Epidemiological Analysis of COVID-19 Outbreaks in Wuhu, China, from January to March 2020

Abstract

Background: COVID-19, caused by SARS-CoV-2, has spread worldwide and become a global pandemic. Objectives: Studies of the earliest events of the COVID-19 pandemic are critical in understanding how the pandemic started and providing insight into the spread of SARS-CoV-2 and its infection in humans. Methods: In this report, we studied the epidemiological characteristics of all 34 confirmed COVID-19 cases in Wuhu, China, from January 3 to March 19, 2020. Results: Our study indicated that cases in male patients (61.76%, 21/34) outnumbered those in female patients (38.24%, 13/34). Studies of the age distribution among the confirmed cases revealed that most COVID-19 patients were 15 to 59 years of age (26/34, 76%), while more than 14% (5/34) were ≥ 60 years old, and less than 9% (3/34) were ≤ 14 years old. Notably, 32 of the 34 confirmed cases were (a) people who had recently resided in or traveled to Wuhan or had close contact with Wuhan residents or visitors (22 cases); and (b) people who had close contact with these 22 confirmed COVID-19 patients (10 cases). Conclusions: This study revealed the epidemiological characteristics of COVID-19 outbreaks in Wuhu between January and March 2020 and provided insight into the earliest events of the COVID-19 pandemic in China. Our analyses suggested that the COVID-19 cases confirmed in Wuhu in 2020 were directly related to or originated from the outbreaks in Wuhan.

Epidemiological Analysis and Effective Control of COVID-19 Outbreaks Caused by the Omicron Subvariant BA.2 in a Medium-sized City in China, 2022

“…In this study, Omicron subvariant BA.2 may occur more frequently in young individuals of 15-59 years old but not the young or elderly age groups in Wuhu city in 2022 (Figure 3). These results are similar to COVID-19 epidemic data reported in Shanghai city in 2022, which was younger than COVID-19 cases identified in Wuhan and Wuhu cities in 2020 (14,17,18). Also, Omicron subvariant BA.2 infections occurred more frequently in females than males in Wuhu city (Figure 3).…”

“…Also, Omicron subvariant BA.2 infections occurred more frequently in females than males in Wuhu city (Figure 3). The results are different from COVID-19 outbreaks reported in Shanghai city in 2022 or Wuhan and Wuhu cities in 2020 (14,17,18).…”

“…First, the geographic distribution of COVID-19 cases was highly concentrated in Wuhu city in 2022, most infections (58/64, 90.62%) were identified in the Fanchang district, and COVID-19 confirmed in other districts of Wuhu city were also directly related to Fanchang district (Figure 1B). Second, the mean age of COVID-19 cases in this study was 39.57 ± 16.39 years old, which was younger than COVID-19 cases reported in Wuhan and Wuhu cities in 2020 (14,17). Third, a relatively independent outbreak pattern in Wuhu city, cases in the first group (37/39, 94.87%) dominated at the beginning of the Wuhu COVID-19 epidemic, and all confirmed COVID-19 cases belonged to the second group since March 29.…”

“…First, each region is divided into low-, medium-, and high-risk according to the different COVID-19 epidemic situations, and the communities and villages were divided into "grids" to achieve segmented management, which made self-isolation and lockdown policies more refined and comprehensive (19). Second, a three-color-based health QR code system (green, yellow, and red), as known as Ankang code in Anhui province, based on big data and GPS positioning technology, was (14).…”

“…The data on the number of confirmed COVID- (14). All data were collected from publicly available sources, and all confirmed COVID-19 cases were fully anonymized before we had access to the data.…”