Deciphering Positive Cytomegalovirus Immunoglobulin M Test Results in Immunocompetent Adults Hospitalized With Illness Suspicious for Acute Cytomegalovirus Infection: A Multihospital Study

Interpreting positive CMV IgM results in immunocompetent adults hospitalized with acute illness is challenging and ambiguous due to test limitations and confounders. Supplemental CMV IgG avidity testing can help determine whether primary CMV infection caused the illness, thereby refining the diagnosis and potentially influencing clinical decision-making.