Malaria expands in mountains. Higher annual temperatures in the Usamabara Mountains have been linked to expanding malaria transmission.
Reference: Epstein, P., H. Diaz, S. Elias, G. Grabherr, N. Graham, W. Martens, E. M. Thompson, and J. Susskind. 1998. Biological and physical signs of climate change: focus on mosquito borne diseases. Bulletin of the American Meteorological Society 79: 409-417.