Table 4 Case fatality ratios (mean and 95% CIs) among laboratory-confirmed A/H1N1 influenza cases by pandemic wave, Mexico, 01 April through 31 December, 2009

Total A/H1N1 deaths (% of total A/H1N1 cases)

2.1% (2.0,2.3)

4.6% (3.1,6.5)

0.7% (0.5,1.0)

2.5% (2.3,2.7)

P < 0.0001

Central

2.7% (2.4,3.0)

5.5% (3.6,8.1)

1.7% (0.8,3.0)

2.7% (2.4,3.0)

P < 0.0001

Southern

0.8% (0.6,1.0)

0% (0,6.2)

0.5% (0.3,0.8)

1.2% (0.8,1.7)

P < 0.0001

Other states

2.3% (2.1,2.6)

3.2% (0.9,8.1)

0.9% (0.4,1.5)

2.6% (2.2,2.9)

P < 0.0001

Demography

Female

2.1% (1.8,2.3)

4.5% (2.5,7.5)

0.6% (0.3,0.9)

2.4% (2.1,2.7)

P < 0.0001

Male

2.2% (2.0,2.5)

4.6% (2.5,7.6)

0.9% (0.6,1.3)

2.5% (2.2,2.8)

P < 0.0001

Age (years)

<18

0.6% (0.5,0.8)

0.7% (0.1,2.6)

0.1% (0.04,0.3)

0.8% (0.6,0.97)

P < 0.0001

18–49

2.8% (2.5,3.1)

6.0% (3.5,9.4)

1.2% (0.8,1.7)

3.2% (2.8,3.6)

P < 0.0001

>50

8.5% (7.2,9.8)

15.7% (7.0,28.6)

3.5% (1.6,6.5)

9.1% (7.7,10.6)

P < 0.0001