Table 4.

Systemic viruses responsible for pneumonia in immunocompromised patients

Virus type	Source	Extra-respiratory manifestations	Diagnosis
HSV (HSV-1, HSV-2)	Donor transmission to transplant recipient Reactivation in T-cell defects	Skin and genital eruption Encephalitis, esophagitis, Keratitis	PCR (blood, BAL, tissue) Tissue culture Serology Histopathology
VZV	Donor transmission to transplant recipient Reactivation in T-cell defects	Varicella, herpes zoster Encephalitis, cerebellitis, hepatitis, myelitis Herpes zoster ophthalmicus	PCR Direct fluorescent antibody testing Viral culture Histopathology
CMV	Donor transmission to transplant recipient Reactivation in T-cell defects	Esophagitis, gastritis, colitis Retinitis, encephalitis, myelitis, polyradiculopathy Neutropenia	PCR (blood, BAL) Histopathology Serology
Adenovirus	Reactivation	Hemorrhagic cystitis, nephritis Colitis, hepatitis, encephalitis	Viral culture (nasal, blood, urine, CSF, tissues) EIA, Immunofluorescence, PCR, serology Histopathology

HSV herpes simplex virus, VZV varicella–zoster virus, CMV cytomegalovirus, PCR polymerase chain reaction, BAL bronchoalveolar lavage, CSF cerebrospinal fluid, EIA enzyme immunoassay