The investigators aim is to determine the incidence of cytomegalovirus resistance to antivirals in a cohort study. The patients are included at their first CMV active infection and are followed during two years thereafter. When criteria for suspected resistance are meet, blood and urine samples are collected for virus isolation and further resistance phenotype, and for resistance genotype determination. Results are compared with baseline samples. Clinical information such as treatment, immunosuppressive regimen and clinical evolution will be collected. Through this study, the investigators aim to organize a national network for the detection and identification of CMV resistant strains that will be useful when new therapeutics will be available.

Inclusion Criteria:

• Allogeneic bone marrow transplant recipient or solid organ transplant recipient, included in the cohort at the time of its firs active CMV infection (ie biological signs of CMV replication (viremia, ADN or ARN aemia, Antigenaemiapp65….) with or without fever, or clinical end organ disease symptoms

Exclusion Criteria:

• Patient without medical care.policy,
• patient that did not signed the médical consent