Ironically, Americans gave Sub-Saharan Africans HIV during the great AIDS scare.
They wanted to understand how it spread, if it was really just a faggot thing or not. So they deliberately infected thousands of people in different age groups and different countries in Africa.
They notice that Muslim Africans had a far lower spread rate than Christian Muslims and assume it was because they were circumcised. The next thing, they started a programme of mass circumcision in Africa but fucked up even more by reusing the same tools without proper sterilisation.
This is why those countries have so much HIV in a very specific age group.