Journal Article

A five-compartment model of age-specific transmissibility of SARS-CoV-2

Xu, Jing-Wen, Su, Yan-Hua, Gao, Li-Dong, Luo, Li, Yin, Ling, Rui, Jia, Yu, Shan-Shan, Xie, Fang, Zhu, Yuan-Zhao, Hu, Shi-Xiong, Wang, Yao, Yang, Meng, Zhao, Ze-Yu, Li, Jia, Su, Ying-Ying, Cui, Jing-An, Hu, Qing-Qing, Lei, Zhao, Chen, Tian-Mu, Liu, Xing-Chun, Liu, Ruo-Yun, Chiang, Yi-Chen, Zhao, Ben-Hua, Zhao, Qing-Long

2020

Overview

Background The novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, also called 2019-nCoV) causes different morbidity risks to individuals in different age groups. This study attempts to quantify the age-specific transmissibility using a mathematical model. Methods An epidemiological model with five compartments (susceptible–exposed–symptomatic–asymptomatic–recovered/removed [SEIAR]) was developed based on observed transmission features. Coronavirus disease 2019 (COVID-19) cases were divided into four age groups: group 1, those ≤ 14 years old; group 2, those 15 to 44 years old; group 3, those 45 to 64 years old; and group 4, those ≥ 65 years old. The model was initially based on cases (including imported cases and secondary cases) collected in Hunan Province from January 5 to February 19, 2020. Another dataset, from Jilin Province, was used to test the model. Results The age-specific SEIAR model fitted the data well in each age group ( P  < 0.001). In Hunan Province, the highest transmissibility was from age group 4 to 3 (median: β 43  = 7.71 × 10 − 9 ; SAR 43  = 3.86 × 10 − 8 ), followed by group 3 to 4 (median: β 34  = 3.07 × 10 − 9 ; SAR 34  = 1.53 × 10 − 8 ), group 2 to 2 (median: β 22  = 1.24 × 10 − 9 ; SAR 22  = 6.21 × 10 − 9 ), and group 3 to 1 (median: β 31  = 4.10 × 10 − 10 ; SAR 31  = 2.08 × 10 − 9 ). The lowest transmissibility was from age group 3 to 3 (median: β 33  = 1.64 × 10 − 19 ; SAR 33  = 8.19 × 10 − 19 ), followed by group 4 to 4 (median: β 44  = 3.66 × 10 − 17 ; SAR 44  = 1.83 × 10 − 16 ), group 3 to 2 (median: β 32  = 1.21 × 10 − 16 ; SAR 32  = 6.06 × 10 − 16 ), and group 1 to 4 (median: β 14  = 7.20 × 10 − 14 ; SAR 14  = 3.60 × 10 − 13 ). In Jilin Province, the highest transmissibility occurred from age group 4 to 4 (median: β 43  = 4.27 × 10 − 8 ; SAR 43  = 2.13 × 10 − 7 ), followed by group 3 to 4 (median: β 34  = 1.81 × 10 − 8 ; SAR 34  = 9.03 × 10 − 8 ). Conclusions SARS-CoV-2 exhibits high transmissibility between middle-aged (45 to 64 years old) and elderly (≥ 65 years old) people. Children (≤ 14 years old) have very low susceptibility to COVID-19. This study will improve our understanding of the transmission feature of SARS-CoV-2 in different age groups and suggest the most prevention measures should be applied to middle-aged and elderly people.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Adolescent / Adult / Age Factors / Age groups / Age-specific dynamics / Aged / Analysis / Asymptomatic / Betacoronavirus - isolation & purification / Compartmental model / Coronavirus Infections - epidemiology / Coronavirus Infections - transmission / Coronaviruses / COVID-19 / Disease transmission / Epidemiology / Female / Health aspects / Humans / Infectious Diseases / Male / Medicine / Medicine & Public Health / Middle Aged / Models, Statistical / Ordinary differential equations / Pandemics / Parameter estimation / Pneumonia, Viral - epidemiology / Pneumonia, Viral - transmission / Public Health / Research Article / SARS-CoV-2 / Severe acute respiratory syndrome / Severe acute respiratory syndrome coronavirus 2 / Transmissibility / Transmission patterns and control of COVID-19 epidemic / Tropical Medicine / Young Adult