Serologic evidence of H1 swine Influenza virus infection in swine farm residents and employees.
We evaluated seropositivity to swine and human H1 influenza viruses in 74 swine farm owners, employees, their family members, and veterinarians in rural south-central Wisconsin, compared with 114 urban Milwaukee, Wisconsin, residents. The number of swine farm participants with positive serum hemagglutination-inhibition (HI) antibody titers > or = 40 to swine influenza viruses (17/74) was significantly higher (p<0.001) than the number of seropositive urban control samples (1/114). The geometric mean serum HI antibody titers to swine influenza viruses were also significantly higher (p<0.001) among the farm participants. Swine virus seropositivity was significantly (p<0.05) associated with being a farm owner or a farm family member, living on a farm, or entering the swine barn > or = 4 days/week. Because pigs can play a role in generating genetically novel influenza viruses, swine farmers may represent an important sentinel population to evaluate the emergence of new pandemic influenza viruses.
University of Wisconsin-Madison, Madison, Wisconsin 53706, USA. olsenc@svm.vetmed.wisc.edu
Christopher W
CW
Olsen
Lynnette
L
Brammer
Bernard C
BC
Easterday
Nancy
N
Arden
Ermias
E
Belay
Inger
I
Baker
Nancy J
NJ
Cox
D000293:Adolescent; D000328:Adult; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002353:Carrier State / Q000276:immunology / Q000635:transmission / Q000662:veterinary; D002648:Child; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D009980:Influenza A virus / Q000276:immunology / Q000302:isolation & purification*; D007251:Influenza, Human / Q000276:immunology / Q000635:transmission* / Q000662:veterinary* / Q000821:virology; D008875:Middle Aged; D012698:Serologic Tests; D011795:Surveys and Questionnaires; D013552:Swine / Q000821:virology*; D013553:Swine Diseases / Q000635:transmission* / Q000821:virology*; D015047:Zoonoses / Q000635:transmission / Q000821:virology
D000914:Antibodies, Viral