Once pneumonitis ensues, the clinical course is very rapid. Other manifestations of CMV infection include fever, oesophagitis, colitis, hepatitis, encephalitis, retinitis, vasculitis, viraemia and bone marrow failure. The highest mortality occurs 2 to 3 months after the transplant when the patients is out of hospital. HSV infection is common in BMT patients and occurs within the first few weeks following transplant. Reactivation may cause severe local or disseminated disease in the form of pneumonitis and oesophagitis.
Most patients develop dermatomal zoster and some develop cutaneous dissemination.
Although EBV infection due to reactivating virus is common, most infections are asymptomatic although in a few instances, life threatening lymphoproliferative syndromes, which may or may not respond to acyclovir, have been observed. The exact role of adenovirus infections in BMT recipients is still to be evaluated . A and RSV have also been reported and have caused severe disease in BMT recipients. Reactivation of JC and BK viruses are common following BMT and is usually asymptomatic. Occasionally, it is associated with acute haemorrhagic cystitis.