Demonstration of IgM cytomegalovirus-antibodies as an aid to early diagnosis in adults.

An indirect immunofluorescence test for titration of IgM cytomegalovirus (CMV)-antibodies is presented as a sensitive and rapid method for the diagnosis of CMV-infection in adults. The development of these antibodies was followed in thirty-two serum samples from nine patients with a CMV-infection. No IgM antibodies were detected in pre-illness sera or in four sera, obtained as early as 1–7 days after onset of symptoms. Positive specimens were collected 11 days or more after the development of symptoms. After reaching a maximum level, antibody titres decreased gradually. In thirty-one control sera, obtained from a group of twenty-four individuals, either healthy, or suffering from other herpes-group virus infections, IgM CMV-antibody titres did not exceed 8. In this investigation, titres of 16 or greater were concluded to be evidence of recent infection. It is suggested that the testing of only one serum specimen can be sufficient to support the clinical diagnosis.