Characterizing the malaria rural-to-urban transmission interface: The importance of reactive case detection.

This study found no evidence supporting the existence of urban malaria transmission in Quibdó. RCD strategy was more efficient for identifying malaria cases than ACD alone in areas where malaria transmission is variable and unstable. Incorporating parasite genotyping allows discovering hidden patterns of malaria transmission that cannot be detected otherwise. We propose to use the term "focal case" for those primary cases that lead to discovery of secondary but genetically unrelated malaria cases indicating undetected malaria transmission.