Cytomegalovirus acute infection with pulmonary involvement in an immunocompetent patient

Cytomegalovirus (CMV) infection in healthy adults is usually asymptomatic or causes a mild mononucleosis syndrome, while severe infections are rare in immunocompetent patients and poorly documented. When described, gastrointestinal tract and the central nervous systems are the most frequent sites of severe CMV infection. Lung disease can occur, but it's rare.

A 29 years old man presenting with a 2-weeks history of fever, headache, malaise, dry non-productive cough and thoracic pleuritic pain, without improvement after one-week therapy with levofloxacin. Blood exams showed lymphocytosis of almost 50%, nine percent of atypical lymphocytes and elevated transaminases. Thoracic CT-scan showed bilateral infiltrate with internal air bronchogram. Blood serology showed positivity for CMV IgG and IgM, with low CMV IgG avidity. Serum and bronchoalveolar detection of CMV by polymerase chain reaction (PCR) technique was also positive. Cultures were all negative. The patient became increasingly hypoxemic and the liver transaminases worsening, the reason for which ganciclovir was started. He made a full recovery and was discharged seven days later with oral valganciclovir, completing a 3 weeks antiviral course at home.

CMV pneumonia is a rare condition, however it's one of the three most common cause of severe viral community acquired pneumonia (CAP), along with influenza and adenovirus. CMV pneumonia should be considered in patients with atypical lymphocytes and mildly elevated serum transaminases.

In immunocompetent hosts, even with severe CMV-CAP, the prognosis is good. However, antiviral treatment should be considered in the rare occasion of severe CMV infection. Nevertheless, more studies are needed to clarify the clinical benefit of antiviral treatment.