All of the following factors contribute to Resurgence of malaria, except:
Drug Resistance in host
Drug Resistance in parasite
Drug Resistance in vectors
Antigenic variations in parasite
Drug resistance in the host does not contribute to Resurgence of malaria, whereas Drug resistance in vectors and parasites and antigenic variations in parasites leads to resugence of malaria. Ref: The Anthropology of Infectious Disease : International Health Perspectives By Marcia Claire Inhorn, Peter J. Brown, Pages 119-127; Medical Disorders in Pregnancy : An Update By Hiralal Konar, Pralhad Kushtagi, Page 77.