First, the local environment itself is suitable for the survival and spread of infectious diseases. Africa has a dense population, poor living conditions, and poor transportation guarantee of water and food sources, which makes it easy for infectious diseases to take advantage of it.
Second, the limitation of sanitary conditions. In a word, no money. Lack of money means that there are not enough medicines, medical equipment and medical workers. In this way, once an infectious disease occurs, effective treatment and isolation cannot be carried out. Even if it is easy for us to deal with, it will cause great damage in Africa. This is the main reason.
Third, living habits. For example, AIDS, the best and most labor-saving way to prevent AIDS is condom. Although Africa is poor, condoms are affordable, and their governments encourage the use of condoms and provide them free of charge. But the point is, they don't. Not only do they not use it themselves, but they also openly resist it and appeal to others not to use it. Because in many African countries and tribes, condoms are evil and should not be used. Just like some Christians resist homosexuality, why? Because that means you can't have children effectively, which is advocated by Christianity and is also a deep-rooted traditional concept of African countries and tribes.