tetano
Editor, Senior Moderator
J Infect Public Health
. 2022 Jan 31;15(3):297-306.
doi: 10.1016/j.jiph.2022.01.015. Online ahead of print.
Transmissibility and pathogenicity of the severe acute respiratory syndrome coronavirus 2: A systematic review and meta-analysis of secondary attack rate and asymptomatic infection
Naiyang Shi[SUP] 1 [/SUP], Jinxin Huang[SUP] 1 [/SUP], Jing Ai[SUP] 2 [/SUP], Qiang Wang[SUP] 1 [/SUP], Tingting Cui[SUP] 1 [/SUP], Liuqing Yang[SUP] 1 [/SUP], Hong Ji[SUP] 2 [/SUP], Changjun Bao[SUP] 2 [/SUP], Hui Jin[SUP] 3 [/SUP]
Affiliations
Abstract
Background: Understanding the transmissibility and pathogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for control policies, but evidence remains limited.
Methods: We presented a systematic and meta-analytic summary concerning the transmissibility and pathogenicity of COVID-19.
Results: A total of 105 studies were identified, with 35042 infected cases and 897912 close contacts. 48.6% (51/105) of studies on secondary transmissions were from China. We estimated a total SIR of 7.8% (95% confidence interval [CI], 6.8%-8.8%), SAR of 6.6% (95% CI, 5.7%-7.5%), and symptomatic infection ratio of 86.9% (95%CI, 83.9%-89.9%) with a disease series interval of 5.84 (95%CI, 4.92-6.94) days. Household contacts had a higher risk of both symptomatic and asymptomatic infection, and transmission was driven between index cases and second-generation cases, with little transmission occurring in second-to-later-generation cases (SIR, 12.4% vs. 3.6%). The symptomatic infection ratio was not significantly different in terms of infection time, generation, type of contact, and index cases.
Conclusions: Our results suggest a higher risk of infection among household contacts. Transmissibility decreased with generations during the intervention. Pathogenicity of SARS-CoV-2 varied among territories, but didn't change over time. Strict isolation and medical observation measures should be implemented.
Keywords: Asymptomatic infections; COVID-19; Incidence; Meta-analysis; SARS-CoV-2; Virulence.
. 2022 Jan 31;15(3):297-306.
doi: 10.1016/j.jiph.2022.01.015. Online ahead of print.
Transmissibility and pathogenicity of the severe acute respiratory syndrome coronavirus 2: A systematic review and meta-analysis of secondary attack rate and asymptomatic infection
Naiyang Shi[SUP] 1 [/SUP], Jinxin Huang[SUP] 1 [/SUP], Jing Ai[SUP] 2 [/SUP], Qiang Wang[SUP] 1 [/SUP], Tingting Cui[SUP] 1 [/SUP], Liuqing Yang[SUP] 1 [/SUP], Hong Ji[SUP] 2 [/SUP], Changjun Bao[SUP] 2 [/SUP], Hui Jin[SUP] 3 [/SUP]
Affiliations
- PMID: 35123279
- DOI: 10.1016/j.jiph.2022.01.015
Abstract
Background: Understanding the transmissibility and pathogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for control policies, but evidence remains limited.
Methods: We presented a systematic and meta-analytic summary concerning the transmissibility and pathogenicity of COVID-19.
Results: A total of 105 studies were identified, with 35042 infected cases and 897912 close contacts. 48.6% (51/105) of studies on secondary transmissions were from China. We estimated a total SIR of 7.8% (95% confidence interval [CI], 6.8%-8.8%), SAR of 6.6% (95% CI, 5.7%-7.5%), and symptomatic infection ratio of 86.9% (95%CI, 83.9%-89.9%) with a disease series interval of 5.84 (95%CI, 4.92-6.94) days. Household contacts had a higher risk of both symptomatic and asymptomatic infection, and transmission was driven between index cases and second-generation cases, with little transmission occurring in second-to-later-generation cases (SIR, 12.4% vs. 3.6%). The symptomatic infection ratio was not significantly different in terms of infection time, generation, type of contact, and index cases.
Conclusions: Our results suggest a higher risk of infection among household contacts. Transmissibility decreased with generations during the intervention. Pathogenicity of SARS-CoV-2 varied among territories, but didn't change over time. Strict isolation and medical observation measures should be implemented.
Keywords: Asymptomatic infections; COVID-19; Incidence; Meta-analysis; SARS-CoV-2; Virulence.