Farm Exposure Is Associated with Reduced Rates of Viral Respiratory Illnesses in Early Life
Saturday, March 5, 2016: 2:45 PM
Room 408B (Convention Center)
Jamee R. Castillo, MD, , , , , , ,
Rationale: Early-life exposure to farm animals is associated with reduced allergic diseases.  The aim of this study is to determine effects of farm exposure on rates of viral infections and illnesses through age 2 years.  We hypothesized that the rate of viral infections will be the same between farm and non-farm children, while the rate of illnesses will be lower in farm children.

Methods: In a prospective birth cohort study, nasal mucous samples were collected from farm and non-farm children at scheduled intervals (2, 9, 12, and 18 months of age), and during respiratory illnesses (at least mild symptoms≥2 days).  Farm children were born to women who reside or work on cattle or dairy farms.  Infection rates were determined by viral detection (multiplex PCR) at scheduled visits. 

Results: 210 nasal specimens from 28 farm children and 24 non-farm children were analyzed.  Mean length of time for follow-up was 10.1 months for farm children and 10.3 months for non-farm children.  Viral detection rates were similar in farm and non-farm children at scheduled visits (2 months: 8/28 vs. 9/24, p=0.49; 9 months: 7/15 vs. 8/15, p=0.72; 12 months: 3/11 vs. 4/6, p=0.11; 18 months: 1/3 vs. 1/3, p=1.00).  Non-farm children had increased numbers of viral respiratory illnesses/child/year (mean 2.69, 95% CI, 1.79-4.04) compared to farm children (mean 1.45, 95% CI 0.94-2.25), a 1.85-fold increase (95% CI 1.02-3.35, p=0.04). 

Conclusions: Despite similar rates of viral infection, farm versus non-farm children have significantly decreased rates of respiratory viral illnesses.  Early-life farming exposures may impact anti-viral immune maturation.