OmniVira

Asymptomatic infection with clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) in carnivore pets, Italy, April 2023.

Ana Moreno1 Francesco Bonfante2 Alessio Bortolami2 Irene Cassaniti3,4 Anna Caruana5 Vincenzo Cottini6 Danilo Cereda7 Marco Farioli7 Alice Fusaro2 Antonio Lavazza1 Pierdavide Lecchini8 Davide Lelli1 Andrea Maroni Ponti8 Claudia Nassuato6 Ambra Pastori2 Francesca Rovida3,4 Luigi Ruocco8 Marco Sordilli8 Fausto Baldanti3,4,9 Calogero Terregino2,9
Affiliations 9 institutions
  1. Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna (IZSLER), Brescia, Italy.
  2. Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Legnaro (Padua), Italy.
  3. Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, University of Pavia, Pavia, Italy.
  4. SC Microbiology and Virology, IRCCS Policlinico San Matteo, Pavia, Italy.
  5. Dipartimento di Igiene e Prevenzione Sanitaria-ATS Brescia, Brescia, Italy.
  6. Dipartimento Veterinario e Sicurezza degli Alimenti di origine animale-ATS Brescia Direzione Generale, Brescia, Italy.
  7. General Directorate of Welfare, Regione Lombardia, Milan, Italy.
  8. Sanità Animale e Farmaci Veterinari, Ministero della Salute, Rome, Italy.
  9. These authors contributed equally to this work and share last authorship.
PMID37650905 DOI10.2807/1560-7917.ES.2023.28.35.2300441 Year2023 Journal Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin Euro Surveill Languageeng Statusppublish

Abstract

In April 2023, an outbreak of clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses carrying the T271A mammalian adaptive mutation in the PB2 protein was detected in a backyard poultry farm in Italy. Five domestic dogs and one cat living on the premises had seroconverted in the absence of clinical signs. Virological and serological monitoring of individuals exposed to the virus proved the absence of human transmission, however, asymptomatic influenza A(H5N1) infections in mammalian pets may have important public health implications.

Supporting text Virus Host Location
highly pathogenic avian influenza H5N1 virus 1 PB2 mutation 1 pet carnivores 1 phylogenetic analysis 66 serology 50 silent infection 1 Influenza A virus 186 Influenza A Virus, H5N1 Subtype 300 Influenza in Birds 341 Animals 1948 Asymptomatic Infections 5 Birds 212 Dogs 176 Humans 1440 Italy 20 Mammals 92

Evidence records

5 total
Zoonotic Surveillance
3 records · 1 evidence types
Evidence type Serological Evidence
3 records
OVE7304 Serological Evidence
Key finding

Domestic dogs and a cat were naturally infected with avian influenza A(H5N1) during a poultry outbreak in Italy, demonstrating an animal-to-mammal spillover event.

Virus
Influenza A virus H5N1
Host
birds Aves Natural host dog Canis lupus familiaris Natural host domestic cat Felis catus Natural host
Location
Italy
Supporting text

In April 2023, an outbreak of clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses carrying the T271A mammalian adaptive mutation in the PB2 protein was detected in a backyard poultry farm in Italy. Five domestic dogs and one cat living on the premises had seroconverted in the absence of clinical signs.

Method
serology | virological monitoring
OVE7301 Serological Evidence
Key finding

Five domestic dogs on the affected premises in Italy showed seroconversion to influenza A(H5N1) without clinical signs.

Virus
Influenza A virus H5N1
Host
dog Canis lupus familiaris Natural host
Location
Not specified
Supporting text

Five domestic dogs and one cat living on the premises had seroconverted in the absence of clinical signs. In April 2023, an outbreak of clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses carrying the T271A mammalian adaptive mutation in the PB2 protein was detected in a backyard poultry farm in Italy.

Method
serological testing | seroconversion detection
OVE7302 Serological Evidence
Key finding

One cat on the affected premises in Italy showed seroconversion to influenza A(H5N1) without clinical signs.

Virus
Influenza A virus H5N1
Host
domestic cat Felis catus Natural host
Location
Not specified
Supporting text

Five domestic dogs and one cat living on the premises had seroconverted in the absence of clinical signs. In April 2023, an outbreak of clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses carrying the T271A mammalian adaptive mutation in the PB2 protein was detected in a backyard poultry farm in Italy.

Method
serological testing | seroconversion detection
Transmission Evidence
1 records · 1 evidence types
Evidence type Outbreak Investigation
1 records
OVE7300 Outbreak Investigation
Key finding

An outbreak of clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) occurred in backyard poultry in Italy in April 2023.

Virus
Influenza A virus H5N1
Host
birds Aves Natural host
Location
Italy
Supporting text

In April 2023, an outbreak of clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses carrying the T271A mammalian adaptive mutation in the PB2 protein was detected in a backyard poultry farm in Italy.

Method
outbreak detection | virological monitoring
Transmission direction
same-species transmission
Geographic raw
Italy
Country inferred
ITA
Outbreak setting
backyard poultry farm
Outbreak time
April 2023
Functional Mechanism
1 records · 1 evidence types
Evidence type Molecular Adaptation
1 records
OVE7303 Molecular Adaptation
Key finding

Clade 2.3.4.4b H5N1 viruses detected in Italy carried the PB2 T271A mammalian adaptive mutation.

Virus
Influenza A virus H5N1
Host
Not specified
Location
Not specified
Supporting text

An outbreak of clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses carrying the T271A mammalian adaptive mutation in the PB2 protein was detected in a backyard poultry farm in Italy.

Genes or proteins
PB2
Mutations
T271A
Mechanism types
replication adaptation | host-range expansion