Table 2. Country of origin for the studies.
| Country of origin | Studies |
| Nigeria | 10 |
| Kenya | 3 |
| Togo | 1 |
| Ethiopia | 2 |
| South Africa | 1 |
| Egypt | 2 |
| Ghana | 1 |
| Congo | 2 |
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.