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Since its outbreak in late 2019, coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spread globally and declared an epidemic by the World Health Organization (1). After experiencing the peak of the COVID-19 epidemic, China entered a normalization stage of prevention and control on April 29, 2020. During this stage, China effectively controlled the outbreak and spread of the epidemic by adopting the strategy of “preventing inbound cases and domestic resurgence”, and effectively reduced the occurrence of death cases (2). On December 7, 2022, China implemented the “Ten New Measures” to deeply improve the prevention and control of COVID-19 (3). These measures were introduced based on the latest epidemic situations and mutation of the virus to contain the epidemic in a more science-based and targeted manner. Couriers are a key population in the prevention and control of the epidemic, as they are in daily contact with numerous clients and coworkers, and may get infected at work and spread the disease to others (4). Studies have revealed that the demand for couriers has risen since the outbreak of COVID-19; a study in the Republic of Korea showed that the average number of times people used a courier service rose from 6.22 to 9.74 per month after the pandemic began (5), and reports from Russia indicated that the demand for couriers has grown 11 times over the past five years (6). However, the working hazards of couriers have rarely been studied. No study has evaluated the SARS-CoV-2 infection among couriers during the wide spread of Omicron variants BA.5.2.48 and BF.7.14 in China. To fill this gap, we aimed to evaluate the national and regional trends of SARS-CoV-2 infection among couriers using a community sentinel surveillance system in China between December 2022 and January 2023 to provide the latest data.
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As shown in Table 1, 21,000 couriers were recruited in the key population surveillance of NSCS. The daily average newly positive rate of SARS-CoV-2 infection decreased from 4.99% in Round 1 (December 16–19, 2022) to 0.41% in Round 8 (January 10–12, 2023), with an EDPC of −33.0% (95% CI: −40.2% to -25.0%, P<0.001). The daily average newly positive rate of SARS-CoV-2 infection for the eight surveillance rounds were 4.99%, 9.49%, 2.94%, 2.58%, 1.55%, 1.08%, 0.31%, and 0.41%, respectively. The epidemic peak occurred during Round 2 (December 20–22, 2022).
Rounds
(investigate date)Number of investigated
couriersNumber of newly
positive casesDaily average newly positive rate of
SARS-CoV-2 infection (%, 95% CI)Round 1 1,990* 397 4.99 (4.03, 5.94) Round 2 9,960* 2,837 9.49 (8.92, 10.07) Round 3 21,861 2,574 2.94 (2.72, 3.17) Round 4 21,012 1,628 2.58 (2.37, 2.80) Round 5 22,247 1,381 1.55 (1.39, 1.71) Round 6 22,081 718 1.08 (0.95, 1.22) Round 7 22,112 276 0.31 (0.24, 0.39) Round 8. 23,009 280 0.41 (0.32, 0.49) Note: Investigations in the study were conducted in 8 rounds, from December 16, 2022 to January 12, 2023. Round 1 was conducted December 16–19, 2022; Round 2 December 20–22, 2022; Round 3 December 23–26, 2022; Round 4 December 27–29, 2022; Round 5 December 30, 2022–January 2, 2023; Round 6 January 3–5, 2023; Round 7 January 6–9, 2023; and Round 8 January 10–12, 2023.
Abbreviation: SARS-CoV-2=severe acute respiratory syndrome coronavirus 2; CI=confidence interval.
* Sample sizes for Rounds 1 and 2 of surveillance did not meet expectations due to the peak of SARS-CoV-2 infection from December 16 to 22, 2022, resulting in many couriers being unable to participate in the survey due to COVID-19 symptoms.Table 1. Trends of SARS-CoV-2 infection among the couriers in sentinel community-based surveillance, China, December 2022 to January 2023.
Table 2 presents the epidemic trends of SARS-CoV-2 in three regions. In eastern China, the daily average newly positive rate of SARS-CoV-2 infection among couriers decreased from 4.18% in Round 1 to 0.76% in Round 8, with an EDPC of −27.7% (P<0.001). For central and western China, EDPCs were −38.0% (decreasing from 2.69% to 0.17%, P<0.001) and −25.5% (decreasing from 5.68% to 0.60%, P<0.001), respectively. The daily average newly positive rates among couriers in eastern, central and western China all peaked at Round 2.
Rounds Number of investigate couriers Number of newly positive cases Daily average newly positive rate of SARS-CoV-2 infection (%, 95% CI) EDPC (%, 95% CI) P value Eastern Round 1 658 110 4.18 (2.65, 5.71) −27.7 (−34.4, −20.4) <0.001 Round 2 3,895 1,172 10.03 (9.09, 10.97) Round 3 6,274 1,306 5.20 (4.65, 5.75) Round 4 4,539 507 3.72 (3.17, 4.27) Round 5 5,732 377 1.64 (1.32, 1.97) Round 6 4,911 253 1.72 (1.35, 2.08) Round 7 5,685 78 0.34 (0.19, 0.49) Round 8 6,046 138 0.76 (0.54, 0.98) Central Round 1 130 14 2.69 (−0.09, 5.47) −38.0 (−46.3, −28.5) <0.001 Round 2 2,881 929 10.75 (9.62, 11.88) Round 3 11,920 302 0.63 (0.49, 0.78) Round 4 12,190 432 1.18 (0.99, 1.37) Round 5 12,284 431 0.88 (0.71, 1.04) Round 6 12,285 239 0.65 (0.51, 0.79) Round 7 12,573 127 0.25 (0.16, 0.34) Round 8 12,607 63 0.17 (0.10, 0.24) Western Round 1 1,202 273 5.68 (4.37, 6.99) −25.5 (−31.9, −18.6) <0.001 Round 2 3,184 736 7.71 (6.78, 8.63) Round 3 3,667 966 6.59 (5.78, 7.39) Round 4 4,283 689 5.36 (4.69, 6.04) Round 5 4,231 573 3.39 (2.84, 3.93) Round 6 4,885 226 1.54 (1.20, 1.89) Round 7 3,854 71 0.46 (0.25, 0.67) Round 8 4,356 79 0.60 (0.37, 0.83) Note: EDPC stands for estimated daily percentage change from Round 1 to Round 8 between December 16, 2022 and January 12, 2023. Round 1 was conducted December 16–19, 2022; Round 2 December 20–22, 2022; Round 3 December 23–26, 2022; Round 4 December 27–29, 2022; Round 5 December 30, 2022–January 2, 2023; Round 6 January 3–5, 2023; Round 7 January 6–9, 2023; and Round 8 January 10–12, 2023. The eastern region included Beijing, Tianjin, Hebei, Liaoning, Shanghai, Jiangsu, Zhejiang, Fujian, Shandong, Guangdong, and Hainan PLADs; the western region included Inner Mongolia, Guangxi, Chongqing, Sichuan, Guizhou, Yunnan, Xizang (Tibet), Shaanxi, Gansu, Qinghai, Ningxia, and Xinjiang PLADs, and XPCC; the central region included Shanxi, Jilin, Heilongjiang, Anhui, Jiangxi, Henan, Hubei, and Hunan PLADs.
Abbreviation: SARS-CoV-2=severe acute respiratory syndrome coronavirus 2; EDPC=estimated daily percentage change; CI=confidence interval; PLAD=provincial-level administrative division; XPCC=Xinjiang Production and Construction Corps.Table 2. Trends of SARS-CoV-2 infection among couriers in sentinel community-based surveillance by regions, China, December 2022 to January 2023.
As Figure 1 shows, the daily average of newly positive rates in the eastern and western regions were generally higher than the national level, while the positive rate in the central region was lower than the national level. After Round 6 (January 3–5, 2023), the daily average of newly positive rates across regions converged and the disparities between regional incidence were noticeably decreasing, with all rates falling below 1% in Round 8.
Figure 1.Trends of SARS-CoV-2 infection among couriers in the sentinel community-based surveillance, China, December 2022–January 2023, stratified by regions.
Note: Investigations in the study were conducted in 8 rounds, from December 16, 2022 to January 12, 2023. Round 1 was conducted December 16–19, 2022; Round 2 December 20–22, 2022; Round 3 December 23–26, 2022; Round 4 December 27–29, 2022; Round 5 December 30, 2022–January 2, 2023; Round 6 January 3–5, 2023; Round 7 January 6–9, 2023; and Round 8 January 10–12, 2023. The eastern region included Beijing, Tianjin, Hebei, Liaoning, Shanghai, Jiangsu, Zhejiang, Fujian, Shandong, Guangdong, and Hainan PLADs; the western region included Inner Mongolia, Guangxi, Chongqing, Sichuan, Guizhou, Yunnan, Xizang (Tibet), Shaanxi, Gansu, Qinghai, Ningxia, and Xinjiang PLADs, and XPCC; the central region included Shanxi, Jilin, Heilongjiang, Anhui, Jiangxi, Henan, Hubei, and Hunan PLAD.
Abbreviation: SARS-CoV-2=severe acute respiratory syndrome coronavirus 2; PLAD=provincial-level administrative division; XPCC=Xinjiang Production and Construction Corps.
As shown in Figure 2, the daily average of newly positive cases among couriers varied across PLADs, but all showed a downward trend after reaching a peak in Round 2, and dropped below 5% in Round 8.
Figure 2.Average daily rate of newly positive couriers in the sentinel community-based surveillance in China, December 2022 to January 2023, stratified by PLAD and XPCC. (A) Round 2; (B) Round 4; (C) Round 6; (D) Round 8.
Note: Round 2 was conducted December 20–22, 2022; Round 4 December 27–29, 2022; Round 6 January 3–5, 2023; and Round 8 January 10–12, 2023.
Abbreviation: SARS-CoV-2=severe acute respiratory syndrome coronavirus 2; PLAD=provincial-level administrative division; XPCC=Xinjiang Production and Construction Corps.
Figure 3 demonstrates that couriers and the community population had a similar temporal trend, with the peak daily average newly positive rate of couriers (9.49%) being higher than that of the community population (6.36%). Following Round 2, the daily average newly positive rate of couriers decreased significantly, becoming lower than that of the community population during the same period.
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