Medically there's a tone of what-doesn't-kill-you-makes-you-stronger, which is kind of bullshit. Malaria might not kill native adults very often, but it is not harmless.
And economically, the argument is similarly patronizing. After going on about the native immunity many people have, it then talks about how economic disruption is causing migrations, leading to people (not just whites) who don't have the immunity to be exposed. The response: people should stay in their place. That the prerequisite for solving any problem is to revert to traditional structures and strengthen those structures (the same basic argument is made about poverty and many other African problems). The idea that Africans may in fact wish to have control of their own personal destiny is disregarded -- that if conditions were better, if economic forces were less manipulative, people might still want to migrate, because the drive to better one's life persists even when life is okay.