A group of researchers at Seoul National University Bundang Hospital (SNUBH) has published a report on the epidemiological and clinical features of the first pediatric COVID-19 patient.

"Current epidemiologic knowledge suggests that relatively few cases are seen among children," the research team said. "Such a low number of cases limit opportunities to address pediatric-specific issues on infection control and the children's contribution to viral spread in the community."

The team, composed of Professors Park Ji-young, Choi Eun-hwa, Han Mi-seon, Park Kyoung-un and Kim Ji-young, presented the mild clinical course of the first pediatric COVID-19 case to give a more direct insight into treating COVID-19-infected pediatric patients.

The patient, a 10-year-old girl, tested positive for the virus after having close contact with her uncle and mother, who also tested positive for the virus.

The patient's uncle, who ran a store in China’s epicenter of Wuhan, arrived in Korea on Jan. 20 and went into self-quarantine at his room from Jan. 29. However, he broke self-quarantine later by having meals with his family members.

The patient's uncle was later confirmed with COVID-19 and was hospitalized in a designated hospital on Feb. 1, while the remaining family members went into self-quarantine from Feb. 2.

Diagram showing how the family members of the first pediatric patient with COVID-19 were in self-quarantine at home. The patient lived with her parents and her cousin, while her aunt and uncle lived upstairs. Her uncle was quarantined in his room but shared meals at her house (grey table) until he was confirmed with COVID-19. The remaining five family members had been placed in self-quarantine without sharing meals in the dining table (white table). The patient and her mother stayed in the same room until her mother's diagnosis. Individuals in black indicate the confirmed cases and bold line means a quarantine room. The actual floor plan may be different.

Although the patient's father, aunt, and cousin stayed in separate rooms, the patient shared the same room with her mother. On Feb. 5, her mother tested positive for the virus.

As the patient lived near her uncle and mother, hospitals tested the patient for the virus on the same day, with the initial tests coming up negative.

However, she was confirmed with the virus 13 days after she developed a slightly high temperature of 37.3 degrees Celsius on Feb. 18. According to the team, the patient had not shown any symptoms until then.

Even after confirming COVID-19 infection, the team found no virus infiltrations on the initial and three follow-up chest X-ray images. However, chest computed tomography (CT) showed patchy or nodular consolidations with peripheral ground-glass opacities in subpleural areas of the right lower lobe.

Despite the CT results, the team did not treat the patient with antivirals as the patient had no underlying disease and only showed a little fever and a small amount of sputum.

"Very little research on COVID-19 in children had been published in China or elsewhere," the team said. "Most of the COVID-19 cases in children resulted from close contacts with family members who had COVID-19." And most of them show mild symptoms difficult to recognize, with some even ending up as asymptomatic, the team added.

The team noted that the most common symptoms in pediatric patients were fever and cough, runny nose, and gastrointestinal symptoms, such as diarrhea, or vomiting, while all of the cases improved, and pediatric deaths have not been reported so far.

The team went on to add that they do not fully understand why children are less infected and less ill and that this has been a recurring trend in past coronavirus-related epidemics, such as the SARS epidemic in 2003 and the MERS in 2015.

"One of the explanations of COVID-19 sparing the pediatric populations might be because children are less exposed to the virus in the first place," the team said. "Children are less likely to be exposed to the virus because this novel virus is initially transmitted among travelers."

Children might also have fewer chances to be tested for COVID-19 as they only present mild symptoms similar to the common cold.

The team also pointed out that the role of innate immunity to respiratory tract infection is higher in pediatric patients as the adaptive immune response is underdeveloped in such a cohort.

"Given that both young children and adults lack adaptive specific immunity to this novel virus, a mild clinical course in young children may be explained by their dominant innate immune response compared to adults," the team said. "Weaker ability to trigger an acute inflammatory response to COVID-19 might also contribute to the children's better outcome."

The researchers did add, however, that such a theory does not entirely rule out the possibility of severe cases and death, especially in children with underlying diseases, as there have been some fatality cases during the MERS epidemics.

Serial viral test results of multiple specimens and chest imaging of the patient. (A) Serial viral test results of the RNA-dependent RNA polymerase region of the ORF1b gene on real-time reverse transcription polymerase chain reaction are shown for multiple specimens according to the onset of symptoms. (B) Chest X-ray shows no infiltrations on admission, day 3 since symptom onset. (C) Chest CT performed on the fourth day since symptom onset demonstrates patchy nodular consolidations with peripheral ground glass opacities in subpleural areas of the right lower lobe in axial and sagittal views of CT.

Also, even though chest CT is a highly sensitive diagnostic tool to detect pneumonia and the sensitivity for COVID-19 is reported to be 97.5 percent, considering the favorable clinical course in children with COVID-19, the necessity of performing CT scans on children should be judged with consideration of the potential health risks of radiation.

The team also noted that it is essential to designate a caregiver for suspected COVID-19 pediatric patients.

"Ideally, any close contacts should stay at home in a separate room and refrain from going out," the team said. "However, unlike adults, isolating young children by themselves is almost impossible because they must be taken care of by adults."

Considering the circumstances, the Korean Centers for Disease Control and Prevention and the Korean Society of Pediatric Infectious Diseases recommend one of the family members to be assigned as a caregiver for infants and young children who are suspected of or confirmed with COVID-19, and the caregiver not to contact other family members, the team added.

Caregivers also should take all possible precautions to avoid being exposed to the virus.

Admitting that the report is based on a single pediatric case, the team said that there needs to be a comprehensive analysis of the data on pediatric patients to describe the clinical findings further and to learn the role of children in a COVID-19 pandemic.

The results of the research were published in the Journal of Korean Medical Science, under the title of “First Pediatric Case of Coronavirus Disease 2019 in Korea."

corea022@docdocdoc.co.kr

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