivitis caused by highly pathogenic avian influenza A(H7N3) viruses in Jalisco, Mexico. Genomic and antigenic analyses of 1 isolate indicated relatedness to poultry and wild bird subtype H7N3 viruses from North America. This isolate had a multibasic cleavage site that might have been derived from recombination with host rRNA.

Keywords: H7N3; Mexico; conjunctivitis; highly pathogenic avian influenza A virus; influenza virus; poultry workers; viruses.

Figure 1

Phylogenetic trees A) of hemagglutinin (HA) and B) neuraminidase (NA) genes of highly pathogenic avian influenza A (H7N3) virus isolated from a poultry worker with conjunctivitis in Jalisco State, Mexico, July 2012, and other influenza viruses. Reassortant vaccine candidates are shown with a V, and hemagglutinin inhibition (HI) reference viruses used in HI tests are shown with an R in the HA tree. Arrows indicate strain names with V and R. Highly pathogenic avian influenza A(H7N3) viruses from Mexico are indicated in boldface. Trees were midpoint rooted with other North American-lineage H7 HA and N3 NA gene sequences, and subtrees containing ancestral and related viruses were produced. Bootstrap values >60 are shown above or below branches in each tree. *Viruses detected in 2011 or 2012. Scale bars indicate nucleotide substitutions per site.

Figure 2

Multibasic cleavage sites of highly pathogenic avian influenza (HPAI) A(H7N3) virus isolated from a poultry worker with conjunctivitis in Jalisco State, Mexico, July 2012, and other influenza viruses. Box indicates novel amino acid cleavage site sequence motif. HA, hemagglutinin; LPAI, low pathogenicity avian influenza. Hyphens indicate gaps in the sequence alignments whereby 1 sequence has an insertion of amino acids relative to shorter sequences.