High Risk of Influenza Virus Infection Among Swine Workers: Examining a Dynamic Cohort in China.

Abstract

BACKGROUND:

China is thought to be a hotspot for zoonotic influenza virus emergence, yet there have been few prospective studies examining the occupational risks of such infections.

METHODS:

We present the first 2 years of data collected from a 5-year, prospective, cohort study of swine-exposed and -unexposed participants at 6 swine farms in China. We conducted serological and virological surveillance to examine evidence for swine influenza A virus infection in humans.

RESULTS:

Of the 658 participants (521 swine-exposed and 137 swine-unexposed), 207 (31.5%) seroconverted against at least 1 swine influenza virus subtype (swine H1N1 or H3N2). Swine-exposed participants' microneutralization titers, especially those enrolled at confined animal feeding operations (CAFOs), were higher against the swine H1N1 virus than were other participants at 12 and 24 months. Despite elevated titers, among the 187 study subjects for whom we had complete follow-up, participants working at swine CAFOs had significantly greater odds of seroconverting against both the swine H1N1 (odds ratio [OR] 19.16, 95% confidence interval [CI] 3.55-358.65) and swine H3N2 (OR 2.97, 95% CI 1.16-8.01) viruses, compared to unexposed and non-CAFO swine workers with less intense swine exposure.

CONCLUSIONS:

While some of the observed increased risk against swine viruses may have been explained by exposure to human influenza strains, study data suggest that even with elevated preexisting antibodies, swine-exposed workers were at high risk of infection with enzootic swine influenza A viruses.

• Authors: Laura K Borkenhagen, Guo-Lin Wang, Ryan A Simmons, Zhen-Qiang Bi, Bing Lu, Xian-Jun Wang, Chuang-Xin Wang, Shan-Hui Chen, Shao-Xia Song, Min Li, Teng Zhao, Meng-Na Wu, Lawrence P Park, Wu-Chun Cao, Mai-Juan Ma, Gregory C Gray
• Journal: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (Clin Infect Dis) Vol. 71 Issue 3 Pg. 622-629 (07 27 2020) ISSN: 1537-6591 [Electronic] United States
• PMID: 31504322 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © The Author(s) 2019. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: [email protected].

Chemical References

• Antibodies, Viral

Topics

• Animals
• Antibodies, Viral
• China (epidemiology)
• Cohort Studies
• Influenza A Virus, H1N1 Subtype
• Influenza A Virus, H3N2 Subtype
• Influenza, Human (epidemiology)
• Orthomyxoviridae Infections (epidemiology, veterinary)
• Prospective Studies
• Seroepidemiologic Studies
• Swine
• Swine Diseases (epidemiology)
• Zoonoses (epidemiology)