Fig. 2: Unraveling red blood cell morphological changes related to an infectious environment.

a Images of blood cells were extracted from thin blood smears sampled from a population of people exposed to malaria. In all, 200 slides were selected as negative for Malaria by microscopists, meaning that no parasites could be found on any of these slides, with nevertheless half of them found to be positive by qPCR. Note that on both qPCR positive and qPCR negative slides, images extracted displayed variable cell densities with variable background, did not contain any parasites, and did not show any identifiable systematic visible differences, scale bar is 10 μm. b In order to identify discriminative features between qPCR+ and qPCR- slides, we used 60,000 such images from these 200 slides to train a conditional GAN. This panel shows three representative generated images of the results found. Z1 displays a visual difference that can be interpreted as an increase of anemia: the content of some blood cells lose hemoglobin (displayed as a hole or a white halo in the cell). This phenotype could barely be identified from real images data because both qPCR+ and qPCR- slides contain anemia cells. Additionally, Z2 displays some deformations of the cell membrane producing crenated cells. Finally, Z3 shows that the negative sample contained more debris due to staining as a translation to qPCR+ tends to remove these artifacts. Indeed, the system cannot discriminate between relevant differences of phenotypes from biologically irrelevant differences related to possible technical or experimental biases.