Peer Review #2 of "Genetic and serologic surveillance of canine (CIV) and equine (EIV) influenza virus in Nuevo León State, México (v0.1)"

Abstract

Background: Despite the uncontrolled distribution of the Influenza A virus through wild birds, the detection of canine (CIV) and equine influenza virus (EIV) in Mexico was absent until now. Recently, outbreaks of equine and canine influenza have been reported around the world; the virus spreads quickly among animals and there is potential for zoonotic transmission. Methods: Amplification of the Influenza A virus matrix gene from necropsies, nasal and conjunctival swabs from trash service horses and pets/stray dogs was performed through RT-PCR. The seroprevalence was carried out through Sandwich ELISA system using the M1 recombinant protein and polyclonal antibodies anti-M1. Results: The matrix gene was amplified from 13 (19.11%) nasal swabs, 2 (2.94%) conjunctival swabs and 5 (7.35%) lung necropsies, giving a total of 20 (29.41%) positive samples in a pet dog population. A total of 6 (75%) positive samples of equine nasal swab were amplified. Sequence analysis showed 96-99% identity with sequences of Influenza A virus matrix gene present in H1N1, H1N2 and H3N2 subtypes. The phylogenetic analysis of the sequences revealed higher identity with matrix gene sequences detected from zoonotic isolates of subtype H1N1/2009.