RESUMO
BackgroundAdolescents and young adults might play a key role in the worldwide spread of Coronavirus Disease 2019 (COVID-19), because they are more involved in overseas studying, business, working, and travelling. However, the epidemiological and clinical characteristics of them are still unknown. MethodsWe collected data of 46 confirmed COVID-19 patients aged 10 to 35 years from the study hospital. The demographics, epidemiological, and clinical data were collected. Several key epidemiological parameters, the asymptomatic cases and transmission to their family members and the clinical characteristics at admission, and during treatment were summarized. RESULTSOf 46 confirmed patients, 14 patients (47.3%) were aged from 10 to 24 years, and 24 (52.7%) patients were male. The mean incubation period for symptomatic cases was 6.6 days (95% confidence interval (CI) 4.4 - 9.6). The median serial interval was 1.9 days (95% CI 0.4 - 6.2). Three of asymptomatic cases showed the transmission to their family members. Only 1 patient was identified as severe cases at admission. The common symptoms at admission were dry cough (34, 91.0%), and fever (29, 69.0%). Nearly 60% of the patients had showed ground-glass opacity by chest CT findings. Three patients developed acute kidney injury during treatment. Majority of patients (78.3%) were discharged by the end of the follow-up. ConclusionsThe adolescent and young adult patients of COVID-19 had a long incubation period, and a short serial interval. The transmission to their family contactors occurred in asymptomatic cases. Few of the study patients have developed complications during treatment.
RESUMO
BackgroundThe ongoing outbreak of novel corona virus disease 2019 (COVID-19) in Wuhan, China, is arousing international concern. This study evaluated whether and when the infected but asymptomatic cases during the incubation period could infect others. MethodsWe collected data on demographic characteristics, exposure history, and symptom onset day of the confirmed cases, which had been announced by the Chinese local authorities. We evaluated the potential of transmission during the incubation period in 50 infection clusters, including 124 cases. All the secondary cases had a history of contact with their first-generation cases prior to symptom onset. ResultsThe estimated mean incubation period for COVID-19 was 4.9 days (95% confidence interval [CI], 4.4 to 5.4) days, ranging from 0.8 to 11.1 days (2.5th to 97.5th percentile). The observed mean and standard deviation (SD) of serial interval was 4.1{+/-}3.3 days, with the 2.5th and 97.5th percentiles at -1 and 13 days. The infectious curve showed that in 73.0% of the secondary cases, their date of getting infected was before symptom onset of the first-generation cases, particularly in the last three days of the incubation period. ConclusionsThe results indicated the transmission of COVID-9 occurs among close contacts during the incubation period, which may lead to a quarantine loophole. Strong and effective countermeasures should be implemented to prevent or mitigate asymptomatic transmission during the incubation period in populations at high risk.
