Note: All figures are cumulative
Source: WHO updates
| DATE | no. of countries w/ confirmed cases | no. of confirmed cases | no. of deaths (out of no. of confirmed cases) |
| April 24, 2009 | 2 | 25 | |
| April 26, 2009 | 2 | 38 | 7 |
| April 27, 2009 | 4 | 73 | 7 |
| April 28, 2009 | 7 | 105 | 7 |
| April 29, 2009 | 9 | 148 | 8 |
| April 30, 2009 | 11 | 257 | 8 |
| May 1, 2009 | 13 | 367 | 10 |
| May 2, 2009 | 16 | 658 | 17 |
| May 3, 2009 | 18 | 898 | 20 |
| May 4, 2009 | 21 | 1,085 | 26 |
| May 5, 2009 | 21 | 1,490 | 30 |
| May 6, 2009 | 23 | 1,893 | 31 |
| May 7, 2009 | 24 | 2,371 | 44 |
| May 8, 2009 | 25 | 2,500 | 46 |
| May 9, 2009 | 29 | 3,440 | 48 |
| May 10, 2009 | 29 | 4,379 | 49 |
| May 11, 2009 | 30 | 4,694 | 53 |
| May 12, 2009 | 30 | 5,251 | 61 |
| May 13, 2009 | 33 | 5,728 | 61 |
| May 14, 2009 | 33 | 6,497 | 65 |
| May 15, 2009 | 34 | 7,520 | 65 |
| May 16, 2009 | 36 | 8,451 | 72 |
| May 17, 2009 | 39 | 8,480 | 72 |
| May 18, 2009 | 40 | 8,829 | 74 |
| May 19, 2009 | 40 | 9,830 | 79 |
| May 20, 2009 | 41 | 10,243 | 80 |
| May 21, 2009 | 41 | 11,035 | 85 |
| May 22, 2009 | 42 | 11,168 | 86 |
| May 23, 2009 | 43 | 12,022 | 86 |
| May 25, 2009 | 46 | 12,515 | 91 |
| May 26, 2009 | 46 | 12,954 | 92 |
| May 27, 2009 | 48 | 13,398 | 95 |
| DATE | no. of countries w/ confirmed cases | no. of confirmed cases | no. of deaths (out of no. of confirmed cases) |
