The Wide Spectrum of Presentations of Cytomegalovirus Infection in Immunocompetent Hosts: An Exhaustive Narrative Review

CMV is a ubiquitous DNA virus that establishes infection and results in 40-100% seropositivity. Viral replication occurs following an acquired primary infection (or reinfection) or by the reactivation of life-long latency. In immunocompetent patients, CMV infection is mostly asymptomatic or mild and self-limited. However, an extensive review of the literature published up to April 2024 reveals that despite immunocompetence, CMV can cause a very large variety of clinical syndromes in any part of the gastrointestinal tract (the most common pattern), the central or peripheral nervous system, and the eyes, as well as hematological, pulmonary, cardiac, and cutaneous disease. Not uncommonly, more than one system is involved, and though the disease is often self-limited, treatment with intravenous ganciclovir or oral valganciclovir may be required, and in isolated cases, fatalities may occur. Thus, a potential CMV infection should be considered in the differential of myriad syndromes in non-immunocompromised patients. Associated systemic symptoms (fever, sweats, and weight loss), lymphocytosis, and hepatitis are not uncommon and can be a useful clue. Some populations, such as critically ill patients in intensive care, pregnant women, elderly patients, and those with inflammatory bowel disease, may be more susceptible. Moreover, the potential of past, latent CMV infection (i.e., CMV seropositivity) to be associated with significant cardiovascular morbidity and all-cause mortality years later is intriguing and requires further study. All these data indicate the outstanding importance of developing a vaccine against CMV, which hopefully will become available in the foreseeable future. Meanwhile, a solid diagnosis of active CMV infection can be quickly established (or ruled out) by widely available serology tests and PCR amplification, and clinicians in all disciplines need to be more aware of the diverse guises of CMV infection and remember to consider it in any host, including an immunocompetent one.