In many countries throughout the world belief in witches is common, and black magic is considered part of everyday life. A 2010 poll of 18 countries in sub-Saharan Africa found that over half of the population believe in magic. Witch doctors are consulted not only for healing diseases, but also for placing, or removing, curses or bringing luck.
One human rights activist in the small African country of Malawi, Seodi White, has been fighting for years to stem many traditional beliefs that help spread HIV, especially among poor and underprivileged women.
According to a CNN story, widows in some parts of southern Africa are expected to engage in unprotected sex in order to “cleanse” them. The belief is that the husband’s spirit will return otherwise, cursing the family.
For the rest of the story: http://www.livescience.com/28118-how-belief-in-magic-spreads-hiv-in-africa.html