The crews often spray out of JNB, despite the fact that the region has no malaria (only beginning around Kruger Park and the Lowveld); sometimes they do not. I have also had the aircraft sprayed out of Nairobi and Entebbe, and both are malaria areas (I got malaria in Uganda ).

I think the official policy is that airlines only spray when returning to the mother land from the colonies that are in malaria areas.