Epstein-Barr virus and cytomegalovirus mononucleosis: Important causes of febrile illness in returned travellers.

Background: Diagnosing the cause of fever in the returned traveller is challenging. Efforts often focus on identifying 'exotic' pathogens. Primary Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections cause clinical features that overlap with many exotic pathogens. The age-matched seroprevalence of both EBV and CMV is greater in tropical than temperate areas. We describe the clinical and laboratory features of returned travellers diagnosed with primary CMV and EBV syndromes.

Methods: Patients with laboratory-confirmed primary EBV and CMV infections who had attended the Hospital for Tropical Diseases (HTD), London between 1st October 2011 and 1st October 2016 were identified. Clinical and laboratory data were obtained and analysed.

Results: Twenty-two patients with primary EBV infection and 31 with primary CMV infection were identified. The commonest presenting features of both infections were fever (81.1%), headache (50.9%) and arthralgia/myalgia (49.1%). Cervical lymphadenopathy was seen more frequently with EBV than with CMV (59.1% vs. 25.8%, P = 0.02). Transaminitis (79.2%) and lymphocytosis (52.8%) were the commonest laboratory abnormalities in both groups.

Conclusions: Primary EBV and CMV infections are important causes of febrile illness in returning travellers. Identification of these pathogens prevents unnecessary, expensive investigations for more 'exotic' pathogens and impacts clinical management for example facilitating prognostication and antimicrobial stewardship.