How long should a fever last with cytomegalovirus infection?

About 2-6 weeks. Transmission of CMV may not even involve any symptoms, let alone fever. If it does occur, clinical illness from cmv, which is most commonly manifested by mononucleosis in normal hosts beyond the neonatal periode, lasts 2-6 weeks, and can include prolonged high fevers, chills, malaise, and fatigue.
Depends on other . Issues. Most CMV infections are clinically silent and do not cause fever. In patients with immune deficiency there may be symptomatic infection with fever and lesions in various tissues and fever. The duration of fever would be determined by the complicating issues.