This is a single-center, non-interventional, retrospective study of data, at the level of the individual without identification, extracted from medical records of adult patients undergoing a kidney transplant procedure after 1st from January 2018 until reaching the sample size enrollment (around 500 individuals); this refers to the period of verification of individuals' eligibility for entry into the study. Individuals under strategy preemptive patients who developed CMV infection/disease within 12 months after transplantation. The data will be collected from date of transplant (including pre-transplant clinical history) until completion of at least 12 months after transplantation, or until graft loss, or recipient death or loss to follow-up, when/if applicable.

Data will be collected from medical records and will include transplant recipient characteristics, transplant-related information, CMV status, clinical outcomes, treatment patterns, healthcare resource utilization and captured on an electronic Intake Form.

Study-specific Case Report (eCRF) The sponsor will create a Statistical Analysis Plan (SAP) before collection begins of data. The eCRF system will comply with research regulations

Inclusion Criteria:

• Received a single kidney transplant after January 1, 2018
• Age over 18 years at time of kidney transplant.
• It was under preemptive strategy.
• Diagnosed with CMV infection/disease within the first 12 months after kidney transplant.
• Follow-up information is available in medical records for at least 12 months after confirmation of CMV infection, or even loss of the allograft, death of the recipient or loss of follow-up of the receiver, when/if applicable.

Exclusion Criteria:

• Diagnosed as a carrier of the human immunodeficiency virus (HIV+), hepatitis B virus and/or hepatitis C before kidney transplantation.
• Participation in any interventional study during the period between kidney transplantation and a period of 12 months after CMV diagnosis.

The study population will be entirely adult kidney transplant recipients (age ≥18 years at the time of time of transplantation) who developed a first episode of CMV infection/disease in the first year of transplant. Eligible individuals will be enrolled consecutively based on transplant date, starting from the first year as defined in the inclusion/exclusion criteria.