Circulation of influenza in backyard productive systems in central Chile and evidence of spillover from wild birds.

Pedro Jimenez-Bluhm1 Francisca Di Pillo1 Justin Bahl2 Jorge Osorio3 Stacey Schultz-Cherry4 Christopher Hamilton-West5
Affiliations 5 institutions
  1. Department of Preventive Medicine, Faculty of Veterinary Science, Universidad de Chile, Santiago, Chile.
  2. Epidemiology, Human Genetics and Environmental Sciences, Center For Infectious Diseases, University of Texas, Houston, TX, United States.
  3. Comparative Biomedical Science Program, School of Veterinary Medicine, University of Wisconsin-Madison, United States.
  4. Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, United States.
  5. Department of Preventive Medicine, Faculty of Veterinary Science, Universidad de Chile, Santiago, Chile. Electronic address: [email protected].

Abstract

Backyard productive systems (BPS) are recognized as the most common form of animal production in the world. However, BPS frequently exhibit inherent biosecurity deficiencies, and could play a major role in the epidemiology of animal diseases and zoonoses. The aim of this study was to determine if influenza A viruses (IAV) were prevalent in backyard poultry and swine BPS in central Chile. Through active surveillance in Valparaiso and Metropolitan regions from 2012 - 2014, we found that influenza virus positivity by real-time RT-PCR (qRT-PCR) ranged from 0% during winter 2012-45.8% during fall 2014 at the farm level. We also obtained an H12 hemagglutinin (HA) sequence of wild bird origin from a domestic Muscovy duck (Cairina moschata), indicating spillover from wild birds into backyard poultry populations. Furthermore, a one-year sampling effort in 113 BPS in the Libertador Bernardo O'Higgins (LGB ÓHiggins) region showed that 12.6% of poultry and 2.4% of swine were positive for IAV by enzyme-linked immunosorbent assay (ELISA), indicative of previous exposure of farm animals to IAV. This study highlights the need for improved IAV surveillance in backyard populations given the close interaction between domestic animals, wild birds and people in these farms, particularly in an understudied region, like South America.

Supporting text Virus Host Location
Disease risk 1 Phylogenetic analysis 66 Real time RT-PCR 1 Small farmers 1 Zoonosis 116 Influenza A virus 186 Animals 1948 Animals, Wild 187 Birds 212 Chile 8 Humans 1440 Influenza in Birds 341 Influenza, Human 286 Poultry Diseases 74 Zoonoses 397

Evidence records

4 total
Zoonotic Surveillance
3 records · 2 evidence types
Evidence type
1 records
OVE2947
Key finding

Influenza A viruses were detected by qRT-PCR in backyard poultry and swine in central Chile during 2012–2014.

Virus
Host
Location
Supporting text

The aim of this study was to determine if influenza A viruses (IAV) were prevalent in backyard poultry and swine BPS in central Chile. Through active surveillance in Valparaiso and Metropolitan regions from 2012 - 2014, we found that influenza virus positivity by real-time RT-PCR (qRT-PCR) ranged from 0% during winter 2012-45.8% during fall 2014 at the farm level.

Method
real-time RT-PCR (qRT-PCR)
Sample type
farm-level samples
Geographic raw
Valparaiso | Metropolitan regions | central Chile
Country inferred
CHL
Evidence type
2 records
OVE2949
Key finding

12.6% of poultry in backyard productive systems in the Libertador Bernardo O'Higgins region of Chile had antibodies to influenza A virus by ELISA, indicating prior exposure.

Virus
Host
Location
Not specified
Supporting text

A one-year sampling effort in 113 BPS in the Libertador Bernardo O'Higgins (LGB ÓHiggins) region showed that 12.6% of poultry ... were positive for IAV by enzyme-linked immunosorbent assay (ELISA), indicative of previous exposure of farm animals to IAV.

Method
enzyme-linked immunosorbent assay (ELISA)
Sample type
serum (ELISA)
OVE2950
Key finding

2.4% of swine in backyard productive systems in the Libertador Bernardo O'Higgins region of Chile had antibodies to influenza A virus by ELISA, indicating prior exposure.

Virus
Host
Location
Not specified
Supporting text

A one-year sampling effort in 113 BPS in the Libertador Bernardo O'Higgins (LGB ÓHiggins) region showed that ... 2.4% of swine were positive for IAV by enzyme-linked immunosorbent assay (ELISA), indicative of previous exposure of farm animals to IAV.

Method
enzyme-linked immunosorbent assay (ELISA)
Sample type
serum (ELISA)
Genomic Evolution
1 records · 1 evidence types
Evidence type
1 records
OVE2948
Key finding

An H12 hemagglutinin sequence of wild bird origin was detected in a domestic Muscovy duck, supporting spillover of influenza A virus from wild birds into backyard poultry in central Chile.

Virus
Host
Location
Supporting text

We also obtained an H12 hemagglutinin (HA) sequence of wild bird origin from a domestic Muscovy duck (Cairina moschata), indicating spillover from wild birds into backyard poultry populations. The aim of this study was to determine if influenza A viruses (IAV) were prevalent in backyard poultry and swine BPS in central Chile.

Analysis methods
real-time RT-PCR (qRT-PCR) | sequence analysis