Respiratory tract infections in cytomegalovirus-excreting and nonexcreting infants

Background. There is evidence of an immunosuppressive effect of cytomegalovirus (CMV), and CMV has been claimed to be a copathogen in respiratory tract infections (RTI). We therefore studied the significance of CMV viral load in infants with RTI, compared the frequency of infection with respiratory viruses and followed the course of RTI in CMV-excreting vs. nonexcreting infants. Methods. We examined 201 infants consecutively admitted to the Department of Pediatrics for RTI. At admission nasopharyngeal aspirates, throat swabs and urine were examined for CMV, and nasopharyngeal aspirates were examined for respiratory viruses. Results. In these patients 23.3% had CMV in the urine, 15.3% had CMV in the throat and 10.9% had CMV in the nasopharynx; 26.2% excreted CMV in at least one site. No relationship was found between CMV viral load and clinical symptoms. Infection with respiratory viruses was as common in infants excreting CMV as in nonexcreting infants. Symptoms and the course of infection were not different in the two groups except that CMV-excreting infants had a significantly higher frequency of rhonchi at admission (P = 0.007) and a tendency for longer duration of cough (P = 0.06). Conclusion. CMV viral load was not related to clinical symptoms. The frequency of infection with common respiratory viruses in infants was independent of CMV excretion. The course of infection was not more complicated in infants excreting CMV; however, a higher frequency of rhonchi was demonstrated in patients with CMV.