Background
Methods
Sources of data and definitions
Statistical analysis
Comparing the age of influenza cases
Results
Country | Latitude (a) | Population (million) | Ageing index (b) | GDP per capita (USD) | % of outpatients (c) | No. influenza cases (seasons) included in the analysis: | |||
---|---|---|---|---|---|---|---|---|---|
A(H1N1) | A(H1N1)pdm2009 | A(H3N2) | B | ||||||
Southern hemisphere | |||||||||
New Zealand | 41.8 S | 4.5 | 0.72 | 30,400 | 30% | 2,274 (5) | 3,763 (3) | 4,840 (8) | 2,763 (7) |
Chile | 35.8 S | 16.6 | 0.48 | 19,100 | 5% | 403 (1) | 5,399 (3) | 3,540 (3) | 897 (2) |
South Africa | 29.0 S | 53.0 | 0.22 | 11,500 | 0% | - (0) | 432 (3) | 421 (3) | 527 (3) |
Australia | 25.8 S | 23.4 | 0.84 | 43,000 | 50% | 3,614 (6) | 50,096 (4) | 13,286 (9) | 28,673 (12) |
Inter-tropical belt | |||||||||
Madagascar | 19.4 S | 21.3 | 0.08 | 1,000 | 100% | 109 (1) | 1,101 (2) | 579 (4) | 1,004 (4) |
Brazil (d) | 10.8 S | 201.0 | 0.32 | 12,100 | NA | - (0) | - (0) | - (0) | 665 (4) |
Ecuador | 2.0 S | 15.4 | 0.24 | 10,600 | 0% | - (0) | 673 (2) | 713 (3) | 185 (1) |
Indonesia | 1.7 S | 237.4 | 0.25 | 5,200 | 95% | 720 (2) | - (0) | 1,397 (4) | 1,281 (4) |
Kenya | 0.4 S | 44.4 | 0.07 | 1,800 | 40% | 365 (2) | 1,285 (3) | 1,183 (5) | 1,454 (5) |
Singapore | 1.2 N | 5.4 | 0.63 | 62,400 | 100% | - (0) | 2,634 (3) | 1,436 (3) | 1,483 (3) |
Cameroon | 5.7 N | 22.5 | 0.07 | 2,400 | 90% | - (0) | - (0) | 259 (2) | 102 (1) |
Ivory Coast | 7.6 N | 23.2 | 0.09 | 1,800 | 83% | - (0) | 344 (2) | 171 (1) | 446 (2) |
Panama | 8.6 N | 3.7 | 0.28 | 16,500 | 39% | - (0) | 744 (1) | 321 (2) | 154 (1) |
Costa Rica | 10.0 N | 4.6 | 0.30 | 12,900 | 27% | - (0) | 4,069 (2) | 1,026 (4) | 387 (2) |
Nicaragua | 12.9 N | 6.1 | 0.16 | 4,500 | 43% | - (0) | 3,113 (3) | 1,089 (4) | 699 (3) |
El Salvador | 13.8 N | 6.1 | 0.25 | 7,500 | 22% | - (0) | 858 (2) | 317 (2) | 437 (3) |
Honduras | 14.8 N | 8.2 | 0.11 | 4,800 | 56% | - (0) | 656 (2) | 277 (2) | - (0) |
Guatemala | 15.7 N | 15.4 | 0.12 | 5,300 | 72% | 263 (1) | 1,681 (3) | 169 (1) | 316 (2) |
Viet Nam | 16.7 N | 89.7 | 0.23 | 4,000 | 40% | 1,218 (2) | 1,368 (3) | 2,781 (6) | 2,982 (8) |
Northern hemisphere | |||||||||
Bhutan | 27.4 N | 0.7 | 0.22 | 2,600 | 97% | - (0) | 510 (2) | 130 (1) | 101 (1) |
China South (e) | 31.1 N | 969.4 | 0.56 | 9,800 | 100% | 5,530 (5) | 40,754 (2) | 30,299 (7) | 35,910 (8) |
Morocco | 32.0 N | 33.2 | 0.24 | 5,500 | 70% | - (0) | 2,076 (2) | 354 (2) | - (0) |
Turkey | 39.0 N | 76.7 | 0.26 | 15,300 | 100% | 1,298 (2) | - (0) | - (0) | 289 (1) |
Portugal | 39.3 N | 10.4 | 1.17 | 22,900 | 97% | - (0) | 648 (3) | 2,085 (8) | 733 (4) |
China North (e) | 39.5 N | 370.9 | 0.56 | 9,800 | 100% | 3,900 (5) | 22,951 (3) | 13,054 (7) | 19,956 (7) |
Italy | 42.9 N | 59.9 | 1.52 | 29,600 | 60% | - (0) | 3,880 (2) | 1,900 (2) | 493 (1) |
Kazakhstan | 48.0 N | 17.9 | 0.28 | 14,100 | 5% | - (0) | 108 (1) | 421 (3) | 163 (1) |
Ukraine | 49.1 N | 44.6 | 1.14 | 7,400 | NA | - (0) | 104 (1) | - (0) | - (0) |
England (f) | 52.3 N | 53.0 | 0.91 | 37,300 | 57% | 179 (1) | 2,438 (3) | 1,743 (6) | 1,319 (3) |
19,873 (33) | 151,685 (60) | 83,791 (102) | 103,419 (93) |
Influenza virus | sRIR | lower CI (a) | upper CI (a) | I2 |
---|---|---|---|---|
Young children (0-4 years) | ||||
A(H1N1) | 3.57 | 3.00 | 4.14 | 97.5% |
A(H1N1)pdm2009 | 2.28 | 2.10 | 2.46 | 97.8% |
A(H3N2) | 3.30 | 2.95 | 3.64 | 98.2% |
B | 2.93 | 2.68 | 3.19 | 97.5% |
Older children (5-17 years) | ||||
A(H1N1) | 1.36 | 1.19 | 1.54 | 95.2% |
A(H1N1)pdm2009 | 1.23 | 1.02 | 1.45 | 99.5% |
A(H3N2) | 1.04 | 0.93 | 1.14 | 97.2% |
B | 1.69 | 1.53 | 1.85 | 98.4% |
Young adults (18-39 years) | ||||
A(H1N1) | 0.84 | 0.72 | 0.96 | 97.1% |
A(H1N1)pdm2009 | 0.94 | 0.87 | 1.01 | 97.5% |
A(H3N2) | 0.73 | 0.68 | 0.78 | 96.0% |
B | 0.65 | 0.59 | 0.71 | 98.1% |
Older adults (40-64 years) | ||||
A(H1N1) | 0.49 | 0.41 | 0.57 | 95.2% |
A(H1N1)pdm2009 | 0.62 | 0.55 | 0.69 | 98.7% |
A(H3N2) | 0.59 | 0.55 | 0.63 | 93.5% |
B | 0.41 | 0.37 | 0.45 | 96.6% |
Elderly (65+ years) | ||||
A(H1N1) | 0.16 | 0.12 | 0.20 | 73.9% |
A(H1N1)pdm2009 | 0.27 | 0.24 | 0.31 | 94.7% |
A(H3N2) | 0.74 | 0.66 | 0.83 | 95.2% |
B | 0.38 | 0.33 | 0.43 | 92.4% |
Influenza virus | I2 | Variables significantly (p<0.05) correlating with sRIRs | |||||
---|---|---|---|---|---|---|---|
Latitude | % of cases accounted for in the same season | % of cases accounted for in the previous season | Ageing index | GDP per capita | % of outpatients (a) | ||
Young children (0-4 years) | |||||||
A(H1N1) | 97.5% | ||||||
A(H1N1)pdm2009 | 97.8% | ✓ | ✓ | ✓ | |||
A(H3N2) | 98.2% | ✓ | ✓ | ✓ | |||
B | 97.5% | ✓ | ✓ | ✓ | |||
Older children (5-17 years) | |||||||
A(H1N1) | 95.2% | ✓ | |||||
A(H1N1)pdm2009 | 99.5% | ✓ | ✓ | ✓ | |||
A(H3N2) | 97.2% | ✓ | ✓ | ✓ | |||
B | 98.4% | ✓ | ✓ | ✓ | ✓ | ✓ | |
Young adults (18-39 years) | |||||||
A(H1N1) | 97.1% | ✓ | ✓ | ||||
A(H1N1)pdm2009 | 97.5% | ✓ | ✓ | ✓ | |||
A(H3N2) | 96.0% | ✓ | ✓ | ✓ | |||
B | 98.1% | ✓ | ✓ | ✓ | ✓ | ||
Older adults (40-64 years) | |||||||
A(H1N1) | 95.2% | ||||||
A(H1N1)pdm2009 | 98.7% | ✓ | ✓ | ||||
A(H3N2) | 93.5% | ✓ | ✓ | ||||
B | 96.6% | ✓ | ✓ | ✓ | ✓ | ||
Elderly (65+ years) | |||||||
A(H1N1) | 73.9% | ||||||
A(H1N1)pdm2009 | 94.7% | ✓ | ✓ | ✓ | ✓ | ||
A(H3N2) | 95.2% | ✓ | ✓ | ✓ | |||
B | 92.4% | ✓ | ✓ |