False-Positive Monospot or Rubella and Mononucleosis

Abstract

To the Editor.— Phillips1reported a case clinically consistent with rubella, in which a positive Monospot test result was noted. Because of persistently negative heterophil antibody titers he concluded that the patient did not have mononucleosis and, therefore, the Monospot test result was a false-positive. However, Evans et al2previously reported a syndrome of heterophil-negative infectious mononucleosis and indicated that many of these patients have elevated EB virus antibody titers. Phillips1reported that EB virus titers could not be obtained in his case. One wonders if this were truly an instance of a false-positive Monospot result or whether it was in fact a case of coexistence of two viral infections—rubella and EB virus. With this in mind, we would like to describe a similar case that is even more suggestive of the coexistence of these two viral diseases. Report of a Case.— A 20-year-old boy from El Salvador