Volume 8, Number 8—August 2002
Serologic Evidence of H1 Swine Influenza Virus Infection in Swine Farm Residents and Employees
|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.