False-Positive Monospot in a Returning Traveler with Dengue Fever.

We present a case of a 46-yr-old male who developed fever, chills, headaches, myalgia, fatigue, and photophobia 1 d after returning from the Philippines. He demonstrated a mild transaminitis and significant thrombocytopenia (12,000 cells/μL). His initial evaluation revealed a positive heterophile antibody test. Without a classic EBV presentation, a fever in returning traveler evaluation was instituted resulting in a positive dengue test by direct fluorescence IgM (8.82 IU) and IgG (7.13 IU), respectively. Both his EBV DNA polymerase chain reaction and IgM by viral capsid antigen were negative. Dengue, an RNA flavivirus, and the dengue antibody have demonstrated cross-reactivity with other flaviviruses including Japanese encephalitis virus, yellow fever virus, West Nile virus, and St. Louis encephalitis. However, EBV is a double-helix DNA herpesvirus and structurally very different. To our knowledge, this is the first reported case of cross-reactivity between dengue and EBV that describes a potential false positive for the heterophile antibody test. PMID: 29514339 [PubMed - in process]
Source: Military Medicine - Category: International Medicine & Public Health Tags: Mil Med Source Type: research