Snapshot A 40-year-old man with a past medical history of HIV presents to the clinic for follow-up. He reports that he has had difficulty swallowing, fevers and chills, nausea, vomiting, and abdominal pain. He reports that he has been compliant with his HIV medications. On physical exam, he has ulcers in his oropharynx. His laboratory tests reveal positive CMV-specific immunoglobulin G but negative heterophile antibodies. He is given an antiviral treatment and is admitted for an endoscopy workup and close monitoring. (CMV esophagitis) Introduction Classification cytomegalovirus (CMV) or human herpesvirus-5 (HHV-5) linear, double-stranded DNA virus largest virus that causes human infections transmission via body fluids or vertical transmission Epidemiology incidence very common risk factors immunosuppression men who have sex with other men poor socioeconomic status working in childcare transplant recipients prone to CMV pneumonia Pathogenesis CMV-caused diseases can either result from a primary infection or reactivation of a latent infection replication of host cells (including epithelial cells, macrophages, and neurons) result in viremia and symptoms from primary infection cellular immunity is crucial in clearing this virus Associated conditions congenital CMV infection jaundice hepatosplenomegaly thrombocytic purpura and petechial rash hearing loss most common cause of non-hereditary congenital sensorineural deafness seizures microcephaly ventriculomegaly intracranial calcifications Prognosis often self-limited in immunocompetent patients Presentation Symptoms immunocompetent patients most cases are asymptomatic if symptomatic, CMV infections often result in a mononucleosis syndrome with fevers, myalgias, arthralgias, and cough immunocompromised patients esophagitis results in linear ulcers vs the punched-out ulcers caused by HSV1 colitis (most common) encephalitis hepatitis pneumonia retinitis congenital CMV hemolytic anemia Physical exam fever cervical lymphadenopathy hepatosplenomegaly maculopapular rash Studies Labs lymphocytosis with atypical lymphocytes thrombocytopenia transaminitis negative heterophile antibody CMV-specific immunoglobulin M (persists for 4-6 months) CMV-specific immunoglobulin G (2-3 weeks) active infection viral load does not distinguish active vs past infection Histology if warranted, may reveal CMV on immunohistochemistry classic "owl's eye" appearance Making the diagnosis based on clinical presentation and laboratory studies Differential Epstein-Barr viral (EBV) mononucleosis distinguishing factors CMV mononucleosis often includes more myalgias, arthralgias, and cough than EBV infection CMV infection also does not typically present with sore throat or lymphadenopathy Treatment Management approach mainstay of treatment is supportive care Conservative supportive care indication all patients modalities hydration Medical antiviral medications indications immunocompromised patients severe disease or organ damage drugs ganciclovir valganciclovir Complications Thrombosis Colitis Permanent vision changes