Infections After Allogeneic Hematopoietic Stem Cell Transplantation

Temporal distribution of infectious complications by pathogen type and transplant phase
Pre-Engraftment
Day 0 – 30
Neutropenia, mucosal damage
Post-Engraftment
Day 30 – 100
Impaired cellular immunity, aGvHD
Late Phase
Day 100 – 1 year+
cGvHD, immune reconstitution
D0D15D30
D30D60D100
D1006 mo1 yr+
Bacterial
Gram-negative bacilli
Gram-positive cocci
Clostridioides difficile
Encapsulated bacteria
Viral
HSV reactivation
CMV reactivation
EBV / PTLD
HHV-6 encephalitis
Adenovirus
BK virus (HC)
VZV reactivation
Respiratory viruses
PML (JC virus)
HBV reactivation
Fungal
Candida spp.
Aspergillus spp.
Pneumocystis jirovecii
Mucorales
Parasitic
Toxoplasma gondii
Strongyloides
Neutrophils
Severe Neutropenia
Recovering
Normal
Cellular Immunity
Absent
Severely Impaired
Reconstituting
Humoral Immunity
Absent
Absent
Slow Recovery
Mucosal Barrier
Disrupted
Healing
Restored
Bacterial
Viral
Fungal
Parasitic
High risk
Lower risk
Bar intensity reflects relative risk. Individual risk varies with conditioning regimen, donor type, GvHD status, and prophylaxis.
HC = hemorrhagic cystitis · PTLD = post-transplant lymphoproliferative disorder · PML = progressive multifocal leukoencephalopathy