Epidemiological analysis on an upper respiratory tract infection outbreak caused by human coronavirus NL63 in Shenzhen, Guangdong, 2020

  Objective  To understand the epidemiological characteristics of an upper respiratory tract infection outbreak caused by human coronavirus NL63 (HCoV-NL63) and improve the prevention measures against coronavirus infection.

  Methods  The field epidemiological investigation was carried out for an upper respiratory tract infection outbreak in Shenzhen, Guangdong, 2020. The descriptive epidemiology was used to analyze the epidemiological characteristics of the outbreak.

  Results  A total of 43 upper respiratory tract infection cases were detected from 120 individuals under detention in 2 cells of a detention centers on 24^th–29^th August, 2020. The peak was during 27^th–29^th August. The attack rates in cell A and cell B were 55.0% (33/60) and 16.7% (10/60), respectively. The difference was significant. HCoV-NL63 was detected in all the 43 upper respiratory tract infection cases, and the infection rate was 35.8% (43/120). The infection rates in cell A and cell B were 51.7% (31/60) and 20.0% (12/60), respectively, and the difference was significant. The overall asymptomatic infection rate was 16.7% (20/120), which was 20.0% (12/60) in cell A and 13.3% (8/60) in cell B. The main symptoms were sore throat, cough and rhinorrhea. The attack rate and infection rate were highest in age group 50–59 years, but the differences had no significance among different age groups.

  Conclusion  HCoV-NL63 is more likely to cause upper respiratory tract infection outbreaks in the unventilated and crowded places. The prevention measures are needed in these places against the human coronavirus, such as HCoV-NL63.