| Sampling Point/LGA | Study Population | |
|
| Cases | Controls |
| Ahoada West | 42 | 126 |
| Asari-Toru | 44 | 132 |
| Etche | 44 | 132 |
| Oyigbo | 44 | 132 |
| Tai | 44 | 132 |
| Port Harcourt City | 57 | 174 |
| Total | 275 | 825 |