Table 1

Characteristics of the controls and patients with laboratory-confirmed, hospital-acquired influenza (HAI) and of the factors associated with HAI in Edouard Herriot Hospital, Lyon (France), in influenza seasons 2004-05, 2005-06 and 2006-07

Characteristics

Patients with confirmed HAI (N = 11)

Controls (N = 44)

P

Crude ORa (95% CI)


Gender, female

8 (73)

33 (75)

1.0

0.89 (0.22-3.72)


Age, years

0.99 (0.97-1.02)b


Median (range)

66.0 (48.5-85.1)

78.7 (42.3-86.7)

0.6


Type of ward

1.0


Medicine

8 (73)

31 (70)

1.0 (Ref.)


Surgery

3 (27)

13 (30)

0.90 (0.21-3.89)


Chronic pulmonary disease

2 (18)

5 (11)

0.6

1.60 (0.31-8.25)


Chronic cardiac disease

5 (45)

21 (48)

1.0

0.92 (0.26-3.28)


Immuno-depression

2 (18)

1 (2)

0.10

8.00 (0.73-88.22)


Potential influenza source in the unitc

7 (64)

13 (30)

0.08

4.06 (1.08-15.33)


Individual influenza vaccinationd, e

2 (20)

21 (48)

0.16

0.34 (0.069-1.70)


Proportion of vaccinated HCW in the unit

0.10


< 35%

8 (73)

19 (43)

1.0 (Ref.)


≥ 35%

3 (27)

25 (57)

0.16 (0.018-1.32)


Data are reported as numbers (%) under descriptive analysis and as OR (95% CI) under logistic regression analysis. Controls were hospitalised patients with ILI and confirmed exclusion of influenza diagnosis after nasal swabbing; they were matched by influenza season (2004-05, 2005-06 and 2006-07). HAI, hospital-acquired influenza; OR, odds ratio; CI, confidence interval; HCW, healthcare workers.

aUnder univariate conditional logistic regression

bPer 1 year older

cPotential sources of exposure to influenza (other patients or HCW) for 5 days before ILI or influenza occurrence in the same ward

dIn current influenza season

eIndividual influenza vaccination was not known in 1 patient

Bénet et al. BMC Infectious Diseases 2012 12:30   doi:10.1186/1471-2334-12-30

Open Data