CMV Refractory and Resistant Infection in Solid Organ Transplant Recipients in Argentina

This study will describe the frequency and characteristics of refractory and resistant cytomegalovirus (CMV) infection in adults who received a solid organ transplant in Argentina between 2017 and 2024. Researchers will review medical records from transplant centers across the country to identify episodes of CMV infection that did not respond adequately to standard antiviral treatment (refractory) or that showed genetic mutations associated with drug resistance. The study will describe the clinical features, treatments used, and outcomes (including graft function and survival) of patients with these episodes, in order to better understand how common this problem is and what factors are associated with it in the local population.

Inclusion Criteria: * Adult patients (≥18 years) who received a solid organ transplant (kidney, liver, heart, lung, pancreas, or combined) at a participating center in Argentina between January 1, 2017 and December 31, 2024 * Documented CMV infection within 18 months post-transplant * Followed for at least 18 months from transplant and at least 12 months from CMV infection onset Exclusion Criteria: * Patients with incomplete medical records precluding assessment of CMV infection status or key study variables * Patients not meeting the minimum follow-up period from transplant or from infection onset