Newest “co-members” of the 1000s club: A case of severe transaminitis secondary to Epstein-Barr and dengue virus co-infection in a returning traveler

Background: Timely identification of the etiology of transaminitis is critical in informing subsequent management as strategies can vary from supportive care to urgent transplant assessment. This is especially important in returning travelers as there may be multiple causes of injury that need to be addressed. Case report: We present a case of severe transaminitis secondary to non-hepatitis viral co-infections. A 28-year-old south Asian male returning traveler presented with an acute liver injury (aspartate aminotransferase/alanine aminotransaminase levels of ≥4000 IU/l) and marked jaundice. A thorough and expanded work-up of acute hepatitis was negative aside from positive mononucleosis spot testing and positive dengue fever serologies. This atypical presentation of mononucleosis and dengue fever was managed conservatively, and the patient was discharged with outpatient follow-up after an eight-day admission. Conclusions: Usually, non-hepatitis viruses typically do not present with severe transaminitis or hyperbilirubinemia. These viruses, such as infectious mononucleosis and dengue fever, may work synergistically to cause an elevated inflammatory response, resulting in severe transaminitis in returning travelers. In the absence of a classic clinical presentation, clinicians should be aware of co-infections in returning travelers and test for them based on a thorough history and physical examination. LEARNING POINTS: The differential diagnosis for severe transaminitis is narrow and commonly includes viral hepatitis (A-E), drug-induced liver injury, vascular and autoimmune causes; however other causes exist, and greater clinical awareness is needed.This case study demonstrates that even in the absence of a classic clinical presentation; in returning travelers, clinicians should have a low index of suspicion to order appropriate screening serologies based on a thorough history and physical examination as they can be sensitive diagnostic tools in detecting the etiology of severe transaminitis.In rare cases, non-hepatitis virus may act synergistically to cause severe transaminitis and should be considered in returning travelers when viral hepatitis serologies are negative.