Final answer:
Patients with hemolytic anemia are particularly susceptible to an aplastic crisis triggered by Parvovirus B19, which affects erythroid progenitor cells and can impair red blood cell production.
Step-by-step explanation:
Patients with hemolytic anemia, such as those with G6PD deficiency or other conditions, are at an increased risk of aplastic crisis when infected with Parvovirus B19. This virus uniquely affects the erythroid progenitor cells in the bone marrow, causing a transient halt in red blood cell production, which can precipitate an aplastic crisis, particularly in individuals with pre-existing conditions that affect red blood cell turnover. It is crucial for these patients to avoid exposure and to be closely monitored during infections to manage any potential complications.