Transmission dynamics of pandemic influenza A(H1N1)pdm09 virus in humans and swine in backyard farms in Tumbes, Peru

Influenza and Other Respiratory Viruses

Yeny O. Tinoco³  Joel M. Montgomery³  Mathew R. Kasper³  Martha I. Nelson⁴  Hugo Razuri³  Maria C. Guezala³  Eduardo Azziz-Baumgartner²  Marc-Alain Widdowson²  John Barnes²  Robert H. Gilman¹  Daniel G. Bausch³ 

[1] Johns Hopkins School of Public Health, Baltimore, MD, USA;U.S. Centers for Disease Control and Prevention, Atlanta, GA, USA;U.S. Naval Medical Research Unit No. 6, Lima, Peru;Fogarty International Center, National Institutes of Health, Bethesda, MD, USA

关键词: Antibodies;    backyard pig farms;    human–animal transmission;    influenza;   

DOI  :  10.1111/irv.12329

来源: Wiley

【 摘 要 】

Abstract

Objectives

We aimed to determine the frequency of pH1N1 transmission between humans and swine on backyard farms in Tumbes, Peru.

Design

Two-year serial cross-sectional study comprising four sampling periods: March 2009 (pre-pandemic), October 2009 (peak of the pandemic in Peru), April 2010 (1st post-pandemic period), and October 2011 (2nd post-pandemic period).

Sample

Backyard swine serum, tracheal swabs, and lung sample were collected during each sampling period.

Main outcome measures

We assessed current and past pH1N1 infection in swine through serological testing, virus culture, and RT-PCR and compared the results with human incidence data from a population-based active surveillance cohort study in Peru.

Results

Among 1303 swine sampled, the antibody prevalence to pH1N1 was 0% pre-pandemic, 8% at the peak of the human pandemic (October 2009), and 24% in April 2010 and 1% in October 2011 (post-pandemic sampling periods). Trends in swine seropositivity paralleled those seen in humans in Tumbes. The pH1N1 virus was isolated from three pigs during the peak of the pandemic. Phylogenetic analysis revealed that these viruses likely represent two separate human-to-swine transmission events in backyard farm settings.

Conclusions

Our findings suggest that human-to-swine pH1N1 transmission occurred during the pandemic among backyard farms in Peru, emphasizing the importance of interspecies transmission in backyard pig populations. Continued surveillance for influenza viruses in backyard farms is warranted.

【 授权许可】

CC BY   
© 2015 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.