Varicella zoster virus infections following allogeneic bone marrow transplantation: Frequency, risk factors, and clinical outcome

Reactivation of varicella tester virus (VZV) is a common event in patients undergoing allogeneic bone marrow transplantation (BMT) and may lead to lif e-threatening complications. We retrospectively analyzed the incidence, cli nical outcome, and risk factors for VZV infections occurring within the fir st 5 years of transplantation in 100 consecutive adults undergoing allogene ic BMT between 1992 and 1997. Forty-one patients (41%) developed VZV reacti vation a median of 227 days (range 45-346 days) post-transplantation. Twelv e percent of VZV reactivation occurred in the first 100 days and 88% within the first 24 months. Among those who survived for 2 or more years after tr ansplantation (n = 47), 59% developed VZV infection. Forty percent of patie nts with VZV reactivation required admission with a mean hospital stay of 7 .2 days. Two patients developed encephalitis, and 1 died despite antiviral therapy. The most frequent complications were post-herpetic neuralgia and p eripheral neuropathy (68%). Thoracic dermatomal tester represented 41% of t he infections; disseminated cutaneous involvement was observed in 17% of pa tients. No clinical or epidemiologic risk factors were associated with recu rrence. Administration of ganciclovir for prevention of cytomegalovirus inf ection delayed the onset of VZV infection beyond 4 months (P = .06). In a f urther subset analysis, patients with a limited chronic graft-versus-host d isease (GVHD) had a lower estimated incidence of VZV reactivation compared with those with extensive chronic GVHD (P = .11). We conclude that complica tions from reactivation of VZV infection are common and associated with con siderable morbidity and mortality in patients undergoing allogeneic BMT.