2323. Clinical Characteristics and Disease Burden of Epstein–Barr Virus and Four β-Herpes Viruses Infections in Children Visiting Emergency Room

BACKGROUND: It is well known that most of infants and young children with primary EBV and CMV infection are inapparent, and primary HHV-6B and HHV-7 infection cause exanthema subitum (ES). However, the precise incidence of apparent infection of these viruses remains unclear. Therefore, we sought to elucidate clinical features and disease burdens of these viral infections in febrile children visiting emergency room (ER). METHODS: Between June 2015 and December 2017, febrile children under 5 years old, who visited ER and received hematological examination, were enrolled in this study. Detection of serum viral DNAs using real-time PCR and measurement of antibody titers in acute-phase serum were carried out. Clinical information was collected from the medical records. RESULTS: In total of the 905 cases, EBV, CMV, HHV-6B and HHV-7 were detected in 18 cases (2%), 12 cases (1.3%), 104 cases (11.5%) and 23 cases (2.5%), respectively. No HHV-6A DNA was detected. Primary infection rates among EBV, CMV, HHV-6B and HHV-7-infected patients accounted for 44%, 25%, 91% and 57%, respectively. Admission rates of the primary-infected patients were 88% of EBV, 68% of CMV, 66% of HHV-6B and 42% of HHV-7, respectively. Five of the 8 cases (62.5%) of primary EBV-infected patients demonstrated typical clinical course of infectious mononucleosis (IM); however, no IM patient was seen in 9 patients with viral reactivation. No IM case was observed in CMV-infected patients, regardless of primary infection or reactivation. Clinical characteristics were compared between patients with primary HHV-6B and HHV-7 infections because of similarity of clinical features. Average age (1.5 vs. 2.8 years old; P < 0.001), duration of fever (4.5 vs. 2.9 days; P < 0.001), the highest body temperature (40.2 vs. 39.6°C; P < 0.001), and the frequency of typical skin rash (ES) (87% vs. 54%; P < 0.001) were statistically different between the two viral infections. The main reason for admission due to primary HHV-6B and HHV-7 infection was complex-type febrile seizure (58.7 vs. 66.7%; P = 0.705). CONCLUSION: The clinical features and disease burden of the 5 human herpesviruses infections were elucidated in the febrile children visiting ER. DISCLOSURES: All authors: No reported disclosures.