小澤 慶

ABSTRACT The recent clinical features of Epstein‐Barr virus (EBV) and cytomegalovirus (CMV) infections in young children in developed countries remain unclear. This study investigated the clinical features of EBV and CMV infections and the latest seroepidemiology in Japan. Seroprevalence was analyzed 303 stored serum samples using commercial Enzyme Immunosorbent Assay kits, and viral infections were investigated in a cohort of febrile children under 5 years of age. After maternal antibody levels declined, the seroprevalences of EBV and CMV gradually increased by adolescence to 42.9% and 57.1%, respectively. Among 2,732 febrile children, serum EBV and CMV DNAs were detected in 1.76% and 1.24%, respectively. Of 25 primary EBV–infected patients, 15 (60.0%) had infectious mononucleosis (IM) with significantly higher IM frequency, WBC, atypical lymphocyte ratios, AST, ALT, LDH, and EBV DNA load compared to EBV–reactivated patients. No CMV DNA–positive patients had IM. Among primary EBV–infected patients, those with IM were older and had more atypical lymphocytes and higher EBV DNA load than those without IM. The age of primary EBV infection appears to have decreased compared to reports from Western countries in the 1990s. Even among children under 5 years of age, 60.0% of those with primary EBV infection developed IM.

This report describes the case of a previously healthy nine-year-old girl who developed a left temporal lobe brain abscess following spontaneous exfoliation of a healthy deciduous tooth. She presented in convulsive status epilepticus without fever or focal neurological symptoms, and the initial MRI revealed a ring-enhancing lesion with adjacent dural inflammation. Surgical drainage and intravenous antibiotic therapy led to a full recovery with no neurological sequelae after six weeks of treatment. Pus culture revealed Streptococcus intermedius and Aggregatibacter aphrophilus, both of which are part of the normal oral flora. The route of infection in this case is suggested to be hematogenous spread from the site of tooth exfoliation, as evidenced by the ipsilateral location of the abscess. This highlights the potential for serious intracranial infections to originate from the exfoliation of a deciduous tooth in healthy children, particularly those with orthodontic appliances.

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection in developed countries. Although a standard therapy has not yet been established, evidence for the management of cCMV infection has been accumulating. The first edition of the "Clinical Practice Guidelines for the Management of Congenital Cytomegalovirus Infection" was published in Japan in 2023. This summary outlines the clinical questions (CQs) in the guidelines, with reference to the Japanese Medical Information Distribution Service Manual. Overall, 20 CQs with statements regarding prenatal risk assessment, prevention and management at diagnosis (CQs 1-1-1-3), diagnosis (CQs 2-1-2-6), treatment (CQs 3-1-3-7) and follow-up requirements (CQs 4-1-4-4) have been discussed. For each statement, the levels of recommendation, evidence and consensus rates were determined. These guidelines will assist in the management of patients with cCMV infection.