Volume 8, Number 8—August 2002
Research
Serologic Evidence of H1 Swine Influenza Virus Infection in Swine Farm Residents and Employees
Christopher W. Olsen*
, Lynnette Brammer†, Bernard C. Easterday*, Nancy Arden†‡, Ermias Belay†, Inger Baker†, and Nancy J. Cox†
, Lynnette Brammer†, Bernard C. Easterday*, Nancy Arden†‡, Ermias Belay†, Inger Baker†, and Nancy J. Cox†Table 3
Variables associated with seropositivity to swine influenza viruses among the farm participants and the statistical strength of these associations a
| Variable | HI titer >40b | HI titer >80b |
|---|---|---|
| Being a farm owner | p=0.04 | p=0.02 |
| Being a farm owner or the family member of a farm owner | p=0.03 | p=0.02 |
| Living on a swine farm | (p = 0.07) | p=0.04 |
| Going into a swine barn >4 days/week | (p = 0.12) | p=0.04 |
| Age >50 yrs | p=0.02 | p=0.03 |
| Having received the swine flu vaccine in 1976–77 | p=0.02 | (p = 0.44) |
| Ever having received any influenza virus vaccine | p=0.03 | (p = 0.19) |
aP values determined by chi-square or two-sided Fisher’s exact analyses; p values >0.05 cut-off for significance are shown in parentheses.
bTo either swine virus. Abbreviation used: HI, hemagglutination-inhibition.
