2 Months after renal transplantation 40yr old developed fever and feature suggestive of bilateral diffuse interstitial pneumonitis which of the following is the most likely etiological agent :

CMV (Cytomegalovirus) is the most likely etiological agent. CMV is the most common viral pathogen complicating transplantation. It most often manifests as pneumonitis in the first four months after transplantation. It can also cause leukopenia in solid organ transplant recipients, obliterative bronchiolitis in lung transplants, and graft atherosclerosis after hea transplantation. Option 1: Herpes simplex: HSV 1 causes mainly oral herpes and HSV 2 causes genital Herpes. Option 3: EBV (Epstein Barr Virus)- cause infectious mononucleosis. Option 4: Varicella zoster can cause chicken pox in primary exposure and Zoster or Shingles on reactivation of primary lesion in old age >60yrs.