<prompt> A 3 yr. old female child presented with low grade fever, poor feeding and a rash shown below described as a slapped cheek rash. Which of the following is the predominant site of action of the above causative organism?SpleenLiverBone marrowNerves  <response>: The above scenario depicts Fifth diseaseErythema infectiosum caused by parvovirus B19. It shows a characteristic slapped cheek erythematous rash The predominant site is the erythroid precursors of the bone marrow and hence parvovirus B19 is also the causative agent of APLASTIC CRISIS in sickle cell disease patients. 