The 10 cases were identified between Jan 31, 2020, and Feb 18, 2020. 7 patients were female. They range in age from 2 to 15 years old(Table 1). All the 10 pediatric patients were native residents in Xiangyang about 350 kilometers away from Wuhan.
The disease timeline of each child
Of the 10 cases, 6 cases (Case1-Case6) had never been to Wuhan but closely contacted with family members with confirmed COVID-19, the incubation period of each child after the first confirmed COVID-19 in the family developed symptoms were 4-13 days (Fig.1). Four cases (Case7-Case10) had made short term trips to Wuhan or visited relatives with confirmed COVID-19 alone, and they started to show symptoms 3-10 days after they went back home.
Four children had been living with their families throughout the whole course of the disease, including elderly grandparents, but no familial members else had been infected (confirmed by nucleic acid test and chest CT) (Table 1). Admittedly, the 6 cases with family cluster demonstrated adult-to-child transmission, however, the other 4 children did not show the viral transmission to long-time closely contacted adult households including elderly people.
In terms of clinical classification, 9 cases were mild (5) or asymptomatic (4), only 1 case developed moderate signs, none of them progressed in severe critical illness. The most common symptoms were cough (5,50%) and fever (4,40%) respectively. Myalgia, fatigue, headache, diarrhea, or other symptoms had not been found in the 10 cases. Among the 6 cases who had symptoms, 4 cases got rid of the symptoms within 1 week, the duration of symptoms lasted for 2-15 days.
Laboratory results and radiologic findings
On admission, the blood routine test of 4 patients(40%) showed leucopenia (Leucocytes count <5×109/L), none had lymphopenia (lymphocyte count <1.1×109/L). Paradoxically, 8 cases (80%) showed relatively higher lymphocyte percent, which was not consistent with previous reports. All the 10 cases had normal serum levels of procalcitonin (PCT, <0.5 ng/mL), and only 1 case had elevated C-reactive protein (CRP) (Table 2). None of the 10 cases showed abnormal liver and kidney function and electrolytes (date not shown). 7 cases (70%) had more than 4 times of nucleic acid tests. The ranges for virus nucleic acid to turn negative were 14 days (5-22 days).
Abnormalities on chest CT sign were detected in 8 cases (80%), mostly manifested as single or multiple localized high-density shadows (4/8), and unilateral ground-glass opacity(3/8, 37.5%), except for 2 cases who showed asymptomatic characteristics. It should be noted that 2 of 4 cases without obvious symptoms also had localized high-density shadow or ground-glass opacity imaging. Representative radiologic findings in two cases were provided in Figure 2.
Treatment and clinical outcomes
At the very beginning, there were neither effective antiviral drugs nor any experience in treatment for pediatric patients with COVID-19. Treatment for pediatric patients was based on the experience of adult treatment. All cases received antiviral treatment, and only one was given empirical antibiotic treatment. No one received systematic corticosteroid or immunoglobulin treatment. Besides, 6 cases were given traditional Chinese medicine (Lianhua Qingwen Capsule) (Table 2).
All cases were discharged without any complication when they met the discharge standard: body temperature returned to normal for more than 3 days, respiratory symptoms improved significantly, and the respiratory pathogenic nucleic acid test was negative for two consecutive times (sampling interval at least 1 day). The median times of hospital stay were 18 days (7-26 days). The prolonged hospital stay was mainly due to prolonged positive nucleic acid tests.