The Epidemiological and Clinical Characteristics of the Largest Outbreak of Enterohemorrhagic Escherichia coli in Korea

Background@#The largest outbreak of enterohemorrhagic Escherichia coli (EHEC) O157:H7 occurred at a preschool in South Korea from June 12 to 29, 2020. This study aimed to analyze the epidemiological and clinical characteristics of EHEC infection in this outbreak. @*Methods@#Epidemiological investigation was performed on all 184 children and 19 workers at the preschool using a standard questionnaire to assess symptoms, food intake, attendance, and special activity history. Pulsed-field gel electrophoresis analysis of confirmed cases was performed to determine genetic relevance. @*Results@#During this outbreak, 103 children were affected, whereas only one infection was identified in adults. Of the 103 pediatric patients, 85 had symptoms (82.5%), including diarrhea, abdominal pain, bloody stool, fever, and vomiting. Thirty-two patients (31.1%) were hospitalized, 15 (14.6%) were diagnosed with hemolytic uremic syndrome, and 4 (3.9%) received dialysis treatment. Pulsed-field gel electrophoresis analysis identified 4 genotypes with high genetic relevance (92.3%). Epidemiological investigation revealed that this outbreak might have occurred from ingesting foods stored in a refrigerator with a constant temperature above 10°C, which was conducive to bacterial growth. Despite several measures after outbreak recognition, new infections continued to appear. Therefore, the preschool was forced to close on June 19 to prevent further person-to-person transmission. @*Conclusion@#Our findings from the response to the largest outbreak will help prepare countermeasures against future EHEC outbreak.

Identification of a novel mutation in the CHD7 gene in a patient with CHARGE syndrome / 소아과

CHARGE syndrome has been estimated to occur in 1:10,000 births worldwide and shows various clinical manifestations. It is a genetic disorder characterized by a specific and a recognizable pattern of anomalies. The major clinical features are ocular coloboma, heart malformations, atresia of the choanae, growth retardation, genital hypoplasia, and ear abnormalities. The chromodomain helicase DNA-binding protein 7 (CHD7) gene, located on chromosome 8q12.1, causes CHARGE syndrome. The CHD7 protein is an adenosine triphosphate (ATP)-dependent chromatin remodeling protein. A total of 67% of patients clinically diagnosed with CHARGE syndrome have CHD7 mutations. Five hundred twenty-eight pathogenic and unique CHD7 alterations have been identified so far. We describe a patient with a CHARGE syndrome diagnosis who carried a novel de novo mutation, a c.3896T>C (p. leu1299Pro) missense mutation, in the CHD7 gene. This finding will provide more information for genetic counseling and expand our understanding of the pathogenesis and development of CHARGE syndrome.