 Late stage studies were later continued by Doctor , founder of the German branch of International Planned Parenthood Federation (IPPF) who is also associated with the compulsory sterilisation in Nazi Germany.Unethical medical experimentation that has occurred for over a century may be the cause of the documented fear and mistrust of doctors and medicine in Africa.For example, polio has been on the rise in Nigeria, Chad, and Burkina Faso because many people there avoid vaccinations because they believe that the vaccines are contaminated with HIV or sterilization agents.