What are the recommended diagnostic tests for confirming CMV infection in immunocompetent patients?

Recommended diagnostic tests for confirming cytomegalovirus (CMV) infection in immunocompetent patients primarily include serological assays to detect CMV-specific IgM and IgG antibodies, which indicate recent or past infection respectively. Detection of CMV IgM antibodies supports recent or active infection, while IgG seroconversion or a significant rise in IgG titres between acute and convalescent samples confirms recent infection. Additionally, polymerase chain reaction (PCR) testing for CMV DNA in blood or other body fluids can be used to detect active viral replication, providing a sensitive and specific diagnostic tool. Antigenemia assays detecting CMV pp65 antigen in peripheral blood leukocytes may also be employed, although these are more commonly used in immunocompromised patients. In immunocompetent individuals, PCR and serology remain the mainstays for diagnosis. Culture methods are less commonly used due to longer turnaround times and lower sensitivity. Combining serology with PCR enhances diagnostic accuracy, especially in symptomatic patients where confirmation of active infection is needed.

Thus, the integrated approach for immunocompetent patients involves initial serological testing for CMV IgM and IgG antibodies, supplemented by PCR for CMV DNA when active infection is suspected or confirmation is required. Antigenemia testing may be considered but is not routinely recommended in this population. This approach aligns with UK clinical practice and is supported by literature emphasizing the diagnostic value of antigenemia and molecular methods alongside serology (The et al., 1990; Grangeot-Keros and Cointe, 2001).