Worldwide over 60 million people adhere to Vodou.
http://www.bondye.com/
In Benin alone over 60% of the population practices Vodou. In Haiti almost a full 100% of the population practices the Vodou faith in some form.

Vodou is a positive and progressive force for health in Africa and Haiti, where traditional Vodou healers work with modern doctors to provide and administer vaccines. The practice of Vodou has been shown to have an actual healing effect, either through true supernatural ability or the power of belief.