| Areas | Lhasa areas (3650 m) | Golmud areas (2780 m) | ||||
| Subjects | With symptoms (cases) | Incidence (%) | Subjects | With symptoms (cases) | Incidence (%) | |
| Kunming | 64 | 44 | 68.75 | 41 | 20 | 48.78 |
| Zhengzhou | 58 | 52 | 89.66 | 44 | 32 | 72.73 |
| Beijing | 50 | 46 | 92.00 | 36 | 26 | 72.22 |