This study is a survey in Japan of Maribavir tablets used to treat participants with Cytomegalovirus (CMV) infection refractory to existing anti-CMV therapy in organ transplantation (including hematopoietic stem cell transplantation).

The main aim of the study is to check if treatment with Maribavir can protect Japanese people against CMV infection, and to check side effect from the study treatment. The study sponsor will not be involved in how the participants are treated but will provide instructions on how the clinics will record what happens during the study.

During the study, participants with CMV infection will take Maribavir tablets according to their clinic's standard practice. The study doctors will check for side effects from Maribavir tablets for 27 weeks.

Inclusion Criteria:

- All participants with Cytomegalovirus (CMV) infection refractory to existing anti-CMV therapy in organ transplantation (including hematopoietic stem cell transplantation).

Exclusion Criteria:

- None

The population of this survey are all participants who meet the inclusion/exclusion criteria.

Takeda provides access to the de-identified individual participant data (IPD) for eligible studies to aid qualified researchers in addressing legitimate scientific objectives (Takeda's data sharing commitment is available on https://clinicaltrials.takeda.com/takedas-commitment?commitment=5). These IPDs will be provided in a secure research environment following approval of a data sharing request, and under the terms of a data sharing agreement.

IPD from eligible studies will be shared with qualified researchers according to the criteria and process described on https://vivli.org/ourmember/takeda/. For approved requests, the researchers will be provided access to anonymized data (to respect patient privacy in line with applicable laws and regulations) and with information necessary to address the research objectives under the terms of a data sharing agreement.