Anti-Infective Prophylaxis, Immunization and Prevention of Recurrent Infectious Complications in Long-Term Survivors

After allogeneic hematopoietic stem cell transplantation (HSCT), immune reconstitution occurs gradually. The risk for infections and specific pathogens during this period is related to the extent and type of immune deficiency. The presence of chronic graft-versus-host disease (GVHD) increases the risk for infections with encapsulated bacteria, such as Streptococcus pneumoniae or Haemophilus influenzae. Persistent defects in cell-mediated and humoral immunity in the months to years following HSCT increase the risk for viral infections (e.g., cytomegalovirus and respiratory viruses). Long-term HSCT survivors also have an increased risk for fungal pneumonia (e.g., Aspergillus spp., Pneumocystis jirovecii). Therefore, prophylaxis and preemptive treatment of opportunistic infections is of critical importance in the setting of chronic GVHD and ongoing immunosuppressive therapy to prevent morbidity and mortality. As the immune system recovers, it is also important to re-immunize against childhood illnesses and to receive the seasonal influenza vaccine.