An influenza A virus (H3N2) of probable swine origin, designated A/Canada/1158/2006, was isolated from
a 7-month-old hospitalized child who lived on a communal farm in Canada. The child recovered
uneventfully. A serosurvey that used a hemagglutination-inhibition assay for A/Canada/1158/2006 was
conducted on 54 of the 90 members of the farm. Seropositivity was demonstrated in the index patient, 4
of 7 household members, and 4 of 46 nonhousehold members; none had a history of hospital admission
for respiratory illness in the preceding year. Serologic evidence for this strain of swine influenza was also
found in 1 of 10 pigs (12 weeks–6 months of age) on the farm. Human infection with swine influenza virus
is underrecognized in Canada, and because viral strains could adapt or reassort into a form that results in
efficient human-to-human transmission, routine surveillance of swine workers should be considered as
part of pandemic influenza preparedness.

07-0615.pdf