Table 2 Searching strategy
| Serial number | Databases | Number of the article found | Number of the article included | Number of Excluded article | Reason for exclusion |
|---|---|---|---|---|---|
| 1 | PubMed | n= | n= | n= | |
| 2 | Google Scholar | n= | n= | n= | |
| 3 | Web of Science | n= | n= | n= | |
| 4 | Cochran Library | n= | n= | n= | |
| 5 | Africa Wide Knowledge | n= | n= | n= | |
| 6 | Africa Index Medicus | n= | n= | n= | |
| 7 | Microsoft Academic | n= | n= | n= | |
| 8 | WHO COVID-19 database | n= | n= | n= | |
| 9 | Unpublished (pre-prent, manuscript, thesis and report from WHO,CDC) | n= | n= | n= |